JP2007253348A - Printing method and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent occurrence of striped variation in a printed image in color printing adapted to prevent overlapping of positions of ejected inks in each main scanning. <P>SOLUTION: There is disclosed a printing method wherein movement of a head having ejection nozzle groups ejecting four colors of inks on image plotting positions 81 arranged in a column direction, respectively is repeated in a main scanning direction and a sub-scanning direction, and controlling of the ejection of four colors of inks on the respective image plotting positions 81 is sequentially carried out, thereby performing printing. In the first main scanning, the controlling of ejection of the ink is carried out on the image plotting position alternately existing in the image plotting positions 81 with respect to the row direction. In the next main scanning, the row to be a target of the controlling of ejection is changed to one from the row of the previous main scanning, and the color of the ink to be ejected on each row of the image plotting position in the first main scanning is changed to a color different from the color of the ink ejected on the row of the image plotting position in the previous main scanning by the previous movement of the head in the sub-scanning direction. As a result, it is possible to prevent occurrence of striped variation extending in the direction of the row or the column in the printed image. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing method and a printing apparatus that perform color printing on a printing medium by an inkjet method.

  2. Description of the Related Art Conventionally, an ink jet printing apparatus that performs printing on a print medium by moving a head on which a plurality of ejection openings, each ejecting minute droplets of ink, are arranged along the print medium such as print paper A printing apparatus that performs color printing by providing a plurality of nozzle units (also referred to as multi-nozzles) that eject inks of different colors on a head has been put into practical use. In a general color printing apparatus, the overlapping order of inks of a plurality of colors at each position on a print medium (more precisely, the order of ejection control relating to the inks of a plurality of colors) is made constant, so that a printed image is obtained. It is possible to prevent color change due to the overlapping order of the inks.

  In recent years, there has been a demand for color printing on various printing media. For example, when color printing is performed on a liquid-repellent printing medium such as plastic, a color that uses ultraviolet curable color ink is used. A printing device is used. In such a color printing apparatus, a plurality of nozzle units that eject inks of different colors and a head having a light irradiation unit that irradiates ultraviolet rays on the printing medium are provided, and the head is relatively positioned with respect to the printing medium. In this way, after a plurality of color inks are sequentially ejected from the ejection openings of a plurality of nozzle units to the same position on the print medium, ultraviolet light is irradiated to the ink on the print medium by the subsequent light irradiation unit. The On the other hand, at each position in the main scanning direction on the print medium, ink of a plurality of colors is applied to each of a plurality of positions arranged at a predetermined pitch in the sub-scanning direction perpendicular to the main scanning direction by one main scanning of the head. Each time the main scanning of the head is completed, the head is moved in the sub-scanning direction with respect to the print medium. Interpolation is also performed during the main scanning (so-called interlaced drawing).

In paragraphs 0014 and 0015 of Patent Document 1, dots are formed by one ejection port with respect to every other position in a plurality of positions aligned in the main scanning direction on the printing paper, and the remaining positions are determined. Is a printing technology that prevents the occurrence of streak unevenness extending in the main scanning direction on the printed image due to variations in the characteristics of the discharge ports by forming dots with other discharge ports (“singling method” or It is called “multi-scan method”).
JP 2005-238484 A

  However, as described above, when a plurality of colors of ink are ejected to the same position on the print medium during one main scan of the head, i) ink droplets of the respective colors ejected to the same position The desired color cannot be expressed by mixing the inks before curing, ii) the amount of ink ejected to each position in one main scan of the head increases, and a large amount of ultraviolet rays need to be irradiated, iii ) When ink droplets of one color are superimposed before the ink droplets of one color are cured, the ink spreads, and in particular, the edge portion of the image is blurred. Iv) The main scanning forward path of the head Since the arrival order of a plurality of nozzle units (usually arranged in the main scanning direction) at each position differs in the return path, and the overlapping order of the inks of a plurality of colors at each position differs, From direction printing The image quality of the printed image there is a problem such as a decrease.

  Therefore, ink is ejected to each position in the main scanning direction in a state where the ejection position of the ink ejected on the print medium in one main scanning of the head is shifted for each color in the sub scanning direction, and the head is moved in the sub scanning direction. After moving, the main scanning of the head is repeated, and the ink of one color is ejected to the position where the ink of one color is ejected in one main scanning (if attention is paid to each color) In this case, interlaced drawing is also possible.) It is conceivable that the inks of a plurality of colors are prevented from being ejected to the same position in each main scan, thereby solving the problems i) to iv). However, in this case, since the overlapping order of the final plurality of colors of ink is the same in the main scanning direction and is different for each position in the sub scanning direction, streak unevenness extending in the main scanning direction occurs in the printed image. Resulting in.

  The present invention has been made in view of the above problems, and an object of the present invention is to prevent streaks from occurring in a printed image in color printing in which overlapping of ink ejection positions in each main scan is prevented.

  The invention according to claim 1 is a printing method for performing color printing on a printing medium by an inkjet method, and a) drawing at drawing positions arranged in a row direction and a column direction orthogonal to each other on the printing medium. A position array is set, and the drawing position array is divided into a plurality of drawing blocks each having a drawing position of M rows and N columns (M and N are integers of 2 or more). A head that ejects ink of 2 or more (an integer less than or equal to (M × N)) is P-drawn in each drawing block through which the head passes while main-scanning the head relative to the printing medium in the column direction. A step of performing ejection control of each of the P color inks once as ejection control with respect to the position; b) while a) changing the arrangement of the P number of drawing positions related to the P color ink in each of the drawing blocks Repeat process A step of performing P times of ejection control relating to the P-color ink for each of all the drawing positions in each drawing block, and adjacent to each other in each row and each column of each drawing block. The order of ejection control relating to the P-color ink at any two drawing positions is different.

  According to a second aspect of the present invention, in the printing method according to the first aspect, in the main scanning of the head, the drawing position which is a target of ink ejection control in the step a) is set as the ejection position. The positional relationship between the discharge positions is preset as a discharge position array, and the arrangement of P discharge positions included in each drawing block in the discharge position array is the same in the plurality of drawing blocks. In step b), the arrangement of the P drawing positions relating to the P color ink in each drawing block is changed by shifting the position of the ejection position array for each main scan of the head. The

  The invention according to claim 3 is the printing method according to claim 2, wherein the P and the N are equal, and the P drawing positions are arranged in the row direction in the step a).

  Invention of Claim 4 is the printing method of Claim 3, Comprising: In said b) process, whenever said a) process is repeated, said P drawing position in each said drawing block is set. The column direction is changed.

  The invention according to claim 5 is the printing method according to any one of claims 2 to 4, wherein in the step b), each time the step a) is repeated, the drawing position of the drawing direction is changed. The head moves relative to the print medium in the row direction by a distance equal to or more than N times the pitch.

  A sixth aspect of the present invention is the printing method according to any one of the first to fifth aspects, wherein the print medium has liquid repellency.

  A seventh aspect of the present invention is the printing method according to the sixth aspect, wherein the head includes an ink curing unit that cures the ink immediately after being ejected onto the print medium.

  The invention according to claim 8 is a printing method for performing color printing on a printing medium by an ink jet method, and a) a plurality of discharge port groups are arranged in a predetermined row direction, and each discharge port group includes A step of performing ink ejection control from the plurality of ejection port groups while performing main scanning with respect to a print medium in a column direction orthogonal to the row direction with respect to a print medium; b ) By repeating the step of moving the head relative to the print medium in the row direction every time the main scanning is completed, and c) the steps a) and b). And sequentially performing ejection control of the inks of the plurality of colors for each of the drawing positions arranged in the row direction and the column direction in step a), and in step a), a predetermined number of drawing is performed in the column direction. Exists every position Ink ejection control is performed for the line at the drawing position, and the line to be subjected to ejection control in each a) process is changed from that in the previous a) process, and the drawing position is changed in each a) process. The color of the ink ejected to each column is changed from the color of the ink ejected to each column in the previous step a) by the previous step b) to a different color.

  The invention according to claim 9 is a printing apparatus that performs color printing on a print medium by an inkjet method, and has a drawing position array that is a drawing position arranged in a row direction and a column direction orthogonal to each other. And a holding unit for holding a print medium divided into a plurality of drawing blocks each having a drawing position arrangement of M rows and N columns (M and N are integers of 2 or more); A head for ejecting ink of a color (P is an integer not less than 2 (M × N)) toward the print medium, and the column direction and the row direction with respect to the print medium held by the holding unit. And a control unit that controls the movement of the head by the scanning mechanism and the ejection of ink from the head in synchronization with each other, and the control unit a) controls the head Retained printing Performing the ejection control of each of the P-color inks once as the ejection control for the P number of drawing positions in each drawing block through which the head passes while performing main scanning relative to the body in the row direction; B) Repeating the step a) while changing the arrangement of the P drawing positions related to the P color ink in each drawing block, for each of all the drawing positions in each drawing block. Performing P times of ejection control relating to the P color ink, and ejecting the P color ink at any two drawing positions adjacent to each other in each row and each column of each drawing block. The order of control is different.

  According to the present invention, it is possible to prevent the occurrence of streak unevenness extending in the row direction or the column direction in a printed image in color printing in which overlapping of ink ejection positions in each main scan is prevented.

  According to the second aspect of the present invention, it is possible to easily perform color printing in which overlapping of ink ejection positions in each main scanning and generation of streak unevenness in a printed image are prevented. It is possible to prevent the ink ejected in step 1 from being connected to each other.

  Further, in the invention of claim 5, it is possible to prevent the occurrence of streaks on the printed image due to the damage or variation of the ejection openings. In the invention of claim 6, the overlapping of the ink ejection positions in each main scan. Therefore, it is possible to appropriately print an image on a print medium having liquid repellency. In the invention of claim 7, it is possible to reliably print an appropriate image on a print medium having liquid repellency. it can.

  FIG. 1 is a perspective view showing an appearance of a printing apparatus 1 according to an embodiment of the present invention. The printing apparatus 1 performs color printing by an inkjet method on a plate-like or sheet-like substrate 9 formed of a liquid-repellent plastic such as polycarbonate or PET (polyethylene terephthalate).

  The printing apparatus 1 in FIG. 1 includes a main body 11 and a control unit 4, and the main body 11 holds a base material 9 on the (+ Z) side surface in FIG. 1 and a stage provided on a base 20. A moving mechanism 22 is provided. A nut of a ball screw mechanism included in the stage moving mechanism 22 is fixed to the surface of the stage 21 opposite to the substrate 9, and a motor connected to the ball screw mechanism rotates, so that the stage 21 becomes Y in FIG. Moves smoothly in the direction (main scanning direction). A position detection module 23 for detecting the position of the stage 21 with respect to the base 20 is further provided on the base 20.

  Above the stage 21, a head 3 that discharges fine droplets of ink toward the substrate 9 is arranged. The head 3 is perpendicular to the main scanning direction by the head moving mechanism 24 having a ball screw mechanism and a motor. Is supported so as to be movable in the sub-scanning direction (X direction in FIG. 1) along the main surface. The base 20 is provided with a frame 25 so as to straddle the stage 21, and the head moving mechanism 24 is fixed to the frame 25. A light source 39 for emitting ultraviolet rays is provided on the frame 25, and a plurality of optical fibers (actually, the plurality of optical fibers are bundled. In FIG. The light from the light source 39 is introduced into the inside of the head 3 through the above.

  FIG. 2 is a bottom view showing the head 3. As shown in FIG. 2, the head 3 includes a plurality of (four in FIG. 2) nozzle units 31 that eject inks of different colors, and the plurality of nozzle units 31 are arranged in the Y direction. 3 is fixed to the main body 30. The most (+ Y) side nozzle unit 31 in FIG. 2 ejects K (black) color ink, and the (−Y) side nozzle unit 31 of the K nozzle unit 31 is C (cyan) color ink. The (−Y) side nozzle unit 31 of the C nozzle unit 31 ejects M (magenta) ink, and the (−Y) side nozzle unit 31 has Y (yellow) color. Ink is ejected. Each color ink contains an ultraviolet curing agent.

  In each nozzle unit 31, a plurality of (for example, 300) discharge ports 311 in the X direction in FIG. 2 have a pitch V of 169 micrometers (μm) corresponding to a constant pitch V (for example, 150 dpi (dot per inch)). (Hereinafter, referred to as “discharge port pitch V”). When attention is paid to the X direction, the other three nozzles 31 are disposed between two adjacent discharge ports 311 of one nozzle unit 31. One discharge port 311 of each of the nozzle units 31 is arranged. For example, in the nozzle unit 31 on the most (+ Y) side in FIG. 2, the discharge port denoted by reference numeral 311a and the discharge port 311e on the (+ X) side of the discharge port 311a (in FIG. 2, parallel to each of these discharge ports). In the X direction, C is located at a position separated from the (−X) side discharge port 311a to the (+ X) side by a quarter of the discharge port pitch V in the X direction. The discharge port 311b of the nozzle unit 31 is disposed, and the discharge port 311c of the M nozzle unit 31 is disposed at a position away from the discharge port 311b by (¼) times (+ X) the discharge port pitch V, and the discharge port 311c. The discharge port 311d of the Y nozzle unit 31 is disposed at a position away from the discharge port by a quarter of the discharge port pitch V (+ X). As described above, in the head 3, a plurality of discharge ports 311 (for example, the discharge ports 311 a to 311 d) that discharge inks of different colors that are adjacent to each other in the X direction are defined as one discharge port group 32. The ejection port group 32 is arranged in the X direction, and in the entire head 3, the plurality of ejection ports 311 are continuous in the X direction at a pitch that is ¼ times the ejection port pitch V. Further, the head 3 is provided with two light irradiation units 38 each connected to the light source 39 with a plurality of nozzle units 31 interposed therebetween in the Y direction. In each light irradiation unit 38, a plurality of optical fibers are arranged along the X direction, and each light irradiation unit 38 irradiates ultraviolet rays onto a linear region extending in the X direction on the base material 9.

  FIG. 3 is a block diagram showing a functional configuration of the control unit 4. As shown in FIG. 3, the control unit 4 performs movement control for performing movement control with respect to the ejection control unit 41, the stage moving mechanism 22, and the head moving mechanism 24 that perform control related to ink ejection from the plurality of nozzle units 31 of the head 3. And a drawing data generation unit 43 that generates drawing data used for ejection control in the ejection control unit 41 from image data to be printed on the substrate 9. In the printing apparatus 1, an image is printed on the substrate 9 by the ejection control unit 41 controlling ejection of ink from the head 3 in synchronization with the movement control by the movement control unit 42.

  Next, a basic ink ejection operation at the time of main scanning with respect to the substrate 9 of the head 3 will be described. FIG. 4 is a diagram showing a drawing position array 80 set on the main surface of the substrate 9. In FIG. 4, the plurality of nozzle units 31 of the head 3 are also indicated by two-dot chain lines, and dots formed on the base material 9 by the respective discharge ports 311 of the K nozzle unit 31 are denoted by “K” inside. The dots formed on the base material 9 by the respective discharge ports 311 of the C nozzle unit 31 are indicated by the circles denoted by “C” inside, and the respective discharge ports 311 of the M nozzle unit 31 Dots formed on the base material 9 are indicated by a circle marked “M” inside, and dots formed on the base material 9 by each discharge port 311 of the Y nozzle unit 31 are indicated by “Y” inside. These are indicated by circles (the same applies to FIGS. 10.A to 10.D, FIGS. 11 and 12 described later). In FIG. 4, dots are virtually formed even when ink is not ejected in accordance with the drawing data.

  The drawing position array 80 is arranged on the main surface of the substrate 9 in a row direction (X direction in FIG. 4) parallel to the sub-scanning direction and a column direction (Y direction in FIG. 4) parallel to the main scanning direction. In FIG. 4, each drawing position is indicated by a rectangle denoted by reference numeral 81. In the present embodiment, both the pitch in the row direction and the pitch in the column direction (hereinafter also referred to as “drawing pitch”) of the drawing position 81 are set to ¼ times the discharge port pitch V, as described above. When the discharge port pitch V corresponds to 150 dpi, the drawing pitch is 42 μm corresponding to 600 dpi. In the printing apparatus 1, when the head 3 moves relative to the base material 9 in the main scanning direction (main scanning), the drawing positions 81 (in which the plurality of ejection ports 311 of the head 3 are arranged in the column direction) ( In the following, each ink outlet 311 performs an ink ejection operation on a predetermined drawing position 81 included in the corresponding drawing position column.

  At the time of printing in the printing apparatus 1, when the head 3 performs a main scan once in the Y direction, drawing positions that exist every other row in the corresponding drawing position row by each discharge port 311 based on the control of the discharge control unit 41. Ink ejection control is performed on 81 to form dots (virtually). Actually, since the drawing positions 81 at the same position in the column direction in the plurality of ejection ports 311 are the targets of ink ejection control, the drawing positions 81 arranged in the row direction are set as the rows of the drawing positions, and one drawing direction 81 is arranged in the column direction. The ejection control of the ink from the plurality of ejection ports 311 is performed for the row of the rendering position that exists every other rendering position 81. In other words, the drawing position 81 that is the target of ink ejection control is referred to as the ejection position. From the (−X) side toward the (+ X) direction, the K ejection position, the C ejection position, the M ejection position, and the Y ejection position. (Four drawing positions 81 at which K dots, C dots, M dots, and Y dots are respectively formed) A row of ejection positions in which the dots are repeated in the row direction has one drawing position 81 in the column direction. It can be said that they are lined up. In the printing apparatus 1 according to the present embodiment, the mutual positional relationship of the ink ejection positions when the head 3 performs one main scanning is set in advance as an ejection position array.

  A set of drawing positions 81 in 2 rows and 4 columns in the drawing position array 80 in FIG. 4 (a set of drawing positions 81 surrounded by a bold rectangle denoted by reference numeral 82 in FIG. In particular, each drawing block 82 includes one K discharge position, one C discharge position, one M discharge position, and one Y discharge position, and the arrangement of these four discharge positions. Are similar to each other in a plurality of drawing blocks 82. In other words, the drawing position array 80 is divided into a plurality of drawing blocks 82 each including only one of the four drawing positions 81 where the ejection control of different color inks is performed by one main scan of the head 3. Yes. The width of the drawing block 82 in the X direction is equal to the discharge port pitch V.

  In practice, as shown in FIG. 4, the positions of the plurality of nozzle units 31 in the Y direction are different from each other, and the ejection port 311 of each nozzle unit 31 has a drawing position 81 (ejection) that is an object of ink ejection control. Since the ink discharge control at the discharge port 311 is performed when the position opposite to (position) is reached (precisely, just before reaching), each head 3 passes during the main scanning of the head 3. In the drawing block 82, the ejection control for the four rendering positions 81 arranged in the row direction and serving as ejection positions is realized by performing the ejection control of each of the four color inks once at different times.

  Next, an operation in which the printing apparatus 1 prints an image on the substrate 9 will be described with reference to FIG. In the printing apparatus 1, first, the base material 9 to be printed is transported into the printing apparatus 1 and placed and held on the stage 21 (step S <b> 11). Subsequently, the movement control unit 42 controls the stage moving mechanism 22 and the head moving mechanism 24, whereby the head 3 is disposed at a predetermined printing start position on the (−Y) side of the substrate 9. Then, the stage 21 starts moving in the (−Y) direction, and the head 3 performs main scanning relative to the base material 9 in the (+ Y) direction (step S12).

  FIG. 6 is a diagram showing one drawing block 82. The numbers “1” to “8” are written in the inside of each drawing position 81, so that the order in which the discharge positions of one color are arranged for each main scan is shown. (It is the same in FIG. 9, FIG. 13.A and FIG. 13.B described later). FIG. A thru | or FIG. H is a diagram for explaining the overlapping order of a plurality of colors of ink ejected to each drawing position 81 of the drawing block 82. FIG. A thru | or FIG. In H, by marking any one of “K”, “C”, “M”, and “Y” inside the circle, it is discharged to each drawing position 81 (more precisely, the target of discharge control for each drawing position 81) The drawing positions 81 are long in the vertical direction for convenience of illustration.

  As described above, the ejection positions of K, C, M, and Y are aligned in the row direction in each ejection position row of the ejection position array (see FIG. 4), and the first main scan of the head 3 in the printing apparatus 1 is performed. In this case, the drawing position 81 on the most (−X) side and (+ Y) side of each drawing block 82 through which the head 3 passes (that is, the drawing corresponding to the position marked “1” in FIG. 6). The position 81 is hereinafter referred to as a “specific position”) and the K discharge position is overlapped. Therefore, FIG. As shown in A, ejection control of K ink is performed on the drawing position 81a, which is a specific position, and C and M are respectively applied to the other three drawing positions 81 from the specific position toward the (+ X) direction. , Y ink ejection control is performed (step S13). At this time, the ink immediately after being ejected onto the base material 9 by the ultraviolet rays irradiated onto the base material 9 from the light irradiation part 38 on the (−Y) side of the head 3 is cured, so that the ink will be described later. It is possible to prevent the inks from being mixed with other color inks ejected at the same position during the other main scans 3 and spreading of the other color inks when they are superimposed. Note that FIG. In A, the color of the ink that is the target of ejection control for each drawing position 81 in the current main scanning is indicated by a broken-line circle (the same applies to FIGS. 7B to 7H).

  In this way, in each drawing block 82 on the base material 9 through which the head 3 passes, the discharge control of inks of different colors is performed for a plurality of drawing positions 81 arranged in the lower stage ((+ Y) side row). When the head 3 reaches the end on the (+ Y) side of the substrate 9, the movement of the stage 21 (main scanning of the head 3) is stopped (step S14).

  Subsequently, after it is confirmed that the next main scanning of the head 3 is performed (step S15), the head 3 moves in the X direction (sub scanning), and each ejection port 311 of the K nozzle unit 31 in the row direction. However, in each drawing block 82 through which the head 3 passes in the main scanning of the next head 3, the drawing position 81 is separated from the drawing position 81 closest to the (−X) side by the drawing pitch in the (+ X) direction. Arranged (step S16). Note that the amount of movement of the head 3 in the row direction in step S16 will be described later.

  When the sub-scanning of the head 3 is completed, the stage 21 starts moving in the (+ Y) direction (step S12), and ink ejection control is performed in synchronization with the second main scanning of the head 3 (step S13). At this time, in each drawing block 82 through which the head 3 passes, the drawing position 81 that is separated from the drawing position 81 on the most (−X) side and (+ Y) side by the drawing pitch in each of the (+ X) direction and the (+ Y) direction. That is, the drawing position 81 corresponding to the position marked “2” in FIG. 6 is set as the specific position, and is overlapped with the K discharge position. Therefore, FIG. As shown in B, the ink discharge control of K is performed for the drawing position 81b which is a specific position, and the ink of C is discharged to the drawing position 81 which is separated from the specific position by the drawing pitch in the (+ X) direction. Control is performed, and M ink ejection control is performed on the drawing position 81 that is separated from the specific position in the (+ X) direction by twice the drawing pitch. Further, Y ink ejection control is performed on the drawing position 81 on the (−X) side of the specific position. Thus, during the second main scan of the head 3, the color of the ink ejected to each column of the drawing position 81 through which the head 3 passes is ejected during the immediately preceding first main scan. The ink color is changed to a different color, and the line of the drawing position that is the target of ejection control is also changed from the previous one at the time of the main scanning. The ink immediately after being ejected onto the substrate 9 is cured by the ultraviolet rays irradiated from the (+ Y) side light irradiation unit 38.

  When the main scanning of the head 3 is completed (step S14), the head 3 moves in the X direction, and each ejection port 311 of the K nozzle unit 31 in the row direction passes through the head 3 in the main scanning of the next head 3. In each drawing block 82, the drawing position 81 that is far from the most (−X) side drawing position 81 in the (+ X) direction by twice the drawing pitch is arranged (steps S15 and S16). Then, ink ejection control is performed in synchronization with the main scanning of the head 3 (steps S12 and S13), and the drawing positions on the most (−X) side and (+ Y) side in each drawing block 82 through which the head 3 passes. Drawing is performed with the drawing position 81 (ie, the drawing position 81 corresponding to the position indicated by “3” in FIG. 6) separated from the 81 in the (+ X) direction by twice the drawing pitch. . Therefore, FIG. As shown in C, the ink discharge control of K is performed for the drawing position 81c at the specific position, and the ink discharge control of C is performed for the drawing position 81 on the (+ X) side of the specific position. M ink ejection control is performed on the drawing position 81 that is two times the drawing pitch in the (−X) direction from the position, and the drawing position 81 is separated from the specific position in the (−X) direction by the drawing pitch. On the other hand, discharge control of Y ink is performed. When the head 3 reaches the end of the base material 9 on the (+ Y) side, the main scanning of the head 3 is stopped (step S14), and the head 3 moves by a predetermined distance in the row direction (steps S15 and S16). .

  In the printing apparatus 1, the specific position in each drawing block 82 through which the head 3 passes during each main scanning is indicated by “4”, “5”, “6”, “7” inside the drawing block 82 shown in FIG. 6. The above operation is repeated while sequentially switching to the drawing position 81 corresponding to the position marked “8” (steps S12 to S16). Therefore, in the fourth main scan of the head 3, FIG. As shown in D, the ejection control of C, M, Y, and K inks is performed in order from the (−X) side to the four drawing positions 81 on the (−Y) side. In main scanning, FIG. As shown in E, Y, K, C, and M ink ejection control is sequentially performed from the (−X) side to the four drawing positions 81 on the (+ Y) side. In scanning, FIG. As shown in F, ejection control of M, Y, K, and C inks is sequentially performed from the (−X) side to the four drawing positions 81 on the (−Y) side. In the seventh main scan of the head 3, FIG. As shown in G, the discharge control of C, M, Y, and K inks is sequentially performed from the (−X) side to the four (+ Y) side drawing positions 81, and the head 3 of the head 3 is controlled for the eighth time. In scanning, FIG. As indicated by H, the ejection control of K, C, M, and Y inks is performed sequentially from the (−X) side to the four (−Y) side drawing positions 81.

  Thus, in the printing apparatus 1, for each main scan of the head 3, the arrangement of the four drawing positions 81 relating to the four color inks K, C, M, and Y in each drawing block 82 that the head 3 passes through is arranged. FIG. 7 shows the state after the completion of the eighth main scan of the head 3, which is changed in the column direction. In the drawing block 82 indicated by H, the four ejection controls relating to the four colors of ink are completed for each of all the drawing positions 81 in the drawing block 82. At this time, in each row of each drawing block 82, the order of ejection control relating to the four colors of ink is different at all the drawing positions 81, and in each column of each drawing block 82, four colors of ink are used at all the drawing positions 81. The order of the discharge control according to is different.

  As will be described later, the above steps S12 to S14 and S16 are repeated until the ejection control for the four colors is performed four times for each of all the drawing positions 81 in the drawing position array 80 (step S15). A color image is printed on the entire substrate 9. In the print image on the substrate 9, in all the drawing blocks 82 included in the drawing position array 80, the order of ejection control related to the four color inks with respect to the drawing positions 81 corresponding to each other in each drawing block 82 is the same. (See Figure 7.H).

  Next, the amount of movement of the head 3 in the row direction in step S16 will be described. FIG. 8 is a diagram for explaining the amount of movement of the head 3 in the row direction. In the upper part of FIG. 8, the plurality of ejection ports 311 arranged in the nozzle unit 31 of one color are shown as one rectangle, and the plurality of ejection ports 311 during the first to ninth main scans of the head 3 are each rectangular. 331-339. Further, the lower part of FIG. 8 shows an image having the same color component as the color of ink ejected from the nozzle unit 31. In the following description, attention is paid only to the nozzle unit 31 of one color, but the same applies to the nozzle units 31 of other colors.

  As described above, 300 ejection ports 311 are formed in each nozzle unit 31 of the printing apparatus 1, and 300 drawing lines arranged in the row direction on the substrate 9 in the first main scanning of the head 3. In a range corresponding to the block 82, ink ejection control for each drawing block 82 is performed. Subsequently, after the end of the first main scanning of the head 3, the head 3 is (37+ (1/4)) times the ejection port pitch V in the (+ X) direction (between the rectangle 331 and the rectangle 332 in FIG. 8). (Distance in the X direction). That is, since the scanning width of one head is 300 · V, if one head is advanced in 8 main scans in the sub-scanning direction (300 ÷ 8 = 37 is too much 4), 37 · V is obtained in the drawing block. The image is sent in the sub-scanning direction by adding 1/4 V corresponding to the shift of the drawing position.

  At this time, the position of the discharge port 311 of the nozzle unit 31 moves in the row direction by a distance obtained by adding 1/4 times the discharge port pitch V to an integral multiple of the discharge port pitch V. Any one of the nozzle units 31 is located at a position separated by a drawing pitch from the drawing position 81 in each drawing block 82 through which the ejection port 311 of the nozzle unit 31 of one color has passed in the main scanning for the first time to the (+ X) side. Are disposed (except for the drawing block 82 through which the 37 (−X) -side ejection ports 311 have passed in the first main scan). Accordingly, for each drawing block 82 through which the nozzle unit 31 passes in the second main scan (more precisely, each drawing block 82 through which the nozzle unit 31 passes in the first and second main scans (hereinafter the same)). Thus, it is possible to perform ink ejection control by switching the specific position from the drawing position 81 corresponding to the position “1” in FIG. 6 to the drawing position 81 corresponding to the position “2”. Further, the amount of movement of the head 3 in the row direction during sub-scanning is larger than four times the drawing pitch (discharge port pitch V), which is the width in the row direction of the drawing block 82, and therefore 1 for each drawing block 82. A discharge port 311 that is different from the discharge port 311 that has passed in the second main scan passes in the second main scan.

  Similarly, after the end of the second main scan, the head 3 moves in the (+ X) direction by (37+ (1/4)) times the ejection port pitch V (that is, between the rectangle 332 and the rectangle 333 in FIG. 8). 6), for each drawing block 82 through which the nozzle unit 31 passes in the third main scan, the drawing position 81 corresponding to the position “2” in FIG. Ink discharge control can be performed by switching the specific position to the drawing position 81 corresponding to the position “3”, and after the third main scan, the head 3 has the discharge port pitch V in the (+ X) direction. By moving by (37+ (1/4)) times (that is, the distance in the X direction between the rectangle 333 and the rectangle 334 in FIG. 8), each nozzle unit 31 passes in the fourth main scan. For the drawing block 82, It is possible to perform ejection control of ink in 6 from the drawing position 81 corresponding to position "3" by switching the specified position at the writing position 81 corresponding to position "4".

  In the printing apparatus 1, the amount of movement of the head 3 in the row direction after the end of the fourth main scanning of the head 3 is (37+ (2/4)) times the ejection port pitch V (that is, the rectangle 334 in FIG. 8). And the rectangle 335 in the X direction). Thus, in the fifth main scan, each drawing block 82 through which the nozzle unit 31 passes is separated from the drawing position 81 corresponding to the position “4” in FIG. 6 by twice the drawing pitch in the row direction. In addition, it is possible to perform ink ejection control by switching the specific position to the drawing position 81 corresponding to the position “5”. Then, the amount of movement of the head 3 in the X direction after the end of the fifth to seventh main scans is (37+ (1/4) of the same discharge port pitch V as the amount of movement after the end of the first to third main scans. ) And the drawing positions 81 corresponding to the positions “6”, “7”, and “8” in FIG. 6 for each drawing block 82 through which the nozzle unit 31 passes in the sixth to eighth main scans. Thus, it is possible to perform ink ejection control with each specified position.

  Here, since the total amount of movement after the end of the first to seventh main scans is 261 times the discharge port pitch V, the plurality of discharge ports 311 (rectangular shapes) of the nozzle unit 31 in the eighth main scan. 338), the ink for each drawing block 82 that has passed through the 39th discharge port 311 in the (−X) direction from the (+ X) side in the first main scan by the discharge port 311 on the most (−X) side. The discharge control is performed. Therefore, ink of one color is ejected to each of all the drawing positions 81 in each drawing block 82 through which the 39 ejection ports 311 on the (+ X) side of the nozzle unit 31 have passed in the first main scanning. The control is executed once. As will be described later, since the head 3 moves intermittently in the (+ X) direction even after the eighth main scan, 261 nozzles on the (−X) side of the nozzle unit 31 in the first main scan. In each drawing block 82 through which the ejection port 311 has passed, there is a drawing position 81 where ink ejection control is not performed. Therefore, in the drawing data generation unit 43 of FIG. 3, the ink is applied to the drawing position 81 of each drawing block 82 through which the 261 discharge ports 311 on the (−X) side of the nozzle unit 31 pass in the first main scan. The drawing data is generated after the dummy data is inserted into the original image data in advance so that the discharge is not performed. In the lower part of FIG. 8, the rectangle K1 and K2 abstractly show the image corresponding to the dummy data and the original image.

  Subsequently, after the end of the eighth main scan, the head 3 moves in the (+ X) direction (39+ (0/4)) times the ejection port pitch V (that is, between the rectangle 338 and the rectangle 339 in FIG. 8). 6), the drawing position 81 corresponding to the position “1” in FIG. 6 is set to the specific position for each drawing block 82 through which the nozzle unit 31 passes in the ninth main scan. It becomes possible to perform the ink ejection control. At this time, in each drawing block 82 through which 37 discharge ports 311 on the (−X) side of the plurality of discharge ports 311 indicated by the rectangle 339 pass, “2” in FIG. ”To“ 8 ”, the ink discharge control with the drawing position 81 as the specific position has already been completed, and 1 for each of the drawing positions 81 in the drawing block 82 by the ninth main scan. The ink ejection control for one time is completed. The head position for the ninth main scan is ((37 + 1/4) · V + (37 + 1/4) · V +... + (39 + 0/4) · V = 300 · V). The position is moved, and continuity in the sub-scanning direction is maintained.

  In the repetition of the main scanning and the sub scanning after the ninth time of the head 3, the moving distance at the time of sub scanning is sequentially changed to that at the time of the sub scanning after the end of the first to eighth main scanning. For each of all the drawing positions 81 in each drawing block 82 (except for the case where ink ejection control based on dummy data is performed), the ink ejection control in the nozzle unit 31 of one color is 1. Performed once. In this manner, four ejection control operations for four colors of ink are performed for each of all the drawing positions 81 in each drawing block 82 on the substrate 9 by the plurality of nozzle units 31 that discharge different colors. And a color image is printed on the substrate 9. The actual drawing data at the time of color printing requires dummy data corresponding to the deviation in the row direction for each nozzle unit 31 in addition to the dummy data described with reference to FIG. Furthermore, it is generated by extracting the value of the pixel corresponding to the drawing position 81 that is the target of ink ejection control during each main scanning from the image data of each color component in which dummy data is inserted. .

  Here, it is assumed that the head 3 performs ink ejection control for each drawing position arranged in the column direction in one main scanning, and after sub-scanning in the row direction, the main scanning is repeated, so that each drawing position is set. In the case of performing the ejection control four times related to the four color inks, the order of the ejection control related to the four color inks is the same in all the drawing positions included in each column of the drawing positions, and the drawing position columns Since this differs for each line, streak unevenness extending in the column direction occurs in the printed image.

  On the other hand, in the printing apparatus 1 of FIG. 1, in the operation of repeating the main scanning and the sub-scanning of the head 3, ink is applied to a row of drawing positions that exist at every other drawing position 81 in the column direction during one main scanning. In the next main scan, the row that is the target of the discharge control is changed from that in the previous main scan, and the color of ink that is ejected to each column at the drawing position in one main scan However, by the sub-scanning of the head 3 immediately before, the color of the ink ejected to the column at the drawing position in the previous main scanning is changed to a different color (that is, the interlace drawing is performed in the row direction and the column direction). Done.) Thus, the order of ejection control relating to a plurality of colors of ink can be made different at the rendering positions 81 included in each row and each column of each rendering block 82. As a result, the ink ejection positions in each main scan In color printing in which the overlapping is prevented, streak unevenness extending in the row direction or the column direction can be prevented from occurring in the printed image.

  In color printing that prevents overlapping of ink ejection positions in each main scan, as described above, color printing that ejects a plurality of colors of ink to the same position on the print medium during one main scan of the head. I) Ink cannot be expressed by mixing ink before the ink droplets of each color ejected at the same position are cured. Ii) The ink is ejected at each position by one main scanning of the head. Iii) Before one color ink is cured, the other ink spreads and the ink spreads, especially at the edge of the image. Iv) The order of arrival of the plurality of nozzle units at each position differs between the forward and backward passes of the main scanning of the head, and the ejection order of the plurality of color inks at each position is different. Problems such that image quality of the printed image is reduced is eliminated than unidirectional printing are. Further, in the printing operation of the printing apparatus 1, when the ejection port 311 that ejects the ink of one color passes through each column of the drawing position twice, the ink of one color corresponding to the drawing position 81 included in this column is passed. However, when the discharge period of the ink from the nozzle unit 31 is constant, in the printing apparatus 1, compared to the method of discharging ink to each position in the column direction in one main scan, Since the main scanning speed of the head 3 can be doubled, the time required for printing on the entire substrate 9 is substantially the same as that of the method (more specifically, the number of movements in the sub-scanning direction is Because it increases, it will take some time.)

  Further, in the print image on the substrate 9, in all the drawing blocks 82 included in the drawing position array 80, the order of ejection control related to a plurality of colors of ink with respect to the drawing positions 81 corresponding to each other is the same. The color of each drawing block 82 which is a local area on the material 9 is constant, and the color of the entire printed image can be uniform. In the print image, the color appearance of each drawing block 82 changes according to the switching order of the specific positions in the drawing block 82. Therefore, in actual color printing, the switching order of the specific positions in the drawing block 82 is plural. The test printing is performed after the change, and the switching order for the desired color appearance is determined, and the color printing is performed in the switching order. In this case, for example, in the drawing block 82 shown in FIG. 9, the drawing position 81 that is separated from the one drawing position 81 by a plurality of times of the drawing pitch in the row direction, such as the positions “1” and “2”, is specified. The position may be switched.

  In the printing apparatus 1, the position of the ejection position array, which is a set of ejection positions during one main scan of the head 3, is shifted in the row direction and the column direction for each main scan of the head 3. In addition, in each drawing block 82 through which the head 3 passes, the arrangement of the four drawing positions 81 to be subjected to the discharge control of the four colors of ink is changed, and a plurality of color inks are changed with respect to each drawing position 81. Discharge control is performed sequentially. Thereby, without complicatedly changing the control algorithm for the plurality of nozzle units 31 for each main scan of the head 3, color printing that prevents overlap of ink ejection positions in each main scan and occurrence of streak unevenness in the printed image is performed. It can be done easily.

  Here, in the printing apparatus 1, if a certain ejection port 311 is damaged or ink ejection characteristics of the ejection port 311 (for example, ink ejection amount or ink ejection direction from the ejection port 311) vary. For example, when ink is ejected from the same ejection port 311 to each rendering position 81 in the rendering block 82 aligned in the column direction, all rendering positions 81 in the rendering block 82 aligned in the column direction are at the ejection port 311. The same influence due to damage and variations in ink ejection characteristics results in streak irregularities on the printed image. However, in the printing apparatus 1, each time main scanning of the head 3 is repeated, the head 3 moves relative to the base material 9 in the row direction by a distance longer than the width of the drawing block 82 in the row direction. By assigning different discharge ports 311 to all the drawing positions 81 in each drawing block 82, it is possible to prevent the occurrence of streak unevenness on the printed image due to damage or variation of the discharge ports 311.

  In the printing apparatus 1, each time the main scanning of the head 3 is repeated, the arrangement of the four drawing positions 81 that are arranged in the row direction in each drawing block 82 and are subject to ink ejection control are arranged in the column direction. Be changed. Thereby, in the two consecutive main scans of the head 3 (relative reciprocal movement of the head 3 in the column direction with respect to the base material 9), the ink ejected in the column direction on the base material 9 is connected to each other. Can be prevented.

  In the above operation example of the printing apparatus 1, the pitch in the row direction and the column direction of the drawing position 81 in the drawing position array 80 is 42 μm corresponding to 600 dpi, but the main scanning speed of the head 3 and the ink ejection By changing the cycle, the pitch of the drawing positions 81 in the column direction can be freely changed.

  Here, in the printing apparatus 1, if the main scanning speed of the head 3 and the ink ejection cycle cannot be changed (for example, if the control when such a change is allowed becomes complicated), the ejection is performed. The pitch in the column direction of the rows of the ejection positions in the position array cannot be changed at 84 μm corresponding to 300 dpi, but even in this case, for example, FIG. As shown in A, it is assumed that the rows of the ejection positions adjacent to each other exist at every two drawing positions 81 in the column direction (that is, the pitch of the drawing positions 81 in the row direction is 28 μm). Color printing with a resolution of 900 dpi can be performed. Under such conditions, the resolution in the column direction can be a predetermined integer α of 300 dpi (where α is an integer equal to or greater than 2). In this case, in one main scan of the head 3, the column direction In other words, the ink ejection control is performed on the rows at the drawing positions that exist at every (α-1) drawing positions (that is, skipping only (α-1) rows). Note that FIG. In A, only a part of the ejection position array is shown, and the drawing block 82 in the above operation example is also shown by a broken line (the same applies to FIGS. 10.B to 10.D described later).

  Further, by changing the moving distance in the sub-scanning in the head 3 shown in FIG. 2 (that is, a head in which the plurality of ejection ports 311 are arranged at a pitch of 42 μm corresponding to 600 dpi in the row direction), the drawing position 81 is changed. You can also change the pitch in the row direction. For example, a distance obtained by adding the movement amount of the head 3 in the row direction in step S16 in the above operation example to the integral multiple of the discharge port pitch V and β / 8 times the discharge port pitch V (where 0 ≦ β ≦ 7). As shown in FIG. As shown in B, color printing can be performed by setting the resolution in the row direction and the column direction to 1200 dpi and 1200 dpi, respectively (in this case, the pitch of the drawing position 81 in both the row direction and the column direction is 21 μm). . As described above, in the head 3 of FIG. 2, the resolution in the row direction can be an integral multiple of 600 dpi. In the printing apparatus 1 under the above conditions (the pitch in the column direction of the rows of ejection positions is 84 μm), Color printing in which the resolution in the direction and the column direction is 1200 dpi and 600 dpi, or 1200 dpi and 900 dpi, respectively, becomes possible.

  The head 3 of the printing apparatus 1 may be provided with a nozzle unit that ejects inks of colors other than K, C, M, and Y. For example, a nozzle unit that ejects light cyan ink and light magenta ink may be provided. 10. A nozzle unit for discharging is added to the head. C and FIG. A discharge position array as shown in D may be set. FIG. C and FIG. In D, the light cyan discharge position is indicated by a circle labeled “LC” inside, and the light magenta discharge position is indicated by a circle labeled “LM” inside. In this case, the discharge port of the nozzle unit that discharges C ink and the discharge port of the nozzle unit that discharges light cyan ink are arranged at the same position in the row direction, and the discharge port of the nozzle unit that discharges M ink. And the discharge port of the nozzle unit for discharging light magenta ink are arranged at the same position.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  In the above operation example, for example, an ejection position array as shown in FIG. 11 may be used. In test printing performed before printing on the substrate 9, the ejection position array is shown in FIGS. As described above, the combination of the switching order and the discharge position array that provide a desired color appearance may be determined. However, from the viewpoint of easily adjusting the discharge timing of the plurality of nozzle units 31 in the printing apparatus 1 and performing control related to ink discharge, the head 3 is subjected to ink discharge control during one main scan. It is preferable to use an ejection position array in which the drawing positions 81 are arranged in the row direction.

  In the printing apparatus 1, as shown in FIG. 12, the number of drawing positions 81 in the drawing block 82 can be matched with the number of colors of ink ejected by the head 3. In this case, ejection control of four colors of ink is performed on all (four) drawing positions 81 in the two-row and two-column drawing block 82 in one main scan of the head 3. Then, by shifting the position of the ejection position array for each main scan of the head 3, the arrangement of the four drawing positions 81 relating to the four color inks in each drawing block 82 is changed, and all of the drawing blocks 82 are all arranged. For each of the drawing positions 81, four times of ejection control relating to four colors of ink are performed.

  From the above description, from the viewpoint of performing interlace drawing in the row direction and the column direction in the printing apparatus 1, the drawing position array 80 set on the main surface by the control unit 4 has M rows and N columns (M, A head for ejecting ink of P color (P is an integer of 2 or more (M × N) or less) to the base material 9 divided into a plurality of drawing blocks at a drawing position of N (an integer of 2 or more). Basic processing for performing each ejection control of the P-color ink once as ejection control for P rendering positions in each rendering block through which the head passes while relatively scanning in the column direction, and each rendering block By repeating the basic process while changing the arrangement of the P drawing positions related to the P color ink, the P discharges related to the P color ink for each of all the drawing positions in each drawing block Control It is important to process and is executed.

  By the way, from the viewpoint of preventing the occurrence of streak unevenness extending in the row direction and the column direction in the printed image, a plurality of print positions at any two drawing positions 81 adjacent to each other in each row and each column of each drawing block 82 are used. Although it is necessary that the order of ejection control related to ink be different, in the printing operation of FIG. 5 in the printing apparatus 1 of FIG. As shown in A, the drawing position 81 of the (+ Y) side row of the drawing block 82 of 2 rows and 4 columns is made a specific position in order from the (−X) side to the (+ X) direction, and then the drawing block 82. When the drawing position 81 of the (−Y) side row is set to a specific position in order from the (−X) side to the (+ X) direction, the four colors at the two drawing positions 81 adjacent to each other in the column direction are displayed. The order of ejection control related to ink becomes the same. FIG. As shown in B, the same applies to the case where the specific position is sequentially switched from the (−X) side toward the (+ X) direction in each row while alternately changing the rows in the drawing block 82. Therefore, when the number of ink colors P ejected by the head 3 is equal to the number N of columns of the rendering block 82, and the P rendering positions 81 subject to ejection control by the main scanning of the head 3 are arranged in the row direction. It is important that the switching order of the specific positions along the X direction focusing only on each row in the drawing block 82 is different from other rows in at least one of the plurality of rows in the drawing block 82. .

  In the above embodiment, each time the main scanning of the head 3 is repeated, the head 3 performs sub-scanning by a distance sufficiently longer than the width of the drawing block 82 in the row direction, but this is caused by damage or variation of the ejection port 311. From the viewpoint of preventing the occurrence of streaks on the printed image, each time the main scanning of the head 3 is repeated, the head 3 is a distance equal to or greater than N (the number of columns of the drawing block 82) times the pitch in the row direction of the drawing position 81. May move relative to the base material 9 in the row direction.

  Further, in the printing apparatus 1, the ink immediately after being ejected onto the substrate 9 by the light irradiation unit 38 is cured while preventing the overlapping of the ink ejection positions in each main scan, thereby providing a base having liquid repellency. An image can be appropriately printed on the material 9, but the ink ejected on the substrate 9 does not necessarily have to be naturally cured before the inks of other colors are superimposed by the subsequent main scanning. The light irradiation unit 38 may not be provided. However, in order to reliably print an appropriate image on the base material 9, it is preferable to provide a light irradiation unit 38 that cures the ink immediately after being discharged onto the base material 9. The ink curing unit that cures the ink immediately after being discharged onto the substrate 9 may be other than the light irradiation unit 38. For example, when thermosetting ink is used, The head 3 may be provided with a heat application unit that provides the heat. As in the above-described embodiment, each time the main scanning of the head 3 is repeated, the ejection positions aligned in the row direction in each drawing block 82 are changed in the column direction. Since the drawing position 81 from which the ink is ejected differs in each main scan, one of the two light irradiation units 38 of the head 3 can be omitted.

  The holding unit that holds the print medium in the printing apparatus 1 may be other than the stage 21. For example, when the print medium is in a sheet form, the holding unit is disposed to face the head 3 and the print medium. The roller may be in contact with a surface opposite to the surface to be printed.

  In the above embodiment, the stage 3 is moved relative to the stage 21 in the column direction and the row direction by the stage moving mechanism 22 that moves the stage 21 in the column direction and the head moving mechanism 24 that moves the head 3 in the row direction. However, the printing apparatus 1 may be provided with a mechanism for moving the head 3 in the column direction and a mechanism for moving the stage 21 in the row direction. As described above, when the holding unit that holds the print medium is a roller, the head 3 is moved relative to the print medium in the row direction by a motor that rotates the roller. Thus, the scanning mechanism that moves the head 3 relative to the print medium in the column direction and the row direction may have any configuration.

  The printing apparatus 1 is particularly suitable for applications in which color printing is performed on a printing medium having liquid repellency (may be other than plastic), but may be used for a printing medium having no liquid repellency. Is possible.

1 is a perspective view illustrating an appearance of a printing apparatus. It is a bottom view which shows a head. It is a block diagram which shows the function structure of a control part. It is a figure which shows the drawing position arrangement | sequence set on the main surface of a base material. It is a figure which shows the flow of the operation | movement which a printing apparatus prints an image on a base material. It is a figure which shows the switching order of the specific position in a drawing block. It is a figure for demonstrating the overlapping order of the ink in each drawing position. It is a figure for demonstrating the overlapping order of the ink in each drawing position. It is a figure for demonstrating the overlapping order of the ink in each drawing position. It is a figure for demonstrating the overlapping order of the ink in each drawing position. It is a figure for demonstrating the overlapping order of the ink in each drawing position. It is a figure for demonstrating the overlapping order of the ink in each drawing position. It is a figure for demonstrating the overlapping order of the ink in each drawing position. It is a figure for demonstrating the overlapping order of the ink in each drawing position. It is a figure for demonstrating the moving amount | distance to the row direction of a head. It is a figure which shows the other example of the switching order of the specific position in a drawing block. It is a figure which shows the other example of a discharge position arrangement | sequence. It is a figure which shows the further another example of a discharge position arrangement | sequence. It is a figure which shows the further another example of a discharge position arrangement | sequence. It is a figure which shows the further another example of a discharge position arrangement | sequence. It is a figure which shows the further another example of a discharge position arrangement | sequence. It is a figure which shows the further another example of a discharge position arrangement | sequence. It is a figure which shows the comparative example of the switching order of the specific position in a drawing block. It is a figure which shows the comparative example of the switching order of the specific position in a drawing block.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing apparatus 3 Head 4 Control part 9 Base material 21 Stage 22 Stage moving mechanism 24 Head moving mechanism 31 Nozzle unit 32 Discharge port group 38 Light irradiation part 80 Drawing position arrangement 81, 81a-81c Drawing position 82 Drawing blocks 311, 311a- 311d Discharge port S12 ~ S16 Step

Claims (9)

A printing method for performing color printing on a printing medium by an inkjet method,
a) A drawing position array which is a drawing position arranged in a row direction and a column direction orthogonal to each other on the print medium is set, and each of the drawing position arrays has M rows and N columns (M and N are 2 or more). Are divided into a plurality of drawing blocks that are drawing positions, and a head that ejects ink of P color (P is an integer of 2 or more (M × N) or less) with respect to the print medium in the column direction. Performing the ejection control of each of the P color inks once as the ejection control for the P rendering positions in each rendering block through which the head passes, while performing main scanning relatively to
b) By repeating the step a) while changing the arrangement of the P drawing positions related to the P color ink in each drawing block, for each of all the drawing positions in each drawing block Performing P times of discharge control relating to the P color ink;
With
The printing method according to claim 1, wherein the order of ejection control relating to the P-color ink at any two drawing positions adjacent to each other is different in each row and each column of each drawing block. The printing method according to claim 1, comprising:
With the drawing position that is the target of ink ejection control in step a) as the ejection position, the mutual positional relationship of the ejection positions during one main scan of the head is preset as an ejection position array, and the ejection The arrangement of P ejection positions included in each drawing block in the position array is the same in the plurality of drawing blocks,
In the step b), the position of the ejection position array is shifted for each main scanning of the head, whereby the arrangement of the P drawing positions relating to the P color ink in each drawing block is changed. A printing method characterized by the above. The printing method according to claim 2,
The printing method, wherein the P and the N are equal, and the P drawing positions are arranged in the row direction in the step a). The printing method according to claim 3, wherein
In the step b), each time the step a) is repeated, the P drawing positions in each drawing block are changed in the column direction. A printing method according to any one of claims 2 to 4,
In the step b), each time the step a) is repeated, the head moves relative to the print medium in the row direction by a distance equal to or more than N times the pitch in the row direction of the drawing position. A printing method characterized by the above. The printing method according to any one of claims 1 to 5,
A printing method, wherein the printing medium has liquid repellency. The printing method according to claim 6, comprising:
The printing method, wherein the head includes an ink curing unit that cures ink immediately after being ejected onto the print medium. A printing method for performing color printing on a printing medium by an inkjet method,
a) A head having a plurality of ejection port groups arranged in a predetermined row direction and ejecting a plurality of colors of ink from each ejection port group is relative to a print medium in a column direction orthogonal to the row direction. A step of performing ejection control of ink from the plurality of ejection port groups while performing main scanning,
b) a step of moving the head relative to the print medium in the row direction each time main scanning ends;
c) By repeating the steps a) and b), the ink discharge control of the plurality of colors is sequentially performed for each of the drawing positions arranged in the row direction and the column direction on the print medium. A process of performing;
With
In the step a), the ink ejection control is performed on the rows at the drawing positions that exist at every predetermined number of the drawing positions with respect to the column direction, and the row subjected to the ejection control in each a) step is the previous time. A) is changed from that in the process,
The color of ink ejected to each column at the drawing position in each a) step is changed from the color of ink ejected to each column in the previous a) step by the previous b) step. A printing method characterized by being changed to a different color. A printing apparatus that performs color printing on a printing medium by an inkjet method,
A drawing position array which is a drawing position arranged in a row direction and a column direction orthogonal to each other is set, and each of the drawing position arrays has M rows and N columns (M and N are integers of 2 or more). A holding unit for holding a print medium divided into a plurality of drawing blocks as drawing positions;
A head that discharges ink of P color (P is an integer of 2 or more (M × N) or less) toward a print medium;
A scanning mechanism for moving the head relative to the print medium held in the holding unit in the column direction and the row direction;
A controller for controlling the movement of the head by the scanning mechanism and the ejection of ink from the head in synchronization with each other;
With
The control unit is
a) As a discharge control for P drawing positions in each drawing block through which the head passes while main-scanning the head relative to the print medium held in the column direction, A step of performing each discharge control once,
b) By repeating the step a) while changing the arrangement of the P drawing positions related to the P color ink in each drawing block, for each of all the drawing positions in each drawing block Performing P times of discharge control relating to the P color ink;
Run
The printing apparatus according to claim 1, wherein in each row and each column of each drawing block, the order of ejection control related to the P-color ink at any two drawing positions adjacent to each other is different.

Images