JP2013035129A - Inkjet recording apparatus and inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus capable of improving reliability of ejection performance by means of a recording head without sacrificing image quality or image solidity due to the use of treatment liquid.SOLUTION: In the recording of outward direction, mist of the treatment liquid is caused to flow in the direction reverse to a scanning direction in accordance with the scanning of a recording head. However, ink is not ejected and consequently, an ejection gas current is not produced. Accordingly, the treatment liquid is not attached to a surface provided with the nozzle of the recording head and passes between the recording head and a recording medium. Therein, likewise upon the recording of outward direction, mist of Y ink is caused to flow in the direction reverse to the scanning direction in accordance with the scanning of the recording head. However, the treatment liquid is not ejected and consequently, the ejection gas current is not produced. As the result, the ink is not attached to the recording head of treatment liquid and passes between the recording head and the recording medium.

Description

  The present invention relates to an ink jet recording apparatus and an ink jet recording method, and more specifically, to reduce the influence on a recording head due to a fixed matter due to insolubilization in an apparatus that performs recording using a liquid that insolubilizes or aggregates ink and its coloring material. It is about technology.

  In the field of recording apparatuses such as ink jet printers, recording using an ink and a liquid that insolubilizes or aggregates the colorant of the ink (hereinafter also referred to as a processing liquid) improves the image quality and robustness of the recorded image. Techniques for improving are known. In other words, the insolubilization or the like can suppress ink bleeding or improve the recording density, and can reduce the deterioration of the recorded image due to light or ozone. However, on the other hand, in a recording apparatus using such a treatment liquid, for example, the insolubilized material or the agglomerate adheres to the surface of the recording head on which the ink discharge nozzles are provided, causing ink discharge failure or being unrecoverable. The non-ejection may shorten the life of the recording head.

  On the other hand, in Patent Document 1, a pixel that discharges a processing liquid is relatively different from a pixel that discharges ink containing a coloring material in a low-concentration recording area, and the processing liquid is driven in a high-concentration recording area. It is described that the amount of the mixture of ink and treatment liquid is reduced by thinning out the amount.

JP 2000-127373 A

  However, when different pixels are used for placing ink and processing liquid, or when thinning out pixels for processing liquid with respect to the ink printing pixels, the ink and the processing liquid are sufficiently mixed. Otherwise, the original function of the treatment liquid may not be exhibited well. As a result, the image quality and image fastness of the recorded image by the processing liquid cannot be satisfactorily realized.

  The present invention solves the above-described problems, and an ink jet recording apparatus and an ink jet recording method capable of improving the reliability of ejection performance by a recording head without sacrificing image quality or image fastness due to the use of a treatment liquid. The purpose is to provide.

  Therefore, in the present invention, a recording head that ejects ink and a recording head that ejects a treatment liquid that insolubilizes or aggregates the coloring material of the ink are scanned in the direction in which the recording heads are arranged, and the recording is performed during the scanning. An ink jet recording apparatus that performs recording by ejecting ink and a treatment liquid onto a medium, wherein the ejection of the ink and the ejection of the treatment liquid are performed in different scans of the respective recording heads with respect to the same scanning region. To do.

  According to the above configuration, it is possible to improve the reliability of the ejection performance by the recording head without sacrificing the image quality and image fastness due to the use of the treatment liquid.

1 is a perspective view showing an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a configuration of a recording head in an embodiment of the present invention. It is a block diagram which shows the electric constitution of an inkjet recording device. FIG. 3 is a schematic diagram illustrating ejection control of a recording head in the first embodiment of the present invention. It is a figure which shows the discharge control of the conventional recording head, and is a schematic diagram. FIG. 10 is a schematic diagram illustrating the flow of ink mist during conventional printhead ejection control. FIG. 4 is a schematic diagram illustrating the flow of ink mist during the ejection control of the recording head according to the first embodiment of the present invention. It is a figure explaining the same scanning discharge determination in the 2nd Embodiment of this invention. It is a figure explaining other same scanning discharge judgment in the 2nd Embodiment of this invention. It is a figure explaining other same scanning discharge judgment in the 2nd Embodiment of this invention. It is a figure explaining the same scanning discharge determination in the 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an ink jet recording apparatus according to an embodiment of the present invention. The ink jet recording apparatus 1 includes a carriage 2 capable of reciprocating scanning in the main scanning direction indicated by an arrow A, and a recording head 3 mounted on the carriage and capable of ejecting ink. An ink tank 4 that contains ink and supplies ink to the recording head 3 is detachably held with respect to the recording head 3. That is, the recording head 3 according to the present embodiment is configured to be provided integrally with the holding unit below the holding unit that holds the ink tank.

  The ink tank 4 is capable of aggregating black (K) ink, cyan (C), magenta (M), and yellow (Y) color materials, and color materials in those inks, and does not contain color materials. Each of the processing liquids is accommodated. One processing liquid is arranged at each end of the ink cartridge 4. Also, the nozzle arrays of the recording head are arranged in the same arrangement for each corresponding ink color and processing liquid. FIG. 2 is a diagram showing this arrangement. As shown in FIG. 2, the recording head 3 includes a nozzle row 31 for ejecting black ink (K) and three nozzle rows 32 used for ejecting each color ink (C, M, Y). 33 and 34 and 35 and 36 for discharging the processing liquid are arranged. Each nozzle row is configured by arranging 1280 ejection openings (nozzles). As described above, the nozzle rows of the processing liquid are arranged at both ends, so that the carriage 2 is processed in both the forward direction of the arrow A (for example, the direction from the home position side to the other end side) and the backward direction. The liquid can be discharged prior to the ink containing the color material.

  The carriage 2 is guided by a guide shaft 8 attached to the housing 7 so as to be movable in the direction of the arrow A in the figure, that is, in the main scanning direction, and is included in the drive mechanism 5 that transmits the drive force of the CR motor M1. 6 is connected. Thus, the carriage 2 reciprocates along the guide shaft 8 by rotating the CR motor M1 forward or backward. Further, a scale (encoder) 9 indicating an absolute position of the carriage 2 in the main scanning direction is disposed in the housing 7 in parallel with the guide shaft 8.

  A paper feed mechanism 10 is disposed on the back of the housing 7, and a plurality of recording media P of various sizes such as A4 size paper and postcard size paper are placed on a paper feed tray 11 included in the paper feed mechanism 10. It can be placed. The paper feed mechanism 10 includes a separation roller (not shown) driven by an LF motor M2 (not shown in FIG. 1), and the recording medium P is fed from the paper feed tray 11 by the separation roller, and the print head on the carriage 2 3 is supplied (conveyed) to a recording position opposite to 3. Further, the ink jet recording apparatus 1 includes a recovery device 15 including a capping unit 13 and a wiping unit 14. When the ink jet recording apparatus 1 is not recording, the recording head 3 is capped by the capping unit 13 and a recovery operation such as a suction recovery process is performed. Ink adhering to the recording head 3 is removed by the wiping unit 14. An ink receiver (hereinafter referred to as a preliminary discharge box) that receives preliminary discharge ink is disposed between the capping unit 13 and the image recordable area (not shown in FIG. 1), and after the carriage has moved to a predetermined position. Discharge recovery processing by preliminary discharge is performed.

  At the time of recording, the carriage 2 moves in the forward direction of the arrow A (for example, the moving direction from the home position side to the other end), and along with the movement, ink droplets are applied to the recording medium P from each nozzle of the recording head according to the recording data. It is discharged toward. Recording with the movement of the carriage is also referred to as recording scanning. When the carriage 2 moves to the other end of the recording medium P, the separation roller rotates by a certain amount, thereby conveying the recording medium P by a predetermined amount in the direction of arrow B (sub-scanning direction, conveyance direction). Then, recording is performed again while moving the carriage 2 in the backward direction of the arrow A (for example, the moving direction from the other end to the home position side). In this way, recording is performed on the entire recording medium by repeating the recording scan of the carriage and the conveying operation of the recording medium.

  The recording head 3 includes an electrothermal converter (hereinafter referred to as a heater) for converting electrical energy into thermal energy. The ink is boiled by the heat energy generated by the heater, and the ink is ejected by utilizing the pressure change caused by the growth and contraction of bubbles due to the film boiling. The heater is provided in each of the ejection ports (also referred to as nozzles) constituting each nozzle row 31 to 36, and a driving pulse voltage is applied to each heater in order to eject ink.

  FIG. 3 is a block diagram showing a control configuration of the inkjet recording apparatus according to the present embodiment described above.

  The ink jet recording apparatus of the present embodiment is connected to a host computer (such as a PC), and records image data including image information and recording information created by using an application of the host computer. Reference numeral 200 denotes a CPU that controls the entire inkjet recording apparatus. The CPU 200 includes a ROM 201 and a random access memory (RAM) 202. The CPU 200 controls the recording apparatus by sending a drive command to each drive unit via the main bus line 205. An image input unit 203 and an image signal processing unit 204 are connected to the main bus line 205, and image information (image data) from the host computer is temporarily input to the image input unit 203 and then input to the image signal processing unit 204. And converted into an image signal (recording data) suitable for recording. The main bus line 205 is further connected to an operation unit 206 for performing various settings relating to recording by an operator and a recovery system control circuit 207 connected to a recovery device for the recording head. Furthermore, the main bus line 205 is connected to a head drive control circuit 215, a carriage drive control circuit 216, and a paper feed (conveyance) control circuit 217, which are each drive unit. In addition, a program for driving each drive unit is stored in the RAM 202 in advance, and the program for each drive circuit is activated in accordance with a drive command from the CPU 200.

  The recording device is connected to the host computer via an interface connected to the main bus. In the above description, the host computer and the recording apparatus are connected. However, in addition to the host computer, a digital camera or a flash memory can be connected. At this time, the recording device records an image captured by the digital camera or an image stored in the flash memory.

  The recovery system control circuit 207 is a circuit that controls a recovery device for maintaining a good discharge state of ink droplets from the recording head, and controls the drive of the recovery system motor 208, the blade 209, the cap 210, and the suction pump 211. . The recovery device includes a blade 209 that wipes off ink droplets and dust adhering to the ejection port surface, and a cap 210 that covers the ejection port surface when recording is not performed so that ink does not evaporate from the ejection port. Further, there is a suction pump 211 that suctions ink in the recording head by forcing a negative pressure in the cap and forcibly discharges the thickened ink in the nozzle.

  The head drive control circuit 215 drives the electrothermal transducer of the recording head 213 in accordance with the recording data, and controls normal ink ejection for preliminary ejection, image recording, and temperature control of the ink / recording head. The recording head 213 performs the operation. Further, a carriage drive control circuit 216 that controls the drive of the carriage, a paper feed control circuit 217 that controls a paper feed mechanism that feeds and transports the recording medium, and the like respectively drive the carriage motor and the carry motor according to the drive program. .

  With the control configuration of the present embodiment described above, print data for each color ink and print data for the treatment liquid are generated. Specifically, the recording data of each color ink is generated by performing a series of known image processing and quantization processing. On the other hand, in this embodiment, the recording data of the treatment liquid is generated by a logical sum (OR) operation of the recording data of K, C, M, and Y inks.

  Several embodiments of the recording method using the ink and the treatment liquid in the embodiment of the present invention described above will be described below.

(First embodiment)
In the first embodiment of the present invention, when scanning in the forward direction indicated by the arrow A in FIG. 1, only the processing liquid is ejected, and when scanning in the reverse direction, the ink containing a coloring material ( Hereinafter, only ink is discharged. 4A and 4B are schematic diagrams for explaining this recording control.

  On the other hand, FIGS. 5 (a) and 5 (b) discharge both ink and processing liquid in accordance with the respective recording data during both forward and backward scanning. In the case of this recording control, the above-mentioned problem may occur. That is, the liquid that does not land on the recording medium, for example, the processing liquid mist, among the processing liquid ejected in the forward recording shown in FIG. 5A, may adhere to the vicinity of the ink nozzles due to the airflow generated by the ink ejection. is there. FIG. 6 is a diagram showing this, and shows an example in which processing liquid and Y ink are ejected. As shown in FIG. 6, the mist of the processing liquid generated by the discharge of the processing liquid flows in the direction opposite to the scanning direction along with the scanning of the recording head. On the other hand, the airflow generated by the Y ink ejection is generated not only in the ejection direction but also in the direction of returning to the recording head near the recording medium. For this reason, the processing liquid mist generated by the discharge of the processing liquid flows between the recording head and the recording medium in the direction opposite to the scanning direction of the recording head, and then the Y ink discharge air current causes the recording of the Y ink. It approaches the head and adheres to the surface of the recording head where the nozzles are provided. As a result, the processing liquid and Y ink react to cause aggregation (in the case of pigment) or insolubilization (in the case of dye) of the Y color material in the vicinity of the Y ink nozzle, resulting in ejection failure such as ejection failure or ejection direction deflection. Will occur. This adversely affects the reliability and durability of the recording head. In addition, a large-scale recovery means is required to prevent ejection failure, resulting in an increase in the size and cost of the apparatus, and an increase in the frequency of recovery operations, resulting in the life of the recovery apparatus and waste ink for recovery. Derives the problem of increasing. In the example shown in FIG. 6, the relationship between the processing liquid mist and the Y ink discharge airflow during forward recording is shown, but the same applies during backward recording. Conversely, the ink mist of the ink may adhere to the vicinity of the recording head of the processing liquid due to the discharge airflow of the processing liquid.

  In response to such a problem, as shown in FIGS. 4A and 4B, the present embodiment discharges only the processing liquid in the forward direction and discharges only the ink in the backward direction. To prevent.

  FIGS. 7A and 7B are diagrams for explaining this. In forward recording, the processing liquid mist is caused to flow in the direction opposite to the scanning direction as the recording head scans. However, since no ink is discharged, no discharge airflow is generated. Thus, the processing liquid passes between the recording head and the recording medium without adhering to the surface of the recording head on which the nozzle is provided. Similarly, during forward recording, as shown in FIG. 7B, Y ink ink mist is caused to flow in the direction opposite to the scanning direction as the recording head scans, but the processing liquid is not discharged. Therefore, the discharge airflow is not generated. As a result, the ink passes between the recording head and the recording medium without adhering to the recording liquid recording head. The treatment liquid mist and ink mist that have passed between the recording head and the recording medium are each diffused into the apparatus or recovered by an ink mist recovery mechanism (not shown). For this reason, there is no reaction or sticking in the vicinity of the recording head.

  As described above, according to the present embodiment, by not performing the ejection of the treatment liquid and the ejection of the ink in the same scan, the reaction between the treatment liquid and the ink on the recording head can be suppressed, The reliability and life of the recording head can be improved.

(Second Embodiment)
In the second embodiment of the present invention, each ejection duty is obtained based on the recording data of each of the ink and the processing liquid, and the ink ejection and the processing liquid ejection are performed by the same scanning of the recording head based on the ejection duty. It is related with the recording control which judges whether it performs by.

  According to the first embodiment, the reliability and life of the recording head can be increased, but there is a problem that the recording speed is lowered. The phenomenon that the mist of the processing liquid adheres to the vicinity of the ink nozzle due to the airflow of ink discharge described above with reference to FIG. 6 is less likely to occur when the processing liquid mist is small or the ink discharge airflow is weak. There are cases where the number of treatment liquid mists is small when the number of discharges of the treatment liquid is small, and there are cases where the number of ink discharges is similarly small as a condition where the ink discharge air current is weak.

  Therefore, in the present embodiment, by determining whether or not the ink ejection and the treatment liquid ejection are performed in the same scan of the recording head based on the ejection duty, the reliability, life and recording speed of the recording head are compatible. Is. Specifically, in this embodiment, the same scanning ejection determination process is performed. FIG. 8 is a diagram showing a determination table used in this process. As shown in FIG. 8, it is determined whether ink ejection and treatment liquid ejection are performed in the same scan according to the number of ejections per unit area of the recording medium of the ink and the treatment liquid, that is, the ejection duty. In this embodiment, for each of the K, C, M, and Y inks, the combination of the ejection duty obtained from the recording data and the ejection duty obtained from the processing liquid recording data corresponds to any combination in the table shown in FIG. Judge whether to do. When it is determined that the ink ejection and the treatment liquid ejection are performed in the same scanning for all of the K, C, M, and Y inks (the combination indicated by a circle in FIG. 8), the ink is scanned in the same scanning. Discharge and treatment liquid discharge are performed. In other cases, as described in the first embodiment, the ink ejection and the treatment liquid ejection are performed in separate scans.

  In the present embodiment, the print data of the processing liquid in the case of obtaining the above-described discharge data is obtained by the logical sum of the K, C, M, and Y print data, as described above. However, when applying the present invention, recording data generation is not limited to this form, and any known generation method can be used. In the present embodiment, the unit for performing the same scanning ejection determination process is performed for each scanning. That is, before each scan, determination is made with reference to the table shown in FIG. 8 based on the recording data of the ink and the processing liquid as described above. Therefore, in one scanning area, the ink and the processing liquid are ejected in the same scanning, and the recording of the area is completed in one scanning, and in the other scanning area, the ejection of the ink and the processing liquid is the same. This is done in another scan of the area, and the recording of that area is completed in two scans.

  According to the present embodiment described above, for example, in an image with a relatively small number of ejections such as a line drawing, the processing liquid ejection and the ink ejection are performed in the same scan, so that the recording time is not sacrificed. . Also, for example, in an image with a relatively high discharge duty such as a solid image, the discharge of the treatment liquid and the discharge of the ink are not performed in the same scan, so a discharge method in consideration of the reliability and life of the recording head is performed. Can do.

  In addition to the control based on the number of ejections per unit area, control based on the number of ejections per unit time, control based on the number of ejections after pass division at the time of multipass printing, and the like may be used.

  In multi-pass printing, control may be performed according to the number of passes by utilizing the fact that the ejection duty for each scan decreases each time the number of passes increases. FIG. 9 shows a table for this purpose.

  Furthermore, the ink ratio to be used may be controlled in accordance with a selected mode such as “line drawing mode” or “ink save mode” that restricts the ink ratio in advance. FIG. 10 is a diagram showing a table for that purpose.

(Third embodiment)
The third embodiment of the present invention relates to a method for determining the second embodiment described above for each distance between a recording head and a recording medium.

  It is known that the ink mist generation rate depends on the distance between the recording head and the recording medium. In the recording apparatus of the present embodiment, the distance between the recording head 3 and the recording medium can be switched between three levels of “low”, “standard”, and “high” according to the type of the recording medium and the usage environment of the apparatus. . For this reason, the same scanning ejection determination is performed according to each of these switched distances. FIGS. 11A to 11C are diagrams illustrating tables for determination according to whether the distance is “high”, “standard”, or “low”. As shown in these figures, the discharge data serving as the threshold is reduced as the distance increases (“high”). That is, the greater the distance (“higher”), the easier it is to generate mist.

  By performing the control according to the distance between the recording head and the recording medium as in the present embodiment, it is possible to further finely control the compatibility of the recording head, the life and the recording speed.

  The present invention is applicable to all devices using a recording medium such as paper, cloth, leather, non-woven fabric, OHP paper, and metal. Specific examples of applicable equipment include office equipment such as printers, copiers, and facsimiles using an ink jet recording method, and industrial production equipment.

2 Carriage 3 Recording head 200 CPU
215 Head drive control circuit 216 Carriage drive control circuit

Claims (6)

A recording head that ejects ink and a recording head that ejects a treatment liquid that insolubilizes or aggregates the ink coloring material are scanned in the direction in which the recording heads are arranged, and the ink and the treatment liquid are applied to the recording medium during the scanning. An inkjet recording apparatus that performs recording by discharging
An ink jet recording apparatus, wherein the ink ejection and the treatment liquid ejection for the same scanning region are performed by different scanning of each recording head. Including the same scanning ejection determining means for determining whether or not the ejection of the ink and the ejection of the processing liquid to the same scanning area is performed by the same scanning of each recording head;
When the same scanning ejection determining unit determines not to perform the same scanning, the ejection of the ink and the ejection of the processing liquid with respect to the same scanning area are performed by different scanning of the respective recording heads. The ink jet recording apparatus according to claim 1.   The same-scan ejection determination unit determines whether or not the ejection of the ink and the ejection of the processing liquid is performed by the same scanning of each recording head according to the ejection duty of the ink and the processing liquid. The inkjet recording apparatus according to claim 2.   The same scanning ejection determining means determines whether or not to perform the ejection of the ink and the ejection of the treatment liquid in the same scanning of each recording head according to the distance between the recording head and the recording medium. The ink jet recording apparatus according to claim 2, wherein: A recording head that ejects ink and a recording head that ejects a treatment liquid that insolubilizes or aggregates the ink coloring material are scanned in the direction in which the recording heads are arranged, and the ink and the treatment liquid are applied to the recording medium during the scanning. An ink jet recording method for recording by discharging
An ink jet recording method, wherein the discharge of the ink and the discharge of the treatment liquid are performed in different scans of the respective recording heads with respect to the same scanning region. Having the same scanning ejection determination step of determining whether or not the ejection of the ink and the ejection of the treatment liquid are performed in the same scanning of the respective recording heads with respect to the same scanning region;
When it is determined not to perform the same scanning in the same scanning ejection determination step, the ejection of the ink and the ejection of the processing liquid with respect to the same scanning region is performed by different scanning of each recording head. The ink jet recording method according to claim 5.

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