JP4687037B2 - Printing control apparatus and printing method control method - Google Patents

Description

The present invention relates to obscure the positional deviation of the landing droplet a simple control to control how the print control apparatus and printing means capable of forming a high quality image.

  2. Description of the Related Art Conventionally, a line type ink jet recording apparatus equipped with a line head in which nozzles are arranged in the maximum print width of a print medium is known. In this line type ink jet recording apparatus, it is only necessary to transport the print medium by a predetermined distance every time printing of one line is completed with the line-in head fixed, and printing is performed if the head is scanned in the main scanning direction. There is an advantage that printing can be performed at a higher speed than a serial type ink jet recording apparatus.

  Here, with reference to FIG. 12, the relationship between the nozzles in the conventional line type ink jet recording apparatus and the landing droplets formed by landing the ink droplets ejected from the nozzles on the printing medium will be described. FIG. 12A is a diagram for explaining an ideal relationship between nozzles and landing droplets in a conventional line type ink jet recording apparatus.

  As shown in FIG. 12A, in the line head 101, five nozzles 102a to 102e are arranged at the same pitch P in the same linear shape (left and right direction in the drawing). Note that the nozzles 102a to 102e are not originally arranged in the same straight line, and the nozzles 102a to 102e are arranged in any one of a plurality of rows arranged in the line head. That is, FIG. 12 shows a state in which the nozzles 102a to 102e for ejecting ink droplets for forming landing droplets arranged in the same straight line are arranged in a pseudo straight line.

  In addition, ink droplets are ejected from the nozzles 102 a to 102 e toward a print medium (not shown) that is conveyed in the conveying direction H (from the upper side to the lower side of the paper) at a position facing the line head 101. Here, the ink droplets ejected from each of the nozzles 102a to 102e land on the print medium, and the size of the area of the landing droplet formed by the landing of the ink droplet is a square pixel (FIG. 12A). It is assumed to be formed in a size that circumscribes (indicated by a one-dot chain line).

  Therefore, when ink droplets are ejected from each of the five nozzles 102a to 102e in the vertical direction toward the printing medium, the ink droplets land on the printing medium and are arranged in a straight line (left and right direction on the paper surface) at a predetermined pitch D. The five landing droplets are formed so as to overlap each other.

  Then, by repeating this operation at a predetermined timing in the process of transporting the printing medium, the landing droplet array A arranged in the vertical direction on the paper surface by the ink droplets ejected from the nozzle 102a, and the landing corresponding to the nozzle 102b similarly. The droplet row B, the landing droplet row C corresponding to the nozzle 102c, the landing droplet row D corresponding to the nozzle 102d, and the landing droplet row E corresponding to the nozzle 102e are formed without a gap.

  However, any of the nozzles 102a to 102e is clogged with dust, dust, solidified ink lump, etc., or the ink adheres around the nozzle and is pulled by the adhered ink. In contrast, ink droplets that should be ejected in the vertical direction may be ejected in an oblique direction with respect to the print medium.

  FIG. 12B shows a nozzle in a state in which ink droplets ejected from the nozzle 102c are ejected in an oblique direction with respect to the print medium for some reason as described above among the five nozzles 102a to 102e. It is a figure for demonstrating the relationship between and a landing droplet.

  As shown in FIG. 12B, when ink droplets are ejected from the nozzle 102c obliquely to the printing medium (closer to the nozzle 102d), the landing droplet array C formed by the ink droplets is the landing droplet. The pitch D2 between the landing droplet row B and the landing droplet row C is formed closer to the row D than the predetermined pitch. Therefore, a gap is formed between the landing droplet row C and the landing droplet row B, and this gap appears to be a streak extending in the print medium conveyance direction H, resulting in a problem that the image quality is deteriorated.

  Therefore, in order to solve this problem, the following Patent Document 1 discloses an ink jet printer including a head vibration unit that vibrates the above-described line head 101. According to this technique, since the line head 101 is vibrated by the head vibrating means, the ink droplets ejected from the nozzles are also shaken according to the vibration of the line head 101, so that the above-described gap can be reduced, and the image quality is improved. Can be suppressed.

As another technique for solving this problem, the following Patent Document 2 provides a plurality of heaters that can be individually driven with respect to one nozzle at different positions in the ink liquid chamber corresponding to one nozzle. A technique for changing a heater to be driven for each line or changing a driving force of a plurality of heaters is disclosed. According to this technique, since the landing position of the ink droplets on the printing medium can be changed, the above-described gap can be reduced, and deterioration in image quality can be suppressed.
JP-A-10-235854 (18th paragraph, FIG. 2 etc.) JP 2002-240287 A (the 52nd paragraph etc.)

  However, the technique disclosed in Patent Document 1 has a problem that it is necessary to mount a head vibration means for vibrating the line head, resulting in an increase in the size of the apparatus and an increase in product cost.

  In addition, for the technique disclosed in Patent Document 2, it is necessary to provide a plurality of heaters that can be individually driven with respect to one nozzle, resulting in a complicated manufacturing process and an increase in product cost. There was a problem that the control for individually controlling the heaters was complicated.

The present invention has been made to solve the above-described problems, and can control a printing control apparatus and a printing unit that can form a high-quality image by making the positional deviation of landing droplets inconspicuous with simple control. It is an object of the present invention to provide a mETHODS.

In order to achieve this object, the printing control apparatus according to claim 1, the ink droplets are ejected from the nozzles so that the landing droplets formed by the ink droplets that land on the printing medium land at a predetermined position corresponding to the print data. An instruction to eject the ink toward the print medium is output to a printing unit having a plurality of nozzles arranged in a first direction orthogonal to the relative movement direction in order to form an image by relative movement in one direction with the print medium. be those, an output means for outputting an instruction to the printing means so that the predetermined landing droplet column shifted in the relative movement direction of the other landing droplet column of landing droplets rows arranged in the relative movement direction, wherein In the case of print data that is printed linearly in the first direction, the output means prints the mark so that ink droplets are ejected further in the direction opposite to the direction of displacement with respect to the nozzle that ejects landing droplets that are displaced in the relative movement direction. And outputs an instruction to the means.
According to a second aspect of the present invention, in the print control apparatus according to the first aspect, the output unit causes the printing unit to shift the landing droplet rows arranged in the relative movement direction in the relative movement direction every predetermined row. Output instructions.
According to a third aspect of the present invention, in the print control apparatus according to the first or second aspect, in the case of print data to be printed in a linear form in the first direction, the output means generates landing droplets that are shifted in the relative movement direction. An instruction is output to the printing means so that an ink droplet is further ejected by one pixel in a direction opposite to the direction of shifting with respect to the ejection nozzle.

The print control apparatus according to claim 4, wherein, in the printing control apparatus according to any one of claims 1 to 3, and the output means, the landing droplets only half the pitch of the landing droplets arranged in the relative movement direction An instruction is output to the printing means so as to shift in the relative movement direction.

The print control device according to claim 5 is the print control device according to any one of claims 1 to 4 , wherein the arrangement of the pixels of the print data is relatively moved by a predetermined number of pixel rows arranged in a relative movement direction. Conversion means for converting so as to deviate in the direction is provided, and the output means outputs an instruction to the printing means so that the landing droplets land according to the arrangement of each pixel converted by the conversion means.

The print control apparatus according to claim 6 is the print control apparatus according to claim 5 , wherein the output unit discharges landing droplets shifted in the relative movement direction in the case of print data to be printed linearly in the first direction. An instruction is output to the printing means so that the density of the landing droplets corresponding to both ends in the relative movement direction is less than the density of the landing droplets corresponding to the print data.

The print control apparatus according to claim 7, wherein, in the print control apparatus according to claim 6, when the print data to be printed in the first direction linearly, with respect to the pixel columns shifted in the relative movement direction, the direction of shifting the Data creation means for additionally creating data so that one pixel is further printed in the opposite direction, and a pixel value that defines the density of the landing droplet is set for each pixel, and printing is performed in a linear form in the first direction In the case of data, pixel value setting means for setting pixel values at both ends of the pixel row to be shifted to be lower than the pixel value corresponding to the print data, and the output means is a pixel set by the pixel value setting. According to the value, an instruction regarding the density of the landing droplet is output to the printing means.

The print control device according to claim 8 is the print control device according to claim 7 , wherein the pixel value setting means is a part of the pixel value of the pixel to be shifted in the case of print data to be printed linearly in the first direction. Are distributed to the pixel value of one pixel added in the direction opposite to the shifting direction, and the distributed pixel value is set as the pixel value of the added pixel.

According to a ninth aspect of the present invention, in the print control apparatus according to the eighth aspect , the ratio of the distributed pixel value is set according to the ratio of the amount of shifting the pixel with respect to the size of one side of each pixel. The

The print control apparatus according to claim 10 , wherein the output means is an ink that lands at a position where the pitch of the landing droplets adjacent in the first direction is formed larger than a predetermined pitch. An instruction is output to the printing unit with respect to at least one of the two nozzles ejecting droplets so that the landing droplet formed by the ink droplet ejected from the first nozzle is shifted in the relative movement direction. The

The print control device according to claim 11, in the print control apparatus according to claim 10, wherein the output means, depending on the pitch of the landing droplet in the relative movement direction that is narrower than the pitch of the landing droplets adjacent in the first direction Thus, an instruction is output to the printing means so that more landing droplets are landed in the relative movement direction than the number corresponding to the print data.

The printing control apparatus according to claim 12 , wherein the output unit is an ink that lands at a position where the pitch of the landing droplets adjacent in the first direction is larger than a predetermined pitch. An instruction is output to the printing unit with respect to at least one of the two nozzles ejecting droplets so that the landing droplet formed by the ink droplet ejected from the first nozzle is shifted in the relative movement direction. The

  A print control apparatus according to a thirteenth aspect is the print control apparatus according to any one of the first to twelfth aspects, wherein the output unit is a print unit that forms an image corresponding to data received from an external device on a print medium. On the other hand, an instruction is output to the printing unit via the interface of the printing unit.

Method for controlling the printing means according to claim 1 4, wherein, as the landing droplets formed by ink droplets landing on the print medium is landed on a predetermined position corresponding to the print data, for the ink droplets to the print medium from the nozzle In order to form an image by relative movement in one direction with respect to the print medium, and to output to the printing means having a plurality of nozzles arranged in a first direction orthogonal to the relative movement direction. An output step of outputting an instruction to the printing means so that a predetermined landing droplet row out of the landing droplet rows arranged in the relative movement direction is shifted in a relative movement direction from other landing droplet rows, and the output step includes: In the case of print data to be printed linearly in the first direction, an instruction is given to the printing means to further eject ink droplets in a direction opposite to the direction of displacement with respect to the nozzles that eject the landing droplets displaced in the relative movement direction. Out To help.

According to the printing control apparatus of claim 1, the printing unit is instructed to land a predetermined landing droplet row out of the landing droplet rows arranged in the relative movement direction so as to deviate from the other landing droplet rows in the relative movement direction. When the instruction is output to the printing unit so that the landing droplets arranged in the relative movement direction are aligned in the relative movement direction even if the landing droplets are displaced in the first direction orthogonal to the relative movement direction for some reason. In comparison, it is possible to reduce a gap generated between the landing droplets adjacent in the first direction. Therefore, there is an effect that a high-quality image can be formed without making the gap generated by the positional deviation of the landing droplets inconspicuous.
In addition, in the case of print data that is printed linearly in the first direction, the printing unit is instructed to eject more ink droplets in the direction opposite to the direction of displacement for the nozzle that ejects the landing droplets displaced in the relative movement direction. In accordance with the print data, a predetermined printing droplet row out of the landing droplet rows arranged in the relative movement direction is landed so as to deviate from the other landing droplet rows in the relative movement direction. There is an effect that the distortion of the image caused by this can be suppressed.

According to the printing control apparatus of the fourth aspect , in addition to the effect produced by the printing control apparatus according to any one of the first to third aspects , the landing droplets that shift in the relative movement direction are the landing droplets arranged in the relative movement direction. since outputs an instruction to the printing means to be shifted by half the pitch, even landing droplets for some reason has shifted in a first direction perpendicular to the relative movement direction, generated between the landing droplets adjacent in the first direction There is an effect that the gap can be reduced most efficiently.

According to the print control apparatus of the fifth aspect , in addition to the effect produced by the print control apparatus according to any one of the first to fourth aspects , the pixel rows arranged in the relative movement direction are shifted in the relative movement direction every predetermined row. Since the instruction is output to the printing means so that the landing droplets land according to the arrangement of each pixel converted into, the landing position of the landing droplets can be adjusted with simple control.

According to the print control device of the sixth aspect , in addition to the effect produced by the print control device according to the fifth aspect , in the case of print data to be printed linearly in the first direction, the landing droplets shifted in the relative movement direction are ejected. Since the instruction is output to the printing means so that the density of the landing droplets corresponding to both ends in the relative movement direction is lower than the concentration of the landing droplets corresponding to the print data, the linear shape is obtained according to the print data. Thus, there is an effect that it is possible to further suppress image distortion caused by landing the landing droplet rows arranged in the relative movement direction so that they are shifted in the relative movement direction every predetermined row.

According to the print control device of the seventh aspect , in addition to the effect produced by the print control device of the sixth aspect , in the case of print data to be printed linearly in the first direction, with respect to the pixel row shifted in the relative movement direction The data is additionally created so that one pixel is further printed in the direction opposite to the shifting direction, and the pixel values at both ends of the shifted pixel row are set to be lower than the pixel values corresponding to the print data, Since an instruction regarding the density of the landing droplet is output to the printing unit according to the set pixel value, there is an effect that the landing position and the density of the landing droplet can be adjusted by simple control.

According to the print control device of the eighth aspect , in addition to the effect produced by the print control device according to the seventh aspect , in the case of print data to be printed linearly in the first direction, a part of the pixel value of the shifted pixel is obtained. The pixel value of one pixel added in the direction opposite to the shifting direction is distributed, and the distributed pixel value is set as the pixel value of the added pixel. There is an effect that the pixel value can be set to be lower than the pixel value corresponding to the print data.

According to the printing control apparatus of the ninth aspect , in addition to the effect produced by the printing control apparatus of the eighth aspect , the ratio of the distributed pixel value is an amount of shifting the pixel with respect to the size of one side of each pixel. Since it is set according to the ratio, the density of the landing droplet can be set according to the amount to be shifted. Therefore, there is an effect that image distortion can be suppressed according to the amount of shift.

According to the printing control apparatus of the tenth aspect , in addition to the effect produced by the printing control apparatus according to the second aspect, the pitch of the adjacent landing droplets in the relative movement direction is set to be larger than the pitch of the adjacent landing droplets in the first direction. Since the instruction is output to the printing means so as to narrow, the pitch of the adjacent landing droplets in the relative movement direction and the pitch of the adjacent landing droplets in the first direction are the same for some reason. Even if the landing droplets lined up in the movement direction are displaced in the first direction, it is possible to make it difficult to generate a gap between adjacent landing droplets lined up in the relative movement direction. Therefore, there is an effect that a high-quality image can be formed without making the gap generated by the positional deviation of the landing droplets inconspicuous.

According to the printing control apparatus of the eleventh aspect , in addition to the effect produced by the printing control apparatus according to the tenth aspect , the pitch of the landing droplets in the relative movement direction is narrower than the pitch of the adjacent landing droplets in the first direction. Accordingly, an instruction is output to the printing means so that more landing droplets are landed in the relative movement direction than the number corresponding to the print data. Therefore, even if the pitch of the landing droplets in the relative movement direction is the landing droplet pitch in the first direction, Even if the pitch is made narrower than the pitch of, the ratio of the sizes of the relative movement direction and the first direction can be made substantially the same as the case where the pitches of the landing droplets in the relative movement direction and the first direction are the same. Therefore, there is an effect that image distortion can be suppressed and a high-quality image can be formed.

According to the printing control apparatus of claim 12, wherein, in addition to the effects of the print control apparatus according to claim 1, lands on the position where the pitch of the landing droplets adjacent in the first direction is larger than a predetermined pitch An instruction is output to the printing unit so that the landing droplet formed by the ink droplet ejected from the first nozzle is shifted in the relative movement direction with respect to at least one of the two nozzles ejecting the ink droplet. Therefore, the pitch of the landing droplets adjacent in the first direction becomes larger than the predetermined pitch, and the gap generated between the adjacent landing droplets can be reduced. Therefore, there is an effect that a high-quality image can be formed without making the gap generated by the positional deviation of the landing droplets inconspicuous.

  According to the print control apparatus of the thirteenth aspect, in addition to the effect produced by the print control apparatus according to any one of the first to twelfth aspects, the output means outputs an image corresponding to the data received from the external apparatus to the print medium. Since an instruction is output to the printing unit via the printing unit interface to the printing unit to be formed, it is possible to control even a printing unit not equipped with this printing control apparatus. Therefore, there is an effect that a high-quality image can be formed using the printing unit without affecting the structure of the printing unit itself or the product cost.

According to the method for controlling the printing means according to claim 1 4, wherein the printing means so as to land shifted in the relative movement direction of the other landing droplet column a predetermined landing droplet column of landing droplets rows arranged in the relative movement direction The instruction is output to the printing means so that the landing droplets aligned in the relative movement direction are aligned in the relative movement direction even if the landing droplets are displaced in the first direction orthogonal to the relative movement direction for some reason. Compared with the case where it does, the clearance gap produced between the landing droplets adjacent to a 1st direction can be reduced. Therefore, there is an effect that a high-quality image can be formed without making the gap generated by the positional deviation of the landing droplets inconspicuous.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a personal computer 1 (hereinafter referred to as “PC1”) as a print control apparatus according to one embodiment of the present invention, and an inkjet printer 1A (hereinafter referred to as “printer 1A”) connected to the PC1 via a communication cable 40. Is a schematic diagram showing.

  The PC 1 instructs the communication cable 40 to eject ink droplets from each nozzle toward the print medium so that the landing droplets formed by the ink droplets that land on the print medium have a predetermined size corresponding to the print data. And an LCD 42 for displaying an output image and a keyboard 43 for inputting instructions to be output to the printer 1A.

  In addition to the PC 1, any printing device such as a tablet or PDA can be used as the print control device. Further, as a communication means for outputting an instruction from the PC 1 to the printer 1A, a wireless LAN module such as WIFI can be adopted in addition to the communication cable 40.

  The printer 1A is a color ink jet printer having four ink jet heads 3, and ejects ink droplets from the nozzles formed in each ink jet head 3 toward a printing medium in accordance with instructions output from the PC 1, and the inks. An image is formed by landing droplets formed by droplets landing on a print medium.

  The printer 1A includes a paper feed unit 4 on the left side in the drawing and a paper discharge unit 5 on the right side in the drawing. Inside the printer 1A, there is a print medium from the paper feed unit 4 toward the paper discharge unit 5. A paper conveyance path for conveyance is formed.

  A pair of feed rollers 6 a and 6 b that sandwich and convey the print medium are disposed immediately downstream of the paper feed unit 4. The print medium is fed from the left to the right in the figure by the pair of feed rollers 6a and 6b.

  Two belt rollers 7a and 7b and an endless conveyor belt 8 wound around the rollers 7a and 7b are disposed in the intermediate portion of the sheet conveyance path. The outer peripheral surface of the conveyance belt 8, that is, the conveyance surface is subjected to silicon treatment, and the print medium conveyed by the pair of feed rollers 6a and 6b is held on the conveyance surface of the conveyance belt 8 by its adhesive force, The belt roller 7a can be conveyed toward the downstream side (right side) by being rotated clockwise (in the direction of arrow 9) in the drawing.

  Holding members 10a and 10b are disposed at insertion and discharge positions with respect to the belt rollers 7a and 7b, respectively. The pressing members 10a and 10b are for pressing the print medium against the conveyance surface of the conveyance belt 8 so that the print medium on the conveyance belt 8 does not float from the conveyance surface and causing the printing medium to adhere securely to the conveyance surface.

  A peeling mechanism 11 is provided immediately downstream of the conveying belt 8 along the sheet conveying path. The peeling mechanism 11 is configured to peel the print medium adhered to the conveyance surface of the conveyance belt 1 from the conveyance surface and send it to the right paper discharge unit 5.

  The four inkjet heads 3 have a head body 12 at the lower end. The head main bodies 12 each have a rectangular cross section, and are arranged close to each other and fixed so that the longitudinal direction thereof is a direction perpendicular to the paper transport direction (the direction perpendicular to the paper surface in FIG. 1). That is, the printer 1A is a line printer. The bottom surfaces of the four head bodies 12 face the sheet conveyance path, and a large number of nozzles having a minute diameter are provided on these bottom surfaces. Magenta, yellow, cyan, and black ink droplets are ejected from each of the four head bodies 12.

  The inkjet head 3 is a line head in which a plurality of nozzles are formed at a predetermined pitch in the main scanning direction. The ink-jet head 3 is fixed to the frame of the printer 1A. The printer 1A moves the print medium in the sub-scanning direction to move the ink-jet head 3 and the print medium relative to each other, and moves from the ink-jet head 3 as the print medium moves. An image is formed on the print medium by ejecting ink droplets.

  In this embodiment, the moving direction of the print medium is the relative moving direction of the claims. Note that the inkjet head 3 may be moved while fixing the print medium. In this case, the movement direction of the inkjet head 3 is the relative movement direction of the claims.

  The head main body 12 is disposed so that a small amount of gap is formed between the lower surface of the head main body 12 and the conveyance surface of the conveyance belt 8, and a sheet conveyance path is formed in the gap portion. With this configuration, when the print medium transported on the transport belt 8 sequentially passes immediately below the four head bodies 12, ink droplets of each color are ejected from the nozzles toward the upper surface of the print medium, that is, the print surface. Thus, a desired color image can be formed on the print medium.

  The printer 1 </ b> A has a maintenance unit 14 for automatically performing maintenance on the inkjet head 3. The maintenance unit 14 is provided with four caps 15 for covering the lower surfaces of the four head bodies 12 and a purge mechanism (not shown).

  The maintenance unit 14 is located at a position (retracted position) immediately below the paper feed unit 4 when printing is performed by the printer 1A. When a predetermined condition is satisfied after the printing is finished (for example, when a state where no printing operation is performed continues for a predetermined time or when the printer 1A is turned off), the four head bodies 12, the cap 15 covers the lower surface of the head body 12 at this position (cap position) to prevent the ink in the nozzle portion of the head body 12 from drying out. .

  The belt rollers 7 a and 7 b and the transport belt 8 are supported by the chassis 16. The chassis 16 is placed on a cylindrical member 17 disposed below the chassis 16. The cylindrical member 17 is rotatable around a shaft 18 attached at a position off the center. Therefore, when the upper end height of the cylindrical member 17 changes with the rotation of the shaft 18, the chassis 16 moves up and down accordingly. When the maintenance unit 16 is moved from the retracted position to the cap position, the cylindrical member 17 is rotated in advance by an appropriate angle so that the chassis 16, the conveyor belt 8 and the belt rollers 7a and 7b are moved by an appropriate distance from the position shown in FIG. It is necessary to secure a space for the maintenance unit 14 to move down.

  In a region surrounded by the conveyor belt 8, a substantially rectangular parallelepiped shape (supporting the conveyor belt 8 and the conveyor belt 8) is supported from the inner peripheral side by contacting the lower surface of the conveyor belt 8 at a position facing the head body 12, that is, the upper side. A guide 19 having a similar width is disposed.

  FIG. 2 is a block diagram showing an outline of an electric circuit configuration of the PC 1 and the printer 1A. The PC 1 includes a CPU 44, a hard disk 47, an interface 48, an LCD 42, and a keyboard 43, which are connected via an input / output port 49.

  A ROM 45 and a RAM 46 are connected to the CPU 44, which is an arithmetic device, via a data bus. The CPU 44 executes various programs stored in the ROM 45.

  The ROM 45 is a non-rewritable nonvolatile memory, and stores a pixel arrangement conversion program 45a executed by the CPU 44, a pixel value distribution program 45b, various control programs, fixed value data, and the like.

  The pixel arrangement conversion program 45a is a program for converting the pixel arrangement as the initial print data or newly arranging the pixels. Specifically, as the initial print data shown in FIG. This is a program for converting the pixel arrangement into the pixel arrangement shown in FIG. 4B or 4C.

  The pixel value distribution program 45b is a program for setting the pixel value of each pixel in the pixel arrangement converted by the pixel arrangement conversion program 45a. Specifically, the pixel value distribution program 45b is a program for executing the processing of the flowchart shown in FIG.

  The RAM 46 is a rewritable volatile memory and temporarily stores various data. The hard disk 47 is a rewritable nonvolatile memory. The interface 48 is a communication unit that is connected to the interface 33 of the printer 1A, which will be described later, via the communication cable 40 and outputs print data to the printer 1A.

  On the other hand, the printer 1A includes a microcomputer (CPU) 20, a ROM 21, a RAM 22, an EEPROM 23, a gate array (G / A) 24, a head driver 25, and the like having a one-chip configuration. The CPU 20, ROM 21, RAM 22, EEPROM 23, gate array 24, and head driver 25 are connected via an address bus 26 and a data bus 27.

  The CPU 20, which is an arithmetic unit, executes control such as ejection of ink droplets, detection of the remaining amount of ink in the cartridge, and presence / absence of ink in accordance with a control program stored in advance in the ROM 21. Further, an ejection timing signal and a reset signal are generated, and each signal is transferred to a gate array 24 described later.

  Further, the CPU 20 is provided with an operation panel 28 for a user to give a print instruction, a motor drive circuit 30 for operating a transport motor (LF motor) 29 for transporting the print medium, and a front end of the print medium. A paper sensor 31 to be detected is connected, and the operation of each device is controlled by the CPU 20.

  The ROM 21 is a non-rewritable nonvolatile memory, and stores various control programs for controlling ink droplet ejection executed by the CPU 20 and other fixed value data. The RAM 22 is a rewritable volatile memory and temporarily stores various data. The EEPROM 23 is a rewritable nonvolatile memory.

  The gate array 24, in accordance with the print timing signal transferred from the CPU 20, based on the image data stored in the image memory 32, print data (drive signal) for printing the image data on a print medium, and the print A transfer clock CLK synchronized with data, a latch signal, a parameter signal for generating a basic print waveform signal, and an ejection timing signal JET output at a constant cycle are output, and these signals are output to the head driver 25. Output to.

  Further, the gate array 24 stores print data transferred from the PC 1 via the interface 33 in the image memory 32.

  The head driver 25 is a drive circuit that applies a drive pulse having a waveform corresponding to a signal output from the gate array 24 to a drive element corresponding to each nozzle. The drive element is actuated by this drive pulse, and ink droplets are ejected from each nozzle.

  Next, a first embodiment in which the printer 1A is controlled by the PC 1 will be described with reference to FIG. FIG. 3A is a diagram for explaining the relationship between the nozzles 35a and the like formed on the inkjet head 3 and the landing droplets formed by the ink droplets ejected from the nozzles 35a and the like. FIG. 3B is a diagram illustrating a state where the ink droplets ejected from the nozzle 35c land near the nozzle 35d for some reason when the landing droplet is landed as illustrated in FIG. 3A.

  In the first embodiment, as shown in FIG. 12A, an instruction is output to the printer 1A so that the landing droplets are aligned and landed in 4 rows and 5 columns as shown in FIG. As shown in a), the printer 1A is instructed so that the landing droplet rows B and D are shifted in the print medium transport direction H (hereinafter referred to as “sub-scanning direction H”) with respect to the landing droplet rows A, C, and E. Output. That is, an instruction is output to the printer 1A so that the landing droplet rows arranged in the sub-scanning direction H are shifted in the sub-scanning direction H every other row.

  Therefore, in the same manner as described with reference to FIG. 12, the ink droplets discharged from the nozzle 35c for some reason are discharged closer to the nozzle 35d, and the landing droplets that should land as shown in FIG. As shown in FIG. 12B, even if the landing droplet row C lands near the landing droplet row D and the distance between the landing droplet row B and the landing droplet row C becomes larger than a predetermined pitch as shown in FIG. Compared to the gap formed between the landing droplet row B and the landing droplet row C, the gap can be reduced, and the deterioration of the image quality can be suppressed.

  Further, in this case, an instruction is output to the printer 1A so that the landing droplet rows B and C are shifted in the sub-scanning direction by approximately half (1/2 * D) of the pitch D of each landing droplet arranged in the sub-scanning direction H. As the landing droplet row C lands closer to the landing droplet row D, the gap between the landing droplet row B and the landing droplet row C is widened, but the gap formed between the landing droplet row B and the landing droplet row C is the largest. It can be reduced efficiently.

  Next, a specific control method for landing the landing droplets as described in FIG. 3 will be described with reference to FIG. FIG. 4A shows a pixel arrangement of 4 rows and 5 columns as initial print data. FIG. 4B and FIG. 4C show a state where the pixel arrangement shown in FIG. 4A is converted. FIG. 4D shows the state of the pixel values set for each pixel in the pixel arrangement shown in FIG.

  Conventionally, the PC 1 outputs to the printer 1A an instruction for landing droplets on each pixel according to the pixel arrangement as the initial print data shown in FIG. 4A, and the printer 1A follows the instruction from the PC 1. Ink droplets are ejected. In this case, the landing droplets land as shown in FIG.

  On the other hand, in the first embodiment, the pixel arrangement shown in FIG. 4A is converted into the pixel arrangement shown in FIG. 4B by the pixel arrangement conversion program 45a. That is, conversion is performed so that the second and fourth pixel columns are shifted in the sub-scanning direction H by half (1/2 * D) of the pixel pitch D in the sub-scanning direction H.

  Then, when an instruction is given from the PC 1 to the printer 1A so that the landing droplets land on each pixel in accordance with the converted pixel arrangement shown in FIG. 4B, the printer 1A ejects ink drops according to the instruction from the PC 1. . Thus, the landing droplet can be landed as shown in FIG.

  Here, when the pixel arrangement shown in FIG. 4A is viewed as print data for printing a linear image extending in the main scanning direction orthogonal to the sub-scanning direction H, the pixel arrangement shown in FIG. It can be viewed as print data for forming a staggered image extending in the scanning direction.

  That is, the pixel arrangement shown in FIG. 4A as the initial print data is converted as shown in FIG. 4B by the pixel arrangement conversion program 45a, so that the image formed in accordance with the converted pixel arrangement is an image. Distortion will occur.

  Therefore, in the first embodiment, in order to suppress the distortion of the image, an instruction is output to the printer 1A so that ink droplets are further ejected by one pixel in the direction opposite to the shifting direction. Therefore, the pixel arrangement shown in FIG. 4A is converted by the pixel arrangement conversion program 45a as shown in FIG. 4C instead of FIG. 4B. Specifically, in the second and fourth columns as the pixel columns shifted in the sub-scanning direction, the pixel “0-2” and the pixel “0−” are newly set so that the landing droplets land in the direction opposite to the shifting direction. 4 ”.

  Further, the PC 1 outputs an instruction to the printer 1A so that the density of the landing droplets corresponding to both ends shifted in the sub-scanning direction is lower than the concentration of the landing droplets corresponding to the print data. Therefore, in the second and fourth columns as the pixel columns shifted in the sub-scanning direction by the pixel value distribution program 45b, the pixel “0-2”, the pixel “4-2”, and the pixel “0” located at both ends thereof -4 "and pixel" 4-4 "are set to be lower than the pixel values corresponding to the print data.

  This pixel value is set for each pixel and defines the density of the landing droplet corresponding to each pixel. For example, the pixel value is expressed by a value from 0 to 255, and the printer 1A has a small ink droplet for a pixel set to a pixel value from 0 to 84, and a pixel set to a pixel value from 85 to 169. , Medium ink droplets are ejected, and large ink droplets are ejected to pixels set to pixel values of 169 to 255.

  As a result, the larger the size of the ink droplet, the deeper the landing droplet. The density of the landing droplet is not limited to the case where it is adjusted depending on the size of the ink droplet, and if a low density ink other than magenta, yellow, cyan, and black is provided, this may be used.

  Therefore, for example, assume that 250 is set as the initial pixel value for each pixel shown in FIG. 4A as the initial print data. In this case, the printer 1A ejects a large ink droplet so as to form a large landing droplet on each pixel according to the pixel value of each pixel.

  On the other hand, in the first embodiment, the PC 1 converts the pixel arrangement shown in FIG. 4A to the pixel arrangement shown in FIG. 4C using the pixel arrangement conversion program 45a, and then converts the pixel arrangement shown in FIG. In the pixel column of the column, the pixel value 125 that is a part of the original pixel value 250 of the pixel “1-2” is distributed to the pixel “0-2”, and the pixel value of the pixel “0-2” is set to 125. Set. The pixel value of the pixel “0-2” newly added by the pixel arrangement conversion program 45a is initially set to 0.

  Then, as a result of distributing a part of the pixel value to the pixel “0-2”, a part of the original pixel value 250 of the pixel “2-2” with respect to the pixel “1-2” having a pixel value of 125 The pixel value 125 is distributed to the pixel “1-2”, and the pixel value of the pixel “1-2” is set again to the same 250 as the initial value.

  When this process is repeated for each pixel constituting the second column, the pixel values of the pixel “0-2” and the pixel “4-2” in the second column are eventually set to 125, The pixel values of the pixels “1-2” to “3-2” are set to 250, which is the same as the initial value.

  A similar process is performed on each pixel constituting the fourth column, and the pixel values of the pixels “0-4” and “4-4” in the fourth column are 125. And the pixel value from pixel “1-4” to pixel “3-4” is set to 250. The pixel values of the pixels constituting the first, third, and fifth columns are left at the original pixel value 250.

  Thus, in the second and fourth columns as the pixel columns shifted in the sub-scanning direction by the pixel value distribution program 45b, the pixel “0-2” and the pixel “4-2” positioned at both ends thereof, By setting the pixel values of “0-4” and the pixel “4-4” to 125, which is half the pixel value 250 corresponding to the initial print data, the pixel “0-2” and the pixel “4-2” Then, an instruction can be output to the printer 1A so that the density of the landing droplets corresponding to the pixels “0-4” and “4-4” is lower than the concentration of the landing droplets corresponding to the other pixels. .

  Therefore, when a linear image is printed in the main scanning direction according to the pixel arrangement shown in FIG. 4A, the pixel arrangement is simply shown in FIG. 4B in order to reduce the gap caused by the landing droplets being displaced. As described above, the pixel arrangement “0-2” and the pixel are arranged in the pixel arrangement shown in FIG. 4A, rather than instructing the landing droplets to land so as to correspond to the converted pixels. “0-4” is newly added, and the density of the landing droplets corresponding to the pixel “0-2” and the pixel “4-2”, and the pixel “0-4” and the pixel “4-4” are further added. Is instructed to be lighter than the density specified in the initial print data, the pixel “0-2”, the pixel “4-2”, the pixel “0-4”, and the pixel “4-4” Corresponding landing droplets become inconspicuous and a more linear image is formed. Image distortion can be suppressed against.

  Next, with reference to FIG. 5, the case where a linear image thinner than the above-mentioned case is printed is demonstrated. FIG. 5A shows a pixel arrangement as initial print data. FIG. 5B shows a state where the pixel arrangement shown in FIG. FIG. 5C shows the pixel values of each pixel in the pixel arrangement shown in FIG.

  In order to instruct the printer 1A to eject ink droplets corresponding to each pixel in accordance with the pixel arrangement shown in FIG. 5A as the initial print data, as in the case described above, FIG. The pixel arrangement shown in FIG. 5A is converted as shown in FIG. 5B by the pixel arrangement conversion program 45a.

  Specifically, the pixel “1-2” and the pixel “1-4” are shifted in the sub-scanning direction, and the new pixel “0-2” so that the landing droplets land in the direction opposite to the shifting direction. And pixel “0-4” are arranged.

  Further, the pixel value of each pixel arranged as shown in FIG. 5B is set as follows from the pixel value distribution program 45b. Note that 250 is set as the initial pixel value for each pixel as the initial print data shown in FIG. 5A, and the newly added pixel “0-2” and pixel “0-4” It is assumed that 0 is set as the pixel value.

  That is, a part of the pixel value 125 of the initial pixel value 250 of the pixel “1-2” shifted in the sub-scanning direction is distributed to the pixel “0-2”, and the newly set pixel “0-2” and pixel The pixel value “1-2” is set to 125. Similarly, a partial pixel value 125 of the initial pixel value 250 of the pixel “1-4” shifted in the sub-scanning direction is distributed to the pixel “0-4”, and the newly set pixel “0-4” and The pixel value of the pixel “1-4” is set to 125. Note that the pixel values of the pixel “1-1”, the pixel “1-3”, and the pixel “1-5” are kept at the original pixel value 250.

  As described above, in the pixel column shifted in the sub-scanning direction by the pixel value distribution program 45b, the pixel “0-2” and the pixel “1-2”, the pixel “0-4”, and the pixel “1” located at both ends thereof are arranged. -4 "is set to 125, which is half the pixel value 250 corresponding to the print data, so that the pixel" 0-2 "and the pixel" 1-2 "and the pixel" 0-4 "and the pixel An instruction can be output to the printer 1A so that the density of the landing droplet corresponding to “1-4” is lower than the density of the landing droplet corresponding to the other pixels.

  Therefore, even when a linear image thinner than that described in FIG. 4 is printed in the main scanning direction according to the pixel arrangement shown in FIG. Since the landing droplets corresponding to “1-2”, the pixel “0-4”, and the pixel “1-4” become inconspicuous and a more linear image is formed, the image is distorted with respect to the linear image. Can be suppressed.

  Next, the pixel value setting method described above with reference to FIGS. 6 and 7 will be described. FIG. 6A is a diagram showing a state in which the pixels subjected to the arrangement conversion by the pixel arrangement conversion program 45a are applied to the XY coordinate system, and FIG. 6B is a partially enlarged view of the arrangement-converted pixels. It is a figure for demonstrating the setting method of a rate.

  As shown in FIG. 6A, in the pixel arrangement shifted by one column in the sub-scanning direction by the pixel arrangement conversion program 45a, the uppermost pixel in the leftmost column is set as the origin, the X axis in the right direction, A coordinate system with the Y axis in the left direction is assigned.

  It is assumed that the pixel value of each pixel is L (X, Y), X is set in the range of “0” to “Xmax”, and Y is set in the range of “0” to “Ymax”.

  As shown in FIG. 6B, the pixel value distribution ratio R is set according to the ratio of the amount S of shifting the pixel to the length T of one side of each pixel. In this embodiment, since the pixel is shifted by half of one side length, the distribution ratio R is “½”.

  FIG. 7 is a flowchart of pixel value distribution processing. This process is a process executed by the CPU 44 based on the pixel value distribution program 45b. In this process, first, the coordinates (X, Y) are initialized (S1). Next, it is determined whether or not X is an even number (S2). If X is an odd number (S2: No), the process proceeds to S9, and “1” is added to X.

  On the other hand, if X is an even number (S2: Yes), the distribution amount M is calculated (S3). The distribution amount M is calculated by multiplying the pixel value L (X, Y + 1) of the pixel adjacent to the target pixel in the positive direction of the Y axis by the distribution ratio R. When the distribution amount M is calculated, the pixel value L (X, Y) of the target pixel is calculated (S4). The pixel value L (X, Y) of the target pixel is calculated by adding the distribution amount M to the pixel value L (X, Y) of the target pixel. Next, the distribution amount M is subtracted from the pixel value L (X, Y + 1) of the pixel adjacent in the positive direction of the Y axis with respect to the target pixel (S5).

  In this way, the process for the target pixel is finished, and “1” is added to Y to process the next target pixel (S6), and whether or not the Y value of the next target pixel has reached the lower end (Ymax−1). Is determined (S7), and if it is reached (S7: Yes), Y is initialized (= 0) (S8). If not reached (S7: No), the processing from S3 is repeated.

  Then, in order to repeat the above-described processing for the pixels in the next column, “1” is added to X (S9), and whether or not X in the state where “1” is added has reached the right end (Xmax + 1) is determined. If it is determined (S10) and has been reached (S10: Yes), this process is terminated. On the other hand, if not reached (S10: No), the processing from S2 is repeated.

  Next, referring to FIG. 8 (a), as a second embodiment of the present invention, the pitch of the nozzles 35a to 35e is set to a pitch q smaller than the pitch p of the conventional nozzle described in FIG. explain. FIG. 8A is a diagram for explaining the relationship between the nozzles 35a and the like and the landing droplets formed by the ink droplets ejected from the nozzles 35a and the like.

  In the second embodiment, the pitch of the nozzles 35a and the like is made smaller than that in the conventional case of FIG. 12, and the ejection timing interval in the sub-scanning direction H is the same as that in the conventional case of FIG. The droplet pitch is made smaller than the pitch of the landing droplets arranged in the sub-scanning direction. Thereby, the overlapping part of the adjacent landing droplets arranged in the main scanning direction becomes larger than the overlapping part of the adjacent landing droplets arranged in the sub scanning direction.

  Therefore, according to the second embodiment, as shown in FIG. 8A, the ink droplets ejected from the nozzle 35c are ejected toward the nozzle 35d, and the landing droplet row B is formed closer to the landing droplet row C. Even if the landing droplet row B and the landing droplet row C are still overlapped, the gap generated between the landing droplet row B and the landing droplet row C is compared with the case shown in FIG. Can be reduced. Therefore, it is possible to form a high-quality image without making the gap inconspicuous.

  On the other hand, by narrowing the nozzle pitch, the overlapping portion of landing droplets in the main scanning direction becomes larger than the overlapping portion in the sub scanning direction, and the ratio of the size of the main scanning direction and the sub scanning direction in the initial print data is the main. It becomes smaller in the scanning direction and the image is distorted.

  Therefore, in the second embodiment, an instruction is output to the printer 1A so that many landing droplets are landed in the main scanning direction according to the interval in which the pitch of the nozzles 35a and the like is reduced. As a result, the size ratio between the main scanning direction and the sub-scanning direction approaches the ratio of the size corresponding to the print data, and distortion of the image can be suppressed.

  Specifically, when the pixel arrangement of 4 rows and 5 columns as shown in FIG. 4A is given as the initial print data, the pixel arrangement conversion program 45a sets the intervals of the nozzles 35a and the like to a close interval. In response to this, for example, an additional four pixel columns are added to convert the pixel arrangement into a 4 × 8 pixel arrangement, and an instruction is output to the printer 1A to eject ink droplets to each pixel of the pixel arrangement after the arrangement conversion. To do. As a result, the size ratio between the main scanning direction and the sub-scanning direction approaches the ratio of the size corresponding to the initial print data, and distortion of the image can be suppressed.

  Next, the control of the third embodiment by the PC 1 will be described with reference to FIG. FIG. 8B is a diagram for explaining the relationship between the nozzles 35a and the like and the landing droplets formed by the ink droplets ejected from the nozzles 35a and the like.

  In the third embodiment, the nozzle pitch is set to be the same as that in the prior art in FIG. 12, and the discharge timing interval in the sub-scanning direction is made shorter than in the prior art in FIG. Thereby, the overlapping part of the adjacent landing droplets arranged in the sub-scanning direction becomes larger than the overlapping part of the adjacent landing droplets arranged in the main scanning direction.

  Therefore, according to the third embodiment, as shown in FIG. 8B, the ink droplets ejected from the nozzle 35c are ejected toward the nozzle 35d, and the landing droplet row B is formed closer to the landing droplet row C. Even if the landing droplet row B and the landing droplet row C are still close to each other, the gap generated between the landing droplet row B and the landing droplet row C is compared with the case shown in FIG. Can be reduced. Therefore, it is possible to form a high-quality image without making the gap inconspicuous.

  On the other hand, by reducing the discharge timing interval in the sub-scanning direction, the overlapping portion of landing droplets in the sub-scanning direction becomes larger than the overlapping portion in the main scanning direction, and the size between the sub-scanning direction and the main scanning direction in the initial print data is increased. The ratio becomes smaller in the sub-scanning direction, and the image is distorted.

  Therefore, in the second embodiment, an instruction is output to the printer 1A so that many landing droplets land in the sub-scanning direction according to the discharge timing interval in the sub-scanning direction to be reduced. As a result, the ratio of the size between the sub-scanning direction and the main scanning direction approaches the ratio corresponding to the print data, and distortion of the image can be suppressed.

  Specifically, when the pixel arrangement of 4 rows and 5 columns as shown in FIG. 4A is given as the initial print data, the pixel arrangement conversion program 45a sets the discharge timing interval in the reduced sub-scanning direction. In response to this, for example, an additional two pixel columns are added to convert the pixel arrangement into a 6 × 5 pixel arrangement, and an instruction is output to the printer 1A to eject ink droplets to each pixel of the pixel arrangement after the arrangement conversion. To do. As a result, the size ratio between the main scanning direction and the sub-scanning direction approaches the ratio of the size corresponding to the initial print data, and distortion of the image can be suppressed.

  Next, the control of the fourth embodiment by the PC 1 will be described with reference to FIG. In the fourth embodiment, the printer 1A is controlled by combining the first embodiment described with reference to FIG. 3 and the second embodiment described with reference to FIG.

  FIG. 9A is a diagram for explaining the relationship between the nozzles 35a and the like and the landing droplets formed by the ink droplets ejected from the nozzles 35a and the like. FIG. FIG. 6 is a diagram illustrating a state when ink droplets ejected from a nozzle 35c land near the nozzle 35d for some reason when landing droplets are landed as shown in a).

  Specifically, in the fourth embodiment, as described in the first embodiment, each landing row or the like aligned in the sub-scanning direction H has a pitch D of landing droplets aligned in the sub-scanning direction H every other row. Substantially half (1/2 * D) is shifted in the sub-scanning direction, and the pitch q is smaller than that of the prior art in FIG. 12 as in the second embodiment of FIG. The discharge timing interval in the scanning direction is the same as that in the conventional case of FIG. 12, and further, an instruction is output to the printer 1A so that many landing droplets are landed in the main scanning direction according to the interval in which the pitch of the nozzles 35a and the like is reduced. To do.

  A specific control method can be achieved by combining the first embodiment and the second embodiment described above, and the description thereof will be omitted.

  By controlling in this way, as shown in FIG. 9B, the landing droplets that should have landed are ejected from the nozzle 35d for some reason from the nozzle 35d. As shown in FIG. 12B, even if the landing droplet row C is formed closer to the landing droplet row D, the gap generated between the landing droplet B and the landing droplet C can be reduced as compared with the conventional case shown in FIG. it can.

  Next, the control of the fifth embodiment by the PC 1 will be described with reference to FIG. FIG. 10A shows the fifth embodiment in which the printer 1A is controlled in a mode in which the first embodiment described in FIG. 3 and the third embodiment described in FIG. 8B are combined. .

  FIG. 10A is a diagram for explaining the relationship between the nozzles 35a and the like and the landing droplets formed by the ink droplets ejected from the nozzles 35a and the like. FIG. FIG. 6 is a diagram illustrating a state when an ink droplet ejected from a nozzle 35c has landed near the nozzle 35d for some reason when landing a landing droplet as shown in a).

  Specifically, in the fifth embodiment, in the same manner as described in the first embodiment, each landing row arranged in the sub-scanning direction H has a pitch D of landing droplets arranged in the sub-scanning direction H every other row. About half (1/2 * D) is shifted in the sub-scanning direction, and the nozzle pitch p is the same as that of the conventional example of FIG. 12, as described in the second embodiment of FIG. The discharge timing interval in the sub-scanning direction is made shorter than that in the conventional case of FIG. 12, and further, the printer 1A is instructed to land a lot of landing droplets in the sub-scanning direction in accordance with the discharge timing interval in the sub-scanning direction to be smaller. Is output. A specific control method can be achieved by combining the first embodiment and the third embodiment described above, and the description thereof will be omitted.

  By controlling in this way, as shown in FIG. 10B, the landing droplets that should have landed are ejected from the nozzle 35d for some reason from the nozzle 35d. As shown in FIG. 12B, even if the landing droplet row C is formed closer to the landing droplet row D, the gap generated between the landing droplet B and the landing droplet C can be reduced as compared with the conventional case shown in FIG. it can.

  Next, the control of the sixth embodiment by the PC 1 will be described with reference to FIG. FIGS. 11A and 11B are views for explaining the relationship between the nozzles 35a and the like and the landing droplets formed by the ink droplets ejected from the nozzles 35a and the like.

  In the first embodiment described above, every other droplet droplet array arranged in the sub-scanning direction is arranged so that it is possible to cope with the fact that the nozzle that ejects in the oblique direction without being ejected in the vertical direction with respect to the print medium can be dealt with. In the sixth embodiment, the nozzles that discharge in the oblique direction without being discharged in the vertical direction with respect to the printing medium are specified in advance, and the control is performed accordingly. Control.

  In the sixth embodiment, the gap formed between the landing droplet rows is read from the density difference using, for example, a CCD line scanner, so that the pitch of the landing droplets adjacent in the main scanning direction is formed larger than the predetermined pitch. Two nozzles for ejecting ink droplets that land on the specified position are specified.

  Specifically, in this embodiment, the ink droplets ejected from the nozzle 35c land near the nozzle 35d, and the pitch D2 between the landing row B and the landing row C is larger than the pitch of other adjacent landing droplet rows. Since they are formed, the nozzle 35b and the nozzle 35c are specified as the two nozzles.

  Then, control is performed so that only one of the two nozzles 35b and 35c is displaced in the sub-scanning direction H by the landing droplet formed by the ink droplets ejected from the nozzle.

  FIG. 11A shows a state in which the landing droplet row B corresponding to the nozzle 35b is shifted in the sub-scanning direction. As a result, even if the ink droplets ejected from the nozzle 35c are ejected from the nozzle 35d and the landing droplet row C is formed from the landing droplet row D, the landing droplet row B and the landing droplet row C are between them. The generated gap can be reduced as compared with the conventional case shown in FIG.

  On the other hand, FIG. 11B shows a state in which the landing droplet row C corresponding to the nozzle 35 c is shifted in the sub-scanning direction H. Even in this case, even when the ink droplets ejected from the nozzle 35c are ejected from the nozzle 35d and the landing droplet row C is formed from the landing droplet row D, as in the case of FIG. The gap generated between the landing droplet row B and the landing droplet row C can be reduced as compared with the conventional case shown in FIG.

  In this way, by specifying nozzles that discharge in an oblique direction without being discharged in the vertical direction with respect to the print medium in advance, every other row as described in the first embodiment is performed by performing control corresponding thereto. As compared with the case where the landing droplet rows are controlled to be shifted, the number of landing droplet rows shifted in the sub-scanning direction can be reduced, and image distortion can be suppressed.

  In the above-described sixth embodiment, the case where the landing droplets constituting the landing droplet array C land with a shift in the main scanning direction has been described. For example, the landing droplets land with a shift in the sub-scanning direction. In this case, the landing droplet rows arranged in the main scanning direction may be shifted in the main scanning direction.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be easily made without departing from the gist of the present invention. It can be done.

  In the fourth to sixth embodiments described above, the case where every other row or a specific row of landing droplets is shifted in the sub-scanning direction has been described. However, in the landing droplet row shifted in the sub-scanning direction, the first embodiment is used. As described above, an instruction may be output so that ink droplets are further ejected by one pixel in the direction opposite to the direction of displacement with respect to the nozzle that ejects landing droplets displaced in the sub-scanning direction. In such a case, image distortion due to conversion of the pixel arrangement can be suppressed.

  In the above embodiment, the case where the PC 1 as the print control means is connected to the printer 1A via the interface 48 has been described. However, various programs stored in the ROM 45 of the PC 1 are installed in the printer 1A, and the PC 1 You may comprise so that the control to perform may be performed in the printer 1A. In such a case, even print data from a PC not equipped with this program can be controlled by the printer 1A.

  In the above-described embodiment, the case where the ink droplets that are displaced from the vertical direction with respect to the printing medium for some reason are displaced in the direction in which the nozzles are aligned (main scanning direction) has been described. In the case of misalignment in the transport direction (sub-scanning direction), the gap formed by the ink droplets misaligned in the transport direction can be reduced by controlling the timing of ejecting ink droplets from the nozzle.

  In the first, third, and fourth embodiments, every other pixel column is shifted in the sub-scanning direction H. However, every second column or every third column is shifted in the sub-scanning direction, or a plurality of columns are grouped into one group. One group of pixel columns may be shifted in the sub-scanning direction every other group.

FIG. 1 is a schematic view showing a personal computer as a print control apparatus according to one embodiment of the present invention and an inkjet printer connected to the PC via a communication cable. FIG. 2 is a block diagram showing an outline of an electric circuit configuration of the PC and the printer. FIG. 5A relates to the first embodiment, and FIG. 6A is a diagram for explaining the relationship between nozzles and landing droplets formed by ink droplets ejected from the nozzles, and FIG. When the landing droplets are landed as shown in (2), the ink droplets are landed obliquely for some reason. (A) shows a pixel arrangement of 4 rows and 5 columns as initial print data. (B) and (c) show a state where the pixel arrangement shown in (a) is converted. (D) shows the state of the pixel value set for each pixel in the pixel arrangement shown in (c) by color coding. (A) shows the pixel arrangement as the initial print data. (B) has shown the state which converted the pixel arrangement | positioning shown to (a). (C) shows the pixel values of each pixel in the pixel arrangement shown in (b) in different colors. (A) is a figure which shows the state which applied the arrangement | positioning conversion pixel to the coordinate system, (b) is a partial enlarged view of the arrangement | positioning conversion pixel, Comprising: The determination method of the distribution rate to set is demonstrated. It is a figure for doing. It is a flowchart of a pixel value distribution process. (A) is a figure regarding 2nd Example, Comprising: It is a figure for demonstrating the relationship between the landing droplet formed with the ink droplet discharged from the nozzle. (B) relates to the third embodiment and is a diagram for explaining the relationship between the nozzles and the landing droplets formed by the ink droplets ejected from the nozzles. This relates to the fourth embodiment, wherein (a) is a diagram for explaining the relationship between nozzles and landing droplets formed by ink droplets ejected from the nozzles, and (b) is (a). FIG. 6 is a diagram illustrating a state where an ink droplet landed obliquely for some reason when landing a landing droplet as shown in FIG. This relates to the fifth embodiment, wherein (a) is a diagram for explaining the relationship between nozzles and landing droplets formed by ink droplets ejected from the nozzles, and (b) is (a). FIG. 6 is a diagram illustrating a state where an ink droplet landed obliquely for some reason when landing a landing droplet as shown in FIG. FIG. 10 is a diagram related to a sixth embodiment and is a diagram for explaining a relationship between a nozzle and landing droplets formed by ink droplets ejected from the nozzle. (A) is a figure for demonstrating the ideal relationship between a nozzle and a landing droplet in the conventional inkjet recording device. (B) illustrates the relationship between a nozzle and a landing droplet in a state where an ink droplet ejected from a predetermined nozzle is ejected in an oblique direction with respect to a print medium for some reason in a conventional inkjet recording apparatus. It is a figure for doing.

Explanation of symbols

1 PC (printing control device)
1A Inkjet printer (printing device)
45a Pixel arrangement conversion program (part of output means, conversion means, data creation means)
45b Pixel value distribution program (part of output means, pixel value setting means)

Claims (14)

An instruction to eject ink droplets from the nozzles toward the print medium in one direction with respect to the print medium so that the landing droplets formed by the ink droplets that land on the print medium land at a predetermined position corresponding to the print data. In a printing control apparatus that outputs to a printing unit having a plurality of nozzles arranged in a first direction orthogonal to the relative movement direction in order to form an image by relative movement of
An output unit that outputs an instruction to the printing unit so that a predetermined landing droplet row out of the landing droplet rows arranged in the relative movement direction deviates from other landing droplet rows in a relative movement direction;
In the case of print data that is printed linearly in the first direction, the output means discharges ink droplets in a direction opposite to the shifting direction with respect to the nozzle that discharges landing droplets shifted in the relative movement direction. A printing control apparatus that outputs an instruction to a printing unit.   The print control apparatus according to claim 1, wherein the output unit outputs an instruction to the printing unit so that the landing droplet rows arranged in the relative movement direction are shifted in the relative movement direction every predetermined row.   In the case of print data to be printed linearly in the first direction, the output means discharges ink droplets by one pixel in a direction opposite to the shifting direction with respect to the nozzle that discharges landing droplets shifted in the relative movement direction. The print control apparatus according to claim 1, wherein an instruction is output to the printing unit.   4. The output unit according to claim 1, wherein the output unit outputs an instruction to the printing unit so as to shift the landing droplets in the relative movement direction by half the pitch of the respective landing droplets arranged in the relative movement direction. A printing control apparatus according to claim 1. Conversion means for converting the arrangement of the pixels of the print data so that pixel rows arranged in the relative movement direction are shifted in the relative movement direction every predetermined row;
5. The print control according to claim 1, wherein the output unit outputs an instruction to the printing unit so that the landing droplets land according to the arrangement of each pixel converted by the conversion unit. apparatus.   In the case of print data that is printed linearly in the first direction, the output means prints the density of the landing droplets corresponding to both ends in the relative movement direction with respect to the nozzles that discharge the landing droplets shifted in the relative movement direction. The print control apparatus according to claim 5, wherein an instruction is output to the printing unit so as to be thinner than a density of the landing droplet corresponding to the print head. In the case of print data to be printed linearly in the first direction, data creation means for additionally creating data so as to further print one pixel in the direction opposite to the shift direction with respect to the pixel row shifted in the relative movement direction;
For each pixel, a pixel value that defines the density of the landing droplet is set. In the case of print data that is printed linearly in the first direction, the pixel values at both ends of the pixel row to be shifted are the pixel values corresponding to the print data. Pixel value setting means for setting to be lower,
The print control apparatus according to claim 6, wherein the output unit outputs an instruction regarding the density of the landing droplet to the printing unit in accordance with a pixel value set by the pixel value setting.   In the case of print data to be printed in a linear form in the first direction, the pixel value setting means distributes a part of the pixel value of the pixel to be shifted to the pixel value of one pixel added in the direction opposite to the direction of shifting. The print control apparatus according to claim 7, wherein the distributed pixel value is a pixel value of the added pixel.   The print control apparatus according to claim 8, wherein the ratio of the distributed pixel value is set according to a ratio of an amount of shifting the pixel with respect to the size of one side of each pixel.   The output means narrows the pitch of the adjacent landing droplets in the relative movement direction perpendicular to the first direction in which the nozzles are arranged over the printing area of the printing medium, smaller than the pitch of the adjacent landing droplets in the first direction. The print control apparatus according to claim 2, wherein an instruction is output to the printing unit.   The output means lands more landing droplets in the relative movement direction than the number corresponding to the print data, according to the pitch of the landing droplets in the relative movement direction narrower than the pitch of the adjacent landing droplets in the first direction. The print control apparatus according to claim 10, wherein an instruction is output to the printing unit.   The output means is configured to output at least one first nozzle of at least one of the two nozzles that eject ink droplets that land on a position where the pitch of the landing droplets adjacent to each other in the first direction is larger than a predetermined pitch. The print control apparatus according to claim 1, wherein an instruction is output to the printing unit so that landing droplets formed by ink droplets ejected from one nozzle are shifted in a relative movement direction.   The output unit outputs an instruction to the printing unit via an interface of the printing unit to a printing unit that forms an image corresponding to data received from an external device on a printing medium. The print control apparatus according to any one of 12. An instruction to eject ink droplets from the nozzles toward the print medium in one direction with respect to the print medium so that the landing droplets formed by the ink droplets that land on the print medium land at a predetermined position corresponding to the print data. In the control method of the printing means for outputting to the printing means having a plurality of nozzles arranged in a first direction orthogonal to the relative movement direction in order to form an image by relative movement of
An output step of outputting an instruction to the printing unit so that a predetermined landing droplet row out of the landing droplet rows arranged in the relative movement direction is shifted from the other landing droplet rows in a relative movement direction;
In the case of print data to be printed linearly in the first direction, the output step is such that the ink droplets are further ejected in a direction opposite to the shifting direction with respect to the nozzles that eject the landing droplets shifted in the relative movement direction. A method for controlling a printing means, characterized in that an instruction is output to the printing means.

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