JP5869289B2 - Inkjet recording apparatus and recording method - Google Patents

Description

  The present invention relates to an ink jet recording apparatus and a recording method.

  2. Description of the Related Art Conventionally, ink jet recording apparatuses that perform recording on a recording medium by discharging ink droplets from nozzles provided in a recording head are known. Among inkjet recording apparatuses, an inkjet recording apparatus for outdoor sign use generally uses a recording head that uses a piezoelectric element as a recording element, and uses an ink containing an organic solvent as a main solvent.

  When continuous recording is performed using such an ink jet recording apparatus, depending on the recording conditions, ejection may become unstable and ink may be ejected by deflecting from the nozzle, or even ink may not be ejected. there were. Various techniques have been disclosed as techniques for avoiding such discharge instability. For example, Patent Document 1 discloses a technique for avoiding instability of discharge by using a blade having a specific configuration and a configuration for controlling the movement thereof.

  There are various recording conditions when performing recording using an ink jet recording apparatus, such as the type of ink, the type of recorded image, the ambient temperature and humidity during recording, the type of recording medium, and the recording mode. In addition, there are various driving head voltages, the distance between the recording head and the recording medium, and the wind force generated by the fan when there is a fan that blows air between the recording head and the recording surface of the recording medium. Depending on the combination of these recording conditions, the ejection speed and ejection amount of ink ejected from the recording head, the number of mists, and the ejection stability when ejected continuously vary.

  Among these, the following techniques are disclosed as techniques for reducing the number of mists. Patent Document 2 discloses a technique for reducing mist by controlling the movement of a mist fan based on data relating to the distance between a recording head and a recording medium. Patent Document 3 discloses a technique for reducing mist by having means for acquiring recording conditions related to mist generation and means for setting mist reduction conditions. Further, Patent Document 4 discloses a technology that includes a distance identifying unit that identifies the distance between the recording head and the recording medium, and that reduces mist by changing the drive pulse in accordance with the distance identified by the distance identifying unit. doing.

JP 2007-261256 A JP 2009-101663 A JP 2007-296754 A JP 2005-246690 A

  However, as a result of intensive studies by the present inventors, when the technique disclosed in Patent Document 1 is used, although the ejection stability is improved, the effect may be insufficient depending on the type of ink used. I understood that.

  In addition, as a result of further intensive studies aimed at improving the ejection stability by the present inventors, the recording conditions for improving the ejection stability and the recording conditions for reducing mist when the recording conditions are variously changed. It turns out that does not necessarily match. That is, it has been found that the techniques disclosed in Patent Document 2 to Patent Document 4 are techniques for reducing mist, but are not necessarily techniques for improving ejection stability.

SUMMARY An advantage of some aspects of the invention is that it provides an inkjet recording apparatus that stably discharges even when continuous recording is performed.
Another object of the present invention is to provide a recording method that stably discharges even when continuous recording is performed using an ink jet recording apparatus.

The present invention for solving the above-mentioned problems includes a recording head unit that includes a recording head that uses a piezoelectric element as a recording element and moves in a direction perpendicular to the conveyance direction of the recording medium, and moves the recording head unit. there line recording by ejecting ink onto the recording medium while, the recording head a row cormorants jet recording apparatus records by scanning a plurality of times for the same recording area of the recording medium, the recording head unit Mounted on the recording head unit, mounted on the recording head unit, a detecting means for detecting the distance between the recording head and the recording medium, a scanning number setting means for setting the number of scans for scanning the same recording area according to the distance A blowing unit that blows air between the recording head and the recording surface of the recording medium and cools the recording head, and wind force generated by the blowing unit. And wind setting means for setting in accordance with the serial distance, said at least have a drive voltage setting means for setting according to the distance the drive voltage of the recording head, the scanning frequency setter is the number of scans as the distance is longer The wind power setting means sets the wind power larger as the distance is longer, the drive voltage setting means sets the drive voltage lower as the distance is longer, and the temperature of the recording head is set to a predetermined temperature range. The ink is recorded on the recording medium while being controlled .

Another aspect of the present invention for solving the above-described problem is that the recording head includes a recording head that uses a piezoelectric element as a recording element, and includes a recording head unit that moves in a direction perpendicular to the conveyance direction of the recording medium. There line recording by ejecting ink onto the recording medium while moving the head unit, recording by scanning a plurality of times said recording head for the same recording area of the recording medium by the recording method of the line power sale ink jet recording apparatus The ink jet recording apparatus is mounted on a recording head unit, detects a distance between the recording head and the recording medium, and determines the number of scans for scanning the same recording area according to the distance. The number of scans setting means to be set and the recording head unit are mounted, and air is blown between the recording head and the recording surface of the recording medium and the recording head. And at least drive voltage setting means for setting the drive voltage of the recording head according to the distance, and a fan voltage setting means for setting the wind force by the blower means according to the distance. A detecting step of detecting a distance between the recording head and the recording medium by a detecting unit; a scanning number setting step of decreasing the scanning number as the distance is longer by the scanning number setting unit; and an air flow by the wind force setting unit. and wind setting step to increase the wind means the longer the distance, the driving voltage setting step of the distance the driving voltage of the recording head is set longer lowered by the drive voltage setting means, and the number of scans setting step the recording while controlling the temperature of said recording head within a predetermined temperature range at the value set by the wind setting step the drive voltage setting step It characterized by having at least a recording step of recording by ejecting the ink on the body.

  According to the present invention, it is possible to provide an ink jet recording apparatus that stably discharges even when continuous recording is performed. In addition, it is possible to provide a recording method that stably discharges even when continuous recording is performed using an inkjet recording apparatus.

1 is a front view schematically showing a schematic configuration of an ink jet recording apparatus according to a preferred embodiment of the present invention. 1 is a block diagram schematically showing a schematic configuration of an ink jet recording apparatus according to a preferred embodiment of the present invention. It is a flowchart which shows preferable embodiment of the recording method of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a front view schematically showing a schematic configuration of an ink jet recording apparatus according to a preferred embodiment of the present invention.

  As shown in FIG. 1, the ink jet recording apparatus 1 of the present embodiment arranges a recording medium 50 horizontally and conveys it in the depth direction of the paper surface of FIG. Record images and text.

  The inkjet recording apparatus 1 includes a transport unit 40 that transports the recording medium 50 and a recording unit 41 that records on the recording medium 50. The recording head 9 includes a recording head 9 that performs reciprocating scanning in a direction orthogonal to the conveyance direction of the recording medium 50, and a cleaning unit 10 that cleans the recording head 9. The inkjet recording apparatus 1 includes a control unit (not shown) that controls the entire apparatus including reception of recording data and control of recording operations.

  The transport unit 40 includes a plurality of pinch rollers 3 that are rotated about a horizontal axis along the paper surface by a motor 5 on the substantially flat platen 2 that extends in the depth direction of the paper surface of FIG. A plurality of grid rollers 4 supported by these pinch rollers 3 so as to be rotatable about a rotation axis parallel to the rotation axis of the pinch roller 3 are arranged in the depth direction of the drawing. These grid rollers 4 are aligned above the platen 2 in a horizontal plane extending in the depth direction in FIG. 1 to form a conveyance path for the recording medium 50.

  The recording unit 41 includes a carriage rail 7 that extends in a direction perpendicular to the conveyance direction of the recording medium 50 above the conveyance unit 40 and the cleaning unit 10, and a recording head that is movable along the carriage rail 7. Unit 8 is provided. In addition, a motor 6 that reciprocates the recording head unit 8 on the carriage rail 7 so as to be capable of position control and speed control is provided. Furthermore, a detachable ink cartridge 17 that supplies recording ink to the recording head unit 8 is provided.

  In the present embodiment, the ink cartridge 17 is provided with a plurality of colors of ink for performing color recording, and the recording head unit 8 is provided for each color via a plurality of ink tubes 16 serving as piping (ink flow paths). Can be supplied.

  The recording head unit 8 is provided with a plurality of recording heads 9 on the lower surface side in accordance with the ink color and recording range, and the ink supplied from the ink tube 16 is distributed to the recording heads 9 that perform recording of the same color. Supplied. The recording head unit 8 can be moved in the height direction by a knob (not shown), and the distance between the recording head 9 and the recording medium 50 can be arbitrarily adjusted. The recording head unit 8 is provided with a distance sensor 13 that detects the distance between the recording head 9 and the recording medium 50. As the distance sensor 13, for example, a sensor using a laser is used, but is not particularly limited.

  Further, the recording head unit 8 is provided with a cooling fan 18 for keeping the temperature of each recording head 9 in an appropriate temperature range. The cooling fan 18 is driven so that the wind passes between the recording heads 9. By driving the cooling fan 18 during recording, air can be sent between the recording head 9 and the recording surface of the recording medium 50. Therefore, the cooling fan 18 also serves as a fan that blows air between the recording head 9 and the recording surface of the recording medium 50.

  Although details of the recording head 9 are not shown, an ink chamber for supplying ink to each nozzle and an ejection mechanism using a piezoelectric element are provided. The recording head 9 is configured to be able to perform an idle driving operation in which the ink is ejected and the ink meniscus of the nozzle is finely oscillated by an ejection mechanism using the piezoelectric element. Further, the nozzles can be provided with an appropriate number and arrangement pitch according to the configuration of the ejection mechanism, the recording pixel pitch, and the like. For example, a large number of nozzles such as 256 can be arranged. The recording head 9 of this embodiment uses a piezoelectric element as the recording element, but may be a recording head using a heater as the recording element.

  The position control and speed control of the motor 6 are performed according to the control signal of the control unit, and the motor 6 moves the recording head unit 8 back on the recording medium 50 at a predetermined speed during the recording operation. Further, the motor 6 can move the recording head unit 8 to a predetermined cleaning position in the cleaning unit 10 during the cleaning operation.

  In this embodiment, the cleaning unit 10 includes a suction cleaning unit 14A that cleans the recording head 9 by sucking the ink in the recording head 9 from the nozzles to the outside, and the recording head 9 by wiping the recording head surface. It consists of a wipe part 14B to be cleaned. The cleaning unit 10 is arranged on the moving path of the recording head unit 8 on the side of the transport unit 40 and below the recording unit 41 in the order of the wipe unit 14B and the suction cleaning unit 14A from the transport unit 40 side. In the present embodiment, the upper positions of the suction cleaning unit 14A and the wipe unit 14B are predetermined cleaning positions.

  The schematic configuration of the suction cleaning unit 14A includes a cap 11, a cap drive unit (not shown), a suction pump 12, a pump drive unit (not shown), an air release valve (not shown), and an air release valve drive unit (not shown). Become.

  Among these, at least the cap 11 is provided for each recording head 9. However, the cap drive unit, the suction pump 12, the air release valve, and the air release valve drive unit may be configured to be provided for each of the plurality of caps 11 when each operation can be made common for each recording head 9. .

  The cap drive unit moves up and down to selectively switch the position of the cap 11 in the vertical direction, and includes, for example, appropriate mechanical, electromagnetic, and fluid lifting means. Therefore, the cap drive unit moves the cap 11 up and down in the vertical direction with respect to the recording head unit 8 which is moved on the carriage rail 7 by the motor 6 and positioned above the suction cleaning unit 14A, and the cap 11 performs recording. The state where the head surface is sealed and the state where the sealing is released can be switched.

  The suction pump 12 is for sucking contents such as air and ink in the suction space and discharging them to the outside of the suction space, and an appropriately configured fluid pump such as a rotary pump can be adopted. In this embodiment, the suction amount can be varied by the pump drive unit. Further, the suction amount of the suction pump 12 may be changed in multiple stages as necessary. The suction pump 12 has a suction port connected to the suction pipe and a discharge port connected to the discharge pipe. The other end of the discharge pipe is connected to the waste liquid bottle 15.

  In the suction cleaning unit 14A, the cap driving unit, the air release valve driving unit, and the pump driving unit are electrically connected to a cleaning control unit (not shown), and their operations are controlled by control signals from the cleaning control unit. It has become so.

  The wipe unit 14B may have any configuration as long as it performs a known wiping process. For example, it is possible to employ a configuration in which the recording head surface is wiped by relatively moving a wiping blade containing a wiping liquid on the recording head surface of the recording head 9 moved above the wiping portion 14B.

FIG. 2 is a block diagram schematically showing a schematic configuration of an ink jet recording apparatus according to a preferred embodiment of the present invention.
In FIG. 2, reference numeral 20 denotes a control unit. The control unit 20 includes a CPU 25 that executes processing operations such as calculation, control, discrimination, and setting, a ROM 26 that stores a control program to be executed by the CPU 25, and a recording data A RAM 27 and the like used as a work area for processing by the buffer and CPU 25 are provided.

  In the inkjet recording apparatus 1 of the present embodiment, the control unit 20 sets a driving voltage for driving the recording head 9 according to the detection distance of the distance sensor 13 that detects the distance between the recording head 9 and the recording medium 50. The drive of the recording head 9 is controlled via the recording head drive unit 22. In the inkjet recording apparatus 1 of the present embodiment, the distance between the recording head 9 and the recording medium 50 can be arbitrarily adjusted by a knob (not shown) provided in the recording head unit 8. In the present embodiment, a position where the distance between the recording head 9 and the recording medium 50 is 2 mm is set as a basic distance, and a driving voltage of the recording head at this time is set as a basic voltage. As the distance between the recording head 9 and the recording medium 50 becomes longer than 2 mm, the driving voltage of the recording head 9 decreases with a predetermined reference, and as the distance becomes shorter than 2 mm, the driving voltage of the recording head 9 with a predetermined reference. Becomes higher.

  Further, the control unit 20 sets the rotation speed of the cooling fan 18 according to the detection distance of the distance sensor 13 that detects the distance between the recording head 9 and the recording medium 50. Further, the control unit 20 controls driving of the cooling fan 18 via the cooling fan driving unit 21. In the ink jet recording apparatus 1 of the present embodiment, the rotation speed of the cooling fan 18 at the basic distance is 2 mm, which is the basic distance between the recording head 9 and the recording medium 50. As this distance becomes longer than 2 mm, the rotational speed increases with a predetermined reference, and as this distance becomes shorter than 2 mm, the rotational speed decreases with a predetermined reference.

  Note that the ink jet recording apparatus 1 of the present embodiment is an ink jet recording apparatus that performs recording by a so-called multipass recording method in which the recording head 9 scans the same recording area of the recording medium 50 a plurality of times to perform recording. The control unit 20 sets the number of passes according to the detection distance of the distance sensor 13 that detects the distance between the recording head 9 and the recording medium 50. In this embodiment, a position where the distance between the recording head 9 and the recording medium 50 is 2 mm is a basic distance, and the number of passes at this time is eight. The number of paths when this distance is longer than the predetermined distance that is the first threshold is 4 paths, and the number of paths when this distance is shorter than the predetermined distance that is the second threshold is 16 paths.

  That is, the control unit 20 decreases the driving voltage of the recording head as the distance between the recording head 9 and the recording medium 50 becomes longer, and the wind force blown between the recording head 9 and the recording surface of the recording medium 50 by the cooling fan 18. Is set large and the number of passes in the multi-pass recording method is set small. By performing recording in such a setting, even when continuous recording is performed using an ink jet recording apparatus, it is possible to discharge stably. It should be noted that, even if only the setting of decreasing the drive voltage of the recording head as the distance between the recording head 9 and the recording medium 50 is increased, there is an effect. However, the cooling head 18 is not effective between the recording head 9 and the recording surface of the recording medium 50. Combining at least one of the setting to increase the wind force blown in between and the setting to reduce the number of passes in the multi-pass recording method further increases the effect.

  In addition, when the distance between the recording head 9 and the recording medium 50 is a basic distance, the value of the driving voltage of the recording head 9, the rotational speed of the cooling fan 18, and the number of passes in the multi-pass recording method are input via the input unit 23. Can be arbitrarily input from an external device. These can be arbitrarily input via the operation panel 24 provided in the inkjet recording apparatus 1. Note that data relating to the drive voltage value of the recording head 9, the rotation number of the cooling fan 18, and the number of passes in the multi-pass printing method are stored in an EEPROM 28 as a nonvolatile memory. The control unit 20 sets the drive voltage value of the recording head 9, the number of rotations of the cooling fan 18, and the number of passes in the multi-pass recording method in accordance with the stored data.

Next, the ink preferably used in the ink jet recording apparatus of the present invention will be described.
The ink preferably used in the ink jet recording apparatus of the present invention is a so-called solvent ink containing an organic solvent as a main solvent. When this solvent ink is used, the effect of the present invention is particularly remarkable.

Next, the recording method of the present invention will be described.
FIG. 3 is a flowchart showing a preferred embodiment of the recording method of the present invention.
The ink jet recording apparatus 1 used in this embodiment has a sensor that detects the distance between the recording head and the recording medium, a fan that blows air between the recording head and the recording surface of the recording medium, It is a multipass inkjet recording apparatus that performs recording by scanning the same recording area of the recording medium a plurality of times.

When image data is input from the host computer, the inkjet recording apparatus first detects the distance between the recording head and the recording medium by a distance sensor in step S110.
Next, in step S120, the control unit 20 sets a drive voltage according to the distance between the recording head 9 and the recording medium 50 detected in step S110.

Next, in step S130, the control unit 20 sets the number of passes according to the distance between the recording head 9 and the recording medium 50 detected in step S110.
Next, in step S140, the controller 20 sets the rotational speed of the fan in accordance with the distance between the recording head 9 and the recording medium 50 detected in step S110.

  Finally, in step S150, the recording method according to this embodiment is performed by performing recording with the driving voltage of the recording head set in step S120, the number of passes set in step S130, and the number of fan rotations set in step S140. This process ends.

  The ink jet recording apparatus and the recording method of the present invention can be used for a general ink jet recording apparatus.

DESCRIPTION OF SYMBOLS 1 Recording device 9 Recording head 13 Distance sensor 20 Control part

Claims (3)

A recording head that uses a piezoelectric element as a recording element is mounted, and a recording head unit that moves in a direction perpendicular to the conveying direction of the recording medium is provided, and recording is performed by ejecting ink to the recording medium while moving the recording head unit. gastric row, the recording head a row cormorants jet recording apparatus records by scanning a plurality of times for the same recording area of said recording medium,
A detecting means mounted on a recording head unit for detecting a distance between the recording head and the recording medium;
A scan count setting means for setting the scan count to be scanned with respect to the same recording area according to the distance;
A blowing unit mounted on the recording head unit, for blowing air between the recording head and the recording surface of the recording medium and cooling the recording head;
Wind force setting means for setting the wind force by the blowing means according to the distance;
Wherein the drive voltage of the recording head at least have a drive voltage setting means for setting in accordance with the distance,
The scan number setting means sets the scan number to be smaller as the distance is longer,
The wind power setting means sets the wind power larger as the distance is longer,
The drive voltage setting means sets the drive voltage lower as the distance is longer,
An ink jet recording apparatus that records by discharging the ink onto the recording medium while controlling a temperature of the recording head within a predetermined temperature range . The inkjet recording apparatus according to claim 1, wherein the ink contains an organic solvent as a main solvent. A recording head that uses a piezoelectric element as a recording element is mounted, and a recording head unit that moves in a direction perpendicular to the conveying direction of the recording medium is provided, and recording is performed by ejecting ink to the recording medium while moving the recording head unit. A recording method of an ink jet recording apparatus for performing recording by scanning the recording head a plurality of times with respect to the same recording area of the recording medium,
The ink jet recording apparatus comprises:
A detecting means mounted on a recording head unit for detecting a distance between the recording head and the recording medium;
A scan count setting means for setting the scan count to be scanned with respect to the same recording area according to the distance;
A blowing unit mounted on the recording head unit, for blowing air between the recording head and the recording surface of the recording medium and cooling the recording head;
Wind force setting means for setting the wind force by the blowing means according to the distance;
At least drive voltage setting means for setting the drive voltage of the recording head according to the distance;
A detecting step of detecting a distance between the recording head and the recording medium by the detecting means ;
A scanning number setting step of decreasing the number of scanning times as the distance is longer by the scanning number setting unit;
A wind power setting step of increasing the wind power of the air blowing means by the wind power setting means as the distance is longer;
A drive voltage setting step of setting the drive voltage of the recording head to be lower as the distance is longer by the drive voltage setting means;
At least a recording step of discharging and recording the ink on the recording medium while controlling the temperature of the recording head within a predetermined temperature range with the values set in the scanning number setting step, the wind force setting step, and the drive voltage setting step. And a recording method.

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