BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to an ink supplying device and an ink jet recording
apparatus having such ink supplying device.
Description of the Related Art
[0002] Recently, it has been recognized that an ink jet recording apparatus is excellent
in that it can perform a high speed recording since a noise during the recording is
very small and it can be easily constructed as a high density multiple discharge port
type ink jet printer. Further, it has been interested in that the ink jet printer
has good color reproducibility for a color image. In general, an ink jet recording
system (ink jet recording apparatus) is so constructed that ink droplets are caused
to he discharged and fly from a discharge port of a recording head, and recording
is carried out with their sticking on a recording sheet. So, in the ink jet recording
apparatus, it is needed to supply surely ink to the ink jet recording head. In the
past, various contrivances have been made for this purpose.
[0003] Hereinafter, its several examples and related problems will be explained. First,
an example which employs an exchangeable ink tank is described. In the past, there
have been developed many arrangements which are provided with a cartridge type ink
tank in the ink jet recording apparatus permitting easy supplement of ink by exchanging
the ink tank by a user when ink has been lost. As for the cartridge type ink tanks,
an arrangement is widely known wherein it is provided with a flexible bag which accommodates
ink therein and which is caused to have both of opening to the air pressure and evaporation
preventing at the same time, as shown in Japanese Laid-Open Patent Application No.
56-41148, for example. This arrangement is very effective as means for forming a low-priced
and compact ink tank since it need no additional complicated mechanism for communicating
to the air.
[0004] Also, as for positioning and alignment means for a joint part for conducting out
ink from the ink tank, a method is known of obtaining a sure connection of the flow
path with the connecting portion of the ink cartridge side by causing the member of
the device side to have a degree of freedom, as shown in Japanese Patent Laid-Open
Application No. 60-137658.
[0005] However, in the above-mentioned prior art connecting arrangement, it can be easily
constructed in a case where the flow path to be connected is one, but in an arrangement
having a plurality of flow paths or connecting portions, moving parts at the device
side must be large in size, or its construction becomes very intricate, and thus,
in a case where a plurality of ink paths are used, for example, seal portions for
connecting portions between the joint portions of the device body which are movable
and the ink paths to the recording head must be increased in number, or distribution
of tubes forming the ink paths would become complex.
[0006] On the other hand, the above-mentioned cartridge type ink tank arrangement is weak
in vibration and shock because it holds ink with a soft bag, and if the manners in
which the bags collapse are nonuniform, then the pressure with which ink is let to
flow would be often caused to change. Accordingly, this arrangement is not suitable
to a large volume ink tank, and in fact it is realized as a relatively small ink tank.
[0007] In order to overcome the above problems, an ink tank shown in Japanese Laid-Open
Patent Application No. 56-13456, for example has been developed, which has a construction
which is strong in vibration and shock and permits it to be voluminous by holding
ink between the outside of the bag which communicates to the air and a frame. However,
the problem relating to the change of the pressure with which ink flows out, which
is due to a difference between the manners in which the bags collapse (or swell) is
not solved entirely, and it is needed to cause ink to flow out compulsively with an
ink pump, store ink temporarily in a sub-tank which is provided with special means
communicating to the air and then supply it to the head, so as thereby to carry out
stabilized ink supplying.
[0008] Moreover, an ink cartridge is also known having its construction wherein a waste
liquid absorbing body is added to the ink tank of the above-mentioned arrangement
and the ink tank and a waste liquid tank are made to be in a body by enclosing them
with a frame, between which a member intervened. In the ink cartridge of this type,
as the waste liquid absorbing body, in general, felt or foaming resin, etc. is used
to hold therein waste ink for the collection thereof. However, in this prior art,
such a problem would be produced that in the case where, for example, the weight of
the ink tank with ink filled up is larger than that of the waste liquid tank, rubbing
is produced between the ink tank and the frame enclosing it, and specially, if the
tank is made in the form of a rigid container having the means communicating to the
air rather than the bag, then because of backlash between the tank and the frame,
a noise would be generated at the time of the application of vibration and a damage
would occur at the time of the application of shock.
SUMMARY OF THE INVENTION
[0009] Accordingly, an object of the present invention is to provide an ink supplying device
wherein recording can be continued suitably, and an ink jet recording apparatus using
this ink supplying device.
[0010] A further object of the present invention is to provide an ink supplying device wherein
ink can be supplyed suitably, and an ink jet printing apparatus using this ink supplying
device.
[0011] Another object of the present invention is to provide an ink supplying device wherein
connection between an ink cartridge and the device body can be carried out easily
and reliably, and an ink jet printing apparatus using this ink supplying device.
[0012] Still another object of the present invention is to provide an ink supplying device
wherein the protection for an ink cartridge is made surely, and an ink jet recording
apparatus using this ink supplying device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Fig. 1A is a cross-sectional side view showing a facsimile apparatus to which an
embodiment of the present invention is applied.
[0014] Fig. 1B is a top plan view of the apparatus shown in Fig. 1A.
[0015] Fig. 2 is a cross-sectional side view showing the state where the apparatus shown
in Fig. 1A is opened.
[0016] Fig. 3 is a perspective view showing the vicinity of a platen roller.
[0017] Fig. 4 is a Perspective view showing an exhaust sheet roller.
[0018] Fig. 5 is a perspective view showing a recording frame.
[0019] Fig. 6 and Fig. 7 are side views showing the vicinity of a recording head.
[0020] Fig. 8 is a perspective view showing the recording head.
[0021] Fig. 9 is a perspective view showing the vicinity of a cap.
[0022] Figs. 10A - 10C are views showing the state immediately after the head and the cap
are in contact with each other.
[0023] Figs. 11A and 11B are views showing the state where the head and the cap are apart
from each other.
[0024] Figs. 12A - 12C are views showing the state where the cap is being moved towards
the head.
[0025] Figs. 13A - 13C are views showing the state where a projection presses a nozzle to
be tightly closed while a spring resiliently deformed.
[0026] Figs. 14A - 14C are views showing the state where the cap is being parted from the
head.
[0027] Figs. 15A - 15C are views showing the standby state of the cap.
[0028] Fig. 15D is a view showing a guide member according to another embodiment of the
present invention.
[0029] Fig. 15E is a view showing a guide member according to still another embodiment of
the present invention.
[0030] Fig. 16 is a typical view schematically showing a structural example of the ink supply
passage of an ink jet recording apparatus according to the present invention.
[0031] Fig. 17 is a perspective view showing a structural example of ink supplying means
of an ink jet recording apparatus according to the present invention.
[0032] Fig. 18 is an exploded perspective view showing an structural example of an ink cartridge
installed in an ink jet recording apparatus according to the present invention.
[0033] Figs. 19A and 19B are a partially cutaway sectional side view showing the structural
example of the ink cartridge and a partially enlarged view thereof to show the state
of mating with the ink supplying means.
[0034] Fig. 20 is a partially cutaway sectional front view of the structural example of
the ink cartridge.
[0035] Fig. 21 is a schematic top view showing the structural example of the ink cartridge.
[0036] Fig. 22 is a flowchart showing an example of sequential recovery applicable to an
ink jet recording apparatus according to the present invention.
[0037] Figs. 23A - 23D are schematic side views sequentially showing the recovery operation.
[0038] Fig. 23E is a typical view showing the contacting amount and contacting angle of
the leading end of a blade being in contact with the face of a discharging port.
[0039] Fig. 24 is a flowchart showing an example of the sequence from the standby state
to the recording state.
[0040] Fig. 25 is a block diagram showing a recording unit according to an embodiment of
the present invention.
[0041] Fig. 26 is a flowchart showing an operation at the time of recording according to
an embodiment of the present invention.
[0042] Fig. 27 is a flowchart showing a recovery operation according to an embodiment of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Research was made by the inventors of this invention to resolve the above-mentioned
problems raised in the prior art, and as a result thereof, it could be found that
with such a construction that connecting portions of the device side are stationary
and the corresponding connecting portions of the ink cartridge side are movable, the
connection therebetween can be carried out suitably. The present invention which will
be explained hereinafter was made on the bases thereof, and relates to a ink jet recording
apparatus comprising ink supplying means for permitting the supply of ink to an ink
jet recording head and an ink cartridge detachably mounted on said ink supplying means
and providing with an ink tank accommodating therewithin ink to be supplied, said
ink supplying means having a stationary ink supplying side joint portion adapted to
be connected to said ink tank, said ink tank within said cartridge having an ink tank
side joint portion connected to said ink supplying side joint portion and supplying
ink, and said ink tank having a freedom of motion in the rotation direction with respect
to the central axis of its joint portion to permit said ink tank to displace when
said ink supply side joint portion and said ink tank side joint portion are connected
to each other.
[0044] In accordance with this invention, the ink container is retained movably within the
frame enclosing it, specially in the direction of its rotation with respect to the
central axis of the connecting portion (joint portion), and thus, a freedom in connection
of the connecting portion of the device side and the corresponding connecting portion
of the ink cartridge side is easily secured, and even though there are provided a
plurality of flow paths to be connected, the positioning of the device side joint
portions to the ink container side joint portion is made easily and surely.
[0045] Also, since the joint portion of the device side (ink supplying means side) is made
to be stationary, the distribution of the ink tube form here to the recording head
can be made to be compact and simple.
[0046] Further, the inventors of this invention studied a construction with which ink is
supplied suitably from a voluminous ink tank to the recording head directly without
the use of any sub-tank, and as a result thereof, obtained a construction defined
by the following. That is, this invention relates to in an ink supplying device having
a plurality of ink paths adapted to be connected to an ink jet recording head, joint
means comprising a first ink coupling portion connected to said ink jet recording
head through an ink pump, a second ink coupling portion different from said first
ink coupling portion and connected to said ink jet recording head, and a connecting
portion for performing communication to the air, whereby an ink tank with said portions
is detachably mounted to said ink jet recording head.
[0047] Therefore, in accordance with the above mentioned construction, the ink supply can
be carried out very suitably without the use of not only the ink bag but also the
sub-tank since the ink supporting port is jointed directly to the member constituting
the ink supplying path. Also, since the port of the ink tank opening to the air is
joined to the connecting portion for performing the communication to the air so that
the ink tank can be caused to communicate to the air, it is possible to provide the
ink tank which does not request that it be in the form of the above-mentioned bag
arrangement, which is strong in vibration and shock and which is voluminous.
avoidable that the recording becomes inactive under a predetermined number of recording
papers.
[0048] Hereinafter the present invention will specifically be described in accordance with
embodiments.
[0049] Fig. 1A is a central sectional view showing an embodiment of facsimile apparatus
characteristically representing the present invention. Fig. 1B is a top plan view
thereof, and Fig. 2 is a cross-sectional view showing the apparatus in an open state.
The facsimile apparatus of the present embodiment roughly comprises original conveying
system A, optical system B, power source unit C, electric circuit board D, recording
sheet conveying system E, decurling system F, ink supply system G, and recovery system
H. Here, aforesaid original conveying system A and optical system B constitute an
original reading unit for reading original images. Then, as the basic action of a
facsimile apparatus, when an original 2 is set for transmitting or copying, original
coveying system A conveys the aforesaid original 2 sequentially by a roller train
(rollers R1, R2, R3, and R4) driven by driving means (not shown) in order to read
the original image of original 2. Thus, the original line information is transferred
by condenser lens Le to line CCD 100 through the reflective optical path of optical
system B (lamp L1, mirrors M1 and M2) from a given position for reading the original
line (main scanning line) in the course of its conveyance, and is converted into electrical
signals for the reading of the original information. At the time of receiving or copying,
recording sheet conveying system E sequentially conveys recording sheet, which is
wound in roll, by a roller train driven by driving means (not shown) to a passage
shown in Fig. 1, and recording is performed in the course thereof by discharging ink
from discharging ports of recording head 38 onto a given recording line of the recording
sheet. Ink is discharged from the discharging ports of recording head 38 with the
utilization of heat energy. This heat energy is generated by an electric heat converter
provided in recording head 38. In this respect, power source unit C received a normal
AC to convert it into all the necessary voltage currents and supplies them respectively
to each of the units of the apparatus. The electric circuits with electric circuit
board D at its center controls the functional operation of each unit of this apparatus
mainly with a cimcrocomputer system provided. It also performs the connection and
disconnection with transmission line as well as the input and output of image information
signals. Ink supply system G supplies ink to the recording head, and recovery system
H performs the cleaning and capping of the face of discharging ports, which are needed
for the maintenance of the head.
[0050] In this respect, as shown in Fig. 1B, rolled recording sheet 1 is positioned almost
in the center of the apparatus, and on the left-hand side thereof, original conveying
system A, optical system B, and power source unit C are arranged in the vertical direction,
and on the right-hand side thereof, recording head 38, record head recovery system
H, and ink supply system G with ink tank 86 are arranged sequentially in that order
from the above. Since recording head 38, recording head recovery system H, and ink
supply system G are thus arranged sequentially from the above, the ratio of pressure
variation of ink tank 86 against the orifice face of recording head 38 is reduced
(i.e., the pressure against each of the discharging ports is equalized) even if the
apparatus is inclined according to the present embodiment, and an excellent recording
can be performed. This is due to an arrangement such that despite the miniaturization
of the apparatus, the space between the orifice face of recording head and the ink
tank 86 is made greater.
[0051] Hereinafter, each structure of recording head and operation will be described following
its operational sequence. Rolled recording sheet 1 is installed, and is pinched by
driving feed roller 7 and free roller (platen roller) 8 which is in contact with said
driving roller 7 through decurling system F for straightening out the curl formed
on this recording sheet 1. Feed roller 7 is driven by driving means (not shown) with,
for example, a stepping motor as its power source.
[0052] Here, Fig. 3 is a perspective view showing parts arranged in the longitudinal direction
in the vicinity of free roller 8 (platen roller). A first platen side plate 13a and
a second platen side plate 13b fixed to or integrally formed with recording frame
19 support free roller 8 with a play in such a manner that the shaft of the free roller
is penetrated through the opening 13c provided each of the side plates, having a larger
diameter than that of the shaft. The E rings 29 and 30 are fixed respectively at both
ends of the shaft of free roller 8 as locks and further, on both shaft parts of free
roller 8, bearings 10a and 10b, the inner and outer diameters of which are accurately
regulated to provide an equal coaxiality, are fittedly mounted on the shaft of free
roller 8 to enable it to be freely rotated. In the meantime, the aforesaid first platen
side plate 13a and second platen side plate 13b are slidably arranged each with the
respective platen pressure shaft 12a and 12b mounted on the inner side thereof as
shown in Fig. 3. Then, by the functions of springs 11a and 11b, the aforesaid platen
pressure shafts 12a and 12b are in contact with bearings 10a and 10b of the aforesaid
free roller 8 respectively to exert pressure against each of them.
[0053] Now, reverting to Fig. 1, recording head 38 is at the recording position. At this
juncture, free roller 8 is positioned by being in contact in two directions with feed
roller 7 by the pressure exerted by free roller 8 as well as with recording head 38
by contacting the aforesaid bearings 10a and 10b. In other words, the direction, in
which the pressures of platen pressure shafts 12a and 12b of free roller 8 are exerted,
is set towards the direction that free roller 8 is in contact with free roller 7 and
that bearings 10a and 10b are in contact with recording head 38. At the same time,
recording guide 14 made of thin plastic plate guides the aforesaid recording head
38, so that the recording head is rotated to the recording position with head shaft
36 as its rotational center.
[0054] Thus, the sheet path is matched with the recording line position, and recording head
38 discharges ink from its discharging ports onto the aforesaid recording line position
for recording at the time of recording.
[0055] Next, recording sheet 1 is pinched by first exhaust sheet roller 21 and the roller
train 17a - 17g and roller train 18a - 18g which are in contact with the aforesaid
first exhaust sheet roller 21 to be conveyed while being guided by first curvature
guide 15 and first exhaust sheet guide 20.
[0056] In this respect, the aforesaid first exhaust sheet roller 21 is driven by the driving
system of the same power source as feed roller 7, and is so arranged that the peripheral
speed of the aforesaid first exhaust sheet roller 21 is slightly faster than that
of the aforesaid feed roller 7.
[0057] Here, Fig. 4 is a perspective view showing the parts arranged in the longitudinal
direction in the vicinity of first exhaust sheet roller 21. Rollers 17a - 17g and
roller 18a - 18g are arranged alternatively with first curvature guides 15a - 15f.
Each of them is rotatably supported by shaft 31 and shaft 32 and both ends of the
shafts are locked by E rings, etc. Also, at both ends, shaft 32 is regulated by receiving
side 9a of the first exhaust sheet rollers, which is fixed to or integrally formed
with recording frame 19 and receiving side 19b of the second exhaust sheet rollers,
and also in the horizontal direction, the shaft is regulated at both ends thereof
by the vertically elongated through holes having the diameter fitted to that of shaft
32, through which the shaft is penetrated. The both ends of the shaft are also locked
by E rings (not shown), etc. In this respect, compression is generated by springs
16a - 16f represented only by a reference numeral 16a in Fig. 4 for recording chassis
19 and first curvature guides 15a - 15f (refer to Fig. 1) to cause rollers 17a - 17g
and roller 18a - 18g to be in contact with exhaust sheet roller 21 by pressure. As
a result, when recording sheet 1 is pinched thereby, the power to convey the recording
sheet is generated. Then, recording sheet 1 is guided to upper exhaust sheet guide
23 and trailing exhaust sheet guide 24 through the space between both edges 22a and
22b which cut the recording sheet into each of the receiving one pages and is further
guided and conveyed by second exhaust sheet roller 25 and the rollers 27a - 27g and
rollers 28a - 28g which are in contact therewith. In this respect, second exhaust
sheet roller 25 is also driven by the driving system in such a manner that the peripheral
speed thereof is set at a speed slightly faster than that of the aforesaid first roller
21. Here, too, as in the vicinity of the aforesaid first exhaust sheet roller 21,
rollers 27a - 27g and rollers 28a - 28g are arranged alternately with second curvature
guides 26a - 26f and are rotatably supported respectively by shaft 33 and shaft 34.
Then, both ends of shaft 34 are locked with E rings, etc. Shaft 33 is regulated at
both ends thereof by exhaust sheet roller receiving sides 19c and 19d fixed to or
integrally formed with recording frame 19, having vertically elongated holes fitted
respectively to the diameter of shaft 33, through which both ends of the shaft are
penetrated horizontally. The ends thereof are also locked by E rings, etc. With springs
35a - 35f, compression is generated between recording frame 19 and second curvature
guides 26a - 26f (refer to Fig. 1) to cause rollers 27a - 27g and rollers 28a - 28g
to be in contact with second exhaust sheet roller 25 by pressure, so that when recording
sheet 1 is pinched thereby, the conveying power is generated. In this way, the recording
sheet is exhausted after recording has been completed, and is further conveyed by
exhaust sheet roller 39 in the form of being cut into the unit of one page while the
leading and thereof is being held smoothly by stacker 40. As a result, an operator
can take out the recording sheet thus stacked on stacker 40.
[0058] As the above describes, the recording sheet conveying system is structured to carry
out its operation. Here, Fig. 1 shows the state of the system at the time of recording,
and at the time of replacing the recording sheets or troubleshooting in conveying
recording sheet, recording frame 19 can be opened or closed with hinge 19e of recording
frame 19 as its pivoting point. In other words, as shown in Fig. 2, the recording
frame can be opened just along the recording sheet conveying path as its boundary,
and the arrangement is designed to place each of the components belonging to recording
frame 19 above this boundary and each of those belonging to main body frame 63 below
the boundary. This recording frame 19 and the assembly of its components thereon are
shown in Fig. 5.
[0059] As set forth above, in the present embodiment, recording head 38, recording head
recovery system H, and ink supply system G are sequentially arranged from the above
in that order. Thus, recording sheet 1 is guided in the horizontal direction above
recording head 38 after the recording has been completed by recording head 38, and
is further conveyed downwards thereafter to exhaust sheet stacker 40 for stacking.
Here, the path through which the aforesaid recording sheet is being guided in the
aforesaid horizontal direction forms the aforesaid boundary along which the main body
is opened. Therefore, according to the present embodiment, it is easy to remove a
clogged sheet if any clogging should occur, and further, it is possible to perform
capping without damaging the head face when a sheet clogging takes place. In addition,
should an ink leakage occur while capping, the recording sheet is not stained.
[0060] Next, the positioning of free roller 8 (platen roller) will be described.
[0061] First, Fig. 6 illustrates the state of parts in the vicinity of free roller 8 when
the main body of the apparatus is in standby. Recording guide 14 is not allowed to
be in contact with free roller 8 unless there is external force to be exerted thereon.
Accordingly, the contacting angle of recording sheet 1 to the periphery of free roller
8 is less in the standby state than in the printing state. At this juncture, the position
of free roller 8 is established by the fact that the periphery of free roller 8 is
pressed by platen pressing shafts 12a and 12b to be in contact with feed roller 7,
and that the shaft of free roller 8 is in contact with through hole 13c, which is
larger than the periphery of the aforesaid shaft by 0.1 mm - several mm, provided
on each of platen side plates 13a and 13b. Here, the aforesaid feed roller 7 and free
roller 8 are made of plastic material such as rubber, etc. rolled around rigid shaft
made of iron, etc.
[0062] Next, Fig. 7 illustrates recording head 38 being rotated clockwide with head shaft
as its rotating center in order to shift itself from the standby state to recording
state. When head 38 is first rotated as described earlier by the driving power generated
by motor KM, a plurality of projections provided on the recording face of head 38
are in contact with the top of recording guide 14 to cause recording guide 14 to begin
resiliently deforming it. Here, projection 38c provided on the recording face of head
38 is made to be increasingly higher towards the corner. Thus, recording guide 14
is deformed apart from recording head 38 by the height (δ in Fig. 7) of the aforesaid
projection.
[0063] The reason why the aforesaid projection 38c is arranged to be increasingly higher
towards the coner is to make it easier to remove ink when the recording face of the
head is wiped as described later.
[0064] Recording head 38 is further rotated clockwise, and when recording head 38 is moved
to be in the recording state as shown in Fig. 1, both ends of the recording face of
recording head 38 are in contact with bearings 10a and 10b. Hence, the space between
the recording face of recording head 38 and platen roller (free roller) 8 is established.
In the present embodiment, the periphery of bearings 10a and 10b is made larger than
that of free roller 8, and the volume thereof is set to be less than the height δ
of the aforesaid projection of recording head 38 by a 1/several mm thereof. Thus,
guide 14 is reliably in contact with the periphery of platen roller 8 to convey the
recording sheet. Here, at the time of recording, the aforesaid feed roller 7 is rotated
clockwise, and platen roller 8 is rotated counterclockwise by the external force generated
by the feed roller, at the same time, being moved in the direction towards the recording
head 38. Hence, with the structure described earlier, the aforesaid platen roller
8 is brought to contact with guide 14 through recording sheet. Therefore, the aforesaid
springs 11a and 11b are not necessarily needed here, and platen roller 8 can also
be incontact with the guide only by its own weight.
[0065] Next, using the perspective view shown in Fig. 8, the structures of peripheral parts
of recording head 38 will be described. Recording head 38 mainly comprises head main
body 38f including a heat generating section, electrical part section, and glass chamber
section for containing liquid ink, front filter 38d and rear filter 38e arranged respectively
at the outside of the head main body, and head front plate 38c. Also, front head ink
connection 38d₁ and rear head ink connection 38e₁ are respectively provided for front
filter 38d and rear filter 38e. These are tightly closed and connected respectively
by front ink supply 71 and ink supply tube threading with sealing members (not shown)
provided therebetween. A reference numeral 38a designates an imaginary two-dot chain
line in Fig. 8 to represent the straight line formed by connecting the center lines
of the nozzles aligned. A plurality of nozzles are aligned in order to form image
on a recording material across the entire width thereof in the direction of main scanning.
Hereinafter, these are referred to as nozzle 38a. In practice, however, holes of several
ten microns in diameter are provided, and the aforesaid holes are connected to ink
supply tubes 71 and 72. Here, the opposite ends of ink supply tubes 71 and 72 are
respectively connected to front supply tube joint 84 and rear supply tube joint 85.
Now, in Fig. 8, a reference numeral 38b designates the face where nozzle 38 is open,
which is called orifice face. In this respect, front head plate 38g is formed by metal
or molding material, and the space between orifice face 38b and front head plate 38g
is filled with silicon rubber, etc. to close them completely. Filters 38d and 38e
are arranged to prevent dusts in ink from being flown into the nozzle section. Reference
numerals 37a and 38b designate front and rear head arms made of engineering plastic,
sintered metal, diecast metal, or the like, which has rigidity and resistivity against
thermal deformation at high temperatures, and each of them is fixedly mounted on BJ
head 38 by means of screw, etc.
[0066] Front head arm 37a and rear head arm 37b are fixedly mounted on head shaft 36 by
means of screw, etc., and with the structure as described earlier, head shaft 36 and
BJ head 38 are fixed arranged. Head shaft 36 is rotatably supported by main body frame
56 through bearings (not shown). Head shaft 36 is connected to driving system comprising
gears, belts KB, etc., and is further connected to stepping motor KM.
[0067] Next, using the perspective view shown in Fig. 9, the structure of peripheral parts
of cap 41 will be described. Although the shape of cap 41 will be described later
in detail later, cap 41 is formed by plastic material such as silicon rubber, etc.
which has a high resistivity against mechanical creep as well as a high ratio of permeability
for water vapor, etc. A reference numeral 42 designates a cap keel made of rigid material
such as aluminum, stainless steel, etc., and as shown in a cross-sectional view in
Fig. 10, short shafts 46a, 46b, 46c, 46d, and 46e are fixedly mounted on cap keel
42 by means of screws. Short shafts 46a - 46e should desirably be made of a corrosion-inhibiting
and rigid material such as stainless steel, etc. In the present embodiment, although
short shafts 46a - 46e are fixed by screws, these can also be coupled by means of
press fitting, bonding, or the like. Also, cap keel 42 and shafts 46a - 46e can be
formed integrally by means of molding, etc.
[0068] Here, the formation of cap 41 is first made by coupling cap keel 42 and short shafts
46a - 46e as described above. Then, the coupled cap keel 42 and short shafts 46a -
46e are buried into an open forming die, and by putting silicon rubber, which is also
the original material of cap 41, into the die or sandwiching silicon rubber between
cap 41 and cap keel 42, these are integrally formed by burning into a one body. Here,
the shape of the aforesaid forming die should match the external contour of cap 41
as a matter of course. Now, a reference numeral 60 designates a recovery frame made
of a corrosion-inhibiting rigid material such as stainless steel, and the four sides
of recovery frame are bent to rise (60a - 60d) in order to enhance the rigidity. To
recovery frame 60, short shaft bearings 61a, 61b, 61c, 61d, and 61e are fixed by screws,
etc. (not shown) to receive short shafts 46a - 46e. In this respect, the method for
coupling bearings 61a - 61e with frame 60 may also be either welding or bonding. Also,
as described later, short shaft 46a is fitted into an elongated hole while short shafts
46b - 46d are fitted into the so-called loose holes, and short shaft 46e is fitted
to perform positioning. In other words, each of the short shafts 46a - 46e has a same
outer diameter, and the inner diameter 61e₁ of short shaft bearing 61e and the outer
diameter of short shaft 46e are made to just fit each other. Short shaft bearings
61a - 61e are made of polyacetal resin having excellent slidability against stainless
steel short shaft 46e.
[0069] As shown in Fig. 9, an elongated hole 61a₁ is formed for short shaft bearing 61a
against short shaft bearing 61e in the longitudinal direction of cap 41. Then, the
dimension of elongated hole 61a₁ in the transverse direction is formed to fit short
shaft 46a. The diameters of holes 61b₁, 61c₁ and 61d₁ opened in short shaft bearings
61b, 61c, and 61d are respectively formed larger than the outer diameters of short
shafts 46b - 46d within a rage of 0.1 mm - 1 mm. Then, at the outside of short shafts
46a - 46e, compression springs 47a - 47e are respectively held by screws from the
reverse side of recording frame 60 with short shaft stoppers 56a - 56e sandwiched
as shown in Fig. 9.
[0070] Compression springs 47a - 47e are pressed between the cap keel and short shaft bearings
61a - 61e because the springs are held by screws. The movement of cap 41 at this juncture
will be described later.
[0071] Next, first wiper 50 and second wiper 52 are made of plastic material such as rubber,
etc. having a good abrasion resistance, and the straight portions of leading ends
50a and 52a of first and second wipers 50 and 52 are strictly controlled to maintain
the straightness as well as to prevent wear and dust, etc. Also, the aforesaid first
wiper 50 and second wiper 52 are respectively fixed to first wiper stay 49 and second
wiper stay 51 by means of screws, etc. (not shown). First and second wiper stays 49
and 51 are both made of corrosion-inhibiting rigid metal such as stainless steel,
etc.
[0072] Further, as shown in Fig. 9, first wiper stay 49 and second wiper stay 51 are held
on recovery frame 60 by screws, and the projection 41a of cap 41, which will be described
later, and the wiper leading ends 50a and 52a are arranged to accurately parallel
themselves at this juncture. Also the aforesaid projection 41a, wiper leading ends
50a and 52a, and the mounting face of recovery frame 60 for wiper stays 49 and 51,
and the imaginary two-dot chain line α in Fig. 9 connecting the center lines of boss
sections 59a₁ and 59b₁ of front cam gear 59a and rear cam gear 59b are arranged to
be in parallel accurately as described later. Also, as shown in Fig. 9, the structure
is formed to enable the height of the leading end 52a of second wiper against recovery
frame 60 to be higher than that of the leading end 50a of first wiper against recovery
frame 60. In order to provide this structure, it is possible to change either the
heights of the aforesaid plastic portions made of rubber, etc. of first and second
wipers 50 and 52 or the height of rigid portions of first and second wiper stays 49
and 51. Now, a reference numeral 54 designates a recovery frame bearing, and recovery
frame shaft 55 shown in Fig. 1C (control cross-sectional view) is allowed to fit the
elongated hole 54a of recovery frame bearing 54 in the transverse direction. Here,
in this respect, recovery shaft 55 is fixed to main body frame 63, but recovery frame
shaft 55 may also be supported rotatably by main body frame 63. Recovery frame shaft
bearing 54 is made of polyacetal resin having a good slidableness and is fixedly screwed
to recovery frame 60. Recovery frame bearing 54 is fixed against recovery frame 60
in the direction indicated by arrow β in Fig. 9 at a position which enables the center
of the depth of elongated hole 54a to be in the central part of recovery frame 60.
Also, here, the center of hole 61c₁ of short shaft bearing 61c is positioned in the
central part of recovery frame 60 in the direction indicated by arrow β as shown in
Fig. 9. Further, the center of hole 61b₁ of short shaft bearing 61b and that of hole
61d₁ of short shaft bearing 61d are symmetrically positioned in the direction indicated
by arrow β with short shaft bearing hole 61c₁ as the center. Also, the center of elongated
hole 61a₁ of short shaft bearing 61a in the direction indicated by arrow β and the
center of hole 61e₁ of short shaft bearing 61e are likewise positioned symmetrically
in the direction indicated by arrow β with the hole 61c₁ as the center. Now, it is
desirable to equalize four distances between the centers of holes, i.e. the distance
between the centers of holes 61a₁ and 61b₁, 61b₁ and 61c₁, 61c₁ and 61d₁, and 61d₁
and 61e₁. Next, a reference numeral 62 designates a recovery frame shaft which is
arranged across both of the side plates of main body frame 63. This recovery frame
shaft 62 is rotatably supported around a bearing (not shown) provided in main body
frame 63. Further, to this recovery frame shaft 62, idler gears 57a and 57b are fixedly
mounted respectively at positions inside the main body frame 63 and outside the front
cap guide 48a and rear cap guide 48b which will be described later. In view of assembling
recovery frame 62 in main body frame 63, parallel pins or spring pins (both not shown)
and E ring stopper are used as means to fix idler gears 57a and 57b to recovery frame
shaft 62. Further, to recovery frame shaft 62, outer idler gear 58 is fixed with D
cut portion formed at an end of recovery frame shaft 62 as its rotation stopper, with
main body frame 63 being sandwiched as shown in Fig. 9. Then, to idler gear 57a and
57b, cam gears 59a and 59b are arranged to engage with each other. Cam gears 59a and
59b are rotatably supported on cam gear shafts 70a and 70b fixed to main body frame
63 respectively at positions outside the cap guides 48a and 48b and inside the main
body frame 63. Here, the modules and number of teeth of gears 57a, 57b, 59a, and 59b
are the same. Furthermore, gear 58 and gears 57a, 57b, 59a, and 59b are of the same
number of teeth. Then, gear 58 is connected to stepping motor CM.
[0073] As above describes, the number of teeth thus arranged enables the gears engaged with
cam gears 59a and 59b to rotate one round exactly the same as the cam gears completing
one round, so that the rotational angles and positions of these gears are detected
by a microswitch slit type sensor (not shown), etc. to detect the position of the
boss section 59a₁ of cam gear 59a and the boss section 59b₁ of cam gear 59b. Therefore,
if only a gear, a timing pulley, or the like, which should complete one round in synchronism
with the one rotation of cam gears 59a and 59b, is arranged in the driving system
for detecting the position of such gear, timing pulley, or the like, it is not necessary
to make the number of teeth identical to each of the gears 57a, 57b, 59a and 59b as
in the present embodiment. To recovery frame 60, cap guides 48a and 48b are fixedly
mounted in addition to these gears. Cap guides 48a and 48b are made of polyacetal
resin having a good slidableness. Then, grooves 48a₁ and 48b₁ are formed on cap guides
48a and 48b to fit the boss sections 59a₁ and 59b₁ of cam gears 59a and 59b in the
transverse direction as shown in Fig. 10. Here boss section 59a₁ and boss section
59b₁ are arranged at positions just opposite to each other.
[0074] Since the structure is of such as described above, recovery frame 60 performs rocking
motion in the direction indicated by arrow X in Fig. 10 (central cross-sectional view)
with recovery frame shaft 55 as the center when outer idler gear 58 is rotated.
[0075] Now, since the vicinity of recovery frame 60 is constructed with the parts described
as above, recovery frame 60 is positioned by the plane formed by two-dot chain line
α and recovery frame shaft 55 as shown in Fig. 9. Here, two-dot chain line α and head
shaft 36 are arranged to be accurately in parallel. Although recovery frame 60 is
positioned by the plane formed by the aforesaid two-dot chain line α and recovery
frame shaft 55, it is not fixed by the aforesaid structural members. Recovery frame
60 is structured to be flexible in the direction indicated by arrow ϑ and by curbed
arrow γ in Fig. 9.
[0076] Next, using Fig. 11, the arranging position of first recovery cap guide 48a and second
cap guide 48b is the direction indicated by arrow ϑ in Fig. 9 towards recovery frame
60 will be described in detail. On both first and second cap guides 48a and 48b, U
letter type holes 48a₁ and 48b₁ are formed, and the space of U letter hole is precisely
defined. The space of the aforesaid U letter holes 48a₁ and 48b₁ is indicated by arrow
in Fig. 11. Then, first and second cap guides 48c and 48b are arranged on recovery
frame 60 to allow the center of the shorter width of projection 41a (indicated by
arrow in Fig. 11) of cap 41 to be placed in the center of the aforesaid space of U
letter holes 48a₁ and 48b₁.
[0077] Next, on first head arm 37a and second head arm 37b, circular projections 37a₁ and
37b₁ are formed respectively on front head arm 37a and rear head arm 37b. Then, the
arranging positions of the aforesaid circular projection 37a₁ and 37b₁ are defined
to allow the ink discharging ports of nozzle section 38a to be placed in the central
position of the circular projection. Also, the diameter of the aforesaid circular
projections 37a₁ and 37b₁ is formed to fit exactly the spaces of U letter holes on
cap guides 48a and 48b.
[0078] Now, since the structure is arranged as described above, when recovery frame 60 is
raised by the rotation of cam gears 59a and 59b at the time of capping, circular projections
37a₁ and 37b₁ of head arms 37a and 37b are respectively guided to U letter holes 48a₁
and 48b₁ of cap guides 48a and 48b, and nozzle section 38a and projection 41a of cap
41 are just oppositely placed.
[0079] Here, in the present embodiment, recovery frame 60 can be displaced in the direction
indicated by arrows ϑ and γ (in Fig. 9) by the construction as described earier. Therefore,
according to the present embodiment, even when there is a slight difference in the
positions of the aforesaid U letter holes 48a₁ and 48b₁ and projection 37a₁ and 37b₁
at the time of fitting, recovery frame can fit them reliably while being guided by
slant 48c and holes 48a₁ and 48b₁ to displace itself in the horizontal direction if
only projections 37a₁ and 37b₁ are in contact with slant 48c of U letter holes 48a₁
and 48b₁.
[0080] Further, the positioning of cap 41 and front head plate 38c, which will be described
later, is performed naturally in this course of event. Also, even if recovery frame
60 approaches nozzle orifice face 38b with some inclination, projection 41a and nozzle
section 38a can approach each other with the face to face positional relationship.
[0081] Next, using Figs. 10 through 15, the shapes and movement of cap 41, cap keel 42,
valve 43, valve cover 44, and waste ink tube will be described.
[0082] Fig. 10 illustrates the state immediately after head 38 and cap 41 are in contact
with each other. Fig. 11 illustrates the state when head 38 and cap 41 are parted.
Fig. 12 illustrates the state when cap 41 is moved forwards head 38. Fig. 13 illustrates
the state where projection 41a closes nozzle 38a by pressure, and spring 47 is resiliently
deformed. Fig. 14 illustrates the state where cap 41 is parted from head 38, and Fig.
15 illustrates the standby state. In each of the figures, A is a side view observed
from the location of side plate; B is a cross-sectional view in the transverse direction;
and C is a cross-sectional view in the longitudinal direction. In Fig. 11, however,
A is also a side view but B is a cross-sectional view in the longitudinal direction.
[0083] At first, Figs. 10A through 10C illustrate the state representing the moment cap
41 has come into contact with front head plate 38c. Cap 41 has not been deformed as
yet. In conjunction with Fig. 10B, the cross-sectional shape of cap 41 is described
in detail. The side portions of cap 41 are formed with inclination so as to widen
the distance between them as the cap is raised upwards as shown in Fig. 10B. The inclined
side portions are connected to the curbed portions indicated by mark a in Fig. 10B,
and the thickness of the portions a are made thinner than the other portions as illustrated
in Fig. 10B. Although, in the present embodiment, the portions a are formed with a
smooth curvature, these portions may also be formed in an abrupt edge. In the case
of an abrupt edge in which these should be formed, the thickness of such edge portions
could be made thinner. Likewise, in Fig. 10C, the cross-sectional shape of cap 41
in the transverse direction is formed to open itself towards the outside as it is
raised upwards as in Fig. 10C.
[0084] The cross-sectional shape of cap 41 in the transverse direction is formed in such
a manner that the thickness of cap 41 contacting with front head plate 38c is made
thicker than that of the cross-sectional shape of cap 41 in the longitudinal direction
shown in Fig. 10B also contacting the aforesaid front head plate 38c. This is due
to the fact that although the positioning of cap 41 against head 38 in the transverse
direction is accurately performed, the positioning in the longitudinal direction is
not performed accurately. Therefore, such construction as is the present embodiment
may not be needed if only the positioning of cap 41 against head 38 is accurately
performed in the longitudinal direction. Now, reverting to Fig. 10C, the side portions
of cap 41 are connected to curbed portions b which change its shape smoothly as in
Fig. 10B, and the thickness of portions b is made thicker. In the present embodiment,
the shape of cap 41 in Figs. 10B and 10C is such that the thickness thereof becomes
increasingly thinner smoothly towards as illustrated in these two figures. Now, reverting
to Fig. 10B, in the closed space in cap 41, projection 41a integrally formed with
cap 41 is provided. The arranging position of projection 41a is defined so as to allow
the top of R shaped portion 41c of projection 41a to be located at a position against
nozzle section 38a. The length of projection 41a in the longitudinal direction at
both ends is made longer than the entire length in which nozzle section 38a is arranged.
Next, through hole 41b is provided on cap 41. The through hole 41b in cap 41 is provided
with through hole 41 provided on cap keel 42. Then, the aforesaid through hole 41b,
valve 43 is fitted. The aforesaid valve 43 being formed with plastic material, it
can produce a state which is closed from the atmosphere without any pressure exerted
on valve 43. Here, the reason why valve 43 can properly function as a valve is that
while cap keel 42 is formed with rigid material as described earlier, the contact
face between valve 43 and cap keel 42 is formed excellent precision.
[0085] Next, around valve 43, valve cover 44 is mounted to enclose valve 43, and cap keel
42 and valve cover 44 are closedly fixed. Further, valve cover 44 is closedly coupled
with wast ink tube 45. Cap 41 begins to approach recording head 38 from the state
shown in Fig. 10 by the rotation of cam gears 59a and 59b in the direction indicated
by arrow d in Fig. 10A. Along the movement of the aforesaid cam gear 59a and 59b,
the sides of cap 41 begin to move in the directions indicated by arrow c in Fig. 10B
and Fig. 10C while maintaining contact with front head plate 38c. This movement occurs
because the sides of cap 41 are formed to open as the cap is raised upwards. Now,
cap 41 is moved in the direction indicated by arrows c due to the shape of cap 41.
In addition to this, it is due to the increasing pressure in the closed space in cap
41 resulting from the reduction of volume of the closed space in cap 41. As the pressure
in the closed space in cap 41 increases, valve 43 begins to open, and air in the closed
space begins to flow from valve 43 and waste ink (not shown) begins to flow towards
waste ink tube 45. Further, Fig. 12 illustrates the state where cam gears 59a and
59b have rotated in the direction indicated by arrow d.
[0086] In Fig. 12B, the side of cap 41 is in contact with the rising portion of the edge
of front head plate 38c and the movement in the direction indicated by arrow c in
Fig. 10 is stopped. The side of cap 41 in the transverse direction shown in Fig. 12C
is formed thinner than the thickness of the side in the longitudinal direction as
described earlier. Therefore, its movement in the direction indicated by arrow c is
stopped by the rigidity of the side itself. In the present embodiment, the thickness
of the side of cap 41 shown in Fig. 12C is changed as described earlier, but if the
thickness of the side of cap 41 in the transverse direction is made thin as in the
case of the thickness of the side in the longitudinal direction as described above,
the same faction as the present embodiment can be materialized by allowing the side
to be in contact with the rising portion of the edge of front plate 38c.
[0087] Now, in Fig. 12B, the portions a of the sides of cap 41 are deformed as shown in
Fig. 12B due to bending stress generated after the sides of the cap are in contact
with the edges of front head plate 38c. The thick portions including the contacting
faces of the sides of cap 41 receive buckling load, and the aforesaid portions a,
being deformed to bend, are not buckled. This results in the similar deformation taking
place in the sides of cap 41 including the portion b in Fig. 12C which is also being
deformed. Here, in Fig. 12C, compression spring 47a has not been pressed as yet.
[0088] In Fig. 12B, the pressure in the aforesaid closed space generated by cap 41 becomes
higher than the pressure in the state represented in Fig. 10, and valve 43 is released
to flow air in the closed space in cap 41 and the aforesaid waste ink to waste ink
tube 45.
[0089] In this respect, when cam gears 59a and 59b are further rotated in the direction
indicated by arrow d, cap 41 further approaches head 38 and the projection 41a of
cap 41 contacts nozzle 38a. Here, there is almost no deformation of cap 41 with the
exception of projection 41a. Also, when cam gears 59a and 59b are still further rotated
in the direction indicated by arrow d, compression spring 47a begins to deform, and
the reaction generated by the aforesaid compression spring 47a causes projection 41a
of cap 41 to press nozzle section 38a. In this respect, only compression spring 47a
is illustrated in Fig. 10 through Fig. 15, but the other compression springs 47b,
47c, 47d, and 47e function in the same way as compression spring 47a. Here, the time
needed for the aforesaid projection 41a to press nozzle 38a is approximately several
seconds which are required for liquid ink to circulate in head 38. At this juncture,
a pump is actuated to circulate liquid ink.
[0090] In the above-mentioned embodiment the cap 41 and the projection 41 a are integrally
formed of an elastic material such as rubber. However, the cap 41 may be a member
separate from the projection 41a and the whole body of the cap 41 does not have elasticity.
At least the head discharge port surface 38c and the contact section may be elastic
and in this case a remaining upper part thereof may be of steel.
[0091] Now, Fig. 13 illustrates the state where compression spring 47a is deformed as the
above describes, and boss sections 59a₁ and 59b₁ of cam gears 59a and 59b are positioned
at the top. In Fig. 13, there is almost no volume change in the closed space formed
by the cap 41, and valve 43 only shows the state to close air. Therefore, the pressure
in the closed space is equal to the atmospheric pressure. Hereinafter, the state of
each part, when cam gears 59a and 59b are rotated from the state shown in Fig. 13
in the direction indicated by arrow e, will be described. Now, the rotational direction
of cam gears 59a and 59b means the required movement of boss sections 50a₁ and 59b₁
from the top to the bottom or from the bottom to the top as shown in Fig. 13, and
even if, for example, cam gears 59a and 59b are rotated in the direction reverse to
that indicated by arrow e in Fig. 13, the movements described below should take place
in the same manner. In Fig. 14, the volume in the closed space in cap 41 is again
increased and the pressure in the closed space becomes negative against the atmosphere,
and valve 43 is closed as shown in Fig. 14. Therefore, in order to supplement the
reduced volume in the closed space in cap 41, ink is discharged from nozzle section
38a of recording head 38. Ink remaining in nozzle section 38a is refleshed.
[0092] Finally, Fig. 15 illustrates the pheripheral parts including cap 41 being in the
standby state where an apparatus according to the present invention has not started
performing operation such as recording, recovering, etc. In Fig. 15, the cam gears
are at rest. In Fig. 15B, the pressure in the closed space in cap 41 is identical
to the atmospheric pressure. At this juncture, there is no force exerted on valve
43 either to open or close to valve 43. However, due to the shape of valve 43, water
vapor in the closed space in cap 41 is not released into the atmosphere.
[0093] Fig. 15D is a view showing another embodiment of guide member according to the present
invention. On first cap guide 48a and second cap guide 48b, V letter holes 48a₂ and
48b₂ are respectively formed, and the spaces in V letter holes are formed with excellent
precision.
[0094] Next, on first head arm 37a and second head arm 37b, square projections 37a₃ and
37b₃ are respectively formed, and the widths of the aforesaid projections are formed
to fit exactly the spaces of the aforesaid V letter holes respectively.
[0095] Then, first head arm 37a₂ and second head arm 37b₂ are arranged to allow the leading
ends of square projections thereof 37a₃ and 37b₃ to mate respectively with V letter
holes 48a₂ and 48b₂ when the projection of cap 41 is in contact with nozzle section
38a of head 38.
[0096] With a structure such as this, even if there is a slight difference in the positions
of the aforesaid V letter holes 48a₂ and 48b₂ and the aforesaid square projections
37a₃ and 37b₃, recovery frame 60 enables the holes 48a₂ and projection 37a₃ and the
hole 48b₂ and projection 37b₃ to be mated reliably because the frame can displace
itself in the directions indicated by ϑ and γ in Fig. 9.
[0097] Fig. 15E is a view showing still another embodiment of guide member according to
the present invention. On first head arm 37a₄ and second head arm 37b₄, U letter holes
37a₅ and 37b₅ are respectively formed, and the spaces of U letter holes are formed
with excellent precision.
[0098] Next, on first cap guide 48a and second cap guide 48b, circular projections 48a₃
and 48b₃ are respectively formed, and the widths of the aforesaid circular projections
are formed to fit exactly the spaces of the aforesaid U letter holes.
[0099] Then, first head arm 37a₄ and second head arm 37b₄ are arranged to allow the leading
ends of U letter holes 37a₅ and 37b₅ to fit circular projections 48a₃ and 48b₃ respectively
when the projection of cap 41 is in contact with nozzle section 38a of head 38.
[0100] With a structure such as this, even if there is a slight difference in the positions
of the aforesaid circular projections 48a₃ and 48b₃ and the aforesaid U letter holes
37a₅ and 37b₅, recovery frame 60 enables the projection 48a₃ and hole 37a₅ and the
projection 48b₃ and hole 37b₅ to be mated reliably because the frame can displace
itself in the directions indicated by arrows ϑ and γ in Fig. 9.
[0101] Next, the ink supply and recovery systems will be described. This unit comprises
an ink tank, ink tubes, an ink pump, etc. to keep ink and supply it regularly to a
recording head and to remove bubbles generated in the tubes, etc., as well as anything
that may clog nozzles.
[0102] Fig. 16 is a view illustrating the concept of an embodiment according to the present
invention. In Fig. 16, an ink cartridge cam prises recording head 38, ink pump 76,
ink tank 86, wast ink absorber 96, and air duct 87 which is called breezer.
[0103] The initial ink supply to recording head 38 is carried out in a manner given below.
In other words, ink pump 76 is actuated in a state where cap 41 is closely contacted
with the recording head (a state shown in Fig. 13 where projection 41a in cap 41 is
in contact with nozzle section 38a of recording head 38) to circulate ink from ink
cartridge 86 in the direction indicated by arrow E, so that the inside of the tubes
including the inside of the recording head is filled with ink. At this time, some
ink is flown out to cap 41, but it is returned to ink cartridge 86 through waste ink
tube 45 and collected to built-in ink absorber 96.
[0104] When the initial ink supply is completed, recording head 38 is ready to discharge
ink. The ink pump used in the present embodiment, however, is a pump which does not
close the flow passage when the pump is at rest. Therefore, the ink supply at the
time of discharging is carried out from both front and rear head ink couplers 38d
and 38e.
[0105] When ink is reduced due to discharging, air should be drawn into the tank in an amount
equal to the reduced amount of ink. Breezer 87 functions as an air duct for this purpose.
In this breezer 87, check valves capable of being opened by an extremely small difference
in pressures are respectively arranged in both directions. Therefore, the valves function
if a slight pressure, either negative or positive, is generated in the tank, and operate
as air holes substantially. However, the valves are also arranged to control dust
intrusion and evaporation.
[0106] A reference numeral 92 designates a no-ink detector for detecting no-ink condition
in tank 94. The detection is carried out in a manner given below. In other words,
since float chamber 90 is open to the atmosphere through breezer 87 which is commonly
provided for ink tank 94, the liquid level therein and float 89 which floats thereon
indicate the same water level 91a as liquid ink level 91 in ink tank 94. Therefore,
at an appropriate location in the lower part of float chamber 90, sensor 88 is arranged
for detecting a light interruption. Thus, when liquid level 91 is lowered, i.e., float
89 is lowered following the lowering of water level 91a in the area for detection,
the emitting light from the sensor 88 is interrupted, thereby detecting the no-ink
condition.
[0107] Next, the recovery operation is described. The recovery operation is an action to
remove bubbles and cloggings which bender the normal discharging, and is performed
in accordance with the recovery sequence, which will be described later, controlled
by the recovery system. The recovery operation, however, is exactly the same as the
initial ink supply operation. In other words, ink pump 76 is actuated while cap 41
is in contact with recording head 38 (the current state is illustrated in Fig. 13)
to circulate ink in the direction indicated by arrow A, so that bubbles are collected
into the ink tank to release them to the outside through the breezer. Also, the contacting
condition between projection 41a in cap 41 and nozzle 38a is released to drive the
pump for the removal of any clogging in the nozzle. At this time, pressurized ink
is flown into float chamber 90. Then, float 89 is raised to closely contact with upper
face of float chamber 90 to cover the passage to breezer 87. Therefor, no ink is flown
into breezer 87.
[0108] Fig. 17 is a perspective view showing the construction of supply and recovery systems,
in which the structure of the present embodiment is actually employed. In Fig. 17,
a reference numeral 73 designates the base of this unit which also functions as a
base for installing ink cartridge 86, which will be described later. Also, a reference
numeral 74 designates a member called joint plate which is formed by fixing each of
various passage couplers. To this joint plate 74, there are coupled cartridge guide
78 for positioning ink cartridge 86, cartridge joints 79a, 79b, and 79c for connecting
tubes to release air, waste ink joint 81 for guiding waste ink produced at the time
of recording to waste ink absorber 96 built in ink cartridge 86 through waste ink
tank, air joint 80 for connecting the breezer for releasing air with air tube 83,
first and second supply tube joints 84 and 85 for connecting first and second ink
supply tubes 71 and 72 with ink pump 76 which is driven by pump motor 77. Thus, ink
joint 79 connected to ink tank 94 accommodated in ink cartridge 79a provides three
functional sections intensively, first ink supply section 79a, second ink supply section
79b, and air passage connecting section 79c, and with its structure, enables first
ink supply inlet 95a, second ink supply inlet 75b and air inlet 95c to be coupled
altogether, which are operationally related to the function of ink tank 94.
[0109] For this purpose, the air passage section leading to the ink tank is formed by joints,
thereby making it possible to construct the ink tank with hard resin material to reserve
a large quantity of ink without employing ink bags.
[0110] Furthermore, by connecting first ink supply inlet 95a and second ink supply inlet
95b, and first ink supply section 79c and second ink supply section 79b, an ink circulation
passage is formed to perform ink supply from both of the ink supply regions at the
time of recording and to circulate ink from the ink tank through the passage with
the pump inbetween, and to circulate ink from the recording head to the ink tank again
at the time of initial ink filling and recovery operation.
[0111] In other words, since the passage is formed by directly joining the tank and the
supply passage, and further the air passage as described earlier, it becomes possible
to eliminate, in spite of the ink tank being made of hard plastic resin, such function
as a sub-tank which has conventionally been indespensable for a stable ink supply.
In the present embodiment, these members are separately fixed to joint board 74, but
the structure may also be such that these members are integrally formed with the joint
board.
[0112] Further, to joint board 74, flow passage board 75 is coupled with flow passage gloove
75a which functions as ink flow passage. In this portion, most of the ink flow passage
pipings and connections are installed.
[0113] In other words, by fixedly arranging joint section 79 which is annexed to joint board
74 connected to ink tank 94, it becomes possible to provide a structure thereby eliminating
the operation related to ink passage 75a in that particular portion.
[0114] As a result, a part of ink passage from ink tank 94 to the recording head can be
formed only by coupling to the reverse side of joint board 79 the flow passage plate
75 which constitutes a flow passage.
[0115] On the other hand, as described later, ink tank 94 built in ink cartridge 86 is flexibly
accommodated in housings 93a and 93b which constitute the cartridge 86.
[0116] By accommodating the ink tank flexibly, it is possible to reliably adjust with ease
the coupling condition of the cartridge which should be installed against joint section
79 which is flexibly arranged, and in this way, the installation of cartridge is carried
out with assurance.
[0117] It is also possible to construct the ink passage from the ink tank without complicated
piping arrangements simply by coupling joint board 74 and flow passage plate 75 to
form the required flow passage.
[0118] As shown in Fig. 18, there are accommodated in ink cartridge 86, the common housings
93a and 93b made of material having a good impact resistance, ink tank 94 made of
resin having a good property against fluid and waste ink absorber 96 made of a water
absorptive material having an excellent ink absorptive property such as felt or porous
material. The ink supply and air releasing are performed by connecting these members
with cartridge 79 on the side of joint plate 74 through joint section 95. Thus, the
entire ink cartridge 86 is structured to be detachably installed as a whole on base
73 provided on the side of the apparatus.
[0119] Figs. 19A and 19B illustrate the structure of this part further in detail. Fig. 19A
is a partially cutaway cross-sectional side view showing the principal parts of ink
cartridge main body 86. Fig. 19B is a partially cutaway cross-sectional view showing
joint section 95 connected to the cartridge joint of the ink supply system. In order
to prevent any ink leakage when ink cartridge 86 is removed, metal ball 99 is provided
in joint section 95 to press it against joint opening 95a by the compression of spring
98. When the ink cartridge is detached from the unit, metal ball 99 is closely in
contact with shealing rubber 101 to close the opening 95a of the joint section.
[0120] Also, as shown in Figs. 19A and 19B and Fig. 20 showing the front cross-section of
ink tank, ink tank has sloped surfaces or slants 94a, 94b at its bottom. In other
words, there are provided slant 94a for gathering ink flow into joint section 95 from
behind, and slant 94b for gathering ink flow into joint section 95 from the side of
ink tank 94. Ink is supplied to the ink supply system through guiding tube 100 which
is bent to be opened at the lowest bottom of the ink tank. A bottom support 93b supports
the rear portion of the sloped surface 94a of the ink tank 94. Thus, it is possible
to collect all ink in the vicinity of guiding tube 100 by forming slants 94a and 94b
at the bottom of ink tank, and to use ink without any waste. Also, it is possible
to draw ink without a waste even if the apparatus is installed with a slight inclanation.
With a structure such as this, the area is provided in the housing to accommodate
the aforesaid waste ink absorber 96 substantially in U shape.
[0121] Furthermore, in the present embodiment, it is necessary to couple three flow passages,
i.e., two ink supply passage and one air releasing passage, in joint section 95, but
in order to obtain reliable couplings, ink tank 94 is held in housings 93a and 93b
as shown in Fig. 20 with space 97 to allow the ink tank to move freely in an appropriate
amount.
[0122] Especially, it is necessary to provide flexibility not only vertically and horizontally
but rotatably when a plurality of joints should be connected. In the present embodiment,
a slight rotatability is maintained to obtain a rotatable flexibility against the
central axis of joint section 95 by supporting ink tank 94 with spaces 97 (in this
embodiment, for example about 1.0 mm) and spaces 97a (for example, about 1.0 - 2.0
mm) provided for both ends of ink tank 94 and by waste ink absorber 96 which is soft
like felt. A projection 93d supports a front bottom of the ink tank 94. Hence it is
possible to make connections reliably without any deviations in positioning. In this
embodiment the joints 95a, 95b and 95c of the ink tank are provided about 0.5 mm lower
with respect to the body joints 79a, 79b and 79c so that the ink tank 94 is connected
to the body joints in a state which it floats about 0.5 mm to the body joints. Furthermore,
in order to prevent any abnormal sound generated by the movement of ink tank 94 by
vibrating impact, etc. or breakage of housing as well as to effectively utilize space,
the central part of waste ink absorber 96 is removed as shown in Fig. 18 to allow
the lowest bottom ink tank 94 to be fitted into the removed part, so that the ink
tank is held by the remaining portion of circumference. With this structure, impact
can be absorbed by the softness of waste ink absorber 96 and the required flexibility
is maintained. In this way, the ink tank is protected from the external impact and
the clattering of ink tank is also prevented because in this structure the waste ink
absorber is fitted at the lowest bottom of the ink tank and at the same time, the
ink tank is held by soft material such as felt of the circumferential portion of the
waste ink absorber.
[0123] Next, the recovery sequence will be described. The recovery operation is needed to
maintain a normal recording. With this operation which is performed by the linkage
of recovery system and ink supply system, bubbles and cloggings in the flow passage
are removed. Fig. 22 is a flowchart showing this operation. Figs. 23A through 23D
are schematic views showing the system in operation. In Figs. 23A through 23D, for
the purpose of simplifying description, a unit comprising recording head 38, head
arms, etc. is defined as head unit 65, another unit comprising cap 41, wipers 50 and
52, recovery frame 60, etc. is defined as cap unit 65. Head unit 65 is rotatable with
head shaft 36 as its rotating center while cap unit 64 is rotatable with recovery
frame shaft 55 as its rotating center. Hereinafter, the sequence of recovery operation
will be described.
[0124] In the normal standby state, the relationship between recording head 38 and cap 41
is, as has been already described, that the closed state is maintained as shown in
Fig. 15 by slightly bending the periphery of the cap. The recovery operation begins
as shown in Fig. 12 with pressing projection 41a in cap 41 against nozzle 38a arranged
on the top of recording head by rotating cam gears 59a and 59b (the cap unit position
at this juncture is referred to as press position) (S22-1). Next, in this state, ink
pump 76 is actuated to circulate ink in the supply passage (S22-2) and remove bubbles
in the tube. Projection 41a is pressed against nozzle 38a in order to prevent ink
from being flown out from the nozzle because otherwise a part of ink is not circulated
by the pressure generated by the ink pump and flown out of the nozzle as useless waste
ink.
[0125] Next, as indicated by arrow F in Fig. 23A, cap unit 64 descends (this state is referred
to as retracted position) (S22-3), and further head unit 65 is rotated as indicated
by arrow G in Fig. 23B while cap unit 64 is rotated as indicated by arrow H in Fig.
23B to be in the wiping starting position (S22-4). Subsequently, head unit 65 is rotated
as indicated by arrow I in Fig. 23C to clean off ink droplets, dusts, etc. on discharging
port face 38b of the recording head with wipers 50 and 52 arranged in cap unit 64
(S22-5). Although Fig. 23C illustrates the state as indicated by arrow I where discharging
port face 38b of the recording head is passing a first wiper, there are two wipers
provided in the present embodiment. Therefore, when the cleaning off by a second wiper
is terminated, cap unit 64 again descends to the retracted position as indicated by
arrow J in Fig. 23D, and head unit 65 returns to the home position (S22-7). Then,
finally, cap unit 64 ascends to the normal standby state as shown in Fig. 1 (S22-8)
to complete the recovery operation.
[0126] The cleaning in the present embodiment will additionally be described. The recording
head employed for the present embodiment has discharging ports formed across the entire
recording width of recording medium, i.e., the so-called full line type as described
earlier. However, in the case where a discharging port face is extremely elongated
as in the present embodiment, a sufficient cleaning cannot be performed with the use
of one blade just for a one-time wiping. This is due to the difficulty in applying
pressure by a blade equally all over the discharging port face, which is now too long
for such a cleaning.
[0127] In the present embodiment, therefore, two blades, blade 50 and 52, are employed to
clean off the discharging port face sequentially to obtain reliability in cleaning
action.
[0128] Particularly, at the time of cleaning, it is important for the two blades to contact
with the discharging port face of recording head each individually to perform cleanings,
so that the effect of double-wiping should be obtained. With a sequential arrangement
of two blades such as this, the cleaning time can be shortened as compared with the
case where a cleaning action is taken twice with one blade. Also, in the present embodiment,
the size of blade 50 which contacts the recording head first differs from the size
of blade 52 which contacts it subsequently. The recording head rotates with head shaft
36 as its rotating center, and in order to place the leading end of the blade to be
in contact with the discharging port face within the path of the recording head to
move, it is necessary to define the length of each blade accordingly. Therefore, it
is also possible to perform the required cleaning by driving the cap unit following
the rotational movement of the recording head while making the length of each blades
50 and 52 the same or making the relational length of each of them reversed.
[0129] Also, by making the length of each of plural blades contacting the rotating head
38 different, it is possible to vary the length ℓ of the leading end of the blade
contacting the discharging port face 38c of the head and/or the contacting degree
ϑ₀ of each blade (Fig. 23E). Hence, it is possible to vary the force and area of each
blade with which to contact discharging port face 38c to control possible splashing
of adhered ink and dust on discharging port face 38c to the surrounding area at the
time of cleaning off.
[0130] Also, by making the contacting amount and/or contacting angle ϑ₀ of each blade against
discharging port face 38c greater sequentially following the order in which each of
the blades are in contact with discharging port face 38c of the head, it becomes possible
to allow the first blades to contact discharging port face 38c lightly when there
are more ink or dusts adhered thereto, which should be cleaned off and the later blades
to contact it sufficiently to clean off the remaining ink and dusts. Consequently,
while controlling the possible splashing of ink and dusts adhered to discharging port
face 38c to the surrounding area, it is possible to remove them completely.
[0131] Furthermore, when the first blade wipes discharging port face 38c, the rest of blades
function as protective wall (Fig. 23C) to prevent the ink and dusts removed by the
first blade from being splashed to surrounding area of the recovery system and eliminate
the causes to stain the recording sheet or to electrically short circuit electronic
circuit board.
[0132] In this respect, it is not necessarily limit the number of the blades for cleaning
to two as described above, but more blades can also be employed. Also, although in
the present embodiment, the same material is used for both blades 50 and 52, a same
material but of different properties or different materials may be used to improve
the cleaning effect.
[0133] Next, referring to Fig. 24, the sequence at the starting time of recording will be
described.
[0134] The recording is started in a manner given below. At first, a signal to start recording
is received by the recording head at a step S24-1, the recording head at this juncture
being in the standby state where only the cap covers the discharging port face of
the recording head as shown in Fig. 15. Then, at a step S24-2, the cap unit is retracted
to the state in which the recording head and the cap are set apart as shown in Fig.
11, i.e., the retracted position.
[0135] Subsequently, at a step S24-3, while maintaining the state shown in Fig. 11, a preparatory
discharging of several ejections to several hundred ejections is effectuated from
the entire nozzles of the recording head.
[0136] Hence, the discharging condition of the entire nozzles of the recording head is equalized.
[0137] Then, after the preparatory discharging is terminated, the cap unit and head unit
are moved at a step S24-4 to constitute a starting condition of wiping action as shown
in Fig. 23A. Then at a step S24-5, a series of wiping action is performed as shown
in Fig. 23B through 23D, and at a step S24-6, the recording unit is moved further
to the recording position as shown in Fig. 1 where such state is held. After that,
recording signals are sequentially inputted to carry out recording as desired.
[0138] Next, the recovery operation which is executed by circulating ink will be described
further in detail. In the present embodiment, as shown in Fig. 16, bubble sensor 103
(for example, a transmitting sensor, etc.) is provided to enable detecting bubbles
in ink supply tubes. Accordingly, it is possible to perform two different types of
recovery operations, i.e., an automatic recovery to be carried out periodically each
at a predetermined time, and an occasional recovery to be performed when bubble sensor
103 detects any incidental bubble or bubbles. The occasional recovery becomes possible
with the installation of bubble sensor 103, and with this, the incidental non-discharging
hitherto experienced can be reduced, thereby making it possible to improve the reliability
of the apparatus. Particularly, in consideration of the safety with which all bubbles
are removed irrespective of the presence of bubbles, the amount and location thereof,
a considerably excessive circulation time and number has been given to perform a sufficient
removal of bubbles. In the present embodiment, however, bubble sensors 103a and 103b
are provided at either sides of up and down streams of ink flow towards the recording
head at the time of circulation. Therefore, if no bubbles are detected by both of
the bubble sensors, the recovery action is immediately suspended. Particularly when
bubble sensor 103b arranged at the down stream of ink flow at the time of circulation
should detect a signal indicating that bubbles have been removed (no bubble presence),
the ink pump is stopped after a while (a period required for the detected bubble exhausted
to the tank from the current position of the sensor). Consequently, there is no need
for providing any excessive circulation time as has been required conventionally,
resulting in the termination of the recovery sequence in a shorter period of time.
Also, there is an advantage that the reliability of bubble removal improves because
the recovery action is terminated after no bubble presence has been detected. In this
way, the amount of ink consumed for recovery becomes small, which leads to the prevention
of no ink condition at the time of receiving facsimile or of no reception state during
the recovery operation.
[0139] Fig. 25 is a block diagram showing the recording unit according to an embodiment
of the present invention.
[0140] In Fig. 25, microcomputer (CPU) 101 controls the operation of the unit in accordance
with the program stored in ROM 112 and data stored in RAM 113.
[0141] Ink jet print head 102 performs recording by control (strobe) signals from CPU after
data each for a one-line portion has been received from CPU.
[0142] Drivers 103, 104, and 105 for each of pulse motors, which will be described later,
supply appropriate currents to drive the motors respectively in accordance with step
instructions from CPU.
[0143] Reference numerals 106, 107 and 108 designate respectively a motor (W motor) for
conveying recording sheet, a motor (K motor) for transporting head, and a motor (C
motor) for transporting cap unit.
[0144] Head position detecting sensor 109 and cap position detecting sensor 110 detect the
positions by means of on-off of microswitches, for example.
[0145] A reference numeral 111 designates a bubble sensor.
[0146] A motor (P motor) 115 for driving the ink pump is a DC motor which rotates with on.
A driver (transistor circuit) 114 supplies current to turn on the P motor by a signal
from CPU.
[0147] Next, in accordance with a flowchart shown in Fig. 26, the operation at the time
of recording will be described.
[0148] At first, when the recording operation is started, W motor is driven for a required
number of steps to convey recording sheet to a predetermined position (S26-2).
[0149] Next, to head 38, a black data for a one-line portion is transmitted (S26-3).
[0150] Then, cap is retracted to the retracted position (S26-4). In this respect, C motor
is driven for a predetermined number of steps, or is continuously driven until the
moment sensor 110 detects that cap 41 has moved to the retracted position. Either
methods are applicable (hereinafter the movement of head and cap are the same).
[0151] Next, the so-called empty discharging is performed by transmitting a predetermined
number of strobe signals (S26-5) to head 38.
[0152] Then, while wiping action is being taken, head 38 is transported to the recording
position. In other words, head 38 and wiper (cap unit 64) are transported to the starting
position for wiping (S26-6 and S26-7), and by advancing head 38 to the recording position
as it is, wiping is terminated (S26-8).
[0153] Also, after that, cap 41 is returned to the retracted position (S26-9).
[0154] The recording operation is executed by repeating the transmission of data each for
a one-line portion to head 38, the transmission of strobe signals, the recording of
the one-line portion (S26-10 and S26-11), and the driving of W motor to convey recording
sheet for a one-line portion (S26-12) until the recording of a one-page portion is
terminated.
[0155] Then, after the recording of the last line has been terminated (S26-13), head 38
is returned to the standby state (S26-14) and cap 41 is returned to the capping position
(S26-15 and S26-16).
[0156] After that, W motor is driven to exhaust recording sheet (S26-17) to terminate the
recording operation.
[0157] Next, in accordance with Fig. 27, the recovery operation will be described.
[0158] While the apparatus is in the standby state, CPU examines timer t₁ in the CPU as
well as the bubble sensor. If timer t₁ indicates a predetermined time T₁ (24 hours,
for example), the recovery operation is started (S27-2).
[0159] Also, even when the timing is not t₁ = T₁, the recovery operation is started if bubble
sensor 111 is on (the presence of bubble indicated) (S27-3).
[0160] The recovery operation is performed as follows:
At first, C motor is driven to transport cap 41 to the pressing position (S27-5).
[0161] Next, P motor on signal is output to rotate P motor (S27-6).
[0162] Then, the output of bubble sensor 111 is detected, and when the sensor output is
turned off, counter t₂ in the CPU starts counting (S27-7 and S28-8). When counter
t₂ indicates a predetermined value T₂ (S27-9), time t₂ is cleared (S27-10), and turn
off P motor (S27-11).
[0163] Then, the wiping action is actuated.
[0164] At first, cap is transported to the retracted position (S27-12). Subsequently, after
transporting head 38 to the starting position for wiping, cap 41 is transported to
the wiping position (S27-13 and S27-14), and then wiping is performed (S27-15) by
transporting head 38 to the position for terminating wiping (printing position). Cap
41 is again returned to the retracted position (S27-16) and to the capping position
after head 38 has been returned to the standby position (S27-17). Then, the apparatus
is again in the standby state.
[0165] This terminates the recovery operation.
[0166] The present invention provides means for generating heat energy (for example, an
electrothermal converter, a laser light, etc.) for the utilization of energy for ink
discharging especially for ink jet recording method, and in a recording head and recording
apparatus using a method to activate changes in a state of ink by utilizing the aforesaid
heat energy, the present invention is particularly effective.
[0167] For the typical structure and principle of an invention of the kind, it is preferable
to employ the fundamental principle disclosed in the specifications of, for example,
U.S. Patents 4723129 and 4740796. This method disclosed in applicable to the so-called
on-demand type as well as to the continuous type. Particularly in the case of the
on-demand type, by applying at least one driving signal, corresponding to recording
information and providing a rapid temperature rise which exceeds nuclear boiling,
to an electrothermal converter arranged for sheet or liquid passage holding liquid
(ink), heat energy is generated in the electrothermal converter, and film boiling
is accordingly generated on the thermal active face of recording head. As a result,
bubbles are formed in the liquid (ink) one to one by this driving signal effectively.
By the growth and contraction of this bubble, the liquid (ink) is discharged through
the discharging port to form at least one droplet. If this driving signal is made
to be a pulse type, the growth and contraction of bubble can be effectuated instantaneously
and appropriately, and it should be more preferable to employ such system because
with it, a discharging of liquid (ink) having an excellent responsibility can be attained.
For a driving signal of the pulse type, those disclosed in the specifications of,
for example, U.S. Patents 4463359 and 4345262 should be suitable. In this respect,
if conditions disclosed in the specification of U.S. Patent 4313124 concerning an
invention of the ratio of temperature rise on the aforesaid thermal active face are
employed, a further excellent recording can be performed.
[0168] For the structure of recording head, those structures, in which a thermal active
unit is arranged in a bending region, disclosed in the specifications of U.S. Patents
4558333 and 4459600 are included in the present invention in addition to a combination
structure (linear liquid flow passage or right angled liquid flow passage) of discharging
ports, liquid passage, and electrothermal converter such as disclosed in each of the
above mentioned specifications. Besides, the present invention is still effective
for the structures based on the structure disclosed in Japanese Laid-Open Patent Application
No. 59-123670 in which common slits against a plurality of electrothermal converters
function as discharging ports of the electrothermal converter, and the structure disclosed
in Japanese Laid-Open Patent Application No. 59-138461 in which an opening for absorbing
the pressure wave of heat energy is used for the discharging port.
[0169] Particularly, the present invention is effectively applicable to the recording head
of a full line type with a length to cover the width of a maximum recording medium
which can be recorded by the recording head. For a recording head such as this, a
structure in which a plurality of recording heads as disclosed in the above-mentioned
specifications are combined to meet the requirements of such length or a structure
in which one recording head, integrally formed, is adopted may be applicable, but
the present invention displays the above-mentioned effects more efficiently.
[0170] In addition, the present invention is effectively applicable to the installation
in the main body of an apparatus either in the case of a recording head of chip type
which is freely replaceable to enable the electrical connection with the main body
of the apparatus or the ink supply from the main body of the apparatus or in the case
of a cartridge type recording head which is integrally mounted in the recording head
itself.
[0171] It is also desirable to add the recovery means for the recording head, preparative
auxiliary means, etc. which constitute a recording apparatus according to the present
invention because such addition makes the effects of the present invention more stable.
These means are specifically capping means for recording head, wiping means, pressuring
or absorbing means, electrothermal converter, or another heating element or preparative
heating means by the combination of these elements, and aside from discharging for
regular recording, it is also effective to effectuate a preparatory discharging mode
for performing a stable recording.
[0172] Furthermore, the present invention is extremely effective for a recording apparatus
having at least one mode for recoloring with different colors or for full color with
mixture of colors by the use of recording heads which are integrally structured into
one head or by the combination of plural heads, not to mention the recording mode
of principal color such as black, etc. as recording mode for a recording apparatus.
[0173] In the embodiment set forth above according to the present invention, the description
has been made of the case where liquid ink is used, but the present invention is also
applicable to solid ink at room temperature as well as to ink becoming soft at room
temperature. In the above-mentioned ink jet apparatus, it is usual to perform temperature
control to make viscosity of ink to be in the range of stable discharging by adjusting
the temperature of ink itself more to be than 30°C but less than 70°C. Therefore,
if only ink becomes fluid at the time of applying recording signals in use, those
kinds of ink are also usable. Furthermore, the present invention is applicable to
the use of ink having the property that the ink becomes fluid only by heat energy
such as the one which can be discharged as liquid ink when it becomes fluid by the
application of heat energy in response to recording signals or ink already becoming
solidified at the time of reaching recording medium by utilizing positively the temperature
rise caused by heat energy as energy to change the state of ink from solid to fluid
for prevention or by using ink which is solidified when it is left for the purpose
of preventing evaporation. In such case, ink can be held as liquid or solid state
in a concave of porous sheet or through holes as described in Japanese Laid-Open Patent
Application No. 54-56847 or Japanese Laid-Open Patent Application No. 60-71260, and
is placed against the electrothermal converter in such mode. In the present invention,
the performance of the above-mentioned film boiling method is most effective when
each of the above-mentioned kinds of ink is employed.
[0174] Furthermore, the mode of an ink jet recording apparatus according to the present
invention is such that in addition to facsimile apparatus having receiving and transmitting
functions as in the present embodiment, it can be used as image output terminal for
information processing apparatus such as computer, etc, copying apparatus combined
with reader, etc. or the like.
[0175] In the present embodiment, a recording head is used for the recovery operation by
circulation with ink supply tubes arranged at both ends respectively, but the present
invention is also applicable to a recording head of such type that it has only one
ink supply tube and performs recovery operation by suction from the front face of
nozzle as a matter of course. It is also possible to reduce manufacturing cost by
forming bubble sensor integrally with the constituents of the head.
[0176] As set forth above, according to the present invention, it is possible to perform
an accurate mating of ink jet recording head and capping means without the precision
of each individual part and precise adjustment at the time of assembly.
[0177] Furthermore, according to the present invention, it is possible to remove ink adhered
to orifice face by a plurality of cleaning members, so that ink can be removed completely.
It is further possible according to the present invention to remove effectively ink
strongly adhered to the orifice face by the plural cleaning members each having different
contacting area, contacting angle, and contacting position provided by different sizes
of the cleaning members.
[0178] In the above-mentioned embodiment, the ink container relating to three flow paths
was explained as a sample, but it is possible to remove any extra backlash by limiting
the degree of freedom in a certain direction depending on the construction or number
of the flow paths.
[0179] In the above-mentioned embodiment, specially, the engagement of the container with
the device is made only with the cylindrical portion at the periphery of the joint
portions, but if such cylindrical portion for the engagement is changed in number
or shape (for example to a polygonal or elliptic cylinder shape), then it is possible
to reduce an extra degree of freedom after the mounting, and improve the stability
of the seal for the connecting portion. The above-mentioned embodiment is so constructed
that three connections relating to the communicating port to the air, the supplying
side to the recording head at the time of the ink circulation and the returning side,
respectively are made, but in order to achieve more effectively the removal of the
babbles due to the ink circulation by decreasing the flow path resistance, correspondingly
to the structure of the recording head, more supplying tubes may be used. At that
time, it is possible to divide the supplying side and the returning side to plural
ones, respectively, by applying thereto the above-mentioned embodiment.
[0180] Further, in the above-mentioned embodiment, the structure in which the waste ink
absorbing body is positioned on the bottom of the ink tank was explained. However,
it is also possible to attain a more certain shock absorbing effect by adding it to
the sides and top of the ink tank as well as the bottom. Also, it is possible to use
a waste ink absorbing body with appropriate elasticity to prevent waste ink which
has been absorbed from being squeezed out by the weight of the ink tank.
[0181] Further, in the above-mentioned embodiment, the soft member positioned at the bottom
of the ink tank are used to have the waste ink and mechanical shock absorbing functions,
but it is possible to achieve the similar effect to the above even when an additional
member with a superior shock absorbing capability, etc. is provided separately to
said soft member, or the frame itself is formed with a soft material.
[0182] Furthermore, in the above-mentioned embodiment, the recording head having at its
both ends the supplying tubes and carrying out the recovery operation by the circulation
is used, but this invention may be applied to a recording head having one supplying
tube and of which recovery operation is carried out by suction from the front face
of the nozzle. Also, it is possible to decrease the cost by forming both of the babble
sensor and the recording head in a body.
[0183] As explained above, in accordance with the embodiments according to the present invention,
the ink jet recording apparatus is provided in which easy registration in position
of the joint portion of the ink supplying side to the joint portion of the cartridge
side is accomplished so that the ink cartridge is surely mounted.
[0184] Also, since the joint portion of the ink supplying side is stationary, the complicated
distribution of the ink supplying path from this joint portion to the recording head
can be avoided and the sealing security after the connection can be improved. Therefore,
the ink jet recording apparatus is provided which has the reliable joint portions
from which any ink leakage due to vibration or shock does not occurred. Further, in
accordance with the embodiments according to the present invention, three connections
for the paths for supplying ink at the time of the circulation, the returning path
and the communicating port to the air are used detachably between the ink tank side
and the joint sides, and thus, it is possible to provide the ink supplying device
which is voluminous, and strong in vibration and shock and which has no use for the
sub-tank. Accordingly, it is possible to provide the ink jet recording apparatus having
the ink supplying device which is low-priced, compact and moreover highly reliable.
Also, in the above-mentioned embodiments, by not only holding the ink tank at its
periphery with a soft member and but also using such soft member as the waste ink
absorbing body, it is possible to achieve an ink cartridge which is strong in vibration
and shock, which can use effectively the space and which is compact and low-priced.
In this connection, it is also possible to provide the ink jet recording apparatus
which is miniaturized and has its decreased running cost and improved reliability.
Further, in accordance with the above-mentioned embodiments, it is possible to provide
an ink jet recording apparatus in which by controlling the operation of the ink pump
using the means for sensing a babble in the ink supplying paths, the recovery operation
can be reduced in frequency and time to minimum necessary values, the volume of waste
ink can be decreased and the number of the recording papers which are recorded with
a predetermined amount of ink can be increased, and thus, its running cost can be
reduced. Also, in a case where the above-mentioned embodiments are applied to a facsimile
machine, since the time necessary to carry out the recovery process is shortened,
a long recording enabling time can be achieved, and a probability of disabling facsimile
signal reception because the facsimile machine is subject to the recovery process
can be made to be small, and since the number of the recording papers which are recorded
with a predetermined amount of ink is increased, it is An ink cartridge adapted to
be loaded detachably to an ink jet recording apparatus for preforming a recording
on a recording medium by discharging ink comprises an ink tank for accommodating ink
therein, leading-out means for leading out ink within said ink tank to the outside,
said leading-out means being provided on said ink tank, and a frame for supporting
displaceably said ink tank on which said leading-out means is provided. Also, an ink
jet recording apparatus for preforming a recording on a recording medium comprises
a recording head for discharging ink from a discharge port to carry out the recording
on the recording medium, a lording part for loading therein an ink cartridge, said
loading part having an ink tank for accommodating ink therein, leading-out means for
leading out ink within said ink tank to the outside, said leading-out means being
provided on said ink tank and a frame for supporting displaceably said ink tank on
which said leading-out means is provided, and ink supplying means for supplying ink
to said recording head by coupling to the lead-out means of said ink cartridge which
is loaded in said loading part.