JP4770138B2 - Inkjet recording apparatus control apparatus, inkjet recording apparatus control program, inkjet recording apparatus control method, and inkjet recording apparatus - Google Patents

Description

  The present invention relates to an inkjet recording apparatus control apparatus, an inkjet recording apparatus control program, an inkjet recording apparatus control method, and an inkjet recording capable of forming a high-quality image without conspicuous positional deviation of landing droplets by simple control. Relates to the device.

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

  Here, with reference to FIG. 9, 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 recording medium will be described. FIG. 9A is a diagram for explaining an ideal relationship between nozzles and landing droplets in the conventional line type inkjet recording apparatus 100.

  As shown in FIG. 9A, in the line head 101, five nozzles 102a to 102e are arranged in a line shape (vertical direction in the drawing) at a predetermined pitch P. 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. 9 shows a state in which the nozzles 102a to 102e for ejecting ink droplets for forming the landing droplets arranged in the same straight line are arranged in the same straight line in a pseudo manner.

  In addition, ink droplets are ejected from the nozzles 102 a to 102 e toward a recording medium (not shown) that is conveyed in the conveying direction H (from the left side to the right side of the paper) at a position facing the line head 101. Here, the ink droplets ejected from the respective nozzles 102a to 102e land on the recording medium, and each pixel has a side length equal to the predetermined pitch P of the nozzles and is a square pixel (indicated by a one-dot chain line in FIG. 9A). ) To be circumscribed.

  Therefore, when ink droplets are ejected from each of the five nozzles 102a to 102e in the vertical direction toward the recording medium, each ink droplet lands on the recording medium and forms a straight line with a predetermined pitch D equal to the predetermined pitch P ( The five landing droplets arranged in the vertical direction of the paper surface are formed so as to overlap each other.

  Then, by repeating this operation at a predetermined timing in the process of transporting the recording medium, the landing droplet array A arranged in the left-right 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, the recording medium is because one of the nozzles 102a to 102e is clogged with dust, dust, solid ink, or the like, or the ink is attached around the nozzle and pulled by the attached ink. In contrast, ink droplets that should be ejected in the vertical direction may be ejected in an oblique direction with respect to the recording medium.

  FIG. 9B illustrates a nozzle in a state in which ink droplets ejected from the nozzle 102c are ejected obliquely with respect to the recording 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. 9B, when ink droplets are ejected from the nozzle 102c obliquely with respect to the recording medium (closer to the nozzle 102d), the landing droplet array C formed by the ink droplets is the landing droplet. The pitch D2 formed between the landing droplet row B and the landing droplet row C is formed larger than a predetermined pitch (the same pitch as the predetermined pitch P). Therefore, a gap (see the colored portion in the figure) is formed between the landing droplet row C and the landing droplet row B, and this gap looks like a streak S extending in the conveyance direction H of the recording medium, resulting in a reduction in image quality. There was a problem to do.

  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 droplet on the recording 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 is a control device for an inkjet recording apparatus 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 recording apparatus control program, an inkjet recording apparatus control method, and an inkjet recording apparatus.

In order to achieve this object, the control device for an ink jet recording apparatus according to claim 1 is configured so that the area of the landing droplet formed by the ink droplet landing on the recording medium has a predetermined size based on the print data. An apparatus that outputs an instruction to eject ink droplets from each nozzle toward a recording medium to an inkjet recording apparatus including a line head that forms an image on the recording medium by relative movement in one direction with the recording medium , The first nozzle of at least one of the two nozzles that ejects ink droplets that land at a position where the pitch of the landing droplets adjacent in the direction perpendicular to the conveyance direction of the recording medium is larger than a predetermined pitch. Do a predetermined size larger ink droplets than is the size of the area of the landing droplets corresponding to the print data formed by the ink droplets ejected from Ri, and, Of the two nozzles located on both sides of the first nozzle, with respect to the second nozzle that ejects ink droplets that land at a position where the pitch between the droplets formed by the ink droplets ejected from the first nozzle is small Te, the size of the area of the landing droplets formed by the ink droplets ejected from the second nozzle, an instruction to the ink jet recording apparatus so that a smaller ink droplets than the predetermined size corresponding to the print data Discharging instruction means for outputting , wherein the discharging instruction means overlaps the landing droplet formed by the large ink droplet and the landing droplet formed by the small ink droplet .

  The ink jet recording apparatus control apparatus according to claim 2 is the ink jet recording apparatus control apparatus according to claim 1, wherein the ejection instructing unit ejects ink from the first nozzle as the pitch between adjacent landing droplets increases. An instruction is output so that the size of the area of the landing droplet formed by the droplet increases.

A control device for an ink jet recording apparatus according to claim 3 is the control device for an ink jet recording apparatus according to claim 1 or 2, wherein the first nozzle is a nozzle that ejects ink droplets that land at an appropriate position; Ink that lands at a position different from the proper position when the pitch of the adjacent landed droplets is formed to be larger than a predetermined pitch by a nozzle that ejects ink droplets that land at a position different from the correct position. This is a nozzle that ejects droplets.

The control apparatus for an ink jet recording apparatus according to claim 4 is the control apparatus for an ink jet recording apparatus according to claim 1 or 2, wherein the first nozzle is a nozzle that ejects ink droplets that land at an appropriate position; A nozzle that ejects ink droplets that land at a position different from the correct position, and ejects ink droplets that land at the appropriate position when the pitch of the adjacent landed droplets is larger than a predetermined pitch. nozzle is Le.

The control apparatus for an ink jet recording apparatus according to claim 5 is the control apparatus for an ink jet recording apparatus according to claim 1 or 2, wherein the first nozzle is landed at a position where the pitch of adjacent landing droplets is larger than a predetermined pitch. Two nozzles for ejecting ink droplets.

A control device for an ink jet recording apparatus according to a sixth aspect is the control device for an ink jet recording apparatus according to the fifth aspect , wherein the discharge instructing means includes two second nozzles located on both sides of the two nozzles as the first nozzle. Inkjet recording so that the size of the area of the landing droplets formed by the ink droplets ejected from the two second nozzles is smaller than the predetermined size corresponding to the print data for two nozzles Output instructions to the device.

According inkjet recording apparatus control device of claim 7, wherein the area of the landing droplet in an ink jet recording apparatus control device according to any one of claims 1 to 6, which is formed by the ink droplets ejected from the first nozzle The first parameter indicating an instruction that the size of the ink droplet is larger than a predetermined size corresponding to the print data, and the size of the area of the landing droplet formed by the ink droplet ejected from the second nozzle is the print data Storage means for storing at least one parameter of the second parameter indicating an instruction to be smaller than a predetermined size corresponding to the discharge instruction means according to the parameter stored in the storage means, An instruction is output to the ink jet recording apparatus.

An ink jet recording apparatus control apparatus according to an eighth aspect of the present invention is the ink jet recording apparatus control apparatus according to the seventh aspect , wherein the parameters stored in the storage means are rewritable.

The ink jet recording apparatus control apparatus according to claim 9 is the ink jet recording apparatus control apparatus according to claim 7 or 8 , wherein the storage unit newly relates to each of the nozzles excluding the first nozzle. The parameter and the second parameter can be stored.

The ink jet recording apparatus control apparatus according to claim 10 is the ink jet recording apparatus control apparatus according to any one of claims 1 to 9 , wherein the discharge instruction means records an image based on data received from an external apparatus. An instruction is output to the inkjet recording apparatus via the interface of the inkjet recording apparatus with respect to the inkjet recording apparatus formed on the medium.

The claims 11 jet recording apparatus control apparatus, wherein in the ink-jet recording apparatus control apparatus according to any one of claims 1 to 10, the discharge instruction means includes a plurality of size ink droplets based on print data An ink jet recording apparatus is configured to output an instruction for ejecting ink to the ink jet recording apparatus and eject ink droplets having a size based on print data to a third nozzle other than the first nozzle and the second nozzle. Outputs instructions.

The method of controlling an ink jet recording apparatus according to claim 12 is the method of controlling the ink droplets from each nozzle to the recording medium so that the landing droplets formed by the ink droplets that land on the recording medium have a predetermined size based on the print data. This is a control method for outputting an instruction to be discharged toward an ink jet recording apparatus having a line head for forming an image on a recording medium by relative movement in one direction with respect to the recording medium, which is perpendicular to the conveyance direction of the recording medium. Formed by ink droplets ejected from at least one first nozzle of two nozzles ejecting ink droplets that land at a position where the pitch of landing droplets adjacent in the direction is larger than a predetermined pitch predetermined size larger ink droplets than is the size of the area of the landing droplets corresponding to the print data that is Do Ri, and, positions on both sides of the first nozzle Among the two nozzles, the second nozzle ejects ink droplets that land at a position where the pitch between the ink droplets ejected from the first nozzle and the landing droplets is small. the dispensing instruction step of the size of the area of the landing droplets formed by the ink droplets, and outputs an instruction to the ink jet recording apparatus so that such a predetermined small ink droplets than the size corresponding to the print data The ejection instructing step in which the landing droplet formed by the large ink droplet and the landing droplet formed by the small ink droplet overlap each other is provided.

An ink jet recording apparatus according to a thirteenth aspect of the present invention is an apparatus for ejecting ink droplets from each nozzle toward a recording medium, and forming an image by landing droplets formed by landing each ejected ink droplet on the recording medium. Te, comprising an ink jet recording apparatus for control equipment according to any one of claims 1 to 11, thus is controlled to the ink jet recording apparatus control equipment.

An ink jet recording apparatus according to a fourteenth aspect is the ink jet recording apparatus according to the thirteenth aspect, wherein a line head for forming an image on the recording medium by relative movement in one direction with respect to the recording medium, and the line head and the recording medium. And a moving means for moving the ink in relative directions in one direction, and the line head causes ink droplets to be discharged from each nozzle in accordance with the instructions from the discharge instructing means or the discharge instructing step in accordance with the relative movement in one direction with respect to the recording medium. To form an image on the recording medium.

According to the control device for an ink jet recording apparatus of the first aspect, the two nozzles that eject the ink droplets that land at a position where the pitch of the landing droplets adjacent to each other in the direction perpendicular to the conveyance direction of the recording medium is larger than the predetermined pitch. At least one of the first nozzles ejects ink droplets such that the area of the landing droplet formed by the ink droplets ejected from the first nozzle is larger than a predetermined size corresponding to the print data. As described above, an instruction is output to an ink jet recording apparatus having a line head that ejects ink droplets toward a recording medium .

Accordingly, in order to land at a position where the pitch of the landing droplets adjacent in the direction perpendicular to the conveyance direction of the recording medium is larger than the predetermined pitch, in the case of landing droplets of a predetermined size corresponding to the print data, the conveyance direction of the recording medium A recording medium is formed so that a gap is generated between the adjacent droplets in a direction perpendicular to the ink droplets, but ink droplets that form a larger droplet than a predetermined size corresponding to the print data corresponding to the first nozzle are ejected. Since an instruction is output to an ink jet recording apparatus having a line head that discharges ink droplets toward the head , the gap 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.
Further, from the two nozzles that are located on both sides of the first nozzle, the second nozzle that ejects ink droplets that land on a position where the pitch between the droplets formed by the ink droplets ejected from the first nozzle is small is used. Ink droplets can be ejected by the ink jet recording apparatus such that the size of the area of the landing droplets formed by the ink droplets ejected from the second nozzle is smaller than a predetermined size corresponding to the print data. .
Accordingly, since the size of the area of the landing droplet corresponding to the second nozzle is reduced, even if the size of the area of the landing droplet corresponding to the first nozzle is increased, the landing droplet and the second corresponding to the first nozzle are increased. The overlapping portion with the landing droplet corresponding to the nozzle can be reduced. Therefore, there is an effect that the range of the overlapping portion where the density becomes high is limited, and a high-quality image with a uniform density can be formed.

  According to the control device for an ink jet recording apparatus according to claim 2, in addition to the effect exhibited by the control device for the ink jet recording apparatus according to claim 1, the ink ejected from the first nozzle as the pitch of the adjacent landing droplets increases. Since the ink jet recording apparatus is instructed to increase the size of the area of the landing droplet formed by the droplet, the landing droplet having a predetermined size corresponding to the print data is generated between adjacent landing droplets. According to the size of the gap, ink droplets that form landing droplets having such a size that the gap can be reduced can be ejected by the ink jet recording apparatus. Therefore, even in a case where a large gap is generated due to the displacement of the landing droplets, there is an effect that a high-quality image can be formed without making the gap inconspicuous.

According to the control device for an ink jet recording apparatus described in claim 3, in addition to the effect exhibited by the control device for ink jet recording apparatus according to claim 1 or 2, the first nozzle ejects ink droplets that land at an appropriate position. a nozzle for a nozzle for ejecting ink droplets landing on a position different from the proper position, by the pitch of the adjacent landing droplets is different from the case, the proper position of the size rather are formed than the predetermined pitch Since this is a nozzle that ejects ink droplets that land at a position, the size of the area of the landing droplets formed by the ink droplets ejected from the first nozzle with a simple control is larger than a predetermined size corresponding to the print data There is an effect that can be made.

According to the control device for an ink jet recording apparatus of the fourth aspect, in addition to the effect exhibited by the control device for the ink jet recording apparatus of the first or second aspect, the first nozzle ejects ink droplets that land at an appropriate position. a nozzle for a nozzle for ejecting ink droplets landing on a position different from the proper position, by the pitch of the adjacent landing droplets when the size rather are formed than the predetermined pitch, lands on the correct position since it is nozzle for ejecting ink droplets, when setting the nozzles which eject ink droplets landing on a position different from the first nozzle proper position as the ink jet recording apparatus control apparatus according to claim 3, wherein In comparison, it is possible to reduce overlapping portions between the landing droplets corresponding to the first nozzle and the landing droplets corresponding to the nozzles on both sides of the first nozzle. Therefore, there is an effect that the range of the overlapping portion where the density becomes high is limited, and a high-quality image with a uniform density can be formed.

According to the control device for an ink jet recording apparatus of the fifth aspect , in addition to the effect exerted by the control device for the ink jet recording apparatus of the first or second aspect, the first nozzle has a pitch of adjacent landing droplets from a predetermined pitch. When the first nozzle is set to one of the two nozzles as in the control device for an ink jet recording apparatus according to claim 3 or 4, the two nozzles eject ink droplets that land at a larger position. In comparison, the size of the area of the landing droplet corresponding to the first nozzle necessary to fill the gap of the same size can be reduced. Therefore, there is an effect that it is possible to form a high-quality image in which graininess is suppressed.

  Further, since the size of the area of the landing droplet corresponding to the first nozzle can be reduced, the overlapping of the landing droplet corresponding to the first nozzle and the landing droplet corresponding to the other nozzle adjacent to the first nozzle The portion can be reduced as compared with the case where the first nozzle is one of the two nozzles as in the control device for an ink jet recording apparatus according to claim 3 or 4. Therefore, there is an effect that the range of the overlapping portion where the density becomes high is limited, and a high-quality image with a uniform density can be formed.

According to the control device for an ink jet recording apparatus of the sixth aspect , in addition to the effect exhibited by the control device for the ink jet recording apparatus of the fifth aspect, the two second nozzles positioned on both sides of the two nozzles as the first nozzle. From the nozzle, ink droplets are ejected by the inkjet recording apparatus so that the size of the area of the landing droplet formed by the ink droplet ejected from the second nozzle is smaller than a predetermined size corresponding to the print data. be able to.

  Accordingly, since the size of the area of the landing droplet corresponding to the second nozzle is reduced, even if the size of the area of the landing droplet corresponding to the first nozzle is increased, the landing droplet and the second corresponding to the first nozzle are increased. The overlapping portion with the landing droplet corresponding to the nozzle can be reduced. Therefore, there is an effect that the range of the overlapping portion where the density becomes high is limited, and a high-quality image with a uniform density can be formed.

According to the control device for an ink jet recording apparatus according to a seventh aspect , in addition to the effect exerted by the control device for the ink jet recording apparatus according to any one of the first to sixth aspects, the ejection instruction means is stored in the storage means. Since an instruction is output to the ink jet recording apparatus in accordance with the parameters set, it is only necessary to eject ink in accordance with the parameters stored in the storage means, and there is an effect that the control of the ink discharge instruction means can be simplified.

According to the control device for an ink jet recording apparatus of the eighth aspect , in addition to the effect exhibited by the control device for the ink jet recording apparatus of the seventh aspect , the parameters stored in the storage means are configured to be rewritable. The first parameter or the second parameter can be changed according to the situation. That is, by changing the first parameter or the second parameter, the size of the area of the landing droplet corresponding to the first nozzle or the second nozzle can be changed.

  For example, if the first parameter is initially set so that the size of the area of the landing droplet corresponding to the first nozzle is 1.2 times the predetermined size corresponding to the print data, the gap is set. Although it was able to cover, there may be a gap later for some reason. In this case, the gap can be reduced by changing the first parameter so that the size of the area of the landing droplet corresponding to the first nozzle becomes 1.4 times. Therefore, there is an effect that a high-quality image can be formed over a long period of time.

According to the control device for an ink jet recording apparatus of the ninth aspect , in addition to the effect exerted by the control device for the ink jet recording apparatus of the seventh or eighth aspect , a first parameter is newly added for each of the nozzles excluding the first nozzle. And the second parameter can be stored, so that even if the nozzle initially ejects ink droplets that land at an appropriate position, what is the proper position of the ink droplets ejected from the nozzle for some reason? It may come to land at different positions. In this case, by setting the first parameter and the second parameter for the nozzle and the nozzle adjacent to the nozzle, it is possible to reduce the gap generated by the ink droplets that land on a position different from the appropriate position. Therefore, there is an effect that a high-quality image can be formed over a long period of time.

According to the ink jet recording apparatus control device according to claim 10, in addition to the effects of the ink jet recording apparatus control apparatus according to any one of claims 1 to 9, the ejection instructing means, the data received from the external device Since an instruction is output to the ink jet recording apparatus via the interface of the ink jet recording apparatus to the ink jet recording apparatus that forms the image based on the recording medium, the ink jet recording apparatus control device is not mounted on the ink jet recording apparatus. This type of ink jet recording apparatus can be controlled. Therefore, there is an effect that a high-quality image can be formed by using this type of ink jet recording apparatus without affecting the structure of the ink jet recording apparatus itself and the product cost.

According to the control device for an ink jet recording apparatus of the eleventh aspect , in addition to the effect exhibited by the control device for the ink jet recording apparatus according to any one of the first to tenth aspects, the third nozzle is based on print data. Since an instruction is output to the ink jet recording apparatus so as to discharge the ink droplet having a predetermined size, the ink droplet having a size based on the print data is discharged from the third nozzle. Therefore, there is an effect that an image can be formed by landing droplets having a size corresponding to the print data.

According to the control method of the ink jet recording apparatus according to claim 12, the two nozzles that eject the ink droplets that land on the position where the pitch of the landing droplets adjacent in the direction perpendicular to the conveyance direction of the recording medium is larger than the predetermined pitch are used. out from at least one of the first nozzle, Ri Na larger than a predetermined size the size of the area of the landing droplets formed by ink droplets ejected from the first nozzle corresponds to the print data, and the first Of the two nozzles located on both sides of the nozzle, the second nozzle that ejects ink droplets that land at a position where the pitch of the droplets formed by the ink droplets ejected from the first nozzle is small is the first. so that the size of the area of the landing droplets formed by the ink droplets ejected from the second nozzle is a small ink drop than a predetermined size corresponding to the print data And outputs an instruction to the ink jet recording apparatus having a line head that ejects ink droplets toward a recording medium such that the ink droplets are ejected.

Accordingly, in order to land at a position where the pitch of the landing droplets adjacent in the direction perpendicular to the conveyance direction of the recording medium is larger than the predetermined pitch, in the case of landing droplets of a predetermined size corresponding to the print data, the conveyance direction of the recording medium A gap is generated between the adjacent droplets in the direction perpendicular to the direction, but a droplet that is larger than a predetermined size corresponding to the print data corresponding to the first nozzle corresponds to the print data corresponding to the second nozzle. Since the instruction is output to the ink jet recording apparatus so as to eject ink droplets that form landing droplets smaller than a predetermined size , the gap 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 ink jet recording apparatus according to claim 13, since it is controlled by an ink jet recording apparatus control apparatus according to any one of claims 1 to 11, similar to the effect described in any of claims 1 to 11 There is an effect that an effect can be produced.

According to the control device for an ink jet recording apparatus of the fourteenth aspect , in addition to the effect exhibited by the control device for the ink jet recording apparatus of the thirteenth aspect , the line head is ejected along with a relative movement in one direction with respect to the recording medium. Ink droplets are ejected from each nozzle and an image is formed on the recording medium according to the instruction by the instruction means or the ejection instruction step, so that the ink droplets are stabilized at a higher speed than when both the head and the recording medium are moved. Can be discharged. Therefore, there is an effect that a high-quality image can be formed at high speed.

  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 control device for an inkjet recording apparatus according to one embodiment of the present invention, and an inkjet printer 1A (hereinafter referred to as “PC1”) connected to the PC1 via a communication cable 40. FIG. 1 is a schematic diagram illustrating a printer 1A ”.

  The PC 1 instructs the communication cable 40 to eject ink droplets from each nozzle toward the recording medium so that the landing droplets formed by the ink droplets that land on the recording medium have a predetermined size corresponding to the print data. And a CRT display 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 control device such as a tablet or PDA can be used as the control device for the ink jet recording apparatus. 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 inkjet printer having four inkjet heads 3, and ejects ink droplets from the nozzles formed in each inkjet head 3 toward a recording 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 recording medium.

  The printer 1A includes a paper feed unit 4 on the left side in the figure and a paper discharge unit 5 on the right side in the figure. Inside the printer 1A, there is a recording 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 recording medium are disposed immediately downstream of the paper feed unit 4. The recording 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 conveying belt 8, that is, the conveying surface is subjected to silicon treatment, and while holding the recording medium conveyed by the pair of feed rollers 6a and 6b on the conveying surface of the conveying 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 recording medium against the conveyance surface of the conveyance belt 8 and securely adhering to the conveyance surface so that the recording medium on the conveyance belt 8 does not float from 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 recording medium adhered to the conveying surface of the conveying belt 1 from the conveying surface and send the recording medium toward 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 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 recording 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 recording medium, that is, the printing surface. Thus, a desired color image can be formed on the recording 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, a CRT display 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 the ink ejection control program 45a and various programs stored in the ROM 45.

  The ROM 45 is a non-rewritable nonvolatile memory, and stores an ink ejection control program 45a executed by the CPU 44, various control programs, and other fixed value data.

  The ink ejection control program 45a makes the size of the area of the landing droplet formed by the ink droplet ejected from the nozzle larger or smaller than a predetermined size corresponding to the print data. Is a program for outputting an instruction to the printer 1A.

  The RAM 46 is a rewritable volatile memory and temporarily stores various data.

  The hard disk 47 is a rewritable nonvolatile memory and stores a dot level table 47a. The dot level table 47a is a table that stores parameters indicating instructions for each nozzle so that the area of the landing droplet formed by the ink droplets ejected from each nozzle as the dot level becomes a predetermined size. is there. The ink ejection control program 45a outputs an instruction to eject ink droplets of a predetermined size from each nozzle according to the parameters stored in the dot level table 47a.

  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 and detection of the remaining amount of ink in the cartridge or the presence or 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 printing instruction, a motor drive circuit 30 for operating a conveyance motor (LF motor) 29 for conveying the recording medium, and a tip of the recording 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 recording 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 is ejected from each nozzle.

  Next, with reference to FIG. 3, the control of the first embodiment by the PC 1 configured as described above will be described. (1) to (4) in FIG. 3A show the types of the size of the landing droplet area formed by the ink droplets discharged from the nozzles 35a to 35d of the printer 1A landing on the recording medium. FIG. 3B is a diagram for explaining the relationship between the nozzles 35a to 35e and the landing droplets formed by the ink droplets ejected from the nozzles 35a to 35e. ) Is a diagram showing a dot level table 47a.

  As shown in FIG. 3A, the printer 1A is configured to be able to form landing droplets of four types of sizes (1) to (4) based on print data from the PC 1. Specifically, the smallest landing droplet is the landing droplet shown in (1), and the larger landing droplet than the landing droplet shown in (1) is the landing droplet shown in (2). The landing droplet shown in (2) The larger landing droplet is the landing droplet shown in (3), and the largest landing droplet is the landing droplet shown in (4). The size of the landing droplet area that can be formed by the printer 1A is not limited to these four types.

  Further, as shown in FIG. 3B, the head 3 of the printer 1A is a so-called line head in which a plurality of nozzles arranged in a line with a predetermined pitch P are formed. In FIG. Five nozzles 35a-35e are shown.

  The nozzles 35a to 35e are not originally arranged in the same straight line, and the nozzles 35a to 35e are arranged in any one of a plurality of rows arranged in the line head. That is, FIG. 3 shows a state in which the nozzles 35a to 35e for ejecting ink droplets for forming landing droplets arranged in the same straight line are arranged in a pseudo straight line.

  In the printer 1 </ b> A, an image is formed on the recording medium by conveying the recording medium and discharging ink droplets from the nozzles 35 a of the fixed head 3. Of the nozzles 35a to 35e, ink droplets ejected from the nozzle 35c are ejected in an oblique direction (closer to the nozzle 35d) with respect to the recording medium for some reason.

  Therefore, for example, in the case of ejecting ink droplets having the size of the landing droplet area shown in (2) of FIG. 3A from each of the nozzles 35a to 35e, the description has been made with reference to FIG. Similarly, the pitch D2 between the landing droplet row B and the landing droplet row C is formed larger than the predetermined pitch P of the nozzle, and a gap is generated between the landing droplet row C and the landing droplet row B, and this gap is recorded. It looks like a streak S extending in the conveyance direction H of the medium.

  Therefore, in the first embodiment, as shown in FIG. 3B, the size of the area of the landing droplet formed by the ink droplet ejected from the nozzle 35c is designated according to the print data. The PC 1 instructs the printer 1A so that the area of the landing droplet formed by the ink droplet ejected from the nozzle 35d is smaller than the size instructed corresponding to the print data. To do.

  That is, in the first embodiment, among the adjacent nozzles 35b and 35c that discharge ink droplets that land at positions where the pitch of adjacent landing droplets is larger than a predetermined pitch, the landing droplets corresponding to the nozzles 35c are selected. The PC 1 instructs the printer 1A to increase the size and reduce the size of the area of the landing droplet corresponding to the nozzle 35d, where the overlapping portion increases accordingly. That is, from the two nozzles 35b and 35d located on both sides of the nozzle 35c, the nozzle 35d that ejects ink droplets that land on a position where the pitch of the droplets formed by the ink droplets ejected from the nozzle 35c is small is used. Ink droplets are ejected such that the size of the area of the landing droplets formed by the ink droplets ejected from the nozzle 35d is smaller than a predetermined size corresponding to the print data.

  In order to form landing droplets in this way, the nozzle position number and the dot level are stored in the dot level table 23a shown in FIG. The nozzle position number is a number assigned corresponding to each of the nozzles 35a to 35e, and the dot level is the area of the landing droplet formed by the ink droplet ejected from each nozzle 35a to 35e landing on the recording medium. It is a parameter indicating an instruction that the size becomes a predetermined size.

  Specifically, the nozzle position number “1” and the dot level “0” for the nozzle 35a, the nozzle position number “2” and the dot level “0” for the nozzle 35b, and the nozzle position number “0” for the nozzle 35c. 3 ”and dot level“ +2 ”, nozzle position number“ 4 ”and dot level“ −1 ”are stored for nozzle 35d, and nozzle position number“ 5 ”and dot level“ 0 ”are stored for nozzle 35e. . In accordance with the dot level table 47a, the PC 1 outputs an instruction to eject ink droplets from each nozzle toward the recording medium to the printer 1A.

  For example, when an instruction to form landing droplets shown in (2) of FIG. 3A is output from the nozzles 35a to 35e corresponding to the print data to the printer 1A, the PC 1 performs dot printing according to the dot level table 47a. For the nozzles 35a, 35b, and 35e whose level is set to “0”, an instruction corresponding to the print data is output. Accordingly, landing droplets having the size shown in FIG. 3A (2) are formed on the recording medium.

  On the other hand, for the nozzle 35c whose dot level is set to “+2”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (the landing droplet shown in (2) of FIG. 3A). An instruction to form landing droplets shown in (4) of FIG. 3 (a) that is two steps larger than the size of the area is output to the printer 1A. Therefore, landing droplets having the size shown in (4) of FIG. 3A are formed on the recording medium.

  For the nozzle 35d whose dot level is set to “−1”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (the landing droplet shown in (2) of FIG. 3A). An instruction to form landing droplets shown in (1) of FIG. 3 (a) which is smaller by one step than the size of the area is output to the printer 1A. Accordingly, landing droplets having the size shown in FIG. 3A (1) are formed on the recording medium.

  More specifically, the dot level “0” is set as a reference level, and a voltage of “20 V” is set for the drive element that drives the nozzle 35a or the like for which the reference level “0” is set, and the dot level is set to “+2”. The driver 25 for driving the nozzle 35c, the voltage of “30V” is applied to the drive element that drives the nozzle 35c, and the voltage of “15V” is applied to the drive element that drives the nozzle 35d set to the dot level “−1”. The PC 1 outputs an instruction to be applied to the head 3.

  Then, for example, a 10 pl ink droplet is ejected from the nozzles 35 a, 35 b, and 35 d by the driving element to which the voltage of “20 V” is applied, and 15 pl from the nozzle 35 c by the driving element to which the voltage of “30 V” is applied. An ink droplet is ejected, and a 7.5 pl ink droplet is ejected from the nozzle 35d by the drive element to which a voltage of “15 V” is applied. That is, an amount of ink droplets approximately proportional to the voltage applied to each drive element is ejected from each nozzle 35a to 35e.

  As a result, the landing droplets having the size shown in (2) of FIG. 3A by the ink droplets ejected from the nozzles 35a, 35b, and 35e, and the droplets of FIG. The landing droplets of the size shown in (4) of FIG. 3 (a), which is two steps larger than the landing droplets of the size shown in 2), are ejected from the nozzle 35d by the ink droplets (2) of FIG. 3 (a). The landing droplets of the size shown in FIG. 3A (1), which is one step smaller than the landing droplets shown in FIG.

  As described above in the first embodiment, among the adjacent nozzles 35b and 35c that discharge ink droplets that land on a position where the pitch of adjacent landing droplets is formed larger than a predetermined pitch, the nozzle 35c By controlling so that the area of the landing droplets formed is increased, the gap between the landing droplet row C and the landing droplet row D generated by the ink droplets corresponding to the print data is changed to the landing droplet row C. Therefore, a high-quality image can be formed.

  On the other hand, if the area of the landing droplet corresponding to the nozzle 35c is increased, the overlapping portion of the landing droplet corresponding to the nozzle 35c and the landing droplet corresponding to the nozzle 35d increases, and this overlapping portion is different from other portions. Since the density is higher than that, the density is not uniform and the image quality is lowered.

  However, by reducing the size of the area of the landing droplet corresponding to the nozzle 35d, even if the size of the area of the landing droplet corresponding to the nozzle 35c is increased, the landing droplet and the nozzle 35d corresponding to the nozzle 35c. It is possible to suppress a decrease in image quality due to a decrease in overlapping portions with landing droplets corresponding to the above.

  In addition, the dot level “+2” set for the nozzle 35c described above is set according to how much ink discharged from the nozzle 35c is discharged closer to the nozzle 35d. In other words, it is set according to the size of the gap generated between the landing droplet row C and the landing droplet row D generated by the ink droplets corresponding to the print data. The size of the gap can be detected by reading the density using a CCD line scanner or the like.

  For example, in the present embodiment, a case has been described in which the pitch between the landing droplet corresponding to the nozzle 35b and the landing droplet corresponding to the nozzle 35c is formed at the pitch D2, but the landing droplet corresponding to this nozzle 35b and the nozzle 35c When the pitch with the corresponding landing droplet is larger than the pitch P and smaller than the pitch D2, the gap is naturally reduced, so that the dot level set for the nozzle 35c is changed from “+2” to “+1”. If the reduction setting is made, the area size of the landing droplet formed by the ink droplet ejected from the nozzle 35c is smaller than the size of the area of the landing droplet shown in (4) of FIG. The size shown in (3) is formed.

  In this way, by setting the size of the area of the landing droplet according to the gap amount, it is possible to fill the gap and further suppress the adjacent landing droplets from being excessively overlapped and causing a density difference.

  Further, since the dot level table 47a is stored in the rewritable hard disk 47 and is configured to be set for each nozzle, for example, in addition to the nozzle 35c among the nozzles 35a to 35e, the dot level table 47a is changed from the nozzle 35a for some reason. When the ejected ink droplets are ejected in the direction away from the nozzle 35b, and the ink droplet corresponding to the print data has a gap between the landing droplet row A and the landing droplet row B, For example, by rewriting the dot level corresponding to the nozzle 35a from “0” to “+1” so that the size of the area of the landing droplet corresponding to the nozzle 35a becomes larger, the area of the landing droplet corresponding to the nozzle 35a And the gap between the landing droplet array A and the landing droplet array B is reduced by the large formed droplets. It can be, it is possible to maintain a high-quality image for a long time.

  Next, with reference to FIG. 4, the control of the second embodiment by the PC 1 configured as described above will be described. (1) to (4) in FIG. 4A show the types of the size of the landing droplet area formed by the ink droplets ejected from the nozzles 35a to 35d of the printer 1A landing on the recording medium. FIG. 4B is a diagram for explaining the relationship between the nozzles 35a to 35e and the landing droplets formed by the ink droplets ejected from the nozzles 35a to 35e. ) Is a diagram showing a dot level table 47a.

  In the second embodiment, as in the first embodiment described with reference to FIG. 3, the ink droplets ejected from the nozzle 35c among the nozzles 35a to 35e are inclined with respect to the recording medium (nozzle). It is assumed that a gap is formed between the landing droplet row C and the landing droplet row B in the ink droplet corresponding to the print data.

  Therefore, in the second embodiment, the size of the area of the landing droplet formed by the ink droplet ejected from the nozzle 35b is made larger than the size instructed corresponding to the print data, and from the nozzle 35a. The PC 1 instructs the printer 1A so that the size of the area of the landing droplet formed by the ejected ink droplet is smaller than the size designated in accordance with the print data.

  In other words, in the second embodiment, among the adjacent nozzles 35b and 35c that discharge ink droplets that land at positions where the pitch of adjacent landing droplets is larger than a predetermined pitch, the landing droplets corresponding to the nozzles 35b are selected. In order to reduce the size of the area of the landing droplet corresponding to the nozzle 35a on the side closer to the nozzle 35b among the nozzles 35a and 35c on both sides of the nozzle 35b, which is increased and the overlapping portion is increased accordingly, the PC 1 is the printer 1A. To instruct. That is, from the two nozzles 35a and 35c located on both sides of the nozzle 35b, the nozzle 35a that ejects ink droplets that land on a position where the pitch with the landing droplets formed by the ink droplets ejected from the nozzle 35b is small. Ink droplets are ejected such that the size of the area of the landing droplets formed by the ink droplets ejected from the nozzle 35a is smaller than a predetermined size corresponding to the print data.

  Therefore, as shown in FIG. 4C, in the dot level table 47a of the second embodiment, the nozzle position number “1” and the dot level “−1” with respect to the nozzle 35a, and the nozzle position with respect to the nozzle 35b. The number “2” and the dot level “+2”, the nozzle position number “3” and the dot level “0” for the nozzle 35 c, the nozzle position number “4” and the dot level “0” for the nozzle 35 d, and the nozzle 35 e On the other hand, the nozzle position number “5” and the dot level “0” are stored.

  For example, when an instruction to form landing droplets shown in (2) of FIG. 4A is output from the nozzles 35a to 35e to the printer 1 corresponding to the print data, the PC 1 performs dot printing according to the dot level table 47a. For the nozzles 35c, 35d, and 35e whose level is set to “0”, an instruction corresponding to the print data is output. Accordingly, landing droplets having the size shown in FIG. 4A (2) are formed on the recording medium.

  On the other hand, for the nozzle 35b whose dot level is set to “+2”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (the landing droplet shown in (2) of FIG. 4A). An instruction to form landing droplets shown in FIG. 4A (4) which is two steps larger than the size of the area is output to the printer 1. Therefore, landing droplets having a size shown in (4) of FIG. 4A are formed on the recording medium.

  For the nozzle 35a whose dot level is set to “−1”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (the landing droplet shown in (2) of FIG. 4A). An instruction to form the landing droplet shown in (1) of FIG. Therefore, landing droplets having the size shown in (1) of FIG. 4A are formed on the recording medium.

  As described in the second embodiment, as described in the first embodiment, it is possible to increase the size of the area of the landing droplet corresponding to the nozzle 35b instead of the nozzle 35c. With the corresponding ink droplets, the gap generated between the landing droplet row B and the landing droplet row C can be reduced by the landing droplet row B, and the high-quality image can be formed without making the gap inconspicuous.

  Further, by reducing the size of the area of the landing droplet corresponding to the nozzle 35a, the overlapping of the landing droplet corresponding to the nozzle 35b and the landing droplet corresponding to the nozzle 35a is the same as described in the first embodiment. It is possible to suppress a decrease in the portion and a decrease in image quality.

  Next, with reference to FIG. 5, the control of the third embodiment by the PC 1 configured as described above will be described. (1) to (4) in FIG. 5A show the types of the size of the landing droplet area formed by the ink droplets ejected from the nozzles 35a to 35d of the printer 1A landing on the recording medium. FIG. 5B is a diagram for explaining the relationship between the nozzles 35a to 35e and the landing droplets formed by the ink droplets ejected from the nozzles 35a to 35e. ) Is a diagram showing a dot level table 47a.

  In the third embodiment, as in the first and second embodiments, the ink droplets ejected from the nozzle 35c among the nozzles 35a to 35e are inclined with respect to the recording medium for some reason (closer to the nozzle 35d). It is assumed that a gap is generated between the landing droplet row C and the landing droplet row B in the ink droplet corresponding to the print data.

  Therefore, in the third embodiment, the size of the area of the landing droplet formed by the ink droplets ejected from the nozzle 35b and the nozzle 35c is larger than the size instructed based on the print data, and The PC 1 instructs the printer 1A so that the size of the area of the landing droplet formed by the ink droplets ejected from the nozzle 35a and the nozzle 35d is smaller than the size designated in accordance with the print data. is there.

  That is, in the third embodiment, of the adjacent nozzles 35b and 35c that discharge ink droplets that land at positions where the pitch of adjacent landing droplets is larger than a predetermined pitch, both the nozzles 35b and 35c are disposed. PC1 so that the size of the landing droplet corresponding to both the nozzle 35a and the nozzle 35d located on both sides of the nozzle 35b and the nozzle 35a, where the overlapping portion increases, is increased. Indicates to the printer 1A.

  Therefore, as shown in FIG. 5B, in the dot level table 47a of the third embodiment, the nozzle position number “1” and the dot level “−1” with respect to the nozzle 35a, and the nozzle position with respect to the nozzle 35b. Number “2” and dot level “+1”, nozzle position number “3” and dot level “+1” for nozzle 35c, nozzle position number “4” and dot level “−1” for nozzle 35d, nozzle 35e In contrast, the nozzle position number “5” and the dot level “0” are stored.

  For example, when an instruction to form landing droplets shown in (2) of FIG. 5A is output from the nozzles 35a to 35e to the printer 1 corresponding to the print data, the PC 1 performs dot printing according to the dot level table 47a. For the nozzles 35e whose level is set to “0”, an instruction corresponding to the print data is output. Therefore, landing droplets having the size shown in FIG. 5A (2) are formed on the recording medium.

  On the other hand, for the nozzles 35b and 35c whose dot level is set to “+1”, the PC 1 determines the size of the landing droplet area corresponding to the print data (shown in (2) of FIG. 5A). An instruction to form the landing droplet shown in (3) of FIG. 5A, which is one step larger than the size of the area of the landing droplet), is output to the printer 1. Therefore, landing droplets having the size shown in (3) of FIG. 5A are formed on the recording medium.

  For the nozzles 35a and 35d whose dot level is set to “−1”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (see (2) in FIG. 5A). An instruction to form the landing droplet shown in (1) of FIG. 5A, which is one step smaller than the size of the landing droplet area shown), is output to the printer 1. Accordingly, landing droplets having the size shown in FIG. 5A (1) are formed on the recording medium.

  As described above in the third embodiment, instead of increasing the area of the landing droplet corresponding to one of the nozzle 35b and the nozzle 35c, both the nozzle 35b and the nozzle 35c are supported. Even if the size of the area of the landing droplets is increased, the gap formed between the landing droplet row B and the landing droplet row C is defined as the landing droplet row B as described in the first and second embodiments. And the landing row C, the gaps are not noticeable, and a high-quality image can be formed.

  Further, by reducing the size of the area of the landing droplets corresponding to the nozzles 35a and 35d, it corresponds to the landing droplets corresponding to the nozzle 35a and the nozzles 35b, as described in the first and second embodiments. It is possible to suppress a reduction in image quality due to a decrease in overlapping portions with the landing droplets and landing portions corresponding to the nozzles 35c and landing droplets corresponding to the nozzles 35d.

  Furthermore, as described in the first and second embodiments, the nozzle 35b and the nozzle 35c correspond to the case where the size of the landing droplet area corresponding to either the nozzle 35b or the nozzle 35c is increased. When increasing the size of the area of both landing droplets, it is only necessary to reduce the gap generated in the ink droplet corresponding to the print data by using both landing droplets. Compared to the case of the example, the degree of enlargement of each landing droplet can be reduced, the granular feeling of the landing droplet can be suppressed, and the image quality can be further improved.

  Next, the control of the fourth embodiment by the PC 1 configured as described above will be described with reference to FIG. (1) to (4) in FIG. 6 (a) show the types of the size of the landing droplets formed by the ink droplets ejected from the nozzles 35a to 35d of the printer 1A landing on the recording medium. FIG. 6B is a diagram for explaining the relationship between the nozzles 35a to 35e and the landing droplets formed by the ink droplets ejected from the nozzles 35a to 35e. ) Is a diagram showing a dot level table 47a.

  In the fourth embodiment, among the nozzles 35a to 35e, the ink droplets ejected from the nozzle 35c are ejected in an oblique direction (closer to the nozzle 35d) with respect to the recording medium for some reason. The ink droplets ejected from 35b are ejected in an oblique direction (closer to the nozzle 35a) with respect to the recording medium for some reason, and the printing data is supported between the landing droplet row B and the landing droplet row C. It is assumed that a larger gap is generated in the ink droplet than in the case described in the first to third embodiments.

  In this case, as described in the first or second embodiment, even if the size of the area of the landing droplet corresponding to either the nozzle 35b or the nozzle 35c is increased, the landing droplet row B and the landing droplet row C Can be reduced.

  However, when a large gap is generated between the landing droplet row B and the landing droplet row C as in the fourth embodiment, the gap is formed only by the landing droplet corresponding to either the nozzle 35b or the nozzle 35c. In order to reduce the gap by increasing the size, it is necessary to considerably increase the size of the landing droplet area. In this case, the graininess is noticeable due to the large landing droplets. Therefore, in the case of the fourth embodiment, as described in the third embodiment, it is preferable to increase the size of the area of the landing droplet corresponding to both the nozzle 35b and the nozzle 35c.

  That is, in the fourth embodiment, as described in the third embodiment, the size of the landing droplet area formed by the ink droplets ejected from the nozzle 35b and the nozzle 35c corresponds to the print data. And the size of the area of the landing droplet formed by the ink droplets ejected from the nozzles 35a and 35d is smaller than the size designated in accordance with the print data. As described above, the PC 1 instructs the printer 1A.

  The size of the gap between the landing droplet row B and the landing droplet row C generated by the ink droplets corresponding to the print data is naturally larger in the fourth embodiment than in the third embodiment. In addition, in the fourth embodiment, the size of the area of the landing droplets formed by the ink droplets ejected from the nozzles 35b and 35c is the same as the ink ejected from the nozzles 35b and 35c in the third embodiment. It becomes larger than the size of the area of the landing droplet formed by the droplet.

  Therefore, as shown in FIG. 6B, in the dot level table 47a of the fourth embodiment, the nozzle position number “1” and the dot level “−1” with respect to the nozzle 35a, and the nozzle position with respect to the nozzle 35b. Number “2” and dot level “+2”, nozzle position number “3” and dot level “+2” for nozzle 35c, nozzle position number “4” and dot level “−1” for nozzle 35d, nozzle 35e In contrast, the nozzle position number “5” and the dot level “0” are stored.

  For example, when an instruction to form landing droplets shown in (2) of FIG. 6A is output from the nozzles 35a to 35e to the printer 1 corresponding to the print data, the PC 1 performs dot printing according to the dot level table 47a. For the nozzles 35e whose level is set to “0”, an instruction corresponding to the print data is output. Accordingly, landing droplets having the size shown in FIG. 6A (2) are formed on the recording medium.

  On the other hand, for the nozzles 35b and 35c whose dot level is set to “+2”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (shown in (2) of FIG. 6A). An instruction to form the landing droplet shown in FIG. 6A (4), which is three steps larger than the size of the landing droplet area), is output to the printer 1. Therefore, landing droplets having the size shown in (4) of FIG. 6A are formed on the recording medium.

  For the nozzles 35a and 35d whose dot level is set to “−1”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (see (2) in FIG. 6A). An instruction to form the landing droplet shown in (1) of FIG. 6A, which is one step smaller than the size of the landing droplet area shown), is output to the printer 1. Therefore, landing droplets having a size shown in FIG. 6A (1) are formed on the recording medium.

  As described above in the fourth embodiment, the large gap generated between the landing row B and the landing row C by increasing the size of the area of the landing droplet corresponding to both the nozzle 35b and the nozzle 35c. Can be reduced while suppressing graininess.

  Next, the control of the fifth embodiment by the PC 1 configured as described above will be described with reference to FIG. (1) to (4) in FIG. 7A show the types of the size of the landing droplet area formed by the ink droplets ejected from the respective nozzles 35a to 35d of the printer 1A landing on the recording medium. FIG. 7B is a diagram for explaining the relationship between the nozzles 35a to 35e and the landing droplets formed by the ink droplets ejected from the nozzles 35a to 35e. ) Is a diagram showing a dot level table 47a.

  In the fifth embodiment, among the nozzles 35a to 35e, the ink droplets ejected from the nozzle 35c are ejected in an oblique direction (closer to the nozzle 35d) with respect to the recording medium for some reason. The ink droplets ejected from 35b are ejected in an oblique direction (closer to the nozzle 35c) with respect to the recording medium for some reason, and for the ink droplets corresponding to the print data, the landing droplet row A and the landing droplet row B It is assumed that a gap is formed between the two. In this fifth embodiment, the pitch D2 between the landing row B and the landing row C is the same as the pitch P of the nozzle, and there is no gap between the landing droplet row A and the landing droplet row B. And

  That is, in the case of the fifth embodiment, the pitch D1 between the landing droplet array A and the landing droplet array B is larger than the pitch P of the nozzle, and the landing droplet array A and the landing droplet array are the ink droplets corresponding to the print data. It is assumed that a gap is formed between the ink droplets B and the pitch D3 between the landing droplet rows C and the landing droplet rows D is smaller than the pitch P of the nozzles.

  In the fifth embodiment, the size of the area of the landing droplet formed by the ink droplet ejected from the nozzle 35b is made larger than the size instructed corresponding to the print data and ejected from the nozzle 35c. The PC 1 instructs the printer 1A so as to make the size of the area of the landing droplet formed by the ink droplets smaller than the size designated in accordance with the print data.

  Accordingly, as shown in FIG. 7C, in the dot level table 47a of the fourth embodiment, the nozzle position number “1” and the dot level “0” for the nozzle 35a, and the nozzle position number for the nozzle 35b. "2" and dot level "+2", nozzle position number "3" and dot level "-1" for nozzle 35c, nozzle position number "4" and dot level "0" for nozzle 35d, and nozzle 35e On the other hand, the nozzle position number “5” and the dot level “0” are stored.

  For example, when an instruction to form landing droplets shown in (2) of FIG. 7A is output from the nozzles 35a to 35e to the printer 1 corresponding to the print data, the PC 1 performs dot printing according to the dot level table 47a. For the nozzles 35a, 35d, and 35e whose level is set to “0”, an instruction corresponding to the print data is output. Therefore, landing droplets having the size shown in FIG. 7A (2) are formed on the recording medium.

  On the other hand, for the nozzle 35b whose dot level is set to “+2”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (the landing droplet shown in (2) of FIG. 7A). An instruction to form the landing droplet shown in FIG. 7A (4) which is two steps larger than the size of the area is output to the printer 1. Therefore, landing droplets having the size shown in (4) of FIG. 7A are formed on the recording medium.

  For the nozzle 35c whose dot level is set to “−1”, the PC 1 determines the size of the area of the landing droplet corresponding to the print data (the landing droplet shown in (2) of FIG. 7A). An instruction to form the landing droplet shown in (1) of FIG. Therefore, landing droplets having a size shown in (1) of FIG. 7A are formed on the recording medium.

  As described above, as described in the fifth embodiment, by increasing the area of the landing droplet corresponding to the nozzle 35b, the ink droplet corresponding to the print data is generated between the landing row A and the landing row B. The gap can be reduced. Further, by reducing the size of the area of the landing droplet corresponding to the nozzle 35c, it is possible to suppress a decrease in image quality.

  Next, an inkjet printer 2A as an inkjet recording which is one of the present invention will be described with reference to FIG. FIG. 8 is a block diagram showing an outline of an electric circuit configuration of the inkjet printer 2A.

  This ink jet printer 2A (hereinafter referred to as “printer 2A”) has an ink discharge control program 45a stored in the ROM 21 of the printer 1A and a dot level table 47a stored in the EEPROM 23.

  As described above, the above-described ink ejection control program 45a and the dot level table 47a mounted on the PC 1 may be directly mounted on the printer 2A, and the process performed on the PC 1 may be executed on the printer 2A. Even in such a case, a high-quality image can be formed by the printer 2A as in the printer 1A described above.

  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 above embodiment, the method of changing the voltage value applied to the drive element that drives each nozzle has been described as the method of changing the size of the area of the landing droplet corresponding to each nozzle. The method for changing the size of the droplet area is not limited to this method.

  For example, by combining a plurality of ink droplets of a predetermined ink amount in the air or on a recording medium, the size of the area of the landing droplet formed by the combined ink droplets may be increased. . Further, instead of the type of printer 1A that ejects ink from each nozzle by driving a drive element, a heat source is provided for each nozzle, and ink is ejected from each nozzle according to the heat generated from the heat source. When a printer is used, the size of the area of the landing droplet corresponding to each nozzle may be controlled by controlling the amount of heat generated from the heat source.

  In the above embodiment, the case where the gap is detected by the CCD scanner as a detection device separate from the printer 1A has been described. However, a detection device for detecting this gap may be incorporated in the printer 1A. . In such a case, it is not necessary to prepare a detection device separately from the printer 1A, and the detection of the gap by the detection device can be performed without stress.

  Further, in the above-described embodiment, the case where the ink droplets that are displaced from the vertical direction for some reason are displaced in the direction in which the nozzles are arranged has been described. By controlling the timing at which the ink droplets are discharged, the gap formed by the ink droplets displaced in the transport direction can be reduced.

  In the above embodiment, the dot level stored in the dot level table 47a is based on “0”, and how many large or small landing droplet areas are formed with respect to “0”. Although the case of storing the indicated parameter has been described, the parameter stored in the dot level is not limited to this, and for example, the voltage value applied to each nozzle may be stored directly. In this case, there is an effect that it is possible to perform processing at high speed without having to confirm the correspondence relationship with the preset parameter.

  Further, for example, as described in FIG. 3 as the first embodiment, when a small gap is generated between the landing row D and the landing row E by reducing the landing droplet corresponding to the nozzle 35d. The dot level corresponding to the nozzle 35e is set from “0” to “+1”, and the size of the area of the landing droplet corresponding to the nozzle 35e is made larger than the size instructed corresponding to the print data. Also good. In such a case, a small gap generated between the landing row D and the landing row E can be reduced by the landing row E, and a high-quality image can be formed.

FIG. 1 is a schematic view showing a personal computer as a control device for an ink jet recording apparatus which is one of the present invention, and an ink jet 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. The first embodiment relates to (a) (1) to (4), in which the size of the area of the landing droplet formed by the ink droplet ejected from each nozzle of the printer landing on the recording medium is as follows. It is a figure which shows a kind, (b) is a figure for demonstrating the relationship between a nozzle and the landing droplet formed with the ink droplet discharged from each nozzle, (c) is a figure which shows a dot level table. It is. (A) (1) to (4) are the size of the area of the landing droplet formed by the ink droplet ejected from each nozzle of the printer landing on the recording medium. It is a figure which shows a kind, (b) is a figure for demonstrating the relationship between a nozzle and the landing droplet formed with the ink droplet discharged from each nozzle, (c) is a figure which shows a dot level table. It is. (A) (1) to (4) are the size of the area of the landed droplet formed by the ink droplet ejected from each nozzle of the printer landing on the recording medium. It is a figure which shows a kind, (b) is a figure for demonstrating the relationship between a nozzle and the landing droplet formed with the ink droplet discharged from each nozzle, (c) is a figure which shows a dot level table. It is. The fourth embodiment relates to (a) (1) to (4), in which the size of the area of the landing droplet formed by the ink droplet ejected from each nozzle of the printer landing on the recording medium is as follows. It is a figure which shows a kind, (b) is a figure for demonstrating the relationship between a nozzle and the landing droplet formed with the ink droplet discharged from each nozzle, (c) is a figure which shows a dot level table. It is. This relates to the fifth embodiment, and (1) to (4) of (a) show the size of the area of the landing droplet formed by the ink droplet ejected from each nozzle of the printer landing on the recording medium. It is a figure which shows a kind, (b) is a figure for demonstrating the relationship between a nozzle and the landing droplet formed with the ink droplet discharged from each nozzle, (c) is a figure which shows a dot level table. It is. It is a block diagram which shows the outline of the electric circuit structure of an inkjet printer. (A) is a figure for demonstrating the ideal relationship between a nozzle and a landing droplet in the conventional inkjet recording device. (B) explains the relationship between a nozzle and a landing droplet in a state where an ink droplet ejected from a predetermined nozzle in a conventional ink jet recording apparatus is ejected in an oblique direction with respect to the recording medium for some reason. It is a figure for doing.

1 PC (Control Device for Inkjet Recording Device)
2A Inkjet printer (inkjet recording device)
45a Ink discharge control program (discharge instruction means, control program for ink jet recording apparatus)
23 EEPROM (part of storage means)
47 Hard disk (part of storage means)
47a dot level table (part of storage means)

Claims (14)

Instructions for ejecting ink droplets from each nozzle toward the recording medium so that the area of the landing droplets formed by the ink droplets that land on the recording medium have a predetermined size based on the print data are sent to the recording medium. In a control device for an ink jet recording apparatus that outputs to an ink jet recording apparatus having a line head that forms an image on a recording medium by relative movement in one direction.
The first nozzle of at least one of the two nozzles that ejects ink droplets that land at a position where the pitch of the landing droplets adjacent in the direction perpendicular to the conveyance direction of the recording medium is larger than a predetermined pitch. The size of the area of the landing droplet formed by the ink droplet ejected from the ink droplet is larger than a predetermined size corresponding to the print data, and two nozzles located on both sides of the first nozzle, Formed by the ink droplets ejected from the second nozzle with respect to the second nozzle ejecting ink droplets that land at a position where the pitch of the landing droplets formed by the ink droplets ejected from the first nozzle is small. An instruction is output to the ink jet recording apparatus so that the size of the landed droplet area is smaller than the predetermined size corresponding to the print data. Discharge instruction means, comprising: the discharge instruction means that overlaps landing droplets formed by the large ink droplets and landing droplets formed by the small ink droplets. Control device.   The ejection instruction means outputs an instruction so that the size of the area of the landing droplet formed by the ink droplet ejected from the first nozzle increases as the pitch of the adjacent landing droplet increases. The control device for an ink jet recording apparatus according to claim 1.   The first nozzle includes a nozzle that ejects ink droplets that land at an appropriate position, and a nozzle that ejects ink droplets that land at a position different from the appropriate position. 3. The control device for an ink jet recording apparatus according to claim 1, wherein the control device is an ink jet nozzle that ejects ink droplets that land at a position different from the proper position when the ink droplet is formed to be larger than the proper position.   The first nozzle includes a nozzle that ejects ink droplets that land at a proper position and a nozzle that ejects ink droplets that land at a position different from the proper position, and the pitch of the adjacent landed droplets is a predetermined pitch. 3. The control device for an ink jet recording apparatus according to claim 1, wherein the control device is a nozzle that ejects ink droplets that land at an appropriate position when the ink droplet is formed to be larger than 3 mm.   3. The ink jet recording apparatus according to claim 1, wherein the first nozzle is two nozzles that eject ink droplets that land at a position where the pitch of the adjacent landing droplets is larger than a predetermined pitch. 4. Control device.   The ejection instructing means has an area of the landing droplet formed by the ink droplets ejected from the two second nozzles with respect to the two second nozzles located on both sides of the two nozzles as the first nozzle. 6. The control device for an ink jet recording apparatus according to claim 5, wherein an instruction is output to the ink jet recording apparatus so that the size of the ink droplet is smaller than a predetermined size corresponding to the print data. A first parameter indicating an instruction that the size of the area of the landing droplet formed by the ink droplet ejected from the first nozzle is larger than a predetermined size corresponding to the print data; and ejecting from the second nozzle Storage means for storing at least one parameter of a second parameter indicating an instruction that the size of the area of the landing droplet formed by the ink droplet to be made is smaller than a predetermined size corresponding to the print data. ,
7. The control apparatus for an ink jet recording apparatus according to claim 1, wherein the discharge instructing unit outputs an instruction to the ink jet recording apparatus in accordance with a parameter stored in the storage unit.   8. The control apparatus for an ink jet recording apparatus according to claim 7, wherein the parameter stored in the storage means is configured to be rewritable.   The inkjet recording according to claim 7 or 8, wherein the storage unit is configured to be able to newly store the first parameter and the second parameter for each of the nozzles excluding the first nozzle. Control device for equipment.   The ejection instructing unit outputs an instruction to the ink jet recording apparatus via an interface of the ink jet recording apparatus to an ink jet recording apparatus that forms an image on a recording medium based on data received from an external apparatus. The control device for an ink jet recording apparatus according to claim 1.   The discharge instruction means outputs an instruction for discharging ink droplets of a plurality of sizes based on print data to an ink jet recording apparatus, and with respect to a third nozzle other than the first nozzle and the second nozzle, The control device for an ink jet recording apparatus according to any one of claims 1 to 10, wherein an instruction is output to the ink jet recording apparatus so as to eject ink droplets having a size based on print data. An instruction to eject ink droplets from each nozzle toward the recording medium so that the landing droplets formed by the ink droplets that land on the recording medium have a predetermined size based on the print data is one direction with respect to the recording medium. In a control method of an ink jet recording apparatus that outputs to an ink jet recording apparatus having a line head that forms an image on a recording medium by relative movement to
The first nozzle of at least one of the two nozzles that ejects ink droplets that land at a position where the pitch of the landing droplets adjacent in the direction perpendicular to the conveyance direction of the recording medium is larger than a predetermined pitch. The size of the area of the landing droplet formed by the ink droplet ejected from the ink droplet is larger than a predetermined size corresponding to the print data, and two nozzles located on both sides of the first nozzle, Formed by the ink droplets ejected from the second nozzle with respect to the second nozzle ejecting ink droplets that land at a position where the pitch of the landing droplets formed by the ink droplets ejected from the first nozzle is small. An instruction is output to the ink jet recording apparatus so that the size of the landed droplet area is smaller than the predetermined size corresponding to the print data. An ink jet recording apparatus comprising: the ink discharge instruction step, wherein the ink discharge instruction step overlaps a landing droplet formed by the large ink droplet and a landing droplet formed by the small ink droplet. Control method. In an ink jet recording apparatus that discharges ink droplets from each nozzle toward a recording medium, and forms an image by landing droplets formed by landing each discharged ink droplet on the recording medium.
An ink jet recording apparatus provided with a control equipment inkjet recording apparatus, and wherein the thus controlled by it to the ink jet recording apparatus for control equipment according to any one of claims 1 to 11. A line head that forms an image on the recording medium by moving relative to the recording medium in one direction;
A moving means for relatively moving the line head and the recording medium in one direction;
The line head is configured to form an image on a recording medium by ejecting ink droplets from each nozzle in accordance with an instruction from the ejection instruction unit or the ejection instruction step in accordance with relative movement in one direction with respect to the recording medium. The inkjet recording apparatus according to claim 13 .

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