JP7006070B2 - Droplet ejection device and droplet ejection program - Google Patents

Description

The present invention relates to a droplet ejection device and a droplet ejection program.

Patent Document 1 describes a plurality of types of landing interference patterns corresponding to landing interference inducing factors including the nozzle arrangement form in the recording head and the landing order of droplets defined from the direction of relative movement between the head and the ejected medium. Based on the correspondence information indicating the correspondence relationship between the nozzle and each nozzle, a correction coefficient for non-ejection correction corresponding to the difference in the impact interference pattern is determined, stored in the storage unit, and based on the non-ejection nozzle position information. Refer to the correction coefficient for non-discharge correction, and correct the output of the non-discharge nozzle by nozzles other than the non-discharge nozzle by performing a correction calculation on the input image data using the corresponding correction coefficient. It is described that the image data is generated.

Japanese Unexamined Patent Publication No. 2011-20121

When correcting with a droplet of a nozzle that ejects a droplet at a position adjacent to the position where the non-ejection nozzle should be ejected in order to correct a streak due to non-ejection, it is adjacent to the correction droplet before the correction droplet to be corrected. It is known that when a droplet is ejected at a position, the correction droplet moves to the previously ejected droplet side due to impact interference. If the amount of the correction drop is increased from the amount normally used in order to suppress the reduction of the correction effect due to the movement, the drive cycle becomes longer due to the ejection, and the printing speed may decrease. An object of the present invention is to suppress a decrease in printing speed as compared with a case where a correction droplet larger than a droplet normally used for correcting a streak due to non-ejection is used.

In the droplet ejection device according to claim 1, a first group of nozzles in which a plurality of nozzles are arranged along an intersecting direction intersecting the relative movement direction of the medium to eject droplets onto the medium, and along the intersecting direction. When a head including a second nozzle group in which a plurality of nozzles are arranged and ejects a droplet to a medium after the first nozzle group and a defective nozzle of the head are corrected, the defective nozzle ejects a droplet. The correction drop is discharged from the nozzle that discharges the droplet to the position adjacent to the position to be discharged, and the correction nozzle that discharges the correction drop and the adjacent nozzle that discharges the droplet to the position adjacent to the correction drop are in the ejection order. The correction nozzle is provided with a control unit for changing the amount of droplets to be ejected from each of the correction nozzle and the adjacent nozzle to control the movement of the correction droplet, and the control unit is provided with the correction nozzle. Increase the amount of droplets to be ejected to the position two adjacent to the droplet ejected from .

The invention according to claim 2 is the invention according to claim 1, wherein the control unit makes the appearance rate of the droplets ejected from the adjacent nozzle smaller than the appearance rate of the droplets ejected from the correction nozzle. By doing so, the appropriate amount of droplets is changed to control the movement of the correction droplets.

The invention according to claim 3 is the invention according to claim 1, wherein the control unit increases the amount of droplets ejected from the correction nozzle from the amount of droplets that should be ejected, and the adjacent nozzle. By thinning out the droplets ejected from, the amount of the droplets is changed to control the movement of the correction droplets.

The invention according to claim 4 includes a first nozzle group in which a plurality of nozzles are arranged along an intersecting direction intersecting the relative movement direction of the medium and ejects droplets to the medium in advance from the first nozzle group. The second head is provided with a first head for ejecting droplets of a predetermined color, and a second nozzle group in which a plurality of nozzles are arranged along the crossing direction and ejects droplets to a medium after the first nozzle group. From the nozzle group, a second head that superimposes and ejects a droplet having a color different from that of the droplet ejected from the first nozzle group on the droplet ejected by the first nozzle group, and along the crossing direction. A plurality of nozzles are arranged, and droplets having a color different from that of the first head and the second head are ejected from the first nozzle group at a timing after the first nozzle group and before the second nozzle group. A head including a third head provided with a third nozzle group for ejecting a droplet superimposed on the droplet ejected by the head, and when correcting a defective nozzle of the head, the defective nozzle is adjacent to a position where the droplet should be ejected. When the ejection order is different between the correction nozzle that ejects the correction droplet from the nozzle that ejects the droplet at the position where the droplet is ejected and the adjacent nozzle that ejects the droplet at the position adjacent to the correction droplet. A control unit that controls the movement of the correction droplet by changing the amount of droplet to be ejected from each of the correction nozzle and the adjacent nozzle, and is the case where a defective nozzle is present in the second nozzle group. The nozzle of the first nozzle group that ejects the droplet to the position where the defective nozzle should eject the droplet is used as the adjacent nozzle to control the movement of the correction drop and is predetermined according to the amount of the correction drop. A control unit for controlling the movement of the correction drop by changing the drop amount of the droplet ejected from the first nozzle group so as to have a drop amount is provided, and the control unit precedes the correction drop. When there are a plurality of heads for ejecting droplets, the amount of droplets ejected from the head having the largest amount of droplets or the amount of droplets ejected from the plurality of heads is changed .

The invention according to claim 5 is a first group of nozzles in which a plurality of nozzles are arranged along an intersection direction intersecting the relative movement direction of the medium to eject droplets onto the medium, and a plurality of droplets along the intersection direction. A first head in which droplets are ejected from a second nozzle group in which droplets are ejected after the first nozzle group is arranged, and a plurality of droplets are arranged along the crossing direction. The first head is provided with a third nozzle group for ejecting a droplet to the medium, and a fourth nozzle group in which a plurality of nozzles are arranged along the crossing direction to eject droplets to the medium after the third nozzle group. After ejecting the droplets, the droplets are ejected from the third nozzle group adjacent to the relative movement direction of the droplets ejected by the first head, and between the droplets ejected by the third nozzle group. When the head including the second head that ejects the droplet from the fourth nozzle group and the defective nozzle of the head are corrected, the droplet is located at a position adjacent to the position where the defective nozzle should eject the droplet. When the correction droplet is ejected from the nozzle that ejects the correction droplet and the ejection order is different between the correction nozzle that ejects the correction droplet and the adjacent nozzle that ejects the droplet at a position adjacent to the correction droplet, the correction nozzle and the adjacent one. A control unit that controls the movement of the correction droplet by changing the amount of the droplet to be ejected from each of the nozzles is provided, and the control unit provides a predetermined drop according to the position of the defective nozzle in the head. The head is further controlled to eject an amount of correction droplet .

The invention according to claim 6 is the invention according to claim 5 , wherein the control unit has a correction amount when the position of a defective nozzle in the head is included in the first nozzle group> the second nozzle group. ≒ Correction amount when included in the 3rd nozzle group> Correction amount when included in the 4th nozzle group. The head is controlled.

In the droplet ejection device according to claim 7 , a first group of nozzles in which a plurality of nozzles are arranged along an intersecting direction intersecting the relative movement direction of the medium to eject droplets onto the medium, and along the intersecting direction. A second nozzle group in which a plurality of nozzles are arranged and ejects droplets to the medium after the first nozzle group is provided, and liquid from the second nozzle group is provided between the droplets ejected by the first nozzle group. The first head for ejecting a droplet, a third group of nozzles in which a plurality of nozzles are arranged along the crossing direction to eject the droplet to the medium, and the first head in which a plurality of nozzles are arranged along the crossing direction. A fourth nozzle group for ejecting a droplet to the medium after the three nozzle group is provided, and after the droplet is ejected from the first head, the droplet is adjacent to the relative moving direction of the droplet ejected by the first head. A head including a second head that ejects droplets from the third nozzle group and ejects droplets from the fourth nozzle group between the droplets ejected by the third nozzle group, and a defect of the head. When the defective nozzle ejects a correction droplet from a nozzle that ejects a droplet at a position adjacent to a position where the defective nozzle should eject the droplet when correcting the nozzle, and the defective nozzle is included in the fourth nozzle group. Provided a control unit that controls the head so that a correction drop having a smaller amount of drops is ejected as compared with the case where the defective nozzle is at another position.

The invention according to claim 8 is the invention according to claim 7 , wherein the control unit has a correction amount when the position of a defective nozzle in the head is included in the first nozzle group> the second nozzle group. The correction amount when it is included in the above ≈ the correction amount when it is included in the third nozzle group> the correction amount when it is included in the fourth nozzle group. Controls the head.

The droplet ejection program according to claim 9 causes the computer to function as the control unit according to any one of claims 1 to 8 .

According to the droplet ejection device according to claim 1, it is possible to suppress a decrease in printing speed as compared with the case where a correction droplet larger than a droplet normally used for correcting a streak due to non-ejection is used. A droplet ejection device can be provided.

According to the second aspect of the present invention, the non-discharge correction can be performed more efficiently than in the case where the non-discharge correction is performed only by the correction nozzle.

According to the third aspect of the present invention, the non-discharge correction can be performed more efficiently than in the case where the non-discharge correction is performed only by the correction nozzle.

According to the fourth aspect of the present invention, a droplet ejection capable of suppressing a decrease in printing speed can be suppressed as compared with a case where a correction droplet larger than a droplet normally used for correcting a streak due to non-ejection is used. Equipment can be provided .

According to the fifth aspect of the present invention, a droplet ejection capable of suppressing a decrease in printing speed can be suppressed as compared with a case where a correction droplet larger than a droplet normally used for correcting a streak due to non-ejection is used. Equipment can be provided .

According to the sixth aspect of the present invention, it is possible to suppress fluctuations in the correction effect of non-ejection due to the ejection order of the droplets, as compared with the case where a correction droplet having a constant amount of droplets is used regardless of the position of the defective nozzle in the head.

According to the droplet ejection device according to claim 7 , it is possible to suppress a decrease in printing speed as compared with the case where a correction droplet larger than a droplet normally used for correcting a streak due to non-ejection is used. A droplet ejection device can be provided.

According to the eighth aspect of the present invention, it is possible to suppress fluctuations in the correction effect of non-ejection due to the ejection order of the droplets, as compared with the case where a correction droplet having a constant amount of droplets is used regardless of the position of the defective nozzle in the head.

According to the invention of claim 9 , a droplet ejection capable of suppressing a decrease in printing speed as compared with a case where a correction droplet larger than a droplet normally used for correcting a streak due to non-ejection is used. Can provide a program.

It is a figure which shows the schematic structure of the image forming apparatus which concerns on this embodiment. It is a figure which shows the schematic structure of a recording head. It is a block diagram which shows the main part structure of the electric system of the image forming apparatus which concerns on this embodiment. (A) is a diagram showing a case where one nozzle is non-ejection, and (B) is a diagram showing a case where a correction drop is ejected to a pixel adjacent to the non-ejection and there is no impact interference. ) Is a diagram showing a case where the correction droplet is ejected to a pixel adjacent to the non-ejection and the correction droplet moves due to landing interference, and FIG. 3D is a diagram showing a case where the correction droplet is enlarged. It is a figure which shows the required drop volume with respect to the dot diameter. (A) is a diagram showing a state in which ink droplets ejected from a nozzle adjacent to a non-ejecting nozzle are thinned out and ejected in the first-strike nozzle group, and (B) is adjacent to non-ejection in the post-castle nozzle group. It is a figure which shows the state which ejected the correction drop which increased the drop amount from the correction nozzle which ejects an ink drop to a position, and (C) is the figure which shows the state which suppressed the landing interference by thinning out the pixels. It is a flowchart which shows an example of the flow of the process performed at the time of forming an image by the image forming apparatus which concerns on 1st Embodiment. (A) is a diagram showing a state in which ink droplets ejected from a nozzle adjacent to a non-ejecting nozzle are thinned out and ejected in the first-strike nozzle group, and (B) is adjacent to non-ejection in the post-castle nozzle group. It is a figure which shows the state which the correction drop which increased the drop amount is ejected from the correction nozzle which ejects an ink drop to a position, and the drop amount is increased at the position adjacent to the position where the pixel is thinned out, and (C) is a pixel. It is a figure which shows the state which increased the drop amount at the position next to two non-ejections while thinning out. It is a flowchart which shows an example of the flow of the process performed at the time of forming an image by the image forming apparatus which concerns on 2nd Embodiment. It is a figure which shows the image which the non-ejection nozzle exists in the recording head which ejects a cyan-colored ink drop at the time of forming the image which superposed the magenta image and the cyan image, (B) is a cyan-colored figure. Ink that ejects correction droplets with an increased amount of ink droplets at a position adjacent to the non-ejection of the recording head and ejects to the non-ejection position of cyan color in the magenta-colored recording head that ejects before the cyan color. It is a figure which shows the state which increased the drops, (C) is the figure which shows the example which added the magenta color image when there is no magenta color image at the position corresponding to non-ejection. It is a flowchart which shows an example of the flow of the process performed at the time of forming an image by the image forming apparatus which concerns on 3rd Embodiment. Two types of non-ejection of cyan color in the magenta recording head, which ejects correction drops with an increased amount of ink droplets at a position adjacent to the non-ejection of the cyan-colored recording head and ejects before the cyan-colored recording head. It is a figure which shows the state which reduced the ink droplets ejected to the adjacent position. It is a flowchart which shows an example of the flow of the process performed at the time of forming an image by the image forming apparatus which concerns on 4th Embodiment. (A) is a state in which magenta-colored ink droplets are ejected to a position corresponding to the non-ejection position to generate landing interference, and the cyan-colored correction droplets to be ejected later are moved to the non-ejection side. It is a figure which shows the state which the density of the cyan color discharged to the non-ejection position is also low when the density around the magenta color is low, it is a figure which shows. (A) is a diagram showing a predetermined correction amount (non-discharge adjacent correction amount) according to the gradation of the non-ejection position, and (B) is a diagram with respect to the correction drop correction amount (non-discharge adjacent correction amount). It is a figure which shows the drop amount of the color to be ejected prior to the ejection-free position (the required droplet amount of the preceding color pixel of the ejection-free position), which is predetermined so as to be the predetermined droplet amount. (A) is a diagram showing an example of the value of each color at the position of the correction drop and the non-ejection, and (B) shows an example of increasing the value of the most color among the values of each color to obtain the required drop amount. It is a figure, (C) is a figure which shows the example which increased to the required drop amount while maintaining the ratio of each color, (D) is the figure which increased the most color after giving weight in advance according to a color characteristic. It is a figure which shows the example which made the required drop amount, and (E) shows the example which increased to the required drop amount while maintaining the ratio of each weighted color after giving weight in advance according to a color characteristic. It is a figure. (A) is a diagram showing two recording heads provided for each color, and (B) is a diagram for explaining the operation of the two recording heads. (A) is a diagram for explaining the movement of the correction droplet when non-ejection occurs in the pre-empted nozzle group of the recording head that ejects the ink droplet first, and (B) is a diagram for explaining the movement of the correction droplet, and (B) ejects the ink droplet first. It is a figure for demonstrating the movement of a correction drop when a non-ejection occurs in the post-adhesion nozzle group of a recording head, and FIG. It is a figure for demonstrating the movement of the correction drop in the case of this, and (D) is for demonstrating the movement of the correction drop when a non-ejection occurs in the post-adhesion nozzle group of a recording head which ejects an ink drop later. It is a figure. It is a flowchart which shows an example of the flow of the process performed by the image forming apparatus which concerns on 6th Embodiment.

Hereinafter, this embodiment will be described with reference to the drawings. In this embodiment, a case where the droplet ejection device is applied to an image forming apparatus that ejects ink droplets as droplets onto a recording medium to form an image will be described. FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to the present embodiment. Further, FIG. 2 is a diagram showing a schematic configuration of a recording head.

As shown in FIG. 1, the image forming apparatus 10 according to the present embodiment includes a transport roller 20, a paper feed roll 30, a rotary encoder 32, a discharge roll 40, a recording head 50C, 50M, 50Y, 50K, and a drying unit 60. I have.

The transfer roller 20 according to the present embodiment rotates by driving a transfer motor 22 connected to the transfer roller 20 via a mechanism such as a gear or the like. Further, a long continuous paper P is wound around the paper feed roll 30 according to the present embodiment as a medium, and the continuous paper P is conveyed in the direction of arrow A in FIG. 1 as the conveying roller 20 rotates. Will be done. Further, the conveyed continuous paper P is taken up by the discharge roll 40. In the following, the direction in which the continuous paper P is conveyed (direction of arrow A in FIG. 1) is simply referred to as “transportation direction”.

The rotary encoder 32 according to the present embodiment is provided on the rotation axis of the paper feed roll 30, and outputs a clock signal each time the paper feed roll 30 rotates at a predetermined angle.

The recording heads 50Y, 50M, 50C, and 50K according to the present embodiment are provided in this order from the upstream in the transport direction along the transport direction. In the following, when it is not necessary to distinguish the recording heads 50Y, 50M, 50C, and 50K, the alphabet at the end of the code is omitted.

Further, as shown in FIG. 2, the recording head 50 has a staggered nozzle group 54 having a plurality of nozzles 52 arranged along an intersecting direction (hereinafter, simply referred to as “intersection direction”) intersecting the transport direction. It is arranged in a shape. The nozzle group 54 has a pre-strike nozzle group 54A as a first nozzle group for ejecting ink droplets first, and a post-launch nozzle group 54B as a second nozzle group for ejecting ink droplets later. The ink droplets are ejected from the post-launched nozzle group 54B between the ink droplets ejected from the nozzle group 54A. That is, after the ink droplets are ejected from the first-strike nozzle group 54A, the ink droplets are ejected from the post-strike nozzle group 54B at the timing when the continuous paper P moves between the first-strike nozzle group 54A and the post-strike nozzle group 54B. .. Then, the recording heads 50C, 50M, 50Y, and 50K continuously spray ink droplets corresponding to each of the four colors of cyan (C), magenta (M), yellow (Y), and black (K) from the nozzle 52. Discharge upwards. By relatively moving the continuous paper P and the recording head 50, an image composed of ink droplets is formed on the continuous paper P.

The drying unit 60 according to the present embodiment includes, for example, a plurality of surface emitting laser elements, and the ink droplets ejected on the continuous paper P are irradiated with a laser from the surface emitting laser element to dry the ink droplets. Then, the ink droplets are fixed on the continuous paper P. As the drying unit 60, another device such as a heater that dries the ink droplets ejected onto the continuous paper P by warm air may be applied.

Next, with reference to FIG. 3, the configuration of a main part of the electrical system of the image forming apparatus 10 according to the present embodiment will be described. FIG. 3 is a block diagram showing a configuration of a main part of the electrical system of the image forming apparatus 10 according to the present embodiment.

As shown in FIG. 3, the image forming apparatus 10 according to the present embodiment includes a CPU (Central Processing Unit) 80 that controls the overall operation of the image forming apparatus 10, and a ROM in which various programs, various parameters, and the like are stored in advance. (Read Only Memory) 82 is provided. Further, the image forming apparatus 10 also includes a RAM (Random Access Memory) 84 used as a work area or the like when executing various programs by the CPU 80, and a non-volatile storage unit 86 such as a flash memory.

Further, the image forming apparatus 10 includes a communication line I / F (Interface) unit 88 that transmits / receives communication data to / from an external device. Further, the image forming apparatus 10 includes an operation display unit 90 that receives an instruction from the user to the image forming apparatus 10 and notifies the user of various information regarding the operating status of the image forming apparatus 10. The operation display unit 90 includes, for example, a display button that realizes reception of operation instructions by executing a program, a touch panel type display on which various information is displayed, and hardware keys such as a numeric keypad and a start button.

The CPU 80, ROM 82, RAM 84, storage unit 86, transfer motor 22, rotary encoder 32, and recording head 50 are connected to each other via a bus 92 such as an address bus, a data bus, and a control bus. Further, in addition to each of these parts, each part of the drying part 60, the communication line I / F part 88, and the operation display part 90 is also connected to each other via the bus 92. Further, a transfer roller 20 is connected to the transfer motor 22.

With the above configuration, the image forming apparatus 10 according to the present embodiment uses the CPU 80 to access the ROM 82, the RAM 84, and the storage unit 86, and to send and receive communication data via the communication line I / F unit 88. Further, the image forming apparatus 10 acquires various data via the operation display unit 90 and displays various information on the operation display unit 90 by the CPU 80. Further, the image forming apparatus 10 receives the clock signal output from the rotary encoder 32 by the CPU 80, and controls the recording head 50 and the drying unit 60 based on the clock signal. Further, the image forming apparatus 10 controls the rotation of the transfer roller 20 via the transfer motor 22 by the CPU 80.

By the way, in the image forming apparatus 10 according to the present embodiment, when a defect of the nozzle 52 such as non-ejection occurs, the amount of ink droplets ejected from the nozzle 52 around the defective nozzle 52 is changed to correct the problem. It has a function to do.

However, in the present embodiment, since the recording head 50 having the first-strike nozzle group 54A and the second-strike nozzle group 54B is used, the ink droplets are placed at a position different from the intended position due to the impact interference of the ink depending on the ink ejection order. Will move. For example, as shown in FIG. 4A, when one nozzle 52 does not eject, it is assumed that the amount of droplets of adjacent pixels is increased to correct the problem. When the nozzle (hereinafter, may be referred to as a correction nozzle 52) 52 for ejecting a correction drop having an increased amount of drops is the pre-strike nozzle group 54A, as shown in FIG. 4 (B), there is no impact interference and the intention is The correction drop is ejected to the position where it is to be. On the other hand, when the correction nozzle 52 is the post-strike nozzle group 54B, ink is ejected toward the ink droplets ejected from the nozzle 52 of the pre-strike nozzle group 54A, which ejects ink droplets at a position adjacent to the correction droplets due to impact interference. The drops will move. If the amount of drops is insufficient, white streaks will occur as shown in FIG. 4 (C). Therefore, as shown in FIG. 4 (D), it is necessary to further increase the amount of droplets to increase the droplet diameter, but as shown in FIG. 5, when the droplet diameter required for correction becomes large, the required droplets are serially required. As the amount increases and the number of rapid fires increases, the speed drops significantly. Note that FIG. 5 shows an example calculated by assuming that the drop volume is a true sphere, the dot spread rate is 2, and the dot diameter = ink drop diameter × spread rate.

Therefore, in the present embodiment, when the defective nozzle (defective nozzle) 52 such as non-ejection is the pre-strike nozzle group 54A, that is, the correction nozzle 52 is the post-launch nozzle group 54B, the non-ejection correction in consideration of the impact interference is taken into consideration. Is supposed to do. Hereinafter, the correction method when the correction nozzle 52 in the image forming apparatus 10 according to the present embodiment is the post-launch nozzle group 54B will be described. In the following, as an example of a defective nozzle, a case of a non-ejection nozzle in which ink droplets are non-ejection will be described.

(First Embodiment)
In the present embodiment, when the non-discharging nozzle 52 is the pre-casting nozzle group 54A, that is, the correction nozzle 52 is the post-launching nozzle group 54B, the side opposite to the non-discharging position adjacent to the position where the correction nozzle 52 discharges the correction droplet. The process of thinning out the pixels at the position of is performed on the image information. In other words, the image information is changed so that the appearance rate of the pixel at the position opposite to the non-ejection of the correction drop is smaller than the appearance rate of the correction drop.

Specifically, on the pre-strike nozzle group 54A, the ink droplets (ink droplets adjacent to the correction droplets) ejected from the nozzle 52 adjacent to the non-ejecting nozzle 52 are thinned out as shown in FIG. 6A. And discharge. FIG. 6A shows an example in which the ink droplet adjacent to one side of non-ejection is thinned out by 3 pixels and the ink droplet adjacent to the other side is thinned out by 4 pixels.

Then, in the post-strike nozzle group 54B, as shown in FIG. 6B, the correction droplet with an increased amount is ejected from the correction nozzle 52 that ejects the ink droplet to the position adjacent to the non-ejection.

As a result, as shown in FIG. 6C, among the correction droplets, the correction droplets existing at the positions adjacent to the ink droplets ejected from the first nozzle group 54A are the ink droplets ejected earlier due to the impact interference. Move towards. On the other hand, among the correction droplets, the ink droplets ejected from the pre-strike nozzle group 54A are thinned out and do not exist at the adjacent positions, so that the impact interference is suppressed and the generation of white streaks is suppressed.

Subsequently, specific processing performed by the image forming apparatus 10 according to the present embodiment will be described. FIG. 7 is a flowchart showing an example of a flow of processing performed when an image is formed by the image forming apparatus 10 according to the present embodiment.

In step 100, the CPU 80 determines whether or not there is a non-ejection nozzle. The determination is made, for example, by forming a detection pattern for detecting a non-ejection nozzle at a predetermined timing, detecting and storing the non-ejection nozzle 52, and determining from the stored information. If the determination is affirmed, the process proceeds to step 102, and if the determination is negative, the process proceeds to step 108.

In step 102, the CPU 80 corrects the image information so as to discharge the correction drop to a position adjacent to the non-discharge, and proceeds to step 104.

In step 104, the CPU 80 determines whether or not the correction drop is the post-striking nozzle group 54B. If the determination is affirmed, the process proceeds to step 106, and if the determination is negative, the process proceeds to step 108.

In step 106, the CPU 80 corrects the image information again so as to thin out the images adjacent to the correction droplets, and proceeds to step 108.

In step 108, the CPU 80 forms an image based on the image information and ends a series of processes.

By correcting the non-ejection in this way, when the nozzle 52 for ejecting the correction droplet is the post-launch nozzle group 54B, the impact interference due to the ink droplet ejected by the pre-strike nozzle group 54A is suppressed. The generation of white streaks is suppressed.

(Second Embodiment)
Next, the non-discharge correction method of the second embodiment will be described. In the present embodiment, the amount of ink droplets ejected to the positions two adjacent to the correction droplets is further changed and increased with respect to the first embodiment.

That is, when the non-discharging nozzle is the pre-strike nozzle group 54A, that is, the correction nozzle 52 is the post-strike nozzle group 54B, the non-ejection nozzle 52 is adjacent to the position where the correction nozzle 52 discharges the correction droplet, as in the first embodiment. The process of thinning out the pixels at the positions opposite to the above is performed on the image information. Then, the amount of ink droplets ejected to the positions two adjacent to the correction droplets is increased. The position where the amount of drops is increased is, for example, a position adjacent to the thinned-out position so that the discomfort is reduced according to the surrounding concentration.

Specifically, on the pre-strike nozzle group 54A, the ink droplets (ink droplets adjacent to the correction droplets) ejected from the nozzle 52 adjacent to the non-ejecting nozzle 52 are thinned out as shown in FIG. 8A. And discharge. FIG. 8A shows an example in which the ink droplet adjacent to one side of non-ejection is thinned out by 3 pixels and the ink droplet adjacent to the other side is thinned out by 4 pixels.

Then, in the post-strike nozzle group 54B, as shown in FIG. 8B, the correction nozzle 52 that ejects the ink droplet to the position adjacent to the non-ejection ejects the correction droplet with an increased amount of the ink droplet, and at the same time, the pixel is ejected. A correction drop with an increased amount of drops, such as a position adjacent to the thinned position, is discharged.

As a result, as shown in FIG. 8C, among the correction droplets, the correction droplets existing at the positions adjacent to the ink droplets ejected from the first nozzle group 54A are the ink droplets ejected earlier due to the impact interference. Move towards. On the other hand, among the correction droplets, the ink droplets ejected from the pre-strike nozzle group 54A are thinned out and do not exist at the adjacent positions, so that the impact interference is suppressed and the generation of white streaks is suppressed. In addition, since the amount of droplets at the positions two adjacent to each other without ejection is increased, the correction that suppresses the discomfort is performed according to the surrounding concentration.

Subsequently, specific processing performed by the image forming apparatus 10 according to the present embodiment will be described. FIG. 9 is a flowchart showing an example of a flow of processing performed when an image is formed by the image forming apparatus 10 according to the present embodiment. The same processing as that of the first embodiment will be described with the same reference numerals hidden.

In step 100, the CPU 80 determines whether or not there is a non-ejection nozzle. The determination is made, for example, by forming a detection pattern for detecting a non-ejection nozzle at a predetermined timing, detecting and storing the non-ejection nozzle 52, and determining from the stored information. If the determination is affirmed, the process proceeds to step 102, and if the determination is negative, the process proceeds to step 108.

In step 102, the CPU 80 corrects the image information so as to discharge the correction drop to a position adjacent to the non-discharge, and proceeds to step 104.

In step 104, the CPU 80 determines whether or not the correction drop is the post-striking nozzle group 54B. If the determination is affirmed, the process proceeds to step 106, and if the determination is negative, the process proceeds to step 108.

In step 106, the CPU 80 corrects the image information again so as to thin out the images adjacent to the correction droplets, and proceeds to step 107.

In step 107, the CPU 80 further corrects the image information so as to increase the drop amount of the image two adjacent to the correction drop, and proceeds to step 108.

In step 108, the CPU 80 forms an image based on the image information and ends a series of processes.

In this way, by correcting the non-ejection, when the nozzle 52 for ejecting the correction droplet is the post-launch nozzle group 54B, the impact interference due to the ink droplet ejected by the pre-strike nozzle group 54A is suppressed. The generation of white streaks is suppressed. Further, by increasing the amount of droplets at the positions two adjacent to the correction droplets, the correction is performed with less discomfort according to the peripheral concentration as compared with the first embodiment.

(Third Embodiment)
Next, a method for correcting non-discharge according to the third embodiment will be described. In the present embodiment, as in the first and second embodiments, the correction drop having an increased amount of drops adjacent to the non-discharge is discharged. In addition, by increasing the amount of droplets ejected from the nozzle 52 of the recording head 50 of the recording head 50 of another color that is ejected before the non-ejection color to the non-ejection position, landing interference is generated and corrected to the non-ejection side. Move the drops.

Specifically, as shown in FIG. 10A, there is a non-ejection nozzle 52 in the recording head 50C that ejects cyan ink droplets when forming an image in which a magenta image and a cyan image are superimposed. The case of doing so will be described.

As shown in FIG. 10B, the correction droplets having an increased amount of ink droplets at positions adjacent to the non-ejection of the cyan color recording head 50C are ejected, and the magenta color is ejected before the cyan color. Increases the amount of ink droplets ejected to the cyan non-ejection position on the recording head 50M.

If there is no magenta color image at the position corresponding to non-ejection, a magenta color image is added as shown in FIG. 10 (C).

As a result, the magenta-colored droplets ejected earlier are affected by the impact interference of the correction droplets and move to the non-ejection side, and the white streaks are suppressed.

In this embodiment, the recording head 50M corresponds to the first head, and the recording head 50C corresponds to the second head.

Subsequently, specific processing performed by the image forming apparatus 10 according to the present embodiment will be described. FIG. 11 is a flowchart showing an example of a flow of processing performed when an image is formed by the image forming apparatus 10 according to the present embodiment.

In step 200, the CPU 80 determines whether or not there is a non-ejection nozzle. The determination is made, for example, by forming a detection pattern for detecting a non-ejection nozzle at a predetermined timing, detecting and storing the non-ejection nozzle 52, and determining from the stored information. If the determination is affirmed, the process proceeds to step 202, and if the determination is negative, the process proceeds to step 206.

In step 202, the CPU 80 corrects the image information so as to discharge the correction drop to a position adjacent to the non-discharge, and proceeds to step 204.

In step 204, the CPU 80 corrects the image information so as to increase the amount of droplets discharged to the position corresponding to the position where the color to be discharged first is not discharged, and proceeds to step 206.

In step 206, the CPU 80 forms an image based on the image information and ends a series of processes.

In this way, by using the recording head 50 of another color to generate landing interference, the correction droplet is moved to the non-ejection side, and the generation of white streaks is suppressed.

(Fourth Embodiment)
Next, a method for correcting non-discharge according to the fourth embodiment will be described. In the present embodiment, as in the first and second embodiments, the correction drop having an increased amount of drops adjacent to the non-discharge is discharged. In addition, by reducing the amount of droplets ejected from the nozzle 52 of the recording head 50 of the recording head 50 of another color that is ejected before the non-ejection color to the position two adjacent to the non-ejection color, landing interference is generated and the droplets are not ejected. Move the correction drop to the discharge side.

Specifically, as in the third embodiment, when the recording head 50C that ejects cyan-colored ink droplets has a non-ejection nozzle 52 when forming an image in which a magenta image and a cyan image are superimposed. Will be explained.

As shown in FIG. 12, a magenta-colored recording head 50M that ejects correction droplets in which the amount of ink droplets at a position adjacent to the non-ejection of the cyan-colored recording head 50C is increased and ejects the correction droplets before the cyan-colored recording head 50M. Reduces the amount of ink droplets ejected to the position next to the cyan non-ejection in (for example, lowering the appearance rate or thinning out the pixels).

As a result, the magenta-colored droplets ejected earlier are affected by the impact interference of the correction droplets and move to the non-ejection side, and the white streaks are suppressed.

Subsequently, specific processing performed by the image forming apparatus 10 according to the present embodiment will be described. FIG. 13 is a flowchart showing an example of a flow of processing performed when an image is formed by the image forming apparatus 10 according to the present embodiment. The same processing as that of the third embodiment will be described with the same reference numerals.

In step 200, the CPU 80 determines whether or not there is a non-ejection nozzle. The determination is made, for example, by forming a detection pattern for detecting a non-ejection nozzle at a predetermined timing, detecting and storing the non-ejection nozzle 52, and determining from the stored information. If the determination is affirmed, the process proceeds to step 202, and if the determination is negative, the process proceeds to step 206.

In step 202, the CPU 80 corrects the image information so as to discharge the correction drop to a position adjacent to the non-discharge, and proceeds to step 203.

In step 203, the CPU 80 corrects the image information so as to reduce the amount of droplets ejected to the position corresponding to the position two adjacent to the position where the color to be ejected earlier is not ejected, and proceeds to step 206.

In step 206, the CPU 80 forms an image based on the image information and ends a series of processes.

In this way, by using the recording head 50 of another color to generate landing interference, the correction droplet is moved to the non-ejection side, and the generation of white streaks is suppressed.

The third embodiment and the fourth embodiment may be combined. That is, the amount of ink droplets ejected to the position corresponding to the non-ejection of another color may be increased, and the amount of ink droplets ejected to the position two adjacent to the non-ejection may be decreased. In this case, the third embodiment may be performed when there is no preceding color at the position where the non-ejection occurs on the original image, and the fourth embodiment may be performed when there is a preceding color.

Further, in the third embodiment and the fourth embodiment, the color for which the drop amount is changed is the drop amount rather than changing the drop amount for the color having good visibility by changing the drop amount for the color having poor visibility. Changes in the image due to changes are suppressed.

(Fifth Embodiment)
Next, a method for correcting non-discharge according to the fifth embodiment will be described. In the present embodiment, as in the third embodiment, ink droplets are ejected from the recording head 50 of another color to a position where the ink is not ejected, so that the correction droplets ejected later due to the impact interference are moved. Here, in the present embodiment, the image information is corrected so that the correction density is lowered when the surrounding density is low and the density of ink droplets of other colors ejected to the non-ejection position is also low.

Specifically, a case where a non-ejection nozzle 52 is present in the recording head 50 that ejects cyan-colored ink droplets when forming a cyan image will be described.

As shown in FIG. 14A, magenta-colored ink droplets are ejected to positions corresponding to non-ejection positions to cause landing interference, and the cyan-colored correction droplets ejected later are discharged on the non-ejection side. Move to. Here, as shown in FIG. 14B, when the density around the magenta color is low, the density of the cyan color discharged to the non-discharge position is also low.

For example, as shown in FIG. 15 (A), the cyan correction drop discharged to the position adjacent to the non-discharge position has a predetermined correction amount (FIG.) according to the cyan gradation of the non-discharge position. The image information is corrected so as to be ink droplets (15 non-emission adjacent correction amounts). In the example of FIG. 15A, the pixel value adjacent to the non-ejection position is about 20% when the non-ejection density gradation is about 0 to 50% with respect to the density gradation of the non-ejection position. An example is shown in which the correction amount of the correction droplet adjacent to the non-ejection is determined (the correction amount of the non-ejection adjacent to the non-discharge) so that the correction amount is gradually increased to 100% for 50% or more.

Then, as shown in FIG. 15 (B), the correction amount of the correction drop (correction amount adjacent to the non-ejection adjacency in FIG. The image information is corrected so that the ink droplets have the amount of droplets of the color to be ejected (the amount of droplets required for the preceding color pixel at the non-ejection position in FIG. 15). In the example of FIG. 15B, an example is shown in the case where the density gradation of the preceding color pixel is 0%, 10%, and 20%. Further, when the density gradation of the preceding color is originally larger than 20%, landing interference due to the preceding color occurs and it is not necessary to change the image information of the preceding color, so that the gradation of the preceding color is 20% or less. In some cases, the image information of the preceding color is corrected.

Further, when a plurality of preceding colors are present, the color ejected immediately before the non-ejecting color may be corrected in order to move the correction droplet due to the impact interference. As a result, landing interference is likely to occur by using the color immediately before non-ejection.

Alternatively, the most abundant color among the values of each color at the non-ejection position may be corrected in order to move the correction drop due to the impact interference. For example, the black (K) color is the correction drop, and the amount of each color at the non-ejection position is larger in the order of cyan (C), magenta (M), and yellow (Y), as shown in FIG. 16 (A). In that case, the image information of cyan is corrected to the required drop amount as shown in FIG. 16 (B). As described above, the required drop amount is obtained from FIG. 15 (B).

Alternatively, as shown in FIG. 16C, the image information of each color may be corrected so that the required drop amount is obtained while maintaining the ratio of each color.

Alternatively, as shown in FIG. 16D, the image information may be corrected so that the required drop amount is obtained by increasing the most colors after weighting in advance according to the color characteristics. In the example of FIG. 16D, after weighting with cyan at 1.1 times, magenta at 1.2 times, and yellow at 1 times, each color is corrected so that the required amount of drops is increased by increasing cyan. Here is an example of how to do it.

Alternatively, as shown in FIG. 16E, after weighting is applied in advance according to the color characteristics, the image information of each color may be corrected so that the required drop amount is obtained while maintaining the ratio of each weighted color. good. In the example of FIG. 16E, the weighting is performed by multiplying cyan by 1.1 times, magenta by 1.2 times, and yellow by 1 times so that the required drop amount is maintained while maintaining the ratio after weighting. An example of correcting the image information of each color is shown in.

(Sixth Embodiment)
From the first to the fifth embodiment, the correction method when the correction nozzle 52 is the post-launch nozzle group 54B has been described, but in the present embodiment, the above-mentioned first to fifth embodiments are different from the configuration of the recording head. However, a case where two recording heads 50 are provided for each color will be described.

Specifically, as shown in FIG. 17A, two recording heads 50A and 50B are provided for each color, and they are arranged in the transport direction of the continuous paper P. The recording head 50A as the first head is arranged on the upstream side in the transport direction of the continuous paper P, and the recording head 50B as the second head is arranged on the downstream side in the transport direction of the continuous paper P.

In each of the recording heads 50A and 50B, nozzle groups 54 having a plurality of nozzles 52 are arranged in a staggered manner. The nozzle group 54 has a pre-strike nozzle group 54A that ejects ink droplets first, and a post-strike nozzle group 54B that ejects ink droplets later. Then, the ink droplets ejected from the first-strike nozzle group 54A and the ink droplets ejected from the post-strike nozzle group 54B are alternately ejected along the intersecting direction intersecting the transport direction of the continuous paper P. That is, as shown in FIG. 17B, ink droplets (gray circles) are ejected from the post-launch nozzle group 54B between the ink droplets (black circles) ejected from the pre-strike nozzle group 54A. .. The pre-strike nozzle group 54A of the recording head 50A corresponds to the first nozzle group, and the post-strike nozzle group 54B of the recording head 50A corresponds to the second nozzle group. Further, the pre-strike nozzle group 54A of the recording head 50B corresponds to the third nozzle group, and the post-strike nozzle group 54B of the recording head 50B corresponds to the fourth nozzle group.

Further, the recording heads 50A and 50B are driven at the timing when the ink droplets ejected from the recording head 50A and the ink droplets ejected from the recording head 50B are alternately positioned along the conveying direction of the continuous paper P. To. That is, as shown in FIG. 17B, the line image formed by the recording head 50A and the line image formed by the recording head 50B are alternately formed to form an image of each color.

Further, similarly to each of the above-described embodiments, a predetermined detection pattern or the like for detecting non-discharge is formed to detect the non-discharge of the nozzle 52 and stored in the storage unit 86 or the like. Then, when the image is formed, the image information is corrected so that the amount of the ink droplets ejected from the nozzle 52 that ejects the ink droplets to the position adjacent to the non-ejection position is increased and the correction droplets are ejected. In the following, an example of correcting the non-ejection by ejecting the correction drop to a position adjacent to the non-ejection will be described, but the correction of the non-ejection is not limited to this. For example, as in the first embodiment, the correction droplet is ejected to a position adjacent to the non-ejection, and the pixel at the position opposite to the non-ejection adjacent to the position where the correction droplet is ejected in consideration of the ejection order. The process of thinning out may be performed on the image information. Alternatively, as in the second embodiment, the image is such that the correction drop is ejected to a position adjacent to the non-ejection, and the correction drop is also ejected to the position adjacent to the position where the pixels are thinned out by performing the process of thinning out the pixels. The information may be corrected.

By the way, in the present embodiment, the two recording heads 50A and 50B eject ink droplets at different timings, and the recording heads 50A and 50B have different timings for the first-strike nozzle group 54A and the second-strike nozzle group 54B. Ink droplets are ejected. Therefore, the method of generating landing interference differs depending on the position of the non-ejection nozzle 52, and the influence on the correction droplet changes depending on the position of the non-ejection nozzle 52.

Therefore, in the present embodiment, the correction amount is changed depending on the position of the non-ejection nozzle 52.

Specifically, when non-ejection occurs in the pre-adhesion nozzle group 54A of the recording head 50A that ejects ink droplets first, the post-adhesion of the recording head 50A that ejects ink droplets to a position adjacent to the non-ejection position. Corrected droplets with an increased amount of droplets ejected from each of the nozzle 52 of the nozzle group 54B and the nozzle 52 of the pre-empted nozzle group 54A of the recording head 50B that ejects ink droplets to a position adjacent to the non-ejection position are ejected. In this case, as shown in FIG. 18A, the correction droplet indicated by the black circle moves to the ink droplet side ejected from the pre-strike nozzle group 54A of the recording head 50A due to landing interference. Therefore, it is necessary to increase the correction amount to suppress white streaks.

If a non-ejection occurs in the post-adhesion nozzle group 54B of the recording head 50A that ejects ink droplets first, the pre-adhesion nozzle group 54A of the recording head 50A that ejects ink droplets to a position adjacent to the non-ejection position. The correction droplets having an increased amount of droplets ejected from each of the nozzle 52 of Nozzle 52 and the nozzle 52 of the post-launching nozzle group 54B of the recording head 50B for ejecting ink droplets to a position adjacent to the non-ejection position are ejected. In this case, as shown in FIG. 18B, the correction droplet on the recording head 50A side indicated by the black circle is ejected first, and therefore does not move due to the impact interference. Therefore, the normal correction amount is sufficient.

On the other hand, if non-ejection occurs in the pre-launched nozzle group 54A of the recording head 50B that ejects ink droplets later, the post-adhesive nozzle group 54B of the recording head 50B that ejects ink droplets to a position adjacent to the non-ejection position. Corrected droplets with an increased amount of droplets ejected from each of the nozzle 52 and the nozzle 52 of the post-launching nozzle group 54B of the recording head 50A that ejects ink droplets to a position adjacent to the non-ejection position are ejected. In this case, as shown in FIG. 18C, the correction droplet indicated by the black circle interferes with the ink droplet ejected from the nozzle 52 of the pre-emptive nozzle group 54A adjacent to the correction droplet of the recording head 50B, but is corrected. It also interferes with the ink droplets ejected from the pre-empted nozzle group 54A of the recording head 50A adjacent to the periphery of the droplets, so that they are offset.

Further, when non-ejection occurs in the post-adhesion nozzle group 54B of the recording head 50B that ejects ink droplets later, the pre-adhesion nozzle group 54A of the recording head 50B that ejects ink droplets to a position adjacent to the non-ejection position. Corrected droplets with an increased amount of droplets ejected from each of the nozzle 52 and the nozzle 52 of the pre-empted nozzle group 54A of the recording head 50A that ejects ink droplets to a position adjacent to the non-ejection position are ejected. In this case, as shown in FIG. 18D, in the correction drop indicated by the black circle, the correction drop of the recording head 50B moves toward the non-ejection position on the correction drop side of the preceding recording head 50A. A lower correction amount is sufficient than in other cases.

Therefore, in the present embodiment, A1 is the case where the pre-strike nozzle group 54A of the recording head 50A is non-ejection, A2 is the case where the post-launch nozzle group 54B of the recording head 50A is non-ejection, and the pre-strike nozzle group 54A of the recording head 50B. A1 correction amount> A2 correction amount ≈ B1 correction amount> B2 correction amount when B1 is the case of non-ejection and B2 is the post-launch nozzle group 54B of the recording head 50B. Therefore, the correction amount is changed according to the position of the non-ejection nozzle 52.

In the present embodiment, the correction drop will be described as an example of a correction that increases the amount of the correction drop, but a correction that increases the appearance rate of the correction drop may be performed.

Subsequently, specific processing performed by the image forming apparatus according to the present embodiment will be described. FIG. 19 is a flowchart showing an example of the flow of processing performed by the image forming apparatus according to the present embodiment.

In step 300, the CPU 80 determines whether or not the non-discharge position is A1. The determination determines whether or not the position of the nozzle 52 in which non-ejection is detected is the nozzle 52 of the pre-emptive nozzle group 54A of the recording head 50A. If the determination is affirmed, the process proceeds to step 302, and if the determination is negative, the process proceeds to step 304.

In step 302, the CPU 80 corrects the non-ejection nozzle 52 by correcting the image information with a predetermined correction amount of A1, and proceeds to step 304.

In step 304, the CPU 80 determines whether or not the non-discharge position is A2. The determination determines whether or not the position of the nozzle 52 in which non-ejection is detected is the nozzle 52 of the post-launch nozzle group 54B of the recording head 50A. If the determination is affirmed, the process proceeds to step 306, and if the determination is negative, the process proceeds to step 308.

In step 306, the CPU 80 corrects the non-ejection nozzle 52 by correcting the image information with a predetermined correction amount of A2, and proceeds to step 308.

In step 308, the CPU 80 determines whether or not the non-discharge position is B1. The determination determines whether or not the position of the nozzle 52 in which non-ejection is detected is the nozzle 52 of the pre-emptive nozzle group 54A of the recording head 50B. If the determination is affirmed, the process proceeds to step 310, and if the determination is negative, the position of the non-discharging nozzle 52 is determined to be the nozzle 52 of the post-launch nozzle group 54B of the recording head 50B, and the process proceeds to step 312. do.

In step 310, the CPU 80 corrects the non-ejection nozzle 52 by correcting the image information with a predetermined correction amount of B1, and proceeds to step 314.

In step 312, the CPU 80 corrects the non-ejection nozzle 52 by correcting the image information with a predetermined correction amount of B2, and proceeds to step 314.

In step 314, the CPU 80 forms an image on the continuous paper P based on the image information and ends a series of processes.

In the above embodiment, the image forming apparatus has been described as an example, but the present invention is not limited to this, and an apparatus for ejecting droplets other than ink droplets may be applied.

Further, the process performed by the image forming apparatus 10 according to the above embodiment (FIG. 7, FIG. 9, FIG. 11, FIG. 13, and FIG. 19) may be performed by software or may be performed by hardware. It may be a process that is performed, or it may be a process that combines both. Further, the processing performed by the image forming apparatus may be stored in a storage medium as a program and distributed.

Further, in the above embodiment, the image forming apparatus 10 for forming an image by ejecting ink droplets has been described as an example of the droplet ejection device, but the droplet ejection device is not limited to this. For example, a device that ejects droplets containing a metal pigment onto a substrate to form a wiring pattern, a device that ejects curable droplets onto an object to be ejected to form a three-dimensional pattern, and a two-dimensional layer for a table. It may be a device for forming a three-dimensional object by stacking, and other industrial devices.

Further, the present invention is not limited to the above, and it is needless to say that the present invention can be variously modified and implemented within a range not deviating from the gist thereof.

10 Image forming device 50 Recording head 52 Nozzle 54 Nozzle group 54A First-strike nozzle group 54B Post-strike nozzle group 80 CPU
P continuous paper

Claims (9)

A first group of nozzles in which a plurality of nozzles are arranged along an intersecting direction intersecting the relative movement direction of the medium to eject droplets to the medium, and a first nozzle group in which a plurality of nozzles are arranged along the intersecting direction. A head including a second nozzle group that ejects droplets to the medium after the group,
When correcting the defective nozzle of the head, the correction droplet is ejected from the nozzle that ejects the droplet at a position adjacent to the position where the defective nozzle should eject the droplet, and the correction droplet is ejected. When the ejection order is different between the adjacent nozzles that eject droplets at positions adjacent to the correction droplets, the amount of droplets to be ejected from each of the correction nozzles and the adjacent nozzles is changed to obtain the correction droplets. A control unit that controls movement,
Equipped with
The control unit is a droplet ejection device that increases the amount of droplets to be ejected to a position two adjacent to the droplet ejected from the correction nozzle . The control unit controls the movement of the correction droplet by changing the appropriate amount of the droplet by making the appearance rate of the droplet ejected from the adjacent nozzle smaller than the appearance rate of the droplet ejected from the correction nozzle. The droplet ejection device according to claim 1. The control unit changes the amount of droplets ejected from the correction nozzle by increasing the amount of droplets ejected from the correction nozzle from the amount of droplets that should be ejected and thinning out the droplets ejected from the adjacent nozzles. The droplet ejection device according to claim 1, wherein the movement of the correction droplet is controlled. A plurality of nozzles are arranged along the intersecting directions intersecting the relative movement directions of the medium, and a first nozzle group for ejecting the droplets to the medium is provided, and droplets of a predetermined color are ejected from the first nozzle group. From the second nozzle group to the first nozzle group, the first head is provided with a second nozzle group in which a plurality of nozzles are arranged along the crossing direction and ejects droplets to the medium after the first nozzle group. A second head that superimposes and ejects droplets of a color different from the droplets ejected from the first nozzle group on the droplets ejected from the first nozzle group, and a plurality of nozzles are arranged along the crossing direction. Droplets of colors different from those of the first head and the second head are superimposed on the droplets ejected by the first nozzle group and ejected after the first nozzle group and at the timing before the second nozzle group. A head including a third head provided with a third nozzle group
When correcting the defective nozzle of the head, the correction droplet is ejected from the nozzle that ejects the droplet at a position adjacent to the position where the defective nozzle should eject the droplet, and the correction droplet is ejected. When the ejection order is different between the adjacent nozzles that eject droplets at positions adjacent to the correction droplets, the amount of droplets to be ejected from each of the correction nozzles and the adjacent nozzles is changed to obtain the correction droplets. A control unit that controls movement, and the nozzle of the first nozzle group that ejects a droplet at a position where the defective nozzle should eject a droplet when a defective nozzle is present in the second nozzle group. As an adjacent nozzle, the movement of the correction drop is controlled, and the drop amount of the droplet discharged from the first nozzle group is changed so as to be a predetermined drop amount according to the drop amount of the correction drop. A control unit that controls the movement of the correction drop,
Equipped with
When the control unit has a plurality of heads that eject droplets prior to the correction droplets, the droplet amount of the droplets ejected from the head of the color having the largest droplet amount, or the liquid ejected from the plurality of heads. A droplet ejection device that changes the amount of droplets . A first group of nozzles in which a plurality of nozzles are arranged along an intersection direction intersecting the relative movement direction of the medium to eject droplets to the medium, and a first nozzle group in which a plurality of nozzles are arranged along the intersection direction. A first head that ejects droplets from a second nozzle group that ejects droplets to a medium after the group, and a third nozzle group that ejects droplets to a medium by arranging a plurality of nozzles along the crossing direction. , And a fourth nozzle group in which a plurality of nozzles are arranged along the crossing direction and ejects droplets to the medium after the third nozzle group, and after ejection of the droplets of the first head, the first The droplets are ejected from the third nozzle group adjacent to the relative movement direction of the droplets ejected by one head, and the droplets are ejected from the fourth nozzle group between the droplets ejected by the third nozzle group. A head including a second head that discharges
When correcting the defective nozzle of the head, the correction droplet is ejected from the nozzle that ejects the droplet at a position adjacent to the position where the defective nozzle should eject the droplet, and the correction droplet is ejected. When the ejection order is different between the adjacent nozzles that eject droplets at positions adjacent to the correction droplets, the amount of droplets to be ejected from each of the correction nozzles and the adjacent nozzles is changed to obtain the correction droplets. A control unit that controls movement,
Equipped with
A droplet ejection device in which the control unit further controls the head so as to eject a predetermined amount of corrected droplets according to the position of a defective nozzle in the head . In the control unit, the correction amount when the position of the defective nozzle in the head is included in the first nozzle group> the correction amount when it is included in the second nozzle group ≈ the correction amount when it is included in the third nozzle group. The droplet ejection device according to claim 5, wherein the head is controlled so as to eject a correction droplet having a predetermined amount of correction droplet so that the correction amount is the correction amount when it is included in the fourth nozzle group . A first group of nozzles in which a plurality of nozzles are arranged along an intersection direction intersecting the relative movement direction of the medium to eject droplets to the medium, and a first nozzle group in which a plurality of nozzles are arranged along the intersection direction. A second nozzle group for ejecting droplets to the medium after the group is provided, and the first head for ejecting droplets from the second nozzle group between the droplets ejected by the first nozzle group and the crossing direction. A third nozzle group in which a plurality of nozzles are arranged along the above to eject droplets to the medium, and a third nozzle group in which a plurality of nozzles are arranged along the crossing direction to eject droplets to the medium after the third nozzle group. A fourth nozzle group is provided, and after the droplets of the first head are ejected, the droplets are ejected from the third nozzle group adjacent to the relative movement direction of the droplets ejected by the first head. A head including a second head that ejects droplets from the fourth nozzle group between the droplets ejected by the third nozzle group.
When correcting the defective nozzle of the head, the defective nozzle ejects the correction droplet from the nozzle that ejects the droplet at a position adjacent to the position where the defective nozzle should eject the droplet, and the defective nozzle is the fourth nozzle group. When included in, a control unit that controls the head so that the defective nozzle ejects a smaller amount of correction droplet than in the case of other positions.
A drop ejection device equipped with . In the control unit , the correction amount when the position of the defective nozzle in the head is included in the first nozzle group> the correction amount when it is included in the second nozzle group ≈ the correction amount when it is included in the third nozzle group. The droplet ejection device according to claim 7 , wherein the head is controlled so as to eject a predetermined amount of correction droplet so that the correction amount> the correction amount when it is included in the fourth nozzle group . A droplet ejection program for operating a computer as the control unit according to any one of claims 1 to 8.

Images