Field of the Invention
[0001] The present invention relates to an apparatus, hereinafter called sorter, used for
sorting or collation of sheet-shaped members such as copy sheets, transfer sheets
or recording sheets (hereinafter called "sheets") discharged from an image forming
apparatus such as a copying machine, a printing press or other recording equipment,
and to an image forming apparatus equipped with such sheet sorter.
Related Background Art
[0002] In general, such sorter is equipped with 10 to 20, or more stepped sheet stackers
(hereinafter called "bins") in a mutually spaced arrangement, and the sheets consecutively
discharged from the image forming apparatus at a predetermined interval are transported
in succession to respective bins by transporting means utilizing a conveyor belt and/or
plural rollers.
[0003] Such sorters can be classified into movable bin sorters in which a group of bins
for sheet collation moves with respect to a fixed transport path, and fixed bin sorters
in which the bins are fixed while a discharge unit moves in succession corresponding
to said bins or sheets are fed into the bins from a main path by means of flappers
(deflecting means).
[0004] In the conventional movable bin sorters there are already proposed methods for moving
the bins so as to widen the entrance of a bin when said bin moves to a sheet receiving
position, as disclosed, for example, in the Japanese Laid-open Patents Nos. 56-78770,
56-78769, 57-4855, 57-4856, and 57-141357.
[0005] In such apparatus, paired trunnions, mounted on the entrance end of each bin, are
made to engage with a widening mechanism utilizing a rotary geneva or a lead cam,
thereby widening the spaces of the bins in succession at the sheet introducing position,
and this operation is gradually displaced over the widening mechanism, thereby achieving
the ascent or descent of the entire bin group.
[0006] An example of the principal part of such sheet sorter is illustrated in Figs. 1A
and 1B. Bin rollers 151a, 151b, 151c provided on both sides of each of plural bins
Ba, Bb, Bc are vertically movably guided by a pair of guide rails 152 positioned at
left and right, and further engage, at the end portions of said bin rollers, with
cam grooves of a pair of lead cams 153a, 153b provided at left and right, thereby
being elevated or lowered by the rotation of said lead cams 153a, 153b in a direction
A, D or in the opposite direction. When the bin rollers 151a, 151b are in the illustrated
position on the lead cams 153a, 153b, the space between the bins Ba and Bb and that
between the bins Bb and Bc are locally widened, thereby facilitating the reception
of sheet from discharge rollers 155 of the main body. The bins Ba, Bb, ... after the
sheet reception are closely stacked in succession above or below.
[0007] Such apparatus achieves high efficiency by supporting the entire weight of the bin
unit (bin group) by the upper faces of the lead cams 153a, 153b and elevating or lowering
each bin roller by a turn of the lead cams 153a, 153b. Thus such apparatus is featured
by a simple mechanical structure and can achieve necessary functions.
[0008] Another advantage of the movable bin sorter lies in a fact that the sheet transportation
can be achieved very reliably with a simple structure, since the transport path to
the discharge rollers 155 for discharging the sheet from the main body of the image
forming apparatus into the sorter is constant regardless of the number of bits.
[0009] On the other hand, Figs. 2A and 2B illustrate examples of the fixed bin sorter. Referring
to Fig. 2A, above plural bins B fixed in the sorter, there is provided a transport
path 157 having plural pairs of guide rollers 156. Paired discharge rollers 159 are
vertically movably provided along the entrances of the bins B, and support a guide
belt 162 in cooperation with upper and lower guide rollers 160, 161. Also a sheet
path 165 for guiding downwards the sheet discharged from the transport path 157 is
formed by said guide belt 162 and by an elastic member 163 of which an end is fixed
on the discharge rollers 159a, 159b and the upper end portion has the tendency to
wind spirally.
[0010] The above-explained apparatus is to introduce the sheet discharged from the transport
path 157 into respective bins by positioning the paired discharged rollers 159a, 159b
respectively corresponding said bins, and said discharge rollers 159a, 159b are used
as an indexer for each bin.
[0011] In the structure shown in Fig. 2B, in a transport path provided facing to all the
bins of the sorter, there are provided deflector means 166, such as flappers, respectively
corresponding to said bins. Thus the sheet discharged from the transport path 157
can be introduced into each bin, by activating the deflector means 166 corresponding
to said bin.
[0012] However the conventional movable bin sorter and the conventional fixed bin sorter
have mutually contradicting drawbacks as will be explained in the following.
[0013] At first, the fixed bin sorter is generally more advantageous than the movable bin
sorter in terms of noises, since the former need not move the considerably heavy bin
unit. On the other hand, in the fixed bin sorter with the discharge unit used as the
indexer, the length of sheet path to the indexer including the discharge rollers 159a,
159b varies according to the bin into which the sheet is to be introduced. For this
reason there is required means for absorbing the difference in path length for example
between the 1st and 20th bins (for example a belt and a tensioner for supporting said
belt, for absorbing the difference in length), thereby inevitably elevating the cost
of the apparatus. Also the reliability of the sheet path itself is deteriorated with
the complication of the structure of the apparatus.
[0014] Also the fixed bin sorter with flappers 166 respectively corresponding to the bins
is advantageous in terms of noise reduction, but the cost is inevitably elevated since
the number of flappers 166 and driving components such as solenoids increases with
the increase in the number of bins.
[0015] In summary, the fixed bin sorter is high in cost, and is inferior in the reliability
of sheet path to the movable bin sorter.
[0016] Then the movable bin sorter is generally superior to the fixed bin sorter in the
reliability of sheet transportation, since the distance from the main body of the
image forming apparatus to the sheet discharge position of the sorter is constant.
[0017] However it is inferior to the fixed bin sorter in noise generation, since the entire
bin unit is so moved that respective bins face the sheet discharge position in succession,
and the impact noises by the inertia at the vertical movement of the bin unit is unavoidable.
With the ever increasing speed of the copying machines, there is required a correspondingly
high-speed sorter in order to maintain the productivity of the entire copying system.
For this purpose it is required to reduce the shifting time of the bins B, thereby
completing the shift of the bins B within the interval of sheets discharged in succession
from the copying machine.
[0018] Consequently it becomes necessary for example to increase the rotating speed of the
above-mentioned lead cam 153a, so that the movable bin sorter is inferior to the fixed
bin sorter in terms of noises, due to the increased impact noises resulting from the
faster vertical movement of the bins. In summary, in comparison with the fixed bin
sorter, the movable bin sorter can simplify the structure and provides higher reliability
of the sheet path, but inferior in the faster operation and the noise reduction.
[0019] Thus, among the conventional sorters, it is generally accepted that the movable bin
sorters are suitable for achieving high reliability with a simple structure of low
cost, while the fixed bin sorters are suitable for achieving high-speed operation
and noise reduction.
[0020] A sorter having the features indicated in the preamble of claim 1 is known from US
4.854.571
SUMMARY OF THE INVENTION
[0021] The object of the present invention is to provide a movable bin sorter which maintains
its inherent features of simplicity in structure and high reliability, and is capable
of achieving high-speed operation and noise reduction, and an image forming apparatus
equipped with such sorter.
[0022] This object is achieved by a sheet sorting apparatus having the features indicated
in claim 1.
[0023] The invention is further developed by the features mentioned in the subclaims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
Figs. 1A and 1B are lateral views showing the relation between a lead cam and bins
in a conventional movable bin sorter;
Figs. 2A and 2B are lateral views showing a principal part of conventional fixed bin
sorters;
Fig. 3 is a cam line chart of a conventional lead cam;
Fig. 4 is a longitudinal cross-sectional view of a sheet sorter constituting a first
embodiment;
Fig. 5 is a view seen in a direction A shown in Fig. 4;
Fig. 6 is a perspective view of said sorter;
Fig. 7 is a view seen in a direction C shown in Fig. 6;
Fig. 8 is a perspective view of a bin unit;
Fig. 9 is a partial cross-sectional plan view of a lead cam and a trunnion;
Fig. 10 is a lateral cross-sectional view of the apparatus shown in Fig. 4, seen from
the opposite side;
Fig. 11 is a lateral view of a flag portion of the lead cam;
Fig. 12 is a plan view of the same;
Figs. 13A to 13D are lateral views showing the relation between the lead cam and the
bins;
Fig. 14 is a plan view of a driving system for the lead cams;
Fig. 15 is a cam line chart of the lead cam;
Figs. 16A and 16B are lateral views of a geneva employed in a second embodiment;
Fig. 17 is a lateral cross-sectional view of a sheet sorter constituting a third embodiment
of the present invention;
Figs. 18A and 18B are cam line charts;
Fig. 19 is an elevation view of spiral cams and bins in a fourth embodiment;
Fig. 20 is a cam line chart therefor;
Fig. 21 is a block diagram of an example of control device to be employed in the sheet
sorter;
Figs. 22 to 30A, 30B are flow charts showing the control sequence of the embodiments;
Fig. 31 is a block diagram of a copying machine;
Fig. 32 is a cross-sectional view of a facsimile apparatus;
Fig. 33 is a block diagram of a control unit employed in the apparatus shown in Fig.
32;
Fig. 34 is a cross-sectional view of a printer; and
Fig. 35 is a block diagram of a control unit employed in the apparatus shown in Fig.
34.
DESCRIPTION OF THE EMBODIMENTS
[0025] Fig. 1 to 16 and 19 to 35 and the corresponding parts of the description (embodiments
1, 2 and 4) represent examples which are not covered by claim 1, but which are useful
for understanding the invention.
[0026] In the following there will be explained a first embodiment, with reference to the
attached drawings.
[0027] Referring to Figs. 4 and 6, a movable bin sheet sorter 1 is provided with a main
body 7 principally composed of a pair of side plates 3, a base member 5 and a cover
6. The sorter 1 is provided with a bin unit 2, incorporating a bin group B of plural
bins B1 ∼ Bn, and is vertically movable along a pair of guide rails (guide members)
9 mounted on said side plates 3.
[0028] Said sorter main body 7 is connected, at the upstream side (right-hand side in Fig.
4), to an image forming apparatus (not shown), and is provided with an entrance 10
and entrance rollers 11 for introducing the sheet P discharged from the image forming
apparatus. From said paired rollers 11 toward said bin unit 2 there is extended a
first sheet transport path 12 and upper discharge rollers 13, from which branched
is a downward second sheet transport path 15 with lower discharge rollers 16 opposed
to the bin unit 2. At the branching portion of said sheet transport paths 12, 15 there
is provided a deflector 17, which is selectively displaced either to introduce the
sheet P, to be discharged from the upper discharge rollers 13 to the bins B, into
the first transport path 12 or to introduce the sheet P, to be discharged from the
lower discharge rollers 16 to the bins B, into the second transport path 15.
[0029] In the vicinity of the sheet discharging portion of the second transport path 15
there is provided a sheet sensor 19 for detecting the sheet P. In the present embodiment
said sheet sensor 19 is composed of a reed switch incorporating a photointerruptor,
but a transmissive sensor may also be used for the same purpose. The sheet P discharged
from the image forming apparatus (not shown) is detected by a discharge sensor provided
in said apparatus. In the present embodiment, there can be measured the passing time
of the sheet P and the interval of succeeding sheets P, and a calculating circuit
incorporated in said apparatus sends a discharge signal and an interval signal to
a microcomputer in said bin unit 2.
[0030] As shown in Figs. 6 to 8, the bin unit 2 has a pair of bin support plates 20 in front
and back, constituting a frame structure. At the front ends of said bin support plates
20 there are mounted bin sliders 21, and a bin cover 22 is fixed to said bin support
plates 20 and bin sliders 21. A bin alignment reference member 23 extends from said
bin cover 22 to a bin support plate 20. Also in a cutout hole 25 formed in each of
all the bins B there penetrates an alignment rod 26, which is supported, at the upper
and lower ends, by a pair of support members 27 in turn supported by a shaft 29 and
which can be rotated about said shaft 29. The sheets P housed in the bins B are pushed
by the rotation of said alignment rod 26 to the alignment reference member 23 and
thus aligned.
[0031] Each bin B in the bin unit 2 is slidably supported, at both sides of the free end,
by one of comb-tooth grooves (not shown) formed on the bin sliders 21. Also on both
sides of the other end of each bin there are fixed pins 30 as shown in Fig. 9. Said
pins 30 respectively pass through slits 31 formed on the bin support plates 20 at
left and right, and trunnions 33 are rotatably mounted on the outside, with o-rings
32 as cushion members.
[0032] Said trunnions 33 of the bins B are fitted in said guide rail 9 in stacked manner,
whereby the lowermost trunnion 33 is in contact with a lower guide roller 35 rotatably
supported by the bin support plate 20, while the uppermost trunnion is in contact
with an upper guide roller 36 rotatably supported by said bin support plate 20, so
that the bins B are supported with an interval equal to the external diameter of said
trunnion 33.
[0033] As shown in Fig. 4, the bin unit 2 can vertically move along the guide rails 9, with
said upper guide rollers 36 and lower guide rollers 35 fitted in the guide rails 9.
Between members 37 fixed to the bin unit 2 and the side plates 3 there are provided
tension springs 39 for pulling the bin unit 2 upwards.
[0034] In a position corresponding to the lower discharge rollers 16 supported by the side
plates 3, there are provided cam shaft holders 40 as shown in Figs. 6 and 10, and
lead cam shafts 42 rotatably supported by bearings 41 extend between said cam shaft
holders 40 and the aforementioned base member 5. At the upper ends of said lead cam
shafts 42 positioned at left and right, there are provided lead cams (spiral cam means)
43a, 43b having spiral cam faces.
[0035] As shown in Figs. 10 and 14, a reversible motor 45 is mounted on a side plate 3,
and the output shaft 45a of said motor is provided with a pulley 46a integral with
a bevel gear 46b. Said pulley 46a is linked, by a belt 47, to a pulley 49 of the lead
cam shaft 42 of the lead cam 43b. Also said bevel gear 46b meshes with a bevel gear
51 mounted on an end of a shaft 50, and a bevel gear 52 mounted on the other end thereof
meshes with a bevel gear (not shown) integral with a pulley 53, linked by a belt 55
with a pulley 53 fixed to the lead cam shaft 42 of the other lead cam 43a, as shown
in Fig. 14. In the above-explained drive system, the forward or reverse rotation of
the motor 45 causes rotation of the lead cams 43a, 43b in a direction indicated by
arrows or in the opposite direction in Fig. 14.
[0036] On the other end (lower end in Fig. 10) of the motor 45, there is mounted a clock
disk 56, which enables to read the revolution of the motor 45 or the lead cams 43a,
43b, in cooperation with an interruptor 59 supported by a sensor holder 57 on a side
plate 3, thereby said revolution can be arbitrarily controlled by a lead cam control
circuit of the sorter 1.
[0037] As shown in Fig. 10, on the cam shaft 42 below the lead cam 43b there are mounted
flags 61, 62 for detecting the position of the lead cams 43a, 43b. As shown in magnified
views in Figs. 11 and 12, a holder 66 fixed on the side plate 3 supports interruptors
63, 65 for reading said flags 61, 62.
[0038] Said interruptors 63, 65 have a same flag angle but are different in phase by a predetermined
amount. The on-off operations of two interruptors 63, 65 with different phases allow
to identify whether the bins B are in the home position in the ascending direction
or that in the descending direction, as will be explained later.
[0039] Each of the lead cams 43a, 43b has a parallel portion over about 180° as will be
explained later, and the phase difference between the flags 61, 62 is determined in
relation to said parallel portion. More specifically said phase different is selected
as about 30°, and the positions of the lead cams 43a, 43b are identified by the on-off
operations of said interruptors 63, 65 resulting from the angular difference of said
flags 61, 62.
[0040] In the following there will be explained the movement of the bin B, determined by
the form of the lead cams 43a, 43b and the trunnion (bin roller) 33 engaging therewith.
[0041] Fig. 13A shows the relation among the left lead cam 43a, trunnions 33 and bins B,
while Fig. 13B shows a similar relation of the right lead cam 43b, and Fig. 14 is
a plan view of the driving system for the lead cams 43a, 43b.
[0042] As shown in these drawings, the lead cams 43a, 43b of the present embodiment have
mutually opposite directions of spiral so as to be rotated in mutually opposite directions,
thereby constituting a mirror image relationship. Also in the present embodiment the
spaces of the bins B are widened in two widening positions X, X', in order to accept
a stapling mechanism 67 that can be introduced into and retracted from the bin B.
For the sorting purpose only, said spaces may be widened only in one position X at
which the sheet P is introduced.
[0043] When the lead cams 43a, 43b are rotated by the motor 45 in the direction of arrow
or in the opposite direction, the trunnions 33 are pressed in the grooves of the lead
cams 43a, 43b and ascent or descend, being guided by the guide rails 9. A bent portion,
formed in a part of the guide rail 9 shown in Fig. 13A or 13B, is to displace the
bin B in the sheet moving direction in cooperation with the sheet stapling mechanism
67 provided in the sorter 1 of the present embodiment, and is not to limit the structure.
[0044] Fig. 15 is a cam line chart of the lead cam 43a of the present embodiment, while
Fig. 3 is a cam line chart of a conventional lead cam, wherein hatched portions indicate
cam grooves. Said cam line charts corresponds to the cams at the left side seen in
the moving direction of the sheet P, and those of the other lead cam 43b are of mirror
symmetry. Each of said cam line charts covers a range of 0° to 360°, and contains
two cam lines.
[0045] The trunnions present in the grooves of the lead cam 43a are indicated by 33a, 33b,
33c. As shown in Fig. 15, the lead cam 43a of the present embodiment has a substantially
parallel portion H which covers a range of about 180° in the present embodiment. In
the above-explained cam line chart, the bins B move upwards when the lead cam 43a
moves to right (with relative movement of the trunnions 33 to left), namely when the
lead cam 43a shown in Fig. 14 rotates in the direction of arrow, and the bins B move
downwards when the lead cam 43a moves to left (with relative movement of the trunnions
33 to right). Said parallel portion H corresponds to the sheet discharge position
of the lead cam 43a, while inclined portions K correspond to shifting positions.
[0046] At the discharge of the sheet P from the lower discharge rollers 16 shown in Fig.
4, the lead cam 43a is so set that the sheet P meets the parallel portion H of the
lead cam 43a. Consequently the home position is defined as 33x when the trunnions
33 ascend, or as 33y when the trunnions 33 descend. The phase difference between said
home positions 33x and 33y is selected as 180° in the present embodiment, as shown
in Fig. 15. The positions 33x, 33y of the lead cam 43a respectively correspond to
flag areas ⓐ and ⓑ shown in Fig. 12.
[0047] In the present embodiment, the revolution R
1 (rpm) of the lead cam 43a can be represented by:
wherein 2π indicates a turn of the lead cam 43a or 43b, θ (rad) indicates the angular
range of the parallel portion H, and t
1 is the time period required by the sheet P to pass through the lower discharge rollers
16.
[0048] Consequently the revolution of the lead cam 43, or the process speed, increases as
the discharging time period of the sheet P decreases.
[0049] Then it is necessary to consider the time interval t
2 of the sheets P discharged in succession from the image forming apparatus. In order
that the lead cam 43 can make a full turn in a period corresponding to the sum of
the sheet discharge time and the sheet interval, the revolution R
2 (rpm) of the lead cam 43 in the remaining portion (2π - θ) (corresponding to the
inclined portion of the cam) has to be:
[0050] Therefore, if the angular range θ of the parallel portion H of the lead cam 43 is
so selected as to satisfy R
1 = R
2, the rotating speed of the lead cam 43 becomes theoretically same at the sheet discharge
and at the interval of sheets, thereby enabling to introduce the sheets P into the
bins B during continuous rotation of the lead cam 43. In this state a series of sheets
P discharged from the image forming apparatus can be sorted during constant-speed
rotation of the lead cam 43.
[0051] When the image forming apparatus is of a high speed, it may not be possible to maintain
the constant-speed rotation of the cam 43 since the interval t
2 becomes very small. Even in such case, the lead cam 43 can still be in continuous
rotation by two-speed control with R
1 and R
2. Consequently the apparatus of the present embodiment can reduce the noise level,
as it is free from the impact noises in the conventional movable-bin sorter, generated
by the inertia of the bin unit, associated with the start and stop of the lead cams
in such sorter.
[0052] The present embodiment is further characterized by the high productivity, suitable
for use in combination with a high-speed copying machine. More specifically, the angular
range of the parallel portion H of the lead cams 43 may be suitable changed, for example
to a value larger than 180°, so that the rotating angle of the lead cams 43 in the
interval between sheets can be reduced. Thus the sorter can follow the operation of
a copying machine of higher speed even with a considerably lower rotating speed of
the lead cams 43.
[0053] Moreover, loss in electric power consumption of the copying machine can be reduced
since the bin unit 2 with a large mass need no longer on-off (start-stop) controlled.
[0054] In the following there will be explained a series of operations of introducing the
sheet P from the image forming apparatus into the sorter 1, discharging said sheet
P into a bin B and shifting said bin B.
[0055] At first, the sheet P discharged from the unrepresented image forming apparatus to
which the sorter 1 (Fig. 4) is connected, is introduced through the entrance 10, guided
through the entrance rollers 11 and the deflector 17, and discharged to the bin B.
Said sheet P is discharged to the bins B through the upper discharge rollers 13 or
the lower discharge rollers 16 respectively in case of unsorting mode or sorting mode.
[0056] The passing time of the sheet P and the interval between the sheets P are measured
by sheet discharge signals from said image forming apparatus, and the measured information
is transmitted by serial communication to a microcomputer (control unit 110 in Fig.
31) in the bin unit 2.
[0057] In case the detection time of a sheet P exceeds a predetermined value or a next sheet
P cannot be detected with a predetermined time due to a failure in the sheet transportation,
a jam signal as in the ordinary sensor is transmitted to the controller of the image
forming apparatus, thereby stopping the function of the entire system.
[0058] In response to the measured information, the microcomputer 110 of the sorter 1 recognizes
the discharge time (time of sheet discharge into the sorter 1) of the sheet and the
interval of sheets, and accordingly controls the rotating speed and position of the
lead cams 43 (cf. Fig. 31). The position control of said lead cams 43 is achieved
by synchronizing the discharge of the sheet P into the bin B with the start of the
parallel portion H of the lead cams 43.
[0059] As explained in the foregoing, the clock disk 56 (Fig. 10) provided on the output
shaft 45a of the motor 45 for driving the lead cams 43 allows to recognize the speed
of the lead cams 43 in cooperation with the interruptor 59, and the flags 61, 62 (Figs.
11 and 12) provided on the lead cam shaft 42 allows to recognize the end positions
of the parallel portion H of the lead cams 43.
[0060] For example, in the sorting operation with the ascending motion of the bin unit 2,
the revolution of the lead cams 43 is so selected that the sheet discharge is started
when the trunnions 33 of a bin B reach the home position 33x shown in Fig. 15 and
the sheet discharge is completed during the movement of the trunnions 33 from the
home position 33x to the position 33y.
[0061] Then the bin unit 2 is shifted during the movement from 33y to 33z. Since the interval
of the sheets is already recognized from the aforementioned information, the rotation
is so conducted that the trunnions 33 move from 33y to 33z in said interval. In this
state the next bin B reaches the position 33x and receives the next sheet P. The above-explained
procedure is repeated for every sheet.
[0062] In the sorting operation with the descending motion of the bin unit 2, the sheet
discharge is started when the trunnions 33 of the bin for receiving the sheet P reach
the position 33y, and is completed while the trunnions 33 move to the position 33x.
The trunnions 33 move from 33x to 33w in the interval between the discharged sheets
P, and the next bin B reaches the sheet receiving position 33y. The above-explained
procedure is repeated for every sheet.
[0063] In the course of sheet discharge, the eventual variation in the process speed or
in the sheet interval of the image forming apparatus is from time to time transmitted
to the microcomputer of the bin unit 2, and the speed of the lead cams is constantly
feedback controlled by the latest information.
[0064] Owing to the above-explained structure, the sorter 1 can not only cope with the difference
in the sheet discharge time resulting from the difference in sheet size, but also
achieve optimum lead cam control in various image forming apparatus with different
process speeds and different sheet intervals. Consequently said sorter 1 can be stably
connected to various copying machines. The above-mentioned sheet interval may be calculated
in the image forming apparatus, or in the sorter.
[0065] In the following there will be explained a second embodiment. The paired lead cams,
positioned in a part of the bins in the first embodiment for achieving vertical movements
of the bin unit 2 and the bins B thereof, may be replaced for example by a geneva
conventionally employing as the vertical movement mechanism of the bins B. Fig. 16B
shows a conventional geneva 72 which has a pair of notches 72a and is rendered rotatable
in forward or reverse rotation, about a shaft 71.
[0066] Said geneva 72 can be replaced by a geneva 73 shown in Fig. 16A, with an increase
number of notches 73a, whereby the revolution of the geneva 73 itself can be reduced
to achieve noise reduction. Such geneva 73 has a larger diameter with the increase
in the number of notches 73a.
[0067] In a third embodiment, a similar effect can be obtained by moving the lower discharge
rollers in synchronization with the bins, instead of stopping the bins during the
rotation of the lead cams, in order to maintain the bins and the lower discharge rollers
in a relative stationary state during the sheet discharge. Fig. 17 shows such sorter.
In this sorter, in order to precisely synchronize the discharge rollers with the bins,
the vertical movement of the discharge rollers 86a is caused by the driving system
of the lead cams 75 as will be explained later.
[0068] Referring to Fig. 17, at the lower end of the lead cam shaft 76 for the lead cam
75, there is fixed a lead cam pulley 77, which is linked, by a timing belt 79, with
a transmission member 80 consisting of a pulley and an integral bevel gear. A bevel
gear 81 meshing therewith is rotatably supported by a shaft 82. Other parts of the
sorter are constructed same as in the foregoing embodiments.
[0069] In the present embodiment, the shaft 82 supports an eccentric cam 83 in a position
different from that of the bevel gear 81. A vertically rotatable arm 85 is articulated,
at the lower end portions thereof, with a shaft 85a, and rotates vertically, following
the rotation of the eccentric cam 83, by the engagement of a rotatable pin 85b, provided
in the middle of said arm 85, with the periphery of said eccentric cam 83.
[0070] The free end of said arm 85 is linked, by a shaft 85c, with the lower end of a link
member 87, of which upper end is connected to a discharge roller unit 86 having paired
discharge rollers 86a. Said link member 87 is rendered vertically movable, as indicated
by an arrow X, by the rotation of the eccentric cam 83, thereby causing vertical movement
of the discharge roller unit 86.
[0071] A transport roller 90 is rotatably supported by a shaft 89a, which is in turn supported
by a rotating guide 89 having a guide plate 91. An end of said rotating guide 89 is
articulated, by a shaft 89b, to said discharge roller unit 86. Thus, in synchronization
with the vertical movement of the link member 87 and the discharge roller unit 86,
the guide plate 91 of the rotating guide 89 vibrates as indicated by an arrow Y.
[0072] The sheet discharged by discharge rollers 92 of the image forming apparatus is introduced
into the sorter 1 from an entrance 93, and is transported into a transport path 97
by a guide roller 96 and a guide plate 95. The sheet guided by said transport path
97 and the guide plate 91 is discharged into one of the bins B by the paired discharge
rollers 86a.
[0073] In the above-explained sorter, rotation of the lead cam 75 causes rotation of the
eccentric cam 83, thereby causing vibration of the arm 85 and vertical movement of
the link member 87. Thus the discharge roller unit 86 and the discharge rollers 86a
thereof move vertically in synchronization with the widening operation of the bins
B.
[0074] Figs. 18A and 18B are cam line charts respectively of the lead cam 75 and the eccentric
cam 83. In the illustrated example, the bin B and the discharge roller unit 86 are
synchronized within a range of 0° - 180°, in which the sheet is discharged into the
bin B. Fig. 17 shows an angular position of 180°. In a range from 180° to 360°, the
bin B continues ascent while the discharge roller unit 86 starts to descend toward
the initial position at 0° for introducing the sheet into the next bin B, and is synchronized
with the next bin B at the position 360°.
[0075] On the other hand, in case of descent of the bins B, a position of 180° is taken
as the home position of the discharge roller unit 86 and the bins B. In this case
the discharge is executed while the bin B and the discharge roller unit 86 are synchronized
in a range from 180° to 0°, and said unit 86 is matched with the next upper bin B
in a range from 360° to 180°.
[0076] The above-explained structure allows to discharge the sheet in the course of rotation
of the lead cams 75 by vertically moving the discharge roller unit 86 in synchronization
with the bin B moving along the inclined portion of the lead cams 75, instead of forming
the parallel (horizontal) portion in said lead cams 75. Therefore the sheet sorting
is rendered possible without repeating stoppage and start of the lead cams 75, as
in the foregoing embodiments.
[0077] The structure shown in Fig. 17, when connected to an apparatus with a short sheet
interval such as a high-speed copying machine, can also achieve sheet sorting with
a revolution of the lead cams 75 considerably lower than that of the conventional
sorter, thereby enabling a higher process speed in the copying machine and noise reduction
in the sorter.
[0078] In the foregoing description relating to Figs. 18A and 18B, it is assumed that the
lead cam 75 and the discharge roller unit 86 are synchronized over an angular range
of 180°, but it is to be understood that this value is variable, similarly as the
angular range of the parallel portion of the lead cams in the foregoing embodiments.
In fact said value can be suitably selected according to the speed and interval of
the sheets and does not limit the structure of the present invention.
[0079] In the following there will be explained a fourth embodiment with reference to Fig.
19.
[0080] The paired lead cams 43 (75), provided in a part of the bins in the 1st and 3rd embodiments
for effecting the vertical movement of the bin unit 2 and the bins B, are replaced
by spiral cams 101, 102 of screw shape as shown in Fig. 19.
[0081] Each of said spiral cams 101, 102 has a sheet discharge position 103 where the screw
pitch is widened and a parallel portion 105 positioned immediately below said discharge
position 103. The winding directions of said cams 101, 102 are mutually opposite,
constituting a mirror image relationship. Said spiral cams 101, 102 engage with the
trunnions 33 of the bins B, which are thus moved upwards or downwards by the rotation
of said cams in either direction.
[0082] The above-mentioned parallel portion 105 is selected as a predetermined angular range,
enabling sheet discharge in the course of rotation of the spiral cams 101, 102 at
a constant revolution. The sheet sorting operation as in the 1st and 3rd embodiments
can be achieved by giving a certain angle to the cam groove other than said parallel
portion 105. Fig. 20 is a cam line chart of the spiral cam 102, wherein 105 indicates
the parallel portion, corresponding to the sheet discharge position 103 to the bin
B.
[0083] The sorter 1 shown in Fig. 4 has a controller 110 provided, as shown in Fig. 21,
with a central processing unit (CPU) 111, a read-only memory (ROM) 112, a random access
memory (RAM) 113, an input port 114, an output port 116, etc.
[0084] The ROM 112 stores a control program, and the RAM 113 stores input data and work
data. The input port 114 is connected to various sensors such as a non-sort path sensor
S1 and various switches, while the output port 116 is connected to various loads such
as a transport motor 17 for driving the entrance rollers 11 and the lower discharge
rollers 16, and the CPU 111 controls various parts according to the control program
stored in the ROM 112. The CPU 111 is also provided with a serial interface and effects
serial communication with the CPU for example of the main body of the copying machine,
thereby controlling the various parts according to the signals from said main body.
[0085] In the following there will be explained the function of the present embodiment,
with reference to flow charts shown in Figs. 22 to 28.
[0086] At first referring to Fig. 22, when the copying operation is started by the depression
of a copy start key of the main body of the copying machine, a sorter start signal
is sent by a serial signal from the main body of the copying machine. Upon reception
of said signal by the sorter 1 (step 101), a step 102 determines the operation mode
of a job until the sorter start signal is terminated, and mode data are stored in
the RAM 113. Then the alignment rod 26 is returned to the home position for detecting
the position thereof (step 103).
[0087] Then various units are operated according to the mode determined in the step 102.
More specifically, a step 104 discriminates whether the non-sorting mode has been
selected, and, if selected, a step 105 discriminates whether stapling has been instructed,
and the sequence proceeds to the staple non-sort mode (step 107) if the stapling is
instructed, or to the non-sort mode (step 108) if the stapling is not instructed.
On the other hand, if the step 104 discriminates that the non-sort mode has not been
selected, a step 106 discriminates whether the sorting mode has been selected. The
sequence proceeds to a step 109 if the sorting mode is selected, or to a step 110
for group mode if the sorting mode is not selected. After the completion of operation
in one of the above-mentioned modes, the sequence proceeds to a step 111 for discriminating
whether the sorter start signal is still present, namely whether a job has been completed.
If the sorter start signal is present, indicating that a job has not been completed,
the sequence returns to the step 104. On the other hand, if the sorter start signal
is absent, the completion of a job is identified and the sequence returns to the initial
step 101.
[0088] In the following there will be explained the function in the staple non-sort mode
with reference to Fig. 23.
[0089] In said mode the bin unit 9 is at the home position, and a step 201 moves the bin
unit 9 to the home position. The stapling mechanism 67 is unable to staple the sheets
placed on the bin cover 22, but is designed to staple the sheets P stored in the bin
B. It is therefore necessary to introduce the sheets P into the bins B in case the
stapling mode is selected, even if the sorting operation is not conducted. For this
reason the flapper solenoid 122 is turned off, thereby selecting the lower discharge
rollers 16 (step 202). Thereafter the reception of a size determination signal is
awaited (step 203), and, upon reception thereof, the size data sent from the main
body of the copying machine are stored in the RAM 113 (step 204). If the sheet discharged
from the main body is the 1st sheet (step 205), the alignment rod 26, which should
have been placed at the home position, is moved to an alignment position 26a (step
206). If the step 205 identifies that the sheet is not the first one, or after the
movement of the alignment rod 26 to the alignment position 26a in the step 206, the
sequence proceeds to a step 207 for awaiting a sheet discharge signal from the main
body. Upon reception thereof, the alignment rod 26 is moved from the alignment position
26a to a standby position 43b (step 208). Then the sheet is introduced into the bin
B (step 209), and the alignment rod 26 is moved to the alignment position 26a for
aligning the sheet (step 210). Then a step 211 discriminates the presence of a staple
signal, and, if present, a stapling operation is conducted (step 211), or, if absent,
the sequence returns to the main routine.
[0090] In the following there will be explained the function in the non-sort mode, with
reference to Fig. 24.
[0091] In the non-sort mode, the sheets are discharged onto the bin cover 22. Therefore
the bin unit 2 is moved to the lowermost home position (step 310), and the flapper
solenoid 122 is energized to discharge the sheets from the upper discharge rollers
15 (step 311). Then, upon reception of a size determination signal (step 312), the
sheet size is determined. Then a step 314 awaits a sheet discharge signal from the
main body, and, upon reception thereof, a step 315 executes sheet discharge on the
bin cover 22 and the sequence returns to the main routine.
[0092] In the following there will be explained the function in the sorting mode, with reference
to Fig. 25.
[0093] At first there is discriminated whether a bin initial signal for returning the bin
unit 2 to the home position is received from the main body (step 401), and, if received,
the bin unit 2 is moved to the home position (step 402). Then the flapper solenoid
122 is turned off for selecting the lower discharge rollers 16 (step 403). Then, upon
reception of the size determination signal (step 404), the size is determined (step
405). Then there is discriminated whether said size determination is for the 1st sheet
(step 406), and, if for the 1st sheet, the alignment rod 26 is moved to the alignment
position 26a (step 407). Subsequently, upon reception of the sheet discharge signal
from the main body (step 408), the alignment rod 26 is moved to the standby position
26b (step 410). Then the sheet is discharged into the bin B (step 411), and the alignment
rod 26 is moved to the alignment position (step 413). A subsequent step 414 discriminates
whether the stapling signal is present, then the stapling operation is conducted only
when said signal is present (step 415), and the sequence returns to the main routine.
[0094] The movement of the bins B in the sorting operation will be explained later.
[0095] In the following there will be explained the function in the group mode, with reference
to Fig. 26.
[0096] At first there is discriminated whether the bin initial signal from the main body
of the copying machine is present (step 501), and, if present, the bin unit 2 is moved
to the home position (step 502). Then, upon reception of the size determination signal
(step 503), a step 504 determines the sheet size, and a step 505 discriminates whether
said size determination is for the 1st sheet. If for the 1st sheet, the alignment
rod 26 is moved to the alignment position 26a (step 506), and, upon reception of the
sheet discharge signal (step 507), the alignment rod 26 is moved to the standby position
26b (step 508). After the sheet transportation into the bin B (step 509), a step 510
discriminates whether a bin shift signal from the main body is present (step 509),
and, if present, the bins B are shifted by a bin (step 511). Then the alignment rod
26 is moved to the alignment position 26a for aligning the sheets (step 512) and the
sequence returns to the main routine.
[0097] In the following there will be explained the transporting operation, with reference
to Fig. 27.
[0098] When the sorter 1 receives a sheet from the main body, if the transporting speed
of said sheet in said sorter is lower than that in the main body, the sheet generates
a loop between the main body and the sorter, thereby resulting in sheet jamming. On
the other hand, if the sheet transporting speed in the sorter is higher than that
in the main body, the sheet is pulled by two units, and there is generated danger
of noises or sheet breakage. Consequently the sheet transporting speed of the sorter
1 is synchronized with the process speed of the main body (step 601).
[0099] Then there is discriminated whether the flapper solenoid is energized, namely whether
the upper discharge rollers 15 or the lower discharge rollers 16 are selected (step
602). The sequence then proceeds to a step 603 for detection with the non-sort path
sensor S1 if the flapper solenoid 122 is energized to select the non-sort discharge
position 15, or to a step 604 for detection with the sort path sensor S2 if the flapper
solenoid 122 is turned off to select the sorting discharge position 16. The step 603
or 604 waits until the non-sort path sensor or the sort path sensor is turned on,
and the sequence proceeds then to a step 605 for setting a counter for measuring the
position for controlling the discharge timing of the transport motor 117. Then a step
606 discriminates whether the counter, set in the step 605, has completed the counting
operation, and the sequence proceeds to a step 609 or 607 respectively if the counting
is completed or not. The step 607 discriminates the presence of the sheet discharge
signal from the main body, and, if absent, the sheet is identified to have been completely
discharged from the main body of the copying machine and the transport speed is increased
to the maximum value (step 608). After the step 608 identifies the point of controlling
the discharge timing, a step 609 controls the transport motor 117 to the sheet discharge
speed of the main body. Thereafter a counter is set for measuring the position of
completion of discharge (step 610), and the sequence is terminated when the counting
operation is completed (step 611).
[0100] In the following there will be explained the stapling operation, with reference to
Fig. 28.
[0101] At first a step 701 activates a stapler moving motor 119 for moving the stapler 67,
until a stapler work position sensor S7 and a stapler positioning sensor S6 are both
activated, namely until the stapler 67 moves to a work position 67a.
[0102] Then a stapler motor 71 is activated to effect a stapling operation. After the start
of said stapler motor 71, there is confirmed the turning-off of a stapler cam sensor
S10, and a stapling operation is completed by turning off the stapler motor 71 after
the turning-on of said sensor S10, namely after a full turn (step 702). Subsequently
the stapler moving motor 119 is activated until the stapler work position sensor S7
is turned off and the stapler positioning sensor S6 is turned on, namely until the
stapler 67 is retracted to a position 67b (step 703). Then there is discriminated
whether the stapling operation is conducted on all the bins B (step 705), and, if
not, the bins are shifted by a bin, and the sequence proceeds to the step 701 for
a next stapling operation. If the stapling operation has been conducted on all the
bins, the stapling sequence is terminated.
[0103] In the following there will be explained the shifting operation in the sorting mode,
which is most characteristic of the present invention, with reference to Fig. 29.
[0104] In the shifting operation in the sorting mode, the sheet discharge signal from the
image forming apparatus is monitored for synchronization with the sheet P (step 801).
Upon reception of said sheet discharge signal, the moment of entry of the leading
end of the sheet P into the bin B is synchronized with the end of the parallel portion
of the lead cams 43. More specifically, a counter for synchronizatlon is set (step
803), and, upon completion of the counting operation (step 805), the sequence proceeds
to a step 807.
[0105] The step 807 discriminates whether the sheet is the last sheet of a series of originals,
and, if it is the last sheet, the rotation of the lead cams 43 is terminated (step
809).
[0106] If not the last sheet, the sequence proceeds to a step 811 to vary the speed of the
lead cams 43. The speed in this state can be obtained by dividing the length of the
parallel portion thereof by the time, obtained by dividing the length of sheet by
the transport speed. Said sheet length is supplied from the main body by serial communication
shown in Fig. 21.
[0107] Then a step 813 awaits the turning-on, of the sort path sensor S2, and a step 815
awaits the turning-off thereof, in order to detect the rear end of the sheet P. Then
there is set a counter for counting the period from the detection of the rear end
of the sheet P to the completion of sheet storage into the bin B (step 817), and,
upon completion of the counting operation (step 819), the sequence proceeds to a step
821.
[0108] The step 821 varies the speed to the shifting speed in the interval of sheets, and
said shifting speed is determined by dividing the amount of movement in the non-parallel
portion by the interval which is supplied by serial communication from the main body.
After the determination of the shifting speed, the sequence returns to the step 801
for processing the next sheet P.
[0109] In the following there will be explained the speed control of the shift motor 45,
with reference to Fig. 30.
[0110] The control of the shift motor 45 is achieved by the timer interruption function
and the clock interruption function of the CPU 111.
[0111] The timer interruption function is to generate interruption at an arbitrary interval
by a hardware counter in the CPU 111, while the clock interruption function is to
generate interruption at the edge of an external pulse. In this embodiment, the clock
interruption is achieved by a clock pulse from a clock sensor S13 of the encoder of
the shift motor 45.
[0112] This control is achieved by setting the interval of the timer interruption at an
ideal time for clock interruption when the shift motor 45 is at the target speed,
and controlling the count of an up-down counter, for measuring the difference between
said ideal time and the number of clocks for interruption, to zero, thereby obtaining
the ideal speed.
[0113] Flow charts of the above-explained control are shown in Figs. 30A and 30B.
[0114] Fig. 30A shows the procedure of clock interruption by increasing the count of the
shift control up-down counter, provided in the RAM 113.
[0115] Fig. 30B shows the procedure of timer interruption. At first a step 951 effects a
decrement of the shift control counter. Then the on-off state of the shift motor 45
is determined by discriminating whether the count of the shift control counter is
larger than zero (step 953), and, if larger than zero, turning off the shift motor
45 as the speed thereof is too large (step 955). On the other hand, if the step 953
identifies that the count of the shift control counter is zero or smaller, a step
957 discriminates whether said count is smaller than zero.
[0116] If said count is not smaller than zero, said count is zero, indicating the target
speed, and the timer interruption procedure is terminated. If said count is smaller
than zero, indicating a speed slower than the target, the shift motor 45 is turned
on (step 959) and the timer interruption procedure is terminated. The speed control
of the shift motor 45, controlling the vertical movement of the bin unit 2 and the
widening operation of the bins B is achieved in this manner.
[0117] In the above-explained embodiment, the spiral cams need not necessarily be provided
with parallel portions, but may be rotated at a relatively low speed in continuous
manner, in synchronization with the sheet discharge.
[0118] In the following there will be explained application of the present invention to
a facsimile apparatus or a printer.
[0119] Fig. 32 is a schematic view of another embodiment in which the image forming apparatus
is composed of a facsimile apparatus, wherein shown are a main body 200 of the facsimile
apparatus; an original reading unit 201; a collator 202 provided in the recording
unit of the main body 200; a sheet discharge unit 203 of the main body 200; a received
document 204; bin trays 205 - 208; and a driving unit 209 of the collator.
[0120] In response to a control signal from the main body 200 of the facsimile apparatus,
the driving unit 209 of the collator moves the bin trays 205 ∼ 208 vertically to align
one of said bin trays with the sheet discharge unit 203, and the received document
204 is placed on thus aligned bin tray. The uppermost bin tray 205 can stack a larger
number of documents than in other bin trays 206 - 208, because of the available upper
space.
[0121] Fig. 33 shows the structure of control system in the facsimile apparatus shown in
Fig. 32.
[0122] In Fig. 33, a CPU 221 for controlling the various units of the facsimile apparatus
is composed for example of a microprocessor. The control system of the facsimile apparatus
is composed of star-shaped connection of the components 222 ∼ 212 to said CPU 221.
[0123] Said components consist of an operation unit 222 for input of instructions for facsimile
operations and for information display; a reading unit 223 for reading the image of
an original; a recording unit 224 for image output; a connector 225 such as modem
or DSU between the facsimile apparatus and a communication network; a communication
line 226; a ROM 227 storing, for example, the control program of the CPU 221; a RAM
228 for temporary storage of various data and image information; a rigid disk drive
229 functioning as a non-volatile memory for storing image information or the like;
a handset 210; a collator control unit 211; and a collator 202 (209).
[0124] In the above-explained facsimile apparatus, the collator 202 (209) is controlled
in the same manner as in the copying machine explained above. For example, in case
of receiving the sheets of a communication in a bin tray and receiving those of another
communication in another bin tray, the bin trays are shifted by continuous rotation
of a motor.
[0125] Figs. 34 and 35 show a laser beam printer as another embodiment of the image forming
apparatus.
[0126] Fig. 35 is a block diagram of the present embodiment, composed of a controller 301
connected to plural host computers; a printer 302 connected to said controller 301;
and a sorter 303 connected to said printer 302. The printer 302 and the sorter 303
are respectively provided with independently operating CPU's 304, 305 each having
a ROM and a RAM, and these units mutually exchange information and data by parallel
or serial communication. In response to a print instruction from one of the host computers,
the controller 301 generates an ID number for each host computer and each instruction
(job) and sends it to the printer 302, which transmits said ID number to the sorter
303. In response to said ID number, the sorter 303 designates a bin of the sorter,
and sends the bin number, corresponding to said ID number, to the controller 301 through
the printer 302.
[0127] The sorter 303 is provided, in addition to the CPU 305, with empty bin sensors PS1
∼ PSn for detecting the presence of sheets in each bin 303a. Also there are provided
a motor for driving the bin moving means for discharging sheet into each bin, a driver
therefor, a motor for driving discharge rollers 303c, etc., and a driver therefor.
[0128] Also in this embodiment shown in Figs. 34 and 35, the sorter 303 is controlled according
to the sheet transport speed of the printer 302, as in the foregoing embodiments.
[0129] The embodiment shown in Fig. 34 is provided with a laser beam printer, but there
may be employed the recording unit of another type. For example, an ink jet printer
is characterized by low noise level, and can be advantageously employed in combination
with the low-noise sorter of the present invention.
[0130] The ink jet recording utilizes a liquid discharge opening for discharging recording
liquid ink as a flying droplet; a liquid path communicating with said discharge opening;
and discharge energy generating means provided in a part of said liquid path and serving
to provide the discharge energy for causing the liquid ink in said path to fly. Said
energy generating means is driven according to image signal, thereby discharging the
ink droplets and recording an image.
[0131] For said discharge energy generating means, there may be employed pressure energy
generating means, for example an electromechanical converter such as a piezoelectric
device; electromagnetic energy generating means such as a laser which heats the liquid
ink with an electromagnetic emission thereby discharging the ink by said heating;
or thermal energy generating means for heating the liquid ink with an electrothermal
converter thereby discharging the ink. Among these methods, so-called bubble jet recording
method, in which the ink discharge is caused by thermal energy generating means such
as an electrothermal converter, can be advantageously employed since recording with
a high resolving power can be achieved with a high-density arrangement of discharge
openings and since the recording head can be realized in a compact form.