TECHNICAL FIELD
[0001] The present invention relates to an inkjet printing device, an inkjet printing method,
a printing control device, a program, and a recording medium.
BACKGROUND ART
[0002] JP-A-2002-36644 discloses an inkjet recording apparatus for reducing the time required to record
a plurality of images.
[0003] US 2011/109682 A1 discloses a printing apparatus, comprising a conveying mechanism configured to convey
a sheet; a printing unit configured to apply an ink onto the sheet conveyed by the
conveying mechanism to perform print operation; a drying unit configured to dry the
sheet on which an ink has been applied by the printing unit; and a control unit configured
to control the conveying mechanism, the printing unit, and the drying unit, wherein
the control unit controls the conveying mechanism to vary a sheet conveyance amount
per unit time while print operation of one job is in progress, and is configured to
control the drying unit depending on variation in the sheet conveyance amount while
the print operation of the one job is in progress.
[0004] WO 2008/069070A1 discloses a printer including a printing head which discharges ink onto a wrapping
film; a drying heater which blows out a warm wind toward the wrapping film after printing
so as to dry the ink attached to the wrapping film and can adjust the temperature
of the warm wind; an encoder which detects the convey speed of the wrapping film when
it passes the position where the warm wind from the drying heater is applied; and
a control unit which controls the temperature of the warm wind from the drying heater
in accordance with the convey speed detected by the encoder.
SUMMARY OF INVENTION
TECHNICAL PROBLEM
[0005] Some of inkjet printing devices of the related art like the inkjet recording apparatus
disclosed in
JP-A-2002-36644 have maintenance systems for regularly stopping and cleaning inkjet heads configured
to eject ink.
[0006] In such an inkjet printing device, even when an inkjet head is in a stop state for
maintenance of the inkjet head, drying of ink ejected on a recording medium progresses.
Therefore, in the portion dried during the printing stop period, unevenness in drying
ink occurs. Further, this unevenness in drying emerges as density unevenness on the
printed material, resulting in a reduction in the quality of the printed material.
Especially, in a case of using ink required to be dried at high temperature by a heater
or the like, such as latex ink, there is a possibility that occurrence of density
unevenness on printed materials will be remarkably appear.
[0007] The present invention was made in order to solve the above described problem, and
an object of the present invention is to provide an inkjet printing device, an inkjet
printing method, a printing control device, a program, and a recording medium capable
of suppressing occurrence of unevenness in drying during cleaning on an inkjet head.
SOLUTION TO PROBLEM
[0008] In order to achieve the above described object, an inkjet printing device according
is provided that has the features of claim 1
[0009] During cleaning on inkjet head, printing using the inkjet head is in a stop state,
whereas drying of ink ejected on the recording medium progresses. For this reason,
in the portion dried during the printing stop period, unevenness in drying ink may
occur. Further, this unevenness in drying emerges as density unevenness on the printed
material, resulting in a reduction in the quality of the printed material. Especially,
in a case of using ink required to be dried at high temperature, such as latex ink,
there is a possibility that occurrence of density unevenness on printed materials
will be remarkably appear.
[0010] As the result of repetition of earnest examination for preventing occurrence of drying
unevenness during cleaning on the inkjet head, the inventors of the present invention
found that it is possible to prevent occurrence of drying unevenness by making the
drying efficiency during cleaning on the inkjet head lower than the drying efficiency
during printing of the inkjet head or making the drying efficiency during printing
of the inkjet head higher than the drying efficiency during manufacturing of the inkjet
head, and finally completed the present invention.
[0011] In other words, if the progress of drying of ink during cleaning on the inkjet head
is slowed down, it becomes difficult for drying unevenness to occur between a portion
dried during a printing period and a portion dried during a printing stop period.
Also, even in a case where the progress of drying of ink during printing of the inkjet
head is accelerated, similarly, it becomes difficult for drying unevenness to occur
between a portion dried during a printing period and a portion dried during a printing
stop period. As a result, it is possible to suppress occurrence of density unevenness
of the printed material attributable to drying unevenness, thereby preventing a reduction
in the quality of the printed material.
[0012] Also, in the inkjet printing device according to the present invention, the drying
means includes a fan configured to blow air toward the printing surface of the recording
medium, and the control means makes the rotation speed of the fan during cleaning
on the inkjet head lower than the rotation speed of the fan during ejection of ink
from the inkjet head.
[0013] According to the above described configuration, it is possible to make the ink drying
efficiency during cleaning on the inkjet head lower than the ink drying efficiency
during ejection of ink from the inkjet head, and it is possible to slow down the progress
of drying of ink during cleaning on the inkjet head. As a result, it is possible to
suppress occurrence of density unevenness of the printed material attributable to
drying unevenness, thereby preventing a reduction in the quality of the printed material.
[0014] Further, in the inkjet printing device according to present invention, the control
means may stop the operation of the fan during cleaning on the inkjet head, and operate
the fan during ejection of ink from the inkjet head.
[0015] According to the above described configuration, since the fan is operated during
ejection of ink, and the fan is stopped during cleaning of ink, it is possible to
make the ink drying efficiency during cleaning on the inkjet head lower than the ink
drying efficiency during ejection of ink from the inkjet head. As a result, it is
possible to slow down the progress of drying of ink during cleaning on the inkjet
head, and it is possible to suppress occurrence of density unevenness of the printed
material attributable to drying unevenness, thereby preventing a reduction in the
quality of the printed material.
[0016] Also, in the inkjet printing device according to the present invention, the drying
means includes a fan configured to blow air toward the printing surface of the recording
medium, and the control means makes the rotation speed of the fan during ejection
of ink from the inkjet head higher than the rotation speed of the fan during cleaning
on the inkjet head.
[0017] According to the above described configuration, it is possible to make the drying
efficiency during printing of the inkjet head higher than the drying efficiency during
cleaning on the inkjet head, and it is possible to accelerate the progress of drying
of ink during printing. As a result, it is possible to suppress occurrence of density
unevenness of the printed material attributable to drying unevenness, thereby preventing
a reduction in the quality of the printed material.
[0018] Further, in the inkjet printing device according to the present invention, the printing
means may have a plurality of inkjet heads, and the control means may stop cleaning
when some of the plurality of inkjet heads have been cleaned by the cleaning means,
and perform printing on the recording medium by ejecting ink from the inkjet heads,
and then perform control such that the cleaning means restarts cleaning and cleans
the other uncleaned inkjet heads of the plurality of inkjet heads.
[0019] According to the above described configuration, it is possible to shorten the period
of one cleaning event on the inkjet head, that is, the printing stop period, and it
becomes difficult for drying unevenness to occur between a portion dried during printing
and a portion dried during the printing stop period. As a result, it is possible to
suppress occurrence of density unevenness of the printed material attributable to
drying unevenness, thereby preventing a reduction in the quality of the printed material.
[0020] Also, in the inkjet printing device according to the present invention, the drying
means includes a heater disposed at a position facing the inkjet head and configured
to heat the recording medium from the surface side that is opposite to the printing
surface, and the control means may make the heating temperature of the heater during
cleaning on the inkjet head lower than the heating temperature of the heater during
ejection of ink from the inkjet head.
[0021] According to the above described configuration, it is possible to make the ink drying
efficiency during cleaning on the inkjet head lower than the ink drying efficiency
during ejection of ink from the inkjet head, and it is possible to slow down the progress
of drying of ink during cleaning on the inkjet head. As a result, it is possible to
suppress occurrence of density unevenness of the printed material attributable to
drying unevenness, thereby preventing a reduction in the quality of the printed material.
[0022] Further, in the inkjet printing device according to the present invention, the drying
means includes a heater disposed at a position facing the inkjet head and configured
to heat the recording medium from the surface side that is opposite to the printing
surface, and the control means may make the heating temperature of the heater during
ejection of ink from the inkjet head higher than the heating temperature of the heater
during cleaning on the inkjet head.
[0023] According to the above described configuration, it is possible to make the drying
efficiency during printing of the inkjet head higher than the drying efficiency during
cleaning on the inkjet head, and it is possible to accelerate the progress of drying
of ink during printing. As a result, it is possible to suppress occurrence of density
unevenness of the printed material attributable to drying unevenness, thereby preventing
a reduction in the quality of the printed material.
[0024] An inkjet printing method is provided that has the features of claim 6.
[0025] According to the above described configuration, the same effects as those of the
inkjet printing device according to the present invention are obtained.
ADVANTAGEOUS EFFECTS OF INVENTION
[0026] According to the present invention, an effect that it is possible to suppress occurrence
of density unevenness of a printed material attributable to drying unevenness, thereby
preventing a reduction in the quality of the printed material is obtained.
BRIEF DESRIPTION OF DRAWINGS
[0027]
[Fig. 1] Fig. 1 is a schematic diagram illustrating an inkjet printing device according
to an embodiment of the present invention.
[Fig. 2] Fig. 2 is a schematic diagram illustrating a portion of the inkjet printing
device according to the embodiment of the present invention.
[Fig. 3] Fig. 3 is a schematic diagram illustrating another example of the portion
of the inkjet printing device according to the embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[INKJET PRINTING DEVICE]
[0028] An inkjet printing device according to an embodiment of the present invention will
be described below with reference to Figs. 1 and 2. Fig. 1 is a schematic diagram
illustrating an inkjet printing device according to an embodiment of the present invention,
and Fig. 2 is a schematic diagram illustrating a portion of the inkjet printing device
according to the embodiment of the present invention. An inkjet printing device 1
includes a printing unit (a printing means) 10, a heater 20 and a fan 40 configured
as drying means, a wiper 12 configured as a cleaning means, and a control unit (a
control means) 30.
[0029] The printing unit 10 has an inkjet head 11 configured to perform printing on a recording
medium 50 by ejecting ink. The printing unit 10 makes the inkjet head 11 scan the
recording medium 50 which is conveyed in a direction shown by arrows in Fig. 1 by
a conveying means 60 composed of a plurality of rollers, over the recording medium.
In this way, the relative position between the recording medium 50 and the inkjet
head 11 is moved. Further, the printing unit ejects ink from the inkjet head 11 moved
to a predetermined position, onto the recording medium 50, thereby performing printing
on the recording medium 50.
[0030] The inkjet head 11 injects ink drops from nozzles 13 arranged on the bottom of the
inkjet head as shown in Fig. 2, onto the recording medium 50. The printing unit 10
needs only to have one inkjet head 11; however, it may be configured to have a plurality
of independently controllable inkjet heads such as inkjet heads 11a and 11b shown
in Fig. 2.
[0031] The heater 20 and the fan 40 accelerate drying of ink that has landed on the recording
medium 50. In the present embodiment, the configuration having both of the heater
20 and the fan 40 as drying means is described as an example; however, the inkjet
printing device may have only one of the heater and the fan. Driving of the heater
20 and the fan 40 is controlled by the control unit 30. Since drying of ink that has
landed on the recording medium 50 is accelerated by the heater 20 and the fan 40,
it is possible to appropriately fix the ink on the recording medium 50 while preventing
bleeding of the ink on the recording medium 50.
[0032] The heater 20 is disposed at a position facing the inkjet head 11 with the recording
medium 50 interposed therebetween, and heats the recording medium 50 from the surface
side that is opposite to the printing surface. In this way, the heater accelerates
drying of ink that has landed on the printing surface of the recording medium 50.
The heater 20 needs only to be configured to heat the recording medium 50 by transmitting
heat to the recording medium 50. As this heater 20, an electric heater or the like
using ceramic or nichrome wire can be used.
[0033] Also, a pre-heater (not shown) for heating the recording medium 50 from the printing
surface side or the surface side that is opposite to the printing surface may be provided
on the upstream side from a position of the recording medium 50 facing the inkjet
head 11. By heating the recording medium 50 before landing of ink by the pre-heater,
it is possible to accelerate drying of ink immediately after landing of ink, and further
prevent bleeding of ink. Also, an after-heater (not shown) for heating the recording
medium 50 from the printing surface side or the surface side that is opposite to the
printing surface may be provided on the downstream side from the position of the recording
medium 50 facing the inkjet head 11. By heating the recording medium 50 after landing
of ink by the after-heater, it is possible to accelerate drying of the ink on the
recording medium 50, and more appropriately fix the ink on the recording medium 50.
[0034] The fan 40 sends air toward the printing surface of the recording medium 50. The
fan 40 needs only to be set, for example, on the ceiling or the like of the inside
of a housing containing the individual components of the inkjet printing device 1,
and circulate air of the inside of the housing, thereby producing a current of air.
Since this current of air is sent to the printing surface of the recording medium
50, drying of ink that has landed on the printing surface of the recording medium
50 is accelerated. Also, a plurality of fans 40 may be provided in the housing containing
the individual components of the inkjet printing device 1.
[0035] The wiper 12 is for cleaning the inkjet head 11. If ink is struck in the nozzles
13 or drew is condensed on the inkjet head 11, it may become impossible to appropriately
eject ink from the inkjet head 11 during printing (such as a failure in ejection of
the nozzles). In order to prevent this, the inkjet head 11 is regularly maintained
and cleaned. A method of cleaning the inkjet head 11 is not particularly limited,
and it is possible to wipe the nozzle surface of the inkjet head 11, like the wiper
12 shown in Fig. 2.
[0036] It is also possible to move the inkjet head 11 into a maintenance station (not shown)
provided at a position spaced from the recording medium 50, and clean the inkjet head
inside the maintenance station. In this case, the cleaned inkjet head 11 is returned
to the position facing the recording medium 50, and printing restarts.
[0037] The control unit 30 controls driving of the printing unit 10, the heater 20, the
fan 40, and the wiper 12. Further, the control unit 30 stops ejection of ink from
the inkjet head 11, and makes the wiper 12 clean the inkjet head 11. At this time,
the control unit 30 controls driving of the heater 20 and the fan 40, thereby dissimilating
drying efficiency during printing of the inkjet head 11 and drying efficiency during
cleaning on the inkjet head 11.
[0038] In other words, the control unit 30 performs at least one of control for making the
ink drying efficiency during cleaning on the inkjet head 11 lower than the ink drying
efficiency during ejection of ink from the inkjet head 11, and control for making
the ink drying efficiency during ejection of ink from the inkjet head 11 higher than
the ink drying efficiency during cleaning on the inkjet head 11.
[0039] During cleaning on the inkjet head 11, printing using the inkjet head 11 is in a
stop state, whereas drying of ink ejected on the recording medium 50 progresses. For
this reason, in the portion dried during the printing stop period, unevenness in drying
ink may occur. Further, this unevenness in drying emerges as density unevenness on
the printed material, resulting in a reduction in the quality of the printed material.
Especially, in a case of using ink required to be dried at high temperature, such
as latex ink, there is a possibility that occurrence of density unevenness on printed
materials will be remarkably appear.
[0040] As the result of repetition of earnest examination for preventing occurrence of drying
unevenness during cleaning on the inkjet head 11, the inventors of the present invention
found that it is possible to prevent occurrence of drying unevenness by making the
drying efficiency during cleaning on the inkjet head 11 lower than the drying efficiency
during printing of the inkjet head 11 or making the drying efficiency during printing
of the inkjet head 11 higher than the drying efficiency during manufacturing of the
inkjet head 11, and finally completed the present invention.
[0041] In other words, if the progress of drying of ink during cleaning on the inkjet head
11 is slowed down, it becomes difficult for drying unevenness to occur between a portion
dried during a printing period and a portion dried during a printing stop period.
Also, even in a case where the progress of drying of ink during printing of the inkjet
head 11 is accelerated, similarly, it becomes difficult for drying unevenness to occur
between a portion dried during a printing period and a portion dried during a printing
stop period.
[0042] As a method of making the ink drying efficiency during cleaning on the inkjet head
11 lower than the ink drying efficiency during ejection of ink from the inkjet head
11, the control unit 30 may make the rotation speed of the fan 40 during cleaning
on the inkjet head 11 lower than the rotation speed of the fan 40 during ejection
of ink from the inkjet head 11. By reducing the rotation speed of the fan 40 during
cleaning on the inkjet head 11, it is possible to slow down the progress of drying
of ink.
[0043] Also, as another method of making the ink drying efficiency during cleaning on the
inkjet head 11 lower than the ink drying efficiency during ejection of ink from the
inkjet head 11, the control unit 30 may make the heating temperature of the heater
20 during cleaning on the inkjet head 11 lower than the heating temperature of the
heater 20 during ejection of ink from the inkjet head 11. By reducing the heating
temperature of the heater 20 during cleaning on the inkjet head 11, it is possible
to slow down the progress of drying of ink.
[0044] As a method of making the drying efficiency during printing of the inkjet head 11
higher than the drying efficiency during cleaning on the inkjet head 11, the control
unit 30 may make the rotation speed of the fan 40 during ejection of ink from the
inkjet head 11 higher than the rotation speed of the fan 40 during cleaning on the
inkjet head 11. By increasing the rotation speed of the fan 40 during printing of
the inkjet head 11, it is possible to accelerate the progress of drying of ink during
printing.
[0045] Also, as another method of making the drying efficiency during printing of the inkjet
head 11 higher than the drying efficiency during cleaning on the inkjet head 11, the
control unit 30 may make the heating temperature of the heater 20 during ejection
of ink from the inkjet head 11 higher than the heating temperature of the heater 20
during cleaning on the inkjet head 11. By increasing the heating temperature of the
heater 20 during printing of the inkjet head 11, it is possible to accelerate the
progress of drying of ink during printing.
[0046] The control unit 30 transmits a drive signal for driving the wiper 12, to a wiper
driving unit (not shown), at a predetermined timing or in response to an input from
a user. The control unit 30 determines whether the inkjet head 11 is being cleaned
by, for example, determining whether the wiper 12 has been driven. Alternatively,
a control means different from the control unit 30 may control the wiper, and the
control unit 30 may recognize whether the wiper is being driven, whereby the control
unit 30 may determine whether cleaning is being performed. Then, if determining that
the inkjet head 11 is being cleaned, the control unit 30 transmits a signal for changing
the drying efficiency depending on at least one of the heater 20 and the fan 40, to
the heater driving unit (not shown) and a fan driving unit (not shown). The signal
for changing the drying efficiency may be a signal for changing the temperature of
the heater 20 or the rotation speed of the fan 40 to a predetermined value, or may
be a signal for changing the temperature of the heater 20 and the rotation speed of
the fan 40 on the basis of a dry state obtained by performing dry-state detection.
Also, it is possible to make the user input a desired drying efficiency, and compute
at least one of the temperature of the heater 20 and the rotation speed of the fan
40 according to the desired drying efficiency, and drive the heater 20 and the fan
40 such that the computed temperature and the computed rotation speed are achieved.
Also, the control unit 30 may determine whether ink has been ejected from the inkjet
head 11, thereby determining whether ink is being ejected from the inkjet head 11.
In this case, if determining that ink is being ejected from the inkjet head 11, the
control unit 30 transmits a signal for making the drying efficiency depending on at
least one of the heater 20 and the fan 40 higher than that during cleaning, to the
heater driving unit and the fan driving unit.
[0047] The control unit 30 may make a voltage value to be applied to the fan 40 during cleaning
on the inkjet head 11 lower than a voltage value to be applied to the fan 40 during
ejection of ink from the inkjet head 11, thereby decreasing the rotation speed of
the fan 40 during cleaning on the inkjet head 11. The control unit 30 may perform
control for applying a voltage of 24 V during ejection of ink from the inkjet head
11, for example, by performing control such a voltage to be applied to the fan 40
during cleaning on the inkjet head 11 becomes 0 V (control for stopping the fan).
[0048] Also, the control unit 30 may stop the operation of the fan 40 during cleaning on
the inkjet head 11, and operate the fan 40 only during ejection of ink from the inkjet
head 11. Also, in a case where the inkjet printing device 1 has a plurality of fans,
it is possible to make the number of fans which are operated during cleaning on the
inkjet head 11 smaller than the number of fans which are operated during ejection
of ink from the inkjet head 11.
[0049] The control unit 30 may make the heating temperature of the heater 20 during cleaning
on the inkjet head 11 lower than the heating temperature of the heater 30 during ejection
of ink from the inkjet head 11, for example, by performing control for stopping heating
of the heater 20 during cleaning on the inkjet head 11 and performing control for
making the heating temperature of the heater 20 during ejection of ink from the inkjet
head 11 equal to or higher than 60°C. Also, the control unit 30 may stop the operation
of the heater 20 during cleaning on the inkjet head 11 and operate the heater 20 only
during ejection of ink from the inkjet head 11.
[0050] Also, control of the control unit 30 for making the ink drying efficiency during
cleaning on the inkjet head 11 lower than the ink drying efficiency during ejection
of ink from the inkjet head 11, or control of the control unit for making the drying
efficiency during printing of the inkjet head 11 higher than the drying efficiency
during cleaning on the inkjet head 11 may be performed by any one of control on the
operation of the heater 20 and control of the operation of the fan 40, or may be performed
by both of control on the operation of the heater and control of the operation of
the fan.
[0051] Cleaning on the inkjet head 11 may be appropriately performed depending on the state
of the inkjet head 11, or may be regularly performed at intervals of a predetermined
period. In order to shorten the printing stop period, it is preferable to perform
control such that the period of one cleaning event becomes short as much as possible,
and it is more preferable that the cleaning period should be equal to or less than
8 seconds.
[0052] Also, in a case where the printing unit 10 has a plurality of inkjet heads 11, such
as inkjet heads 11a and 11b, as shown in Fig. 2, the control unit 30 may stop cleaning,
for example, when the inkjet head 11a has been cleaned by the wiper 12, and perform
printing on the recording medium 50 by ejecting ink from at least one of the inkjet
heads 11a and 11b, and move the wiper 12 toward the inkjet head 11b, and clean the
inkjet head 11b.
[0053] In other words, the control unit 30 stops cleaning when some of the plurality of
inkjet heads 11 have been cleaned by the wiper 12, and performs printing on the recording
medium 50 by ejecting ink from the inkjet heads 11, and then restarts cleaning by
the wiper 12, thereby cleaning the other uncleaned inkjet heads 11 of the plurality
of inkjet heads 11. As a result, it is possible to reduce the period of one cleaning
event, that is, the printing stop period, and it becomes difficult for drying unevenness
to occur between a portion dried during printing and a portion dried during the printing
stop period.
[0054] Information on a timing to stop cleaning, a cleaning range representing where the
wiper 12 should clean until the corresponding timing, and a timing to restart cleaning
may be input in advance, for example, by the user, and the control unit 30 may make
the user input a desired printing speed and the degree of suppression of drying unevenness,
and compute the timings and the cleaning range described above, from the information
input by the user. According to the information input by the user and/or the information
computed by the control unit 30, the control unit 30 drives the wiper 12, the inkjet
head 11, and the like.
[0055] As described above, in the inkjet printing device 1, since the control unit 30 performs
at least one of control for making the ink drying efficiency during cleaning on the
inkjet head 11 lower than the ink drying efficiency during ejection of ink from the
inkjet head 11, and control for making the ink drying efficiency during ejection of
ink from the inkjet head 11 higher than the ink drying efficiency during cleaning
on the inkjet head 11, it becomes difficult for drying unevenness to occur between
a portion dried during a printing period and a portion dried during a printing stop
period, and it is possible to suppress occurrence of density unevenness of the printed
material attributable to drying unevenness, thereby preventing a reduction in the
quality of the printed material.
[0056] Also, although the case where the inkjet heads 11a and 11b are arranged side by side
in the transverse direction as shown in Fig. 2 has been described, the present invention
is not limited thereto. For example, as shown in Fig. 3, the inkjet heads 11a and
11b may be staggered. Fig. 3 is a schematic view illustrating the modification of
the inkjet heads 11. Even by inkjet heads staggered as shown in Fig. 3, it is possible
to suppress density unevenness, and provide high-quality printed materials.
[INKJET PRINTING METHOD]
[0057] An inkjet printing method according to an embodiment of the present invention includes
a printing process of printing by ejecting ink from an inkjet head onto a recording
medium, a drying process of drying ink that has landed on the recording medium, and
a cleaning process of stopping ejection of ink from the inkjet head and cleaning the
inkjet head, and performs at least one of control for making the ink drying efficiency
of the cleaning process lower than the ink drying efficiency of the printing process,
and control for making the ink drying efficiency of the printing process higher than
the ink drying efficiency of the cleaning process.
[0058] In other words, the embodiment of the inkjet printing method according to the present
invention is a printing method which is performed by the inkjet printing device of
the present invention described above. Therefore, the embodiment of the inkjet printing
method according to the present invention conforms the above description of the inkjet
printing device of the present invention.
[PRINTING CONTROL DEVICE]
[0059] A printing control device according to an embodiment of the present invention is
a printing control device configured to control a printing device having an inkjet
head for performing printing by ejecting ink onto a recording medium, and performs
at least one of control for making the ink drying efficiency during cleaning on the
inkjet head lower than the ink drying efficiency during ejection of ink from the inkjet
head, and control for making the ink drying efficiency during ejection of ink from
the inkjet head higher than the ink drying efficiency during cleaning on the inkjet
head.
[0060] In other words, the embodiment of the printing control device according to the present
invention is the control unit of the inkjet printing device of the present invention
described above. Therefore, the embodiment of the printing control device according
to the present invention conforms the above description of the inkjet printing device
of the present invention.
[IMPLANTATION EXAMPLE USING SOFTWARE]
[0061] Control of the control unit 30 may be implemented by a logic circuit (hardware) formed
on an integrated circuit (an IC chip) and so on, or may be implemented by software
which is executed by a CPU (Central Processing Unit).
[0062] In the latter case, the control unit 30 includes a CPU configured to execute commands
of a program which is software for implementing its individual functions, a ROM (Read
Only Memory) or a storage unit (referred to as the "recording medium") in which the
above described program and a variety of data have been recorded so as to be readable
in a computer (or a CPU), a RAM (Random Access Memory) for developing the program,
and so on. Therefore, if the computer (or the CPU) reads the program from the recording
medium and executes the program, the object of the present invention is achieved.
As the above described recording medium, a "non-transitory tangible medium", such
as a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit,
can be used. Also, the program may be supplied to the computer via an arbitrary transmission
medium (such as a communication network or a broadcast wave) capable of transmitting
the program. Also, the present invention can be implemented in the form of a data
signal embedded as an embodiment of the program based on electronic transmission in
a carrier wave.
[SUPPLEMENTARY INFORMATION]
[0063] The inkjet printing device 1 includes the printing unit 10 having the inkjet head
11 for performing printing by ejecting ink onto the recording medium 50, the drying
means for drying ink that has landed on the recording medium 50, the wiper 12 for
cleaning the inkjet head 11, and the control unit 30 for performing at least one of
control for making the ink drying efficiency during cleaning on the inkjet head 11
lower than the ink drying efficiency during ejection of ink from the inkjet head 11,
and control for making the ink drying efficiency during ejection of ink from the inkjet
head 11 higher than the ink drying efficiency during cleaning on the inkjet head 11.
[0064] During cleaning on the inkjet head 11, printing using the inkjet head 11 is in a
stop state, whereas drying of ink ejected on the recording medium 50 progresses. For
this reason, in the portion dried during the printing stop period, unevenness in drying
ink may occur. Further, this unevenness in drying emerges as density unevenness on
the printed material, resulting in a reduction in the quality of the printed material.
Especially, in a case of using ink required to be dried at high temperature, such
as latex ink, there is a possibility that occurrence of density unevenness on printed
materials will be remarkably appear.
[0065] As the result of repetition of earnest examination for preventing occurrence of drying
unevenness during cleaning on the inkjet head 11, the inventors of the present invention
found that it is possible to prevent occurrence of drying unevenness by making the
drying efficiency during cleaning on the inkjet head 11 lower than the drying efficiency
during printing of the inkjet head 11 or making the drying efficiency during printing
of the inkjet head 11 higher than the drying efficiency during manufacturing of the
inkjet head 11, and finally completed the present invention.
[0066] In other words, if the progress of drying of ink during cleaning on the inkjet head
11 is slowed down, it becomes difficult for drying unevenness to occur between a portion
dried during a printing period and a portion dried during a printing stop period.
Also, even in a case where the progress of drying of ink during printing of the inkjet
head 11 is accelerated, similarly, it becomes difficult for drying unevenness to occur
between a portion dried during a printing period and a portion dried during a printing
stop period. As a result, it is possible to suppress occurrence of density unevenness
of the printed material attributable to drying unevenness, thereby preventing a reduction
in the quality of the printed material.
[0067] Also, in the inkjet printing device 1, the drying means includes the fan 40 for sending
air toward the printing surface of the recording medium 50, and the control unit 30
makes the rotation speed of the fan 40 during cleaning on the inkjet head 11 lower
than the rotation speed of the fan 40 during ejection of ink from the inkjet head
11.
[0068] According to the above described configuration, it is possible to make the ink drying
efficiency during cleaning on the inkjet head 11 lower than the ink drying efficiency
during ejection of ink from the inkjet head 11, and it is possible to slow down the
progress of drying of ink during cleaning on the inkjet head 11. As a result, it is
possible to suppress occurrence of density unevenness of the printed material attributable
to drying unevenness, thereby preventing a reduction in the quality of the printed
material.
[0069] Further, in the inkjet printing device 1, the control unit 30 stops the operation
of the fan 40 during cleaning on the inkjet head 11, and operates the fan 40 during
ejection of ink from the inkjet head 11.
[0070] According to the above described configuration, since the fan 40 is operated during
ejection of ink, and the fan 40 is stopped during cleaning of ink, it is possible
to make the ink drying efficiency during cleaning on the inkjet head 11 lower than
the ink drying efficiency during ejection of ink from the inkjet head 11. As a result,
it is possible to slow down the progress of drying of ink during cleaning on the inkjet
head 11, and it is possible to suppress occurrence of density unevenness of the printed
material attributable to drying unevenness, thereby preventing a reduction in the
quality of the printed material.
[0071] Also, in the inkjet printing device 1, the drying means includes the fan 40 for sending
air toward the printing surface of the recording medium 50, and the control unit 30
makes the rotation speed of the fan 40 during ejection of ink from the inkjet head
11 higher than the rotation speed of the fan 40 during cleaning on the inkjet head
11.
[0072] According to the above described configuration, it is possible to make the drying
efficiency during printing of the inkjet head 11 higher than the drying efficiency
during cleaning on the inkjet head 11, and it is possible to accelerate the progress
of drying of ink during printing. As a result, it is possible to suppress occurrence
of density unevenness of the printed material attributable to drying unevenness, thereby
preventing a reduction in the quality of the printed material.
[0073] Also, in the inkjet printing device 1, the printing unit 10 includes the plurality
of inkjet heads 11, and the control unit 30 performs control for stopping cleaning
when some of the plurality of inkjet heads 11 have been cleaned by the wiper 12, and
performing printing on the recording medium 50 by ejecting ink from the inkjet heads
11, and then restarting cleaning by the wiper 12, thereby cleaning the other uncleaned
inkjet heads 11 of the plurality of inkjet heads 11.
[0074] According to the above described configuration, it is possible to shorten the period
of one cleaning event on the inkjet heads 11, that is, the printing stop period, and
it becomes difficult for drying unevenness to occur between a portion dried during
printing and a portion dried during the printing stop period. As a result, it is possible
to suppress occurrence of density unevenness of the printed material attributable
to drying unevenness, thereby preventing a reduction in the quality of the printed
material.
[0075] Also, in the inkjet printing device 1, the drying means includes the heater 20 disposed
at a position facing the inkjet head 11 and configured to heat the recording medium
50 from the surface side that is opposite to the printing surface, and the control
unit 30 makes the heating temperature of the heater 20 during cleaning on the inkjet
head 11 lower than the heating temperature of the heater 20 during ejection of ink
from the inkjet head 11.
[0076] According to the above described configuration, it is possible to make the ink drying
efficiency during cleaning on the inkjet head 11 lower than the ink drying efficiency
during ejection of ink from the inkjet head 11, and it is possible to slow down the
progress of drying of ink during cleaning on the inkjet head 11. As a result, it is
possible to suppress occurrence of density unevenness of the printed material attributable
to drying unevenness, thereby preventing a reduction in the quality of the printed
material.
[0077] Also, in the inkjet printing device 1, the drying means includes the heater 20 disposed
at a position facing the inkjet head 11 and configured to heat the recording medium
50 from the surface side that is opposite to the printing surface, and the control
unit 30 makes the heating temperature of the heater 20 during ejection of ink from
the inkjet head 11 higher than the heating temperature of the heater 20 during cleaning
on the inkjet head 11.
[0078] According to the above described configuration, it is possible to make the drying
efficiency during printing of the inkjet head 11 higher than the drying efficiency
during cleaning on the inkjet head 11, and it is possible to accelerate the progress
of drying of ink during printing. As a result, it is possible to suppress occurrence
of density unevenness of the printed material attributable to drying unevenness, thereby
preventing a reduction in the quality of the printed material.
[0079] The inkjet printing method includes the printing process of performing printing by
ejecting ink from the inkjet head 11 onto the recording medium 50, the drying process
of drying ink that has landed on the recording medium 50, and the cleaning process
of stopping ejection of ink from the inkjet head 11 and cleaning the inkjet head 11,
and performs at least one of control for making the ink drying efficiency in the cleaning
process lower than the ink drying efficiency in the printing process, and control
for making the ink drying efficiency in the printing process higher than the ink drying
efficiency in the cleaning process.
[0080] According to the above described configuration, the same effects as those of the
inkjet printing device 1 are achieved.
[0081] The printing control device is a printing control device configured to control the
inkjet printing device 1 having the inkjet head 11 for performing printing by ejecting
ink onto the recording medium 50, and performs at least one of control for making
the ink drying efficiency during cleaning on the inkjet head 11 lower than the ink
drying efficiency during ejection of ink from the inkjet head 11 , and control for
making the ink drying efficiency during ejection of ink from the inkjet head 11 higher
than the ink drying efficiency during cleaning on the inkjet head 11.
[0082] According to the above described configuration, the same effects as those of the
inkjet printing device 1 are achieved.
[0083] The printing control device may be implemented by a computer. In this case, a printing-control-device
control program for implementing the printing control device in a computer by making
the computer operate as means for performing the control which the printing control
device performs, and a computer-readable recording medium retaining that program are
also included in the scope of the present invention.
[0084] The present invention is not limited to the above described embodiments, and can
be variously modified within the scope defined by claims, and embodiments which can
be obtained by appropriately combining the individual technical means disclosed in
the different embodiments are also included in the technical scope of the present
invention.
EXAMPLE
[0085] The inventors conducted experiments using an inkjet printer (JV400-160LX made by
MIMAKI ENGINEERING CO., LTD.) similar to the inkjet printing device 1, with respect
to occurrence of drying unevenness of printed materials depending on regular cleaning
on inkjet heads using a wipe.
[0086] The inventors performed printing on media under the condition of a printing speed
of 11 m
2/h, 900×900 ND, 12 pB (6p×2layer), and 65/55/70+10. As an example, the inventors conducted
wiping on two inkjet heads alternately at regular intervals of 5 minutes. As a comparative
example, the inventors conducted wiping on two inkjet heads once at regular intervals
of 10 minutes. Also, in the example, the period of each of regular wiping events was
set to 7 seconds, and in the comparative example, the period of each of regular wiping
events was set to 15 seconds. Further, in the example, a voltage to be applied to
a ceiling fan was set to 24 V, and the ceiling fan was stopped during wiping. In the
comparative example, a voltage to be applied to the ceiling fan during printing and
during wiping was set to 20 V.
[0087] As a result, strip patterns attributable to wiping and corresponding to printing
parts dried during wiping were seen thinly on the printed materials of the example,
but were seen thickly and clearly on the printed materials of the comparative example.
Also, the color difference ΔE (between stripe patterns and the normal state) in the
printed materials of the example was 0.9; however, the color difference ΔE in the
printed materials of the comparative example was 3.5.
INDUSTRIAL APPLICABILITY
[0088] The present invention can be used in printing using an inkjet printing device.
LIST OF REFERENCE NUMERALS
[0089]
- 1
- inkjet printing device
- 10
- printing unit (printing means)
- 11
- inkjet head
- 12
- wiper (cleaning means)
- 13
- nozzle
- 20
- heater (drying means)
- 30
- control unit (control means)
- 40
- fan (drying means)
- 50
- recording medium
- 60
- conveying means
1. Tintenstrahldruck-Vorrichtung (1), aufweisend:
ein Druck-Mittel mit einem Tintenstrahlkopf (11), welcher dazu eingerichtet ist, ein
Drucken durch Ausgeben von Tinte auf ein Aufnahme-Medium (50) auszuführen;
ein Trocknungs-Mittel (20, 40), welches dazu eingerichtet ist, eine auf dem Aufnahme-Medium
(50) aufgetroffene Tinte zu trocknen, wobei die Trocknungs-Mittel (20, 40) ein Gebläse
(40) aufweisen, welches dazu eingerichtet ist, Luft in Richtung der Druckoberfläche
des Aufnahme-Mediums (50) zu blasen,
dadurch gekennzeichnet, dass:
die Trocknungs-Mittel ferner eine Heizung (20) aufweisen, welche an einer dem Tintenstrahlkopf
(11) gegenüberliegenden Position angeordnet ist und eingerichtet ist, das Aufnahme-Medium
(50) von der Oberflächenseite her, welche der Druckoberfläche gegenüberliegt, zu erwärmen;
und
die Tintenstrahldruck-Vorrichtung (1) ferner aufweist:
ein Reinigungs-Mittel (12), welches dazu eingerichtet ist, den Tintenstrahlkopf (11)
zu reinigen; und
ein Steuer-Mittel (30), welches dazu eingerichtet ist, den Tintenstrahlkopf (11),
das Gebläse (20) und die Heizung (20) zu steuern,
wobei das Steuer-Mittel (30) dazu eingerichtet ist, zu bewirken, dass die Tintentrocknungseffizienz
während eines Reinigens des Tintenstrahlkopfs (11) niedriger ist als die Tintentrocknungseffizienz
während eines Abgebens von Tinte aus dem Tintenstrahlkopf (11), und zwar durch Reduzieren
der Drehgeschwindigkeit des Gebläses (40) während des Reinigens des Tintenstrahlkopfs
(11) im Vergleich zur Drehgeschwindigkeit des Gebläses (40) während des Abgebens von
Tinte aus dem Tintenstrahlkopf (11), und durch Erhöhen der Drehgeschwindigkeit des
Gebläses (40) während des Abgebens von Tinte aus dem Tintenstrahlkopf (11) im Vergleich
zur Drehgeschwindigkeit des Gebläses (40) während des Reinigens des Tintenstrahlkopfs
(11).
2. Tintenstrahldruck-Vorrichtung (1) gemäß Anspruch 1, wobei:
das Steuer-Mittel (30) den Betrieb des Gebläses (40) während des Reinigens des Tintenstrahlkopfs
(11) stoppt, und das Gebläse (40) während des Ausgebens von Tinte aus dem Tintenstrahlkopf
(11) betreibt.
3. Tintenstrahldruck-Vorrichtung gemäß Anspruch 1, wobei:
das Druck-Mittel mehrere Tintenstrahlköpfe (11) aufweist, und
das Steuer-Mittel das Reinigen stoppt, wenn einige der mehreren Tintenstrahlköpfe
(11) durch das Reinigungs-Mittel (12) gereinigt wurden, und ein Drucken auf das Aufnahme-Medium
(50) durch Ausgeben von Tinte aus den Tintenstrahlköpfen (11) ausführt, und dann das
Reinigungs-Mittel (12) derart steuert, dass das Reinigungs-Mittel (12) ein Reinigen
erneut startet und die anderen nicht-gereinigten Tintenstrahlköpfe (11) der mehreren
Tintenstrahlköpfe (11) reinigt.
4. Tintenstrahldruck-Vorrichtung gemäß einem der Ansprüche 1 bis 3, wobei:
das Steuer-Mittel (30) die Heiztemperatur der Heizung (20) während des Reinigens des
Tintenstrahlkopfs (11) verringert im Vergleich zur Heiztemperatur der Heizung (20)
während des Ausgebens von Tinte aus dem Tintenstrahlkopf (11).
5. Tintenstrahldruck-Vorrichtung gemäß einem der Ansprüche 1 bis 4, wobei:
das Steuer-Mittel (30) die Heiztemperatur der Heizung (20) während des Ausgebens von
Tinte aus dem Tintenstrahlkopf (11) erhöht im Vergleich zur Heiztemperatur der Heizung
(20) während des Reinigens des Tintenstrahlkopfs (11).
6. Verfahren zum Tintenstrahldrucken, aufweisend:
einen Druck-Prozess zum Ausführen eines Druckens durch Ausgeben von Tinte aus einem
Tintenstrahlkopf (11) auf ein Aufnahme-Medium (50);
einen Trocknungs-Prozess eines Trocknens von auf dem Aufnahme-Medium (50) aufgetroffener
Tinte mit einem Trocknungs-Mittel (20, 40), das ein Gebläse (40) aufweist, welches
dazu eingerichtet ist, Luft in Richtung der Druckoberfläche des Aufnahme-Mediums (50)
zu blasen, und einer Heizung (20), die an einer dem Tintenstrahlkopf (11) gegenüberliegenden
Position angeordnet ist und eingerichtet ist, das Aufnahme-Medium (50) von der Oberflächenseite
her, welche der Druckoberfläche gegenüberliegt, zu erwärmen;
einen Reinigungs-Prozess eines Stoppens der Ausgabe von Tinte aus dem Tintenstrahlkopf
(11) und eines Reinigens des Tintenstrahlkopfs (11), und
ein Verringern der Drehgeschwindigkeit des Gebläses (40) während des Reinigens des
Tintenstrahlkopfs (11) im Vergleich zur Drehgeschwindigkeit des Gebläses (40) während
der Ausgabe von Tinte aus dem Tintenstrahlkopf (11),
wobei die Tintentrocknungseffizienz bei dem Reinigungs-Prozess im Vergleich zur Tintentrocknungseffizienz
bei dem Druck-Prozess verringert wird, und die Tintentrocknungseffizienz bei dem Druck-Prozess
im Vergleich zur Tintentrocknungseffizienz bei dem Reinigung-Prozess erhöht wird.
7. Programm zum Veranlassen eines Computers, als die Druck-Steuervorrichtung gemäß Anspruch
5 zu fungieren, sodass der Computer als Mittel fungiert, das dazu eingerichtet ist,
die Steuerung auszuführen.
8. Computerlesbares Aufnahme-Medium, welches das Programm gemäß Anspruch 7 speichert.