JP2015189115A - Liquid discharge recording device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge recording device which reliably prevents the occurrence of beading, can obtain high image quality and has high reliability.SOLUTION: A liquid discharge recording device includes: a liquid discharge head which discharges liquid from a nozzle and forms an image on a recording medium; and a control part which performs control so as to divide image data of the image into a plurality of divided image data and performs discharge control so as to separate a liquid region of liquid in accordance with the divided image data precedently discharged from the liquid discharge head and a liquid region of liquid in accordance with the divided image data subsequently discharged and performs control so as to repeat the discharge control by the same number of times as the number of divisions of the image data.

Description

  Embodiments relate to a liquid discharge recording apparatus and an image forming method that repeatedly discharge liquid onto a recording medium using divided image data.

  In order to prevent beading that causes image density unevenness, there is a sheet in which an ink-receiving layer made of a water-soluble resin is provided on a support to improve water absorption. In addition, there is an ink jet printer that separates image data into a plurality of images and prints a print process using a plurality of separated image data on the same position of a print medium.

  However, when a sheet with improved water absorption is used, the image forming cost cannot be reduced, and the application may be limited. Even when the image data is separated, if the printing process is performed on the printing medium in the dot order according to the separated image data, the inks of adjacent dots may be mixed.

Japanese Patent Laid-Open No. 10-305657 JP 2008-1091 A

  The problem to be solved by the present invention is to reliably prevent the occurrence of beading (a phenomenon in which ink of adjacent dots overflows and mixes) without increasing the cost, and to obtain high image quality. It is an object of the present invention to provide a liquid ejection recording apparatus and an image forming method with high accuracy.

  In order to achieve the above object, a liquid discharge recording apparatus according to an embodiment includes a liquid discharge head that discharges liquid from nozzles to form an image on a recording medium, and the image data of the image is divided into a plurality of divided image data. Controlling and discharging the liquid region of the liquid corresponding to the divided image data ejected in advance from the liquid ejection head and the liquid region of the liquid corresponding to the divided image data ejected subsequently. And a controller that controls the ejection control to be repeated the same number of times as the number of divisions of the image data.

1 is a schematic configuration diagram illustrating an inkjet printer according to a first embodiment. FIG. 2 is a schematic block diagram illustrating a control system of the ink jet printer according to the first embodiment. A general beading phenomenon due to a liquid will be described. (A) is a schematic explanatory diagram illustrating a case where liquids are individually fixed, and (b) is a schematic explanatory diagram illustrating a case where liquids are combined by generating beading. FIG. 3 shows an example of printing for each pass according to (Example 1) of the first embodiment, where (a) is the nozzle spacing of the inkjet head and the pitch of the divided dots, and (b) is the dot position printed in the first pass. , (C) is the dot position printed in the second pass, (d) is the dot position printed in the third pass, (e) is the dot position printed in the fourth pass, and (f) is printed in the fifth pass. Schematic explanatory drawing which shows a dot position. 6 is a flowchart illustrating a printing operation according to (Example 1) of the first embodiment. (Example 1) Schematic explanatory drawing which shows the final printing position of an upstream row | line | column and the printing start position of a subsequent row | line | column of 1st Embodiment. Schematic explanatory drawing which shows the nozzle position of the inkjet head of (Example 2) of 1st Embodiment. FIG. 6 shows an example of printing for each pass of the second embodiment, where (a) is the dot pitch between nozzles of the inkjet head, (b) is the dot position to be printed in the first pass, and (c) is in the second pass. (D) is the dot position to be printed in the third pass, (e) is the dot position to be printed in the fourth pass, (f) is the dot position to be printed in the fifth pass, and (g) is the six passes. Schematic explanatory drawing which shows the dot position printed on eyes. FIG. 6 shows a print example for each pass of the third embodiment, where (a) is the dot pitch between nozzles of an inkjet head, (b) is the dot position printed in the first pass, and (c) is in the second pass. (D) is a dot position for printing in the third pass, (e) is a dot position for printing in the fourth pass, and (f) is a schematic explanatory diagram showing a dot position for printing in the fifth pass. g) is a schematic explanatory diagram showing a dot position printed in the sixth pass, and (h) is a schematic explanatory diagram showing a dot position printed in the seventh pass.

  Embodiments will be described below.

(First embodiment)
A liquid discharge recording apparatus according to a first embodiment will be described with reference to FIGS. FIG. 1 shows an example of an ink jet printer 10 which is a liquid discharge recording apparatus. The ink jet printer 10 shown in FIG. 1 enables multipass printing.

  In the multipass printing, image data of an image to be printed is divided into a plurality of parts, and printing by the divided image data is repeated a number of times to obtain an image to be printed on a recording medium. The inkjet printer 10 is a recording medium, and includes, for example, a cassette 11 that stores a non-water-absorbing resinous sheet S, a sheet supply unit 12, a holding roller 13, and a sheet discharge unit 14. The ink jet printer 10 includes a suction unit 16 a, an image forming unit 17, and a peeling unit 16 b around the holding roller 13.

  The recording medium is not limited and is arbitrary, such as plain paper having water absorption. The non-water-absorbing recording medium may be any resin sheet or resin card made of PET (Polyethylene terephthalate) resin, vinyl chloride resin, polypropylene resin, etc., and glass products, earthenware, metal substrates, etc. May be. The holding roller 13 includes, for example, a thin insulating layer on the surface of an aluminum cylindrical frame that is grounded. The holding roller 13 rotates in the direction of the arrow r while holding the sheet S on the surface, and conveys the sheet S. The adsorbing unit 16a adsorbs the sheet S to the holding roller 13 by, for example, electrostatic force due to charging.

  The image forming unit 17 includes, for example, inkjet heads 18Y, 18M, 18C, and 18K that are liquid ejection heads. The ink jet heads 18Y, 18M, 18C, and 18K are liquids, and discharge aqueous resin emulsion ink (hereinafter abbreviated as emulsion ink) in which a resin is dispersed. The inkjet heads 18Y, 18M, 18C, and 18K discharge yellow, magenta, cyan, and black emulsion inks, respectively. The inkjet heads 18Y, 18M, 18C, and 18K of the image forming unit 17 have the same configuration although different inks are used. Therefore, description will be made using common reference numerals.

  The inkjet head 18 may be a line head or a serial head. The ink jet head 18 ejects the emulsion ink onto the sheet S taken out from the cassette 11 and held on the surface of the holding roller 13 to print a desired image. The ink jet printer 10 peels the sheet S on which a desired image is printed from the holding roller 13 by the peeling unit 16b and discharges the sheet S to the discharge tray 14a of the sheet discharge unit 14.

  The structure of the liquid discharge recording apparatus is not limited to the ink jet printer 10. The liquid ejection recording apparatus is optional, for example, by supporting the sheet S with a flat table and ejecting ink from the inkjet head while moving the table or the inkjet head to print an image. The number of liquid discharge heads of the liquid discharge recording apparatus or the liquid to be used is not limited to ink, but may be any characteristic or color.

  The control system 30 of the inkjet printer 10 will be described with reference to the block diagram shown in FIG. The control system 30 includes, for example, a CPU 31 that is a control unit that controls the entire inkjet printer 10. The control system 30 includes a ROM (Read Only Memory) 32a that stores various control programs, and a RAM (Random Access Memory) 32b that provides a temporary work area.

  The CPU 31 is connected to the control panel 33 and is connected to the external device 34 a via the interface 34. The CPU 31 is connected to an image processing unit 36 that processes image data of an image formed by the inkjet head 18 and a head drive unit 37 that drives the inkjet head 18. The CPU 31 is connected to a conveyance drive unit 38 that drives the sheet supply unit 12, the holding roller 13, the sheet discharge unit 14, the suction unit 16a, the peeling unit 16b, and the like.

  The ROM 32a stores a control program and control data for performing basic operations of the inkjet printer 10. The RAM 32b stores, for example, control parameters, the number of printed sheets, a printing time, and the like. The RAM 32b stores image data to be printed, for example. The image data may be data received from an external device 34a connected to the inkjet printer 10, or may be data read by a scanner or the like provided in the inkjet printer 10. The CPU 31 controls to store the data of the image processing result processed by the image processing unit 36 in the RAM 32b.

  The head drive unit 37 drives the inkjet head 18 under the control of the CPU 31. For example, the head driving unit 37 selectively drives the nozzles (Nn) of the inkjet head 18 according to the image processing result stored in the RAM 32b, and discharges the emulsion ink onto the sheet S.

  When emulsion ink discharged from the inkjet head 18 to the non-water-absorbing sheet S comes into contact, the individual emulsion inks may be combined (mixed) and beading may occur. When the individual emulsion inks on the sheet S overflow from the discharge area (image forming area) before fixing, adjacent emulsion inks come into contact and generate beading. The occurrence of beading mainly depends on the relationship between the characteristics of the emulsion ink discharged onto the sheet S, the amount of the emulsion ink, and the time until the emulsion ink is fixed. The ink jet printer 10 sets the order (pass order) of ejecting the emulsion ink from the ink jet head 18 to the dot position so as not to cause beading.

  In general, when individual liquids ejected on a recording medium are independently fixed, the liquid (I) is independently fixed in a desired shape and density as shown in FIG. . On the other hand, when each liquid overflows and comes into contact with the discharge area (image forming area) before fixing, the liquid (I) generates beading and combines as shown in FIG. End up.

  The ink jet printer 10 prevents the adjacent dots on the sheet S from coming into contact before fixing when the ejection of emulsion ink corresponding to the divided image data is repeated by the multi-pass method. When the inkjet ink 10 is continuously ejected according to the divided image data, the inkjet printer 10 prints the subsequent emulsion ink in a region separated from the preceding ejection region. When the ink jet printer 10 repeats printing according to the divided image data by the multi-pass method, the ink jet printer 10 repeats the ejection of the emulsion ink so that the preceding printing position and the subsequent printing position are not adjacent to each other.

  Inkjet printer 10 prints an image by a multi-pass method, and image processing unit 36 divides the image data into a plurality of parts under the control of CPU 31. The number of divisions of image data is not limited. After the emulsion ink is discharged onto the sheet S, it is sufficient that the previously discharged emulsion ink is fixed before the emulsion ink is discharged onto the next adjacent dot. However, it is desirable that the number of divisions is small in order to increase the printing speed.

(Example 1)
For example, the inkjet head 18 is a 150 dpi line head, and the interval between the nozzles (Nn) is 169 μm as shown in FIG. When the resolution of the image data is 750 dpi, the CPU 31 divides the image data into five divided image data of 150 dpi. When the image data is divided into five, the CPU 31 sets a pass order for ejecting the amount of emulsion ink corresponding to the divided image data to the dot positions that are ejection regions on the sheet S. The CPU 31 sets an interval of one dot or more between the dot position of the emulsion ink discharged before the sheet S and the dot position of the emulsion ink discharged subsequently.

  FIG. 4 shows a multipass printing example of the inkjet printer 10. FIG. 4A shows a case where image data of 750 dpi is divided into five parts for printing with a 150 dpi inkjet head 18 having a nozzle (Nn) interval of 169 μm. The inkjet head 18 divides the nozzles into the positions of 5 dots (a) to (e), and ejects the emulsion ink five times. The pitch between adjacent dots of (a)-(e) is 169 ÷ 5 = 33.6 μm.

  The CPU 31 divides the image data into five and sets the pass order of the emulsion ink corresponding to the divided image data to the dot positions (a) to (e). The CPU 31 sets the nozzle (Nn) of the inkjet head 18 so as not to discharge the emulsion ink to the positions of dots that are continuously adjacent. For example, the CPU 31 sets the order of passes to the dot positions (a) to (e) by the inkjet head 18 in the order of (1), (3), (5), (2), and (4).

  As shown in FIG. 4B, the CPU 31 causes each nozzle (Nn) of the inkjet head 18 to discharge emulsion ink to the dot position (a) in the first pass. In the second pass, each nozzle (Nn) ejects emulsion ink to a dot position (d) that is separated from the dot position (a) by 3 dots, as shown in FIG. 4C. After the first pass, the CPU 31 moves the inkjet head 18 in the direction of arrow 33.6 × 3 = 100 μm by the head drive unit 37 to eject the emulsion ink to the dot position (d) in the second pass. To do.

  After printing the second pass, each nozzle (Nn) ejects emulsion ink to the dot position (d) and the dot position (b) separated by two dots as shown in FIG. 4 (d) in the third pass. . In order to discharge emulsion ink to the dot position (b) in the third pass, as shown in FIG. 4D, the CPU 31 causes the head driving unit 37 to move the inkjet head 18 to 33.6 × 2 = 67. Move in the direction of 2 μm arrow z. Similarly, in the fourth pass, the inkjet head 18 is moved in the direction of the arrow y of 33.6 × 3 = 100 μm, and as shown in FIG. 4E, each nozzle (Nn) is moved to the dot position (b). Emulsion ink is ejected to the dot position (e) separated by 3 dots. In the fifth pass, the inkjet head 18 is moved in the direction of 33.6 × 2 = 67.2 μm arrow z, and each nozzle (Nn) moves to the dot position (e) and 2 as shown in FIG. Emulsion ink is discharged to the dot position (c) where the dots are separated.

  When the emulsion ink in the second pass is ejected, even if the emulsion ink at the dot position (a) in the first pass is not fixed, the emulsion ink is separated by 3 dots in the first pass and the second pass. The emulsion ink does not bead. After the discharge of the emulsion ink at the dot position (a) is completed in the first pass, the emulsion ink is discharged in the third pass to the dot position (b) adjacent to the dot position (a). When the emulsion ink is ejected to the dot position (b) in the third pass, the first pass printing at the dot position (a) has been fixed. Since the emulsion ink at the dot position (a) is fixed, it does not combine with the emulsion ink at the adjacent dot position (b), and the emulsion ink does not generate beading.

  Similarly to the second pass and the third pass, the emulsion ink is discharged to dot positions that are sequentially spaced by one dot or more in the fourth pass and the fifth pass. No dating occurs. Adjacent emulsion inks do not cause beading.

  After the first-pass to fifth-pass multipass printing is performed and the printing of one line is completed, the inkjet head 18 prints the next line. As shown in FIG. 6, the inkjet head 18 starts to discharge the first-pass emulsion ink of the next line from the dot position (a). Since the ejection position of the emulsion ink in the fifth pass, which is the final pass of the previous line, is the dot position (c), the emulsion ink ejected from the inkjet head 18 continuously in the previous line and the next line. Are separated. In the sub-scanning direction, the emulsion ink in the 5th pass of the previous line and the emulsion ink in the 1st pass of the next line are not combined, and the inkjet printer 10 can prevent the occurrence of beading of the emulsion ink also in the sub-scanning direction. .

  A printing operation mainly for preventing the occurrence of emulsion ink beading will be described with reference to the flowchart of FIG. When image data is input from the external device 34a or the like, the inkjet printer 10 starts a printing operation. When the printing operation starts, the CPU 31 stores the input image data in the RAM 32b (ACT 100). In order to print an image using the multi-pass method, the CPU 31 controls the image processing unit 36 to divide the image data stored in the RAM 32b (ACT 101).

  In ACT 101, the CPU 31 divides the image data into, for example, five parts. Further, the CPU 31 sets the pass order of the emulsion ink to the dot positions (a) to (e) by the inkjet head 18 according to the divided image data.

  The pass order to the dot positions (a) to (e) of the divided image data is stored in the RAM 32b (ACT 102), and the process proceeds to ACT 103. In ACT 103, the CPU 31 resets the number of passes to 0 and proceeds to ACT 104. In ACT 104, the CPU 31 controls the conveyance driving unit 38 to attract the sheet S to the holding roller 13 and convey it to the position of the image forming unit 17. In ACT 104, the CPU 31 controls the head driving unit 37 to discharge the first-pass emulsion ink from the nozzle (Nn) onto the sheet S at the dot position (a) according to the pass order stored in the RAM 32 b.

  The CPU 31 adds 1 to the number of passes (ACT 106). If the number of passes reaches the number of divisions (Yes in ACT 107), the CPU 31 proceeds to ACT 111. When the number of passes has not reached the number of divisions (No in ACT 107), the CPU 31 controls the head drive unit 37 to move the inkjet head 18 to the next set dot position (d) and the second pass. Emulsion ink is discharged from the nozzle (Nn) onto the sheet S (ACT 108).

  The CPU 31 repeats ACT106-ACT108 until the number of passes reaches the number of divisions 5 (Yes in ACT107). The CPU 31 repeats ACT106-ACT108, and repeats the ejection of the emulsion ink from the nozzle (Nn) to the set dot position while moving the inkjet head 18. Emulsion ink ejection from the nozzle (Nn) is repeated five times as many as the number of divisions of the image data (Yes in ACT 107). When all lines of the image data are printed (Yes in ACT 111), the CPU 31 proceeds to ACT 112. .

  When printing of all lines of image data has not been completed (No in ACT 111), the CPU 31 controls the conveyance driving unit 38 to rotate the support roller 13 in the direction of the arrow r, and the next on the sheet S. Is conveyed to the position of the image forming unit 17 (ACT 116). The CPU 31 returns to ACT 103 and prints the next line image by the multi-pass method. When ACT103, ACT104, ACT106-ACT108, ACT111, and ACT116 are repeated and multi-line printing is completed for all lines (Yes in ACT111), the CPU 31 completes the ejection of emulsion ink from the inkjet head 18 ( ACT 112). After completing the ejection of the emulsion ink, the CPU 31 controls the transport driving unit 38 to discharge the sheet S to the discharge tray 14a (ACT 113), and the printing operation is ended.

  In the first embodiment, the inkjet head 18 (nozzles (Nn)) is moved in the scanning direction, and printing is performed by the multi-pass method. The nozzle (Nn) moves a distance of one dot or more in the scanning direction for each pass, and sequentially discharges the emulsion ink to dot positions separated by one dot or more. The preceding emulsion ink and the subsequent emulsion ink sequentially discharged from the nozzles (Nn) do not come into contact with each other, and no beading occurs. Further, since the emulsion ink ejected to adjacent dot positions is separated by a time of one pass or more, the emulsion ink ejected first is fixed. Accordingly, emulsion inks at adjacent dot positions can be fixed individually without being combined, and no beading occurs.

  In (Embodiment 1), for example, the sheet S is supported by a flat table and the inkjet head 18 is fixed, while the sheet S is moved in the scanning direction and the sub-scanning direction by table movement to perform multi-pass printing. May be. When moving the sheet S as (Modified Example 1), for example, the moving direction in the scanning direction of the sheet S is set to a direction opposite to the moving direction of the inkjet head 18 in (Example 1), and the fixed nozzle (Nn) is used. Emulsion ink is ejected.

  In (Modification 1), after printing is started, after printing on the dot position (a) in the first pass of one line, the sheet S is moved by 100 μm in the direction of the arrow z in FIG. Print on d). Thereafter, the sheet S is moved by 100 μm in the direction of the arrow y and printed at the dot position (b) in the third pass, and the sheet S is moved by 100 μm in the direction of the arrow z and printed at the dot position (e) in the fourth pass. Then, the sheet S is moved by 100 μm in the arrow y direction, and printing is performed at the dot position (c) in the fifth pass.

  After printing the fifth pass, the table is moved in the sub-operation direction by one line and the printing operation for the second line is started. These are repeated to print all lines, and the multipass printing operation is completed.

  In (Modification 1), when the emulsion ink is sequentially discharged, the subsequent emulsion ink is discharged with a gap of one dot or more from the preceding emulsion ink. In (Modification 1), the sequentially ejected emulsion inks are separated and do not come into contact with each other. (Modification 1) prevents the preceding emulsion ink and the subsequent emulsion ink from being combined to prevent the occurrence of beading.

  In (Example 1), for example, a multi-pass printing may be performed using a serial head as the inkjet head 18. When the inkjet head 18 is a serial type as (Modification 2), the inkjet head 18 performs multi-pass printing within the width, and further moves the inkjet head 18 in the scanning direction from the start end side to the end end side in the scanning direction. Move and print one line. The pass order to the dot position of the emulsion ink ejected from the nozzle (Nn) for each pass by the inkjet head 18 of (Modification 2) is the same as in (Example 1). In (Modification 2), emulsion ink is ejected sequentially to dot positions separated by an interval of one dot or more.

  In (Modification 2), when the inkjet head 18 has moved to the end side in the scanning direction and has finished printing one line, the printing operation for the next line is started. By repeating these, all lines are printed, and the multipass printing operation using the serial type inkjet head 18 is completed.

  In (Modification 2), when the inkjet head 18 is moved in the scanning direction and the emulsion ink is sequentially discharged by the multi-pass method, the subsequent emulsion ink is discharged with a gap of one dot or more from the preceding emulsion ink. . In (Modification 2), the sequentially ejected emulsion inks are separated and do not come into contact with each other. (Modification 2) prevents the preceding emulsion ink and the succeeding emulsion ink from being combined, thereby preventing the occurrence of beading.

(Example 2)
For example, when the inkjet head 18 has a sufficient number of nozzles to satisfy the resolution of the image, the inkjet printer 10 prints an image by a multi-pass method by changing the nozzle position driven by the inkjet head 18. The plurality of nozzles of the inkjet head 18 of (Example 2) discharges emulsion ink to the dot positions of 5 dots (a) to (e) similar to (Example 1). For example, the inkjet head 18 of (Example 2) includes five nozzles (An)-(En) as shown in FIG. 7 between 169 μm.

  In (Embodiment 2), for example, image data with a resolution of 750 dpi is divided into five and the driving order of nozzles arranged in the inkjet head 18 is set. The CPU 31 sets which nozzles (An) to (En) of the inkjet head 18 are driven in order when the image data is divided into five divided image data. When ejecting emulsion ink from the inkjet head 18, the CPU 31 sets the nozzle drive order so as to drive the nozzles (An)-(En) that are sequentially separated by one nozzle or more. The inkjet head 18 drives the nozzles (An)-(En) in the set driving order, and sequentially discharges the emulsion ink onto the sheet S.

  The driving order of the nozzles (An)-(En) corresponds to the pass order to the dot position of the emulsion ink ejected from the nozzle (Nn) of (Example 1). The CPU 31 sets the driving order of the nozzles (An)-(En) of the inkjet head 18 in the order of (1), (3), (5), (2), (4).

  The CPU 31 drives the nozzle (An) in the first pass of the multi-pass to discharge the emulsion ink to the dot position (a), and drives the nozzle (Dn) in the second pass to the dot position (d). Emulsion ink is discharged, the nozzle (Bn) is driven in the third pass to discharge the emulsion ink to the dot position (b), and the nozzle (En) is driven in the fourth pass to the dot position (e). Emulsion ink is discharged, and in the fifth pass, the nozzle (Cn) is driven to discharge the emulsion ink to the dot position (c).

  After finishing the fifth pass printing, the CPU 31 rotates the support roller 13 by one line in the arrow r direction. The CPU 31 starts the second line printing operation by the inkjet head 18. These operations are repeated to print all lines, and the inkjet printer 10 ends the multipass printing operation.

  (Example 2) sets the driving order of the nozzles (An)-(En) of the inkjet head 18 and performs printing by the multi-pass method. The ink jet head 18 drives the nozzles (An)-(En) set for each pass, and sequentially discharges the emulsion ink to dot positions separated by an interval of one dot or more. The ejection positions of the emulsion inks that are sequentially ejected from the inkjet head 18 are spaced apart and do not come into contact. The emulsion inks that are sequentially ejected according to the driving order of the nozzles (An)-(En) are not combined and no beading occurs. In addition, since the emulsion ink ejected to the adjacent dot positions is separated by a time of one pass or more, the emulsion inks at the adjacent dot positions are individually fixed, do not combine, and do not generate beading. .

  According to the first embodiment, the CPU 31 divides the image data into five parts in order to print an image with a resolution of 750 dpi by the multipass method in the 150 dpi inkjet head 18. Furthermore, the CPU 31 sets the ejection order to the dot positions so that the preceding dot position and the subsequent dot position of the emulsion ink corresponding to the divided image data are separated by one dot or more. According to the first embodiment, when emulsion inks are sequentially ejected from the inkjet head 18, the preceding emulsion ink and the succeeding emulsion ink are spaced apart from each other without being adjacent to each other. The preceding emulsion ink and the subsequent emulsion ink are not brought into contact and bonded before fixing, and no beading occurs. In addition, since the emulsion ink is discharged to the adjacent dot positions after a time of one pass or more, the emulsion ink previously discharged is already fixed at the time of printing at the adjacent dot positions. ing. Accordingly, emulsion inks at adjacent dot positions are fixed individually without being combined, and no beading occurs, and a good image can be obtained.

  Further, in the first embodiment, the last dot position of the previous line and the start dot position of the next line are also separated in the sub-scanning direction of the inkjet head 18, and the occurrence of beading in the sub-scanning direction can be prevented.

(Second Embodiment)
A liquid discharge recording apparatus according to a second embodiment will be described with reference to FIG. The second embodiment is different from the first embodiment in the dot position pitch. In the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the second embodiment, image data having a resolution of, for example, 900 dpi is printed by the inkjet head 18 having 150 dpi and a nozzle (Nn) interval of 169 μm. In the second embodiment, the CPU 31 divides the image data into 150 dpi divided image data and performs multi-pass printing with the inkjet printer 10.

  FIG. 8 shows a multi-pass printing example of the inkjet printer 10. When dividing 900 dpi image data into 6 parts, as shown in FIG. 8A, the inkjet head 18 divides the nozzles into the positions of 6 dots (h)-(m) and ejects the emulsion ink 6 times. To do. The pitch between each dot (h)-(m) and the adjacent dot is 169 ÷ 6 = 28 μm.

  The CPU 31 divides the image data into 6 and sets the pass order of the emulsion ink corresponding to the divided image data to the dot positions (h)-(m). The CPU 31 sets, for example, the order of (1), (4), (6), (2), (5), and (3) as the pass order to the dot positions (h)-(m) by the inkjet head 18. To do.

  As shown in FIG. 8B, the CPU 31 discharges the emulsion ink to the dot position (h) in the first pass by the nozzles (Nn) of the inkjet head 18. As shown in FIG. 8C, the CPU 31 moves the inkjet head 18 in the direction of the arrow y of 28 × 3 = 84 μm in order to eject the emulsion ink to the dot position (k) in the second pass.

  After printing the second pass, the CPU 31 moves the ink jet head 18 to 28 × 2 = 56 μm in the direction of the arrow y and, as shown in FIG. 8D, the emulsion ink to the dot position (m) in the third pass. Is discharged. Similarly, in the fourth pass, the inkjet head 18 is moved in the direction of the arrow z of 28 × 4 = 112 μm, and the emulsion ink is ejected to the dot position (i) as shown in FIG. In the fifth pass, the inkjet head 18 is moved in the direction of the arrow y of 28 × 3 = 84 μm, and each nozzle (Nn) ejects emulsion ink to the dot position (l) as shown in FIG. . In the sixth pass, the inkjet head 18 is moved in the direction of 28 × 2 = 56 μm arrow z, and each nozzle (Nn) ejects emulsion ink to the dot position (j) as shown in FIG. .

  When the ejection of the divided number of multi-pass emulsion inks is completed, the inkjet head 18 proceeds to print an image of the next line. Similarly, when the multi-pass printing for all lines is completed, the inkjet head 18 ends the printing operation.

  According to the second embodiment, in the ink jet head 18 with 150 dpi, the CPU 31 divides the image data into six parts in order to print an image with a data resolution of 900 dpi by the multi-pass method. Furthermore, the CPU 31 sets the ejection order to the dot positions so that the preceding dot position and the subsequent dot position of the emulsion ink corresponding to the divided image data are separated by one dot or more. According to the second embodiment, when the emulsion ink is sequentially ejected from the inkjet head 18, as in the first embodiment, the dot positions of the preceding emulsion ink and the subsequent emulsion ink are not adjacent to each other and the emulsion ink is separated. To do. Sequentially, the emulsion ink ejected from the inkjet head 18 does not come into contact and bind before fixing, and the emulsion ink does not bead. In addition, since the emulsion ink is ejected to the adjacent dot positions after a time of one pass or more, as in the first embodiment, the ink is ejected in advance when printing is performed on the adjacent dot positions. The emulsion ink is already fixed. Emulsion inks at adjacent dot positions are fixed individually without being combined, and no beading occurs, and a good image can be obtained.

(Third embodiment)
A liquid discharge recording apparatus according to a third embodiment will be described with reference to FIG. The third embodiment is different from the first embodiment in the number of lines of the inkjet heads arranged. In the third embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the third embodiment, two lines of inkjet heads 18a and 18b of the same type having 150 dpi and a nozzle (Nn) interval of 169 μm are provided, and image data having a resolution of, for example, 1050 dpi is simultaneously printed. In the third embodiment, the CPU 31 divides the image data into 150 dpi divided image data, and performs multi-pass printing at the same time for two rows by the two rows of inkjet heads 18a and 18b.

  FIG. 9 shows a multi-pass printing example of the inkjet printer 10. In the third embodiment, the image data of 1050 dpi is divided into seven, and as shown in FIG. 9A, the nozzles of the inkjet head 18a in the first row are positioned at the 7-dot positions of (o1)-(u1). The nozzles of the inkjet head 18b in the second row are divided into 7 dot positions (o2)-(u2). The pitch of each dot of (o1)-(u1) or (o2)-(u2) with the adjacent dots is 169 ÷ 7 = 24.1 μm.

  The CPU 31 divides the image data into seven parts, and the order of the emulsion ink according to the divided image data to the (o1)-(u1) dot position and the pass order to the (o2)-(u2) dot position. Set. The CPU 31 determines the order of the passes to the dot positions of (o1)-(u1) by the inkjet head 18a in the first row (1), (3), (7), (5), (2), (4), Set in the order of (6). The CPU 31 determines the order of the passes to the dot positions of (o2)-(u2) by the inkjet head 18b in the second row (4), (6), (1), (3), (7), (5), Set in the order of (2).

  As shown in FIG. 9B, the CPU 31 causes the ink jet head 18a to discharge the emulsion ink from each nozzle (Nn) to the dot position (o1) whose pass order is (1) in the first pass. The CPU 31 causes the inkjet head 18b to move 24.1 × 2 = 48.2 μm in the direction of arrow y in the first pass, and from each nozzle (Nn) to the dot position (q2) where the pass order is (1). Is discharged. As shown in FIG. 9C, in the second pass, the CPU 31 moves the inkjet head 18a in the direction of the arrow y by 24.1 × 4 = 96.4 μm, and the dot position (s2) where the pass order is (2). Emulsion ink is discharged, and the inkjet head 18b is further moved 24.1 × 4 = 96.4 μm in the direction of arrow y to discharge the emulsion ink to the dot position (u2) where the pass order is (2).

  Thereafter, the CPU 31 moves the inkjet head 18a or the inkjet head 18b in the direction of the required distance arrow y or the arrow z, and the pass order is set by the cudget head 18b in the third pass as shown in FIG. The emulsion ink is discharged to the dot position (p1) of 3), and the emulsion ink is discharged to the dot position (r2) of the pass order (3) by the inkjet head 18b. Similarly, as shown in FIG. 9E, in the fourth pass, emulsion ink is ejected to the dot position (t1) of the pass order (4) by the ink jet head 18a, and the pass order is (4) by the ink jet head 18b. Emulsion ink is ejected to the dot position (o2). As shown in FIG. 9F, in the fifth pass, the ink jet head 18a ejects the emulsion ink to the dot position (r1) of the pass order (5), and the ink jet head 18b sets the dot position of the pass order (5). At (t2), the emulsion ink is discharged. As shown in FIG. 9G, in the sixth pass, emulsion ink is ejected by the inkjet head 18a to the dot position (u1) whose pass order is (6), and the pass order is (6) dot position by the inkjet head 18b. At (p2), the emulsion ink is discharged. As shown in FIG. 9 (h), in the seventh pass, the inkjet head 18a discharges the emulsion ink at the dot position (q1) of the pass order (7), and the ink jet head 18b sets the pass order of the dot (7). Emulsion ink is ejected to the position (s2).

  In the printing for every two lines by the inkjet head 18a and the inkjet head 18b, the dot positions when the emulsion ink is sequentially ejected are not adjacent in either the scanning direction or the sub-scanning direction.

  When the inkjet head 18a and the inkjet head 18b finish printing two lines by the multi-pass method, the inkjet head 18a and the inkjet head 18b proceed to printing the next two lines of images. When printing of all lines is completed by the multi-pass method of two lines at a time, the inkjet head 18a and the inkjet head 18b end the printing operation.

  According to the third embodiment, the CPU 31 divides the image data into seven parts in order to perform printing by the multi-pass method using the two rows of the inkjet head 18a and the inkjet head 18b. Further, the CPU 31 releases the emulsion ink discharged from the two rows of the inkjet head 18a and the inkjet head 18b so that the preceding dot position and the subsequent dot position are separated by one dot or more in both the scanning direction and the sub-scanning direction. Set the pass order to the dot position.

  According to the third embodiment, the printing speed is increased by printing with the two rows of inkjet heads 18a and 18b. According to the third embodiment, when the emulsion ink is sequentially ejected from the two rows of the inkjet head 18a and the inkjet head 18b, the preceding emulsion ink and the subsequent emulsion ink are both in the scanning direction and the sub-scanning direction. The dot positions are not next to each other and the emulsion ink is separated. The emulsion ink sequentially ejected from the ink jet head 18a and the ink jet head 18b does not contact and combine before fixing, and the emulsion ink does not cause beading. In addition, since the emulsion ink is ejected to the adjacent dot positions after a time of one pass or more, at the time of printing at the adjacent dot positions, the previously ejected emulsion ink is already fixed. Yes. Emulsion inks at adjacent dot positions are individually fixed without being bonded, and a good image can be obtained without causing beading.

  In the third embodiment, if the preceding dot position and the succeeding dot position by the multi-pass method are not adjacent in any of the scanning direction and the sub-scanning direction, three or more inkjet heads are arranged and three lines are arranged. The above may be printed simultaneously.

  In the third embodiment, the arrangement intervals in the sub-scanning direction of the plurality of rows of inkjet heads may be arranged with a pitch of one line or more of the image. For example, a plurality of rows of inkjet heads may be arranged at intervals of one line in the sub-scanning direction, and images may be simultaneously printed every other line by the rows of inkjet heads. In the scanning direction, the plurality of rows of inkjet heads are arranged so that the emulsion ink is ejected from the plurality of rows of inkjet heads 18a and 18b so that the emulsion ink is not ejected continuously to the positions of adjacent dots. Set. In the sub-scanning direction, an image that is simultaneously printed by a plurality of rows of inkjet heads is free for one line, and the printing positions in the sub-scanning direction are not adjacent. Therefore, even when the emulsion ink is sequentially ejected from the plurality of rows of inkjet heads, the preceding emulsion ink and the subsequent emulsion ink are not combined to generate beading, and a good image can be obtained.

  According to at least one embodiment described above, adjacent dot regions of the liquid sequentially ejected from the liquid ejection head to the recording medium are separated without contacting each other. The preceding liquid and the subsequent liquid sequentially ejected from the liquid ejection head do not come into contact with each other on the recording medium, and the liquid does not bead. Further, liquid is ejected to adjacent dot positions on the recording medium with a time interval of at least one pass. The liquid discharged from the liquid discharge head in advance is fixed when the liquid is discharged to the adjacent dot position. Therefore, the liquid ejected to the adjacent dot positions on the recording medium is fixed without being combined, and the liquid does not cause beading and a good image can be obtained.

  The present invention is not limited to the above embodiment, and various modifications are possible. For example, the liquid discharge recording apparatus may be one that discharges water-based ink onto plain paper, or a device that discharges liquid containing conductive particles for forming a wiring pattern on a printed wiring board. . The characteristics of the liquid ejected by the liquid ejection head are not limited, and the recording medium may be glass or the like. The structure of the liquid discharge recording apparatus is not limited, and a drying unit such as a heater or a fan may be provided to quickly dry the liquid discharged from the liquid discharge head onto the recording medium.

  Further, the separation distance on the recording medium of the liquid sequentially discharged onto the recording medium is not limited as long as the preceding liquid and the subsequent liquid sequentially discharged onto the recording medium overflow and do not come into contact with each other. Further, the liquid discharge head is arbitrary such as a line head or a serial head, and the number or size of the heads is not limited.

  The control for dividing the image data and repeating the printing operation for continuously ejecting the amount of liquid corresponding to the divided image data to the separated positions on the recording medium as many times as the number of divided image data is an automatic flowchart or It is optional, such as selecting manually. For example, the liquid discharge recording apparatus may read that the recording medium is non-water-absorbing, and may be controlled by an automatic flowchart, or may be controlled by the user specifying the type of the recording medium from a control panel or the like.

  Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 ... Inkjet printer 18 ... Inkjet head 31 ... CPU
36: Image processing unit 37: Head drive unit Nn: Nozzle

Claims (10)

A liquid ejection head that ejects liquid from a nozzle to form an image on a recording medium;
The image data of the image is controlled to be divided into a plurality of divided image data, and a liquid region of liquid corresponding to the divided image data discharged in advance from the liquid discharge head, and the divided image discharged subsequently. A liquid discharge recording apparatus comprising: a control unit that controls discharge so as to separate a liquid region of a liquid according to data and repeats the discharge control as many times as the number of divisions of the image data.   The ejection control of the control unit includes: a dot position on the recording medium of the liquid ejected from the liquid ejection head; and a dot position on the recording medium of the liquid ejected subsequently. The liquid discharge recording apparatus according to claim 1, wherein the liquid discharge recording apparatus is separated by one dot or more.   In the ejection control of the control unit, the nozzle that ejects the liquid ejected in advance and the nozzle that ejects the liquid ejected subsequently are separated by one nozzle or more on the liquid ejection head. The liquid discharge recording apparatus according to claim 1, wherein:   The liquid discharge recording apparatus according to claim 1, wherein the liquid is water-based ink in which a resin is dispersed.   The liquid discharge recording apparatus according to claim 1, wherein the recording medium is non-water-absorbing. A dividing step of dividing the image data of the image formed on the recording medium into a plurality of divided data;
According to the divided image data divided by the dividing step, a discharge step of separating a liquid region of the liquid discharged to the recording medium in advance from a liquid region of the liquid discharged to the recording medium subsequently;
An image forming method comprising the step of repeating the ejection step as many times as the number of divisions of the image data.   In the ejection step, the dot position on the recording medium of the liquid ejected in advance from the liquid ejection head and the dot position on the recording medium of the liquid ejected subsequently are equivalent to one dot. 7. The image forming method according to claim 6, wherein the image forming method is separated from the above.   The discharge step is characterized in that the nozzle for discharging the previously discharged liquid and the nozzle for discharging the subsequently discharged liquid are separated by one nozzle or more on the liquid discharge head. 6. The image forming method according to 6   9. The image forming method according to claim 6, wherein the liquid is a water-based ink in which a resin is dispersed.   9. The image forming method according to claim 6, wherein the recording medium is non-water-absorbing.

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