JP7357240B2 - Control method for inkjet printing device and inkjet printing device - Google Patents

Description

The present invention relates to a method for controlling an inkjet printing apparatus used for forming a light emitting layer and a sealing film of a display panel for a display device such as an organic EL (Electro Luminescence), and an inkjet printing apparatus.

Currently, the mainstream manufacturing process for organic EL displays is a method using vapor deposition, but in order to reduce costs, a method using inkjet equipment that does not require a vacuum and has high material usage efficiency is being considered. There is.

In an organic EL display manufacturing method using an inkjet device, ink is ejected from nozzles of an inkjet head into display cells (hereinafter referred to as cells) separated by partition walls called banks provided on a display panel. A common method is to form a functional film within the cell.

Inkjet printing devices use a plurality of nozzles arranged in a row from the viewpoint of manufacturing efficiency, but as display panels become higher resolution and larger, the number of nozzles used is in the tens of thousands. Due to adhesion of dried ink or foreign matter, the position or amount of ink applied from this large number of nozzles may deviate greatly from the designed value, resulting in defective nozzles that cannot be corrected. When a defective nozzle occurs, there are methods that do not eject ink from the defective nozzle and instead increase the number of ejections from other nearby nozzles to supplement the amount of ink applied (Patent Document 1), or There is a method of supplementing the amount of ink applied with a spare nozzle capable of ejecting the ink (Patent Document 2).

In recent years, as the resolution of display panels has increased, the number of times each nozzle can apply coating to the same coating area is becoming limited. Therefore, as described in Patent Document 1, for example, the method of increasing the number of times of application to the coating area of a nozzle adjacent to a defective nozzle has a limit, and the method of Patent Document 2 is now used.

Patent No. 5157348 Patent No. 6387580

However, in the method of Patent Document 2, it is necessary to search for available spare nozzles in the same cell one nozzle at a time by conditional branching processing, which makes data processing more complicated than the complementation process of Patent Document 1, and calculations are difficult. The problem was that it took time.

In inkjet printing equipment, if a defective nozzle occurs, it will not be possible to supply specified droplets to the display cell, resulting in the production of defective products. Therefore, it is necessary to stop production during the complementary process, and the complementary process will not be completed in time for printing. If not, the production tact will be delayed, which will directly affect productivity. Therefore, it is desirable that the computational processing for selecting complementary nozzles has a low load.

In addition, in the following, among the plurality of nozzles that an inkjet printing device (i.e., inkjet head) has, a nozzle that is not a defective nozzle and is caused to perform ejection will be referred to as an "ejection nozzle", and a defective nozzle. A nozzle that does not perform discharge is referred to as a "non-discharge nozzle." Further, a discharge nozzle that complements a non-discharge nozzle is referred to as a "complementary nozzle."

The present invention has been made in view of the above-mentioned problems, and provides a control method for an inkjet printing device that makes it possible to select a nozzle to perform complementary processing while suppressing the calculation load, and a method for controlling an inkjet printing device. The purpose is to provide.

The main invention that solves the above-mentioned problems is as follows:
A method of controlling an inkjet printing device having a plurality of nozzles and configured to be able to apply ink to each separate cell of a display panel using the plurality of nozzles, the method comprising:
A first step (a) of acquiring data related to a first bit string in which each of the nozzles that require ejection and the nozzles that do not need ejection among the plurality of nozzles is expressed in units of 1 bit from the print data holding memory;
a second step (b) of acquiring data related to a second bit string in which each of the ejection nozzle and the ejection failure nozzle among the plurality of nozzles is expressed in units of 1 bit from the ejection failure nozzle holding memory;
a third step (c) of generating a third bit string by bitwise OR of the first bit string and the second bit string;
a fourth step (d) of generating a fourth bit string by bit-wise logical AND of the first bit string and the second bit string;
updating the fourth bit string so as to shift a bit related to the complementation destination candidate nozzle specified in the fourth bit string and changing the complementation destination candidate nozzle to another nozzle among the plurality of nozzles; 5 step (e) and
a sixth step (f, g) of generating a fifth bit string by bitwise OR or AND of the third bit string and the fourth bit string;
including;
The fifth step (e) and the sixth step (f, g) are repeatedly executed in this order, and the fifth bit string generated in the sixth step ( f, g) is used to complement the non-ejecting nozzle. If it is shown that it is possible, selecting the complementation destination candidate nozzle set at that time as a nozzle to complement the non-ejection nozzle;
This is a method of controlling an inkjet printing device.

Also, in other situations,
An inkjet printing device having a plurality of nozzles and configured to be able to apply ink to each cell of a display panel using the plurality of nozzles,
A first step (a) of acquiring data related to a first bit string in which each of the nozzles that require ejection and the nozzles that do not need ejection among the plurality of nozzles is expressed in units of 1 bit from the print data holding memory;
a second step (b) of acquiring data related to a second bit string in which each of the ejection nozzle and the ejection failure nozzle among the plurality of nozzles is expressed in units of 1 bit from the ejection failure nozzle holding memory;
a third step (c) of generating a third bit string by bitwise OR of the first bit string and the second bit string;
a fourth step (d) of generating a fourth bit string by bit-wise logical AND of the first bit string and the second bit string;
updating the fourth bit string so as to shift a bit related to the complementation destination candidate nozzle specified in the fourth bit string and changing the complementation destination candidate nozzle to another nozzle among the plurality of nozzles; 5 step (e) and
a sixth step (f, g) of generating a fifth bit string by bitwise OR or AND of the third bit string and the fourth bit string;
Equipped with a control device that executes
The control device repeatedly executes the fifth step (e) and the sixth step (f, g) in this order so that the fifth bit string generated in the sixth step ( f, g) is When it is indicated that the ejection nozzle can be complemented, selecting the complementation destination candidate nozzle set at that time as the nozzle for complementing the non-ejection nozzle;
It is an inkjet printing device.

According to the control method for an inkjet printing apparatus according to the present invention, it is possible to select a nozzle to perform complementary processing while suppressing the calculation load.

Block diagram of an ejection circuit of an inkjet printing device in a conventional control configuration Operation of inkjet printing equipment when using conventional configuration Block diagram of an ejection circuit of an inkjet printing device in a control configuration of the present invention Operation of an inkjet printing device when using the configuration of the present invention Flowchart illustrating the flow of ejection failure compensation processing of the present invention A diagram explaining the ejection required pixel acquisition process in step 501 of FIG. 5 A diagram explaining the ejection impossible pixel acquisition process in step 502 in FIG. A diagram illustrating the processing contents of ejection failure compensation according to the present invention in order.

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
Hereinafter, an embodiment of the head arrangement and printing method of this embodiment will be described with reference to the drawings, but this embodiment is not limited to these embodiments.

(Explanation of conventional control configuration)
Here, in order to explain the contents of this embodiment, first, the operation when printing using a conventional control configuration will be explained. FIG. 1 is a block diagram of an ejection circuit of an inkjet printing apparatus Ua in a conventional control configuration.

First, the constituent elements of the block diagram in FIG. 1 will be explained.

101 is a substrate to be printed (ie, a display panel), and 101a is a cell formed on the substrate 101, which is arranged on the substrate at a constant pitch with respect to the print scanning direction x.

Reference numeral 102 denotes an inkjet head, and one or more heads are arranged side by side in the direction y perpendicular to the print scanning direction. 102a is a nozzle hole of an inkjet head, which is arranged in the direction y perpendicular to the print scanning direction. The inkjet head 102 is configured to be able to apply ink to each cell 101a using a plurality of nozzles 102a.

Reference numeral 103 denotes a print data generation section, which includes a print data generation section 103a, a data transmission section 103b, cell pattern data 103c, cell arrangement data 103d, and non-ejection nozzle data 103e.

Reference numeral 104 denotes an inkjet head control section (corresponding to the "control device" of the present invention), which includes a data reception section 104a, a print data holding memory 104b, a position detection section 104c, a print timing generation section 104d, a drive signal generation section 104e, and It is composed of a drive signal selection section 104f. Note that the inkjet head control unit 104 includes a microcomputer (not shown) including, for example, a CPU, ROM, RAM, input port, output port, etc., and includes a data receiving unit 104a and a print data holding memory. 104b, position detection section 104c, print timing generation section 104d, drive signal generation section 104e, and drive signal selection section 104f are collectively controlled by the microcomputer.

Note that the print data generation section 103 is disposed within the main body of the inkjet printing apparatus Ua, and the inkjet head control section 104 is attached to the inkjet head 102, for example.

Next, the operation of the block diagram in FIG. 1 will be explained.

First, the flow of data from generation to transfer of print data will be explained.

The print data generation unit 103a of the print data generation unit 103 generates cell placement data 103d, which is the placement position of the cell 101a on the substrate 101 to be printed, cell pattern data 103c, which is the ink ejection pattern in the cell 101a, and data on the inkjet head 102. Image data for printing is generated based on non-ejection nozzle data 103e, which is nozzle clogging information, and positional deviation information.

The data transmitter 103b transmits the image data generated by the print data generator 103a to the data receiver 104a in the inkjet head controller 104.

The data receiving unit 104a stores the image data received from the data transmitting unit 103b in the print data holding memory 104b.

Next, the flow of data during printing will be explained.

During printing, the substrate 101 to be printed moves in the x direction. At this time, the position detection unit 104c of the inkjet head control unit 104 detects a change in the relative position between the substrate 101 and the inkjet head 102, and adjusts the position according to the change in relative position. generates a timing pulse.

The print timing generation unit 104d divides the timing pulse output from the position detection unit 104c based on the print resolution Rx, and generates a print timing signal that defines the generation timing of the voltage waveform that drives the nozzles of the inkjet head. Output.

The drive signal generator 104e outputs a nozzle drive waveform for the inkjet head 102 based on the print timing signal generated by the print timing generator 104d.

The drive signal selection unit 104f turns on/off the nozzle drive waveform sent from the drive signal generation unit 104e for each nozzle based on the print data sent from the print data holding memory 104b, thereby changing the ink of the inkjet head 102. The presence or absence of discharge is controlled.

(Issues with conventional control configurations)
FIG. 2 shows the operation of the inkjet printing apparatus Ua when using a conventional configuration. FIG. 2(a) is an operational flow when printing for the first time, and FIG. 2(b) is an operational flow when a non-ejecting nozzle is changed.

First, FIG. 2(a) will be explained.

Step 201 in FIG. 2A is a print data reading process, in which cell arrangement data 103d, which is the arrangement position of the cell 101a on the substrate 101 to be printed, cell pattern data 103c, which is the ink ejection pattern in the cell 101a, and This is a process of reading non-ejection nozzle data 103e, which is information on clogging of nozzles of the inkjet head 102.

Step 202 is a print data generation process, in which print data is generated according to cell placement data 103d, which is the placement position of the cell 101a on the substrate 101, and cell pattern data 103c, which is the ink ejection pattern in the cell 101a. .

Step 203 is a non-discharge complementing process, in which a non-discharge nozzle complement process is performed on the print data generated in step 202 according to the non-discharge nozzle data 103e, which is nozzle clogging information. This is the process of generating print data.

Step 204 is a transfer process in which the print data after ejection failure compensation is transferred from the print data generation unit 103 in FIG. 1 to the inkjet head control unit 104.

Step 205 is a printing process in which print data stored in the print data 104b is sequentially printed in accordance with the movement of the substrate 101 to be printed in FIG.

Next, FIG. 2(b) shows a processing flow when changing a non-ejection nozzle.

If the non-discharge nozzle is changed, the print data after the non-discharge complement will change, so it is necessary to transfer all the data again. Therefore, in the conventional control configuration, the processing flow when changing the non-ejecting nozzle is the same as that shown in FIG. 2(a). That is, in the conventional control configuration, all data of print data after ejection failure compensation is generated and transferred again.

(Description of control method of the present invention)
The embodiments of the present invention have been devised in view of the above-mentioned problems of the conventional control system.

FIG. 3 shows a block diagram of the ejection circuit of the inkjet printing apparatus U in this embodiment, and FIG. 4 shows the operation of the inkjet printing apparatus U when the configuration of this embodiment is used.

First, the components of the block diagram in FIG. 3 will be explained.

101 is a substrate to be printed, and 101a is a cell formed on the substrate, which is arranged on the substrate at a constant pitch with respect to the printing scanning direction x.

Reference numeral 102 denotes an inkjet head, and one or more heads are arranged side by side in the direction y perpendicular to the print scanning direction. 102a is a nozzle hole of an inkjet head, which is arranged in the direction y perpendicular to the print scanning direction. The inkjet head 102 is configured to be able to apply ink to each cell 101a using a plurality of nozzles 102a.

Reference numeral 103 denotes a print data generation section, which includes a print data generation section 103a, a data transmission section 103b, cell pattern data 103c, cell arrangement data 103d, and non-ejection nozzle data 103e.

104 is an inkjet head control section, which includes a data receiving section 104a, a print data holding memory 104b, a position detecting section 104c, a print timing generating section 104d, a driving signal generating section 104e, a driving signal selecting section 104f, a cell arrangement holding memory 104h, and , a non-ejection nozzle holding memory 104i.

Note that the inkjet head control unit 104 includes a microcomputer (not shown) including, for example, a CPU, ROM, RAM, input port, output port, etc., and includes a data receiving unit 104a and a print data holding memory. 104b, position detection section 104c, print timing generation section 104d, drive signal generation section 104e, and drive signal selection section 104f are collectively controlled by the microcomputer.

Note that the print data generation section 103 is disposed within the main body of the inkjet printing apparatus U, and the inkjet head control section 104 is attached to the inkjet head 102, for example.

Next, the operation of the block diagram in FIG. 3 will be explained.

First, the flow of data from generation to transfer of print data will be explained.

The print data generation unit 103a of the print data generation unit 103 performs printing based on cell placement data 103d, which is the placement position of the cell 101a on the substrate 101 to be printed, and cell pattern data 103c, which is the ink ejection pattern in the cell 101a. image data is generated.

The data transmitter 103b transmits the image data generated by the print data generator 103a, cell arrangement data 103d, and ejection failure nozzle data 103e to the data receiver 104a in the inkjet head controller 104.

The data receiving unit 104a stores the image data received from the data transmitting unit 103b in the print data holding memory 104b, stores the cell arrangement data 103d in the cell arrangement holding memory 104h, and stores the non-ejection nozzle data 103e in the non-ejection nozzle holding memory. Save to 104i.

Next, the flow of data during printing will be explained.

During printing, the substrate 101 to be printed moves in the x direction. At this time, the position detection section 104c of the inkjet head control section 104 detects a change in the relative position with respect to the substrate 101, and generates a timing pulse in accordance with the change in relative position. let

The print timing generation unit 104d divides the timing pulse output from the position detection unit 104c based on the print resolution Rx, and generates a print timing signal that defines the generation timing of the voltage waveform that drives the nozzles of the inkjet head 102. and output it.

The ejection failure nozzle complementing section 104g reads out the print data stored in the print data holding memory 104b based on the print timing signal generated by the print timing generating section 104d, and reads out the cell arrangement data 103d read out from the cell arrangement holding memory 104h. The non-discharging nozzle complement process is performed using the non-discharging nozzle data 103e read from the non-discharging nozzle holding memory 104i. The ejection failure nozzle complementing process will be explained later using FIGS. 5 to 8.

The drive signal generator 104e outputs a nozzle drive waveform of the inkjet head based on the print timing signal generated by the print timing generator 104d.

The drive signal selection unit 104f controls the inkjet head 102 by turning on/off the nozzle drive waveform sent from the drive signal generation unit 104e for each nozzle based on the print data sent from the non-ejection nozzle complementing unit 104g. Controls whether or not ink is ejected.

(Advantages of the control configuration of the present invention)
FIG. 4 shows the operation of the inkjet printing apparatus U when using the configuration of the embodiment. FIG. 4(a) shows the operation flow when printing for the first time, and FIG. 4(b) shows the operation when changing a non-ejecting nozzle. Note that the processes shown in FIGS. 4A and 4B are processes that are executed by each part of the inkjet printing apparatus U according to a computer program, for example.

First, FIG. 4(a) will be explained. Step 201 in FIG. 4A is a print data reading process, and in this process, the print data generation unit 103a generates cell placement data 103d, which is the placement position of the cell 101a on the substrate 101 to be printed in FIG. The cell pattern data 103c, which is the ink ejection pattern in 101a, is read.

Step 202 in FIG. 4 is a print data generation process, in which print data is generated according to cell placement data 103d, which is the placement position of the cell 101a on the substrate 101 in FIG. 3, and cell pattern data 103c, which is the ink ejection pattern in the cell 101a. generate.

Step 204 in FIG. 4 is a transfer process, in which the print data, cell arrangement data 103d, and ejection failure nozzle data 103e in FIG. This is the process of transferring the data to.

Step 206 in FIG. 4 is a non-discharge complementing and printing process, in which printing is performed while sequentially performing non-discharge complementing processing on the print data stored in the memory 104b as the substrate 101 to be printed in FIG. 3 moves. be.

Next, FIG. 4(b) shows a processing flow when changing a non-ejection nozzle. In the non-ejection nozzle transfer 207 in FIG. 4, the data transmission unit 103b transfers the non-ejection nozzle data 103e in FIG. 3 to the non-ejection nozzle holding memory 104i.

Step 206 in FIG. 4 is a non-discharge complementing and printing process, in which print data stored in the print data holding memory 104b is sequentially printed while performing non-discharge complementing process as the substrate 101 to be printed in FIG. 3 moves. This is a process that performs

As described above, in the control configuration of the present invention, even if a non-discharging nozzle is changed, printing can be performed by performing the non-discharging nozzle transfer 207, and printing can be performed as shown in FIG. 2(b). There is no need to regenerate or transfer data. Therefore, it is possible to shorten the time required for data generation and transfer.

(Flow of ejection failure compensation processing of the present invention)
Here, the flow of the ejection failure compensation process of the present invention will be explained using the flowchart of FIG.

Step 501 is ejection required pixel acquisition processing, in which the ejection failure nozzle complementing unit 104g performs ejection corresponding to the cell position according to the contents of the print data holding memory 104b to the cell arrangement holding memory 104h in FIG. Get the required pixels. A method for acquiring pixels requiring ejection will be explained later using FIG. 6.

Step 502 is an ejection impossible pixel acquisition process, in which the ejection failure nozzle complementing unit 104g corresponds to the cell position according to the contents of the ejection failure nozzle holding memory 104i to the cell arrangement holding memory 104h in FIG. Obtain the pixels that cannot be ejected. A method for acquiring pixels that cannot be ejected will be explained later using FIG. 7.

The details of the complementary processing from step 503 to step 509 will be explained later using FIG.

Step 503 is a pixel calculation process that cannot be complemented. In this process, the non-ejection nozzle complementing unit 104g determines whether a pixel that requires ejection or a pixel that cannot be ejected is determined by ORing the print pixel and the pixel that cannot be ejected. Therefore, find pixels that cannot be used for ejection failure compensation.

Step 504 is a pixel calculation process to be complemented. In this process, the ejection failure nozzle complementing unit 104g takes the AND of the print pixel and the non-ejection pixel to designate the ejection-required pixel as the non-ejection pixel. , find pixels that require non-ejection complementation.

Step 505 is a complementation target pixel calculation process, and in this process, the non-ejection nozzle complementing unit 104g shifts the complementation target pixel by circularly shifting the complementation target pixel obtained in step 504 by a predetermined shift number. .

Step 506 is a pixel calculation process after the complementation process, and in this process, the ejection failure nozzle complementation unit 104g performs complementation by ORing the non-complementable pixel found in step 503 and the complementation destination pixel found in step 505. Find the next pixel.

Step 507 is a completion failure pixel calculation process. In this process, the non-ejection nozzle complementation unit 104g performs an AND operation of the completion failure pixel obtained in step 503 and the completion target pixel obtained in step 505. Find pixels.

Step 508 is a process for determining the number of repetitions. In this process, the non-ejection nozzle complementing unit 104g repeats the processes of steps 505, 506, and 507 for the number of pixels in the cell minus one time, so that all pixels in the cell are This means that we have calculated whether it is possible to complete the calculation.

Step 509 is an ejection failure nozzle exclusion process. In this process, the ejection failure nozzle complementing unit 104g performs an AND operation between the final complemented pixel calculated in step 506 and the logically inverted value of the ejection failure pixel in step 502. By taking the data, the final ejection data after non-ejection complementation is obtained without using the ejection failure nozzle.

(Ejection required pixel acquisition process)
Next, the ejection required pixel acquisition process in step 501 of FIG. 5 will be described using FIG. 6. FIG. 6 shows the arrangement of pixels that require ejection on the memory when the number of droplets that can be arranged in the print scanning direction changes.

601 in FIG. 6 represents a droplet arrangement within a cell when one droplet in the printing scanning direction and four nozzles can be allocated to the nozzle direction orthogonal to the printing scanning direction for ejection into the cell. The X direction 601 represents the printing scanning direction, and pixels 0 to 3 within the cell are arranged in a direction perpendicular to the printing scanning direction, and are ejected from different nozzles. A black circle at 601 represents a droplet that has been ejected, and a white circle represents a droplet that has not been ejected.

Reference numeral 602 indicates a pixel requiring ejection on the memory 601, and indicates the presence or absence of ejection in 1-bit units, with 1 representing a pixel requiring ejection and 0 representing a pixel requiring no ejection. Further, each bit corresponds to pixels 0 to 3 of 601, and the bits at addresses 0 and 2 are pixels that do not require ejection, and the bits at addresses 1 and 3 are pixels that do not require ejection.

Reference numeral 603 represents the droplet arrangement within the cell when two droplets can be allocated to ejection into the cell in the printing scanning direction and four nozzles can be allocated to the nozzle direction perpendicular to the printing scanning direction.

The X direction 603 represents the printing scanning direction, and pixels 0 to 3 in the first row within the cell are arranged in a direction perpendicular to the printing scanning direction, and are ejected from different nozzles. The pixels 4 to 7 in the second row within the cell are arranged in a direction perpendicular to the print scanning direction, and are ejected from different nozzles. Further, pixels 0 and 7, 1 and 6, 2 and 5, and 3 and 4 within the cell are ejected from the same nozzle. A black circle 603 represents a droplet that was ejected, and a white circle represents a droplet that was not ejected. In the case of 603, it means that the droplet was ejected at positions 0, 2, 4, and 6 among pixels 0 to 7.

Reference numeral 604 indicates a pixel requiring ejection on the memory 603, and indicates the presence or absence of ejection in units of 1 bit, with 1 representing a pixel requiring ejection and 0 representing a pixel requiring no ejection. Also, each bit corresponds to 603 pixels 0 to 7, and the bits at addresses 0, 2, 4, and 6 are for ejection, and the bits at addresses 1, 3, 5, and 7 are for ejection. This is an unnecessary pixel.

Reference numeral 605 represents the droplet arrangement within the cell when three droplets can be allocated to ejection into the cell in the print scanning direction and four nozzles can be allocated to the nozzle direction perpendicular to the print scanning direction.

The X direction 605 represents the printing scanning direction, and pixels 0 to 3 in the first row within the cell are arranged in a direction perpendicular to the printing scanning direction, and are ejected from different nozzles. The pixels 4 to 7 in the second row within the cell are arranged in a direction perpendicular to the print scanning direction, and are ejected from different nozzles. The pixels 8 to B in the third row within the cell are arranged in a direction perpendicular to the print scanning direction, and are ejected from different nozzles. Further, pixels 0, 7, and 8, 1, 6, and 9, 2, 5, and A, and 3, 4, and B within the cell are ejected from the same nozzle. The black circles in 605 indicate droplets that have been ejected, and the white circles indicate droplets that have not been ejected. become.

Reference numeral 606 indicates a pixel requiring ejection on the memory 605, and indicates the presence or absence of ejection in units of 1 bit, with 1 representing a pixel requiring ejection and 0 representing a pixel requiring no ejection. In addition, each bit corresponds to 0 to B of 605, and the bits at addresses 0, 2, 4, 6, 8, and A are unnecessary pixels, and the bits at addresses 1 and 3 are unnecessary pixels. , 5th address, 7th address, 9th address, and B address are pixels that require ejection.

When arranging multiple rows of droplets in the print scanning direction within a cell as described above, adjacent droplets are read out consecutively like a single stroke and placed on the memory, as shown by the dotted lines 603 and 605. do. By arranging the nozzles in the memory in such a format, the nozzles near the non-ejecting nozzle are preferentially complemented when the later-described complementation process is performed. Furthermore, although the droplet arrangement within a cell is explained here as an example when four nozzles can be allocated in the nozzle arrangement direction, the number of nozzles allocated within a cell can be arbitrarily changed using the cell arrangement data 103d. .

(Unable to eject pixel acquisition process)
Next, the ejection impossible pixel acquisition process in step 502 of FIG. 5 will be described using FIG. 7. FIG. 7 shows the arrangement of pixels that require ejection on the memory when the number of droplets that can be arranged in the print scanning direction changes.

701 in FIG. 7 represents an inkjet head, 0 to 3 represent nozzles in the head, black circles are non-discharging nozzles, and white circles are discharge nozzles. In the case of 701, the third nozzle is a non-discharging nozzle, and the 0th to 2nd nozzles are discharge nozzles.

Reference numeral 702 represents the droplet arrangement within the cell when one droplet in the print scanning direction and four nozzles can be allocated to the nozzle direction orthogonal to the print scanning direction for ejection into the cell.

The X direction 702 represents the printing scanning direction, and pixels 0 to 3 within the cell are arranged in a direction perpendicular to the printing scanning direction, and are ejected from different nozzles. A black circle 702 represents a droplet corresponding to a non-ejection nozzle, and a white circle represents a droplet corresponding to an ejection nozzle. Since the third nozzle 701 is a non-ejecting nozzle, in the in-cell droplet arrangement 702, the third droplet corresponds to the non-ejecting nozzle (that is, a droplet with a small ejection amount).

Reference numeral 703 indicates the arrangement of pixels that cannot be ejected on the memory 702, and indicates the presence or absence of pixels that cannot be ejected in units of 1 bit, where 1 represents a pixel that cannot be ejected and 0 represents a pixel that can be ejected. Further, each bit corresponds to pixels 0 to 3 of 702, and the bits at addresses 0 to 2 are ejectable pixels, and the bit at address 3 is a non-ejectable pixel.

704 represents the droplet arrangement within the cell when two droplets can be allocated to ejection into the cell in the print scanning direction and four nozzles can be allocated to the nozzle direction perpendicular to the print scanning direction.

The X direction 704 represents the printing scanning direction, and pixels 0 to 3 in the first row within the cell are arranged in a direction perpendicular to the printing scanning direction, and are ejected from different nozzles. The pixels 4 to 7 in the second row within the cell are arranged in a direction perpendicular to the print scanning direction, and are ejected from different nozzles. Furthermore, pixels 0 and 7, 1 and 6, 2 and 5, and 3 and 4 within the cell are ejected from the same nozzle. A black circle 704 represents a droplet corresponding to a non-ejection nozzle, and a white circle represents a droplet corresponding to an ejection nozzle. Since the No. 3 nozzle of 701 is a non-ejecting nozzle, in the droplet arrangement in the cell of 704, the third and fourth droplets correspond to the non-ejecting nozzle (that is, droplets with a small ejection amount). .

Reference numeral 705 indicates the arrangement of pixels that cannot be ejected on the memory 704, and indicates the presence or absence of pixels that cannot be ejected in units of 1 bit, where 1 represents a pixel that cannot be ejected and 0 represents a pixel that can be ejected. Further, each bit corresponds to pixels 0 to 7 of 705, and the bits at addresses 0 to 2 and 5 to 7 are pixels that can be ejected, and the bits at addresses 3 and 4 are pixels that cannot be ejected.

Reference numeral 706 represents the droplet arrangement within the cell when three droplets can be allocated in the print scanning direction and four nozzles can be allocated to the nozzle direction perpendicular to the print scanning direction for ejection into the cell.

The X direction 706 represents the printing scanning direction, and pixels 0 to 3 in the first row within the cell are arranged in a direction perpendicular to the printing scanning direction, and are ejected from different nozzles. The pixels 4 to 7 in the second row within the cell are arranged in a direction perpendicular to the print scanning direction, and are ejected from different nozzles. The pixels 8 to B in the third row within the cell are arranged in a direction perpendicular to the print scanning direction, and are ejected from different nozzles. Furthermore, pixels 0, 7, and 8, 1, 6, and 9, 2, 5, and A, and 3, 4, and B within the cell are ejected from the same nozzle. A black circle 706 represents a droplet corresponding to a non-ejection nozzle, and a white circle represents a droplet corresponding to an ejection nozzle. Since the No. 3 nozzle of 701 is a non-ejecting nozzle, in the droplet arrangement in the cell of 706, the 3rd, 4th, and B-th droplets correspond to the non-ejecting nozzle (that is, droplets with a small ejection amount). becomes.

Reference numeral 707 indicates the arrangement of non-ejectable pixels on the memory 705, which indicates the presence or absence of ejectable pixels in units of 1 bit, where 1 represents a non-ejectable pixel and 0 represents an ejectable pixel. Further, each bit corresponds to 706 pixels 0 to B, and the bits at addresses 0 to 2 and 5 to A are pixels that can be ejected, and the bits at addresses 3, 4, and B are pixels that cannot be ejected.

As described above, pixels that cannot be ejected are acquired using the same procedure as the ejection required pixel acquisition process (step 501). Furthermore, although the explanation here uses an example of droplet arrangement within a cell when four nozzles can be assigned to each nozzle direction, the number of nozzles assigned to each nozzle direction within a cell can be arbitrarily changed using the cell arrangement data 103d. It is.

(Explanation of ejection failure compensation process)
FIG. 8 sequentially explains the processing contents of ejection failure compensation according to the present invention.

(a) of FIG. 8 shows the data of pixels requiring ejection acquired by the ejection required pixel acquisition process in step 501 of FIG. (a bit string indicating the position of). Note that the bit string in (a) expresses, for example, the position where each nozzle needs to eject in the order of the nozzle arrangement of the inkjet head 102. In the bit string in (a), positions where ejection is required are expressed as 1, and positions where ejection is not necessary are expressed as 0.

(b) shows the data of the non-ejectable pixel acquired by the non-ejectable pixel acquisition process in step 502 (that is, the bit string indicating the position of the non-ejecting nozzle among the nozzle arrays of the inkjet head 102). . Note that the bit string in (b) represents, for example, a position in the order of the nozzle arrangement of the inkjet head 102 where ink cannot be ejected. In the bit string in (b), positions where ejection is not possible are expressed as 1, and positions where ejection is possible are expressed as 0.

(c) is obtained by performing a bit-by-bit OR of the data (a) of the pixel requiring ejection and the data (b) of the pixel that cannot be ejected by the non-complementable pixel calculation process in step 503. (That is, a bit string indicating the position of a nozzle that cannot be used for ejection failure compensation among the nozzle arrays of the inkjet head 102) is shown. In the bit string (c), positions where ejection cannot be complemented are expressed as 1, and positions where ejection can be complemented are expressed as 0.

In (d), data of the pixel to be complemented (i.e., the inkjet head 102 The process of generating a bit string indicating the position of a nozzle that needs to be complemented by an ejection nozzle among the nozzle arrays shown in FIG. In the bit string (d), positions where complementary ejection is required are expressed as 1, and positions where complementary ejection is not required are expressed as 0.

When implementing the control configuration of the present invention in hardware, by configuring a multi-stage circuit of the number of pixels in a cell minus one stage in the non-ejection nozzle complementing section 104g, it becomes possible to perform complementary verification calculations for all pixels. . Note that in the inkjet head 102 according to the present embodiment, since it is possible to eject from four nozzles into one cell, the ejection failure nozzle complementing unit 104g performs the following three stages of verification calculations. configured to run.

(e), (f), and (g) are first-stage verification calculations for searching for complementary nozzles.

In (e), the data of the pixel to be complemented generated in (d) is circularly shifted by 1 bit to the left by the pixel calculation process to be complemented in step 505. The process of generating a bit string indicating the position of a complementary candidate nozzle in a nozzle array is shown. Note that the data of the complement target pixel in (e) is data whose complement target has been changed to a different location from the data of the complement target pixel in (d). In the bit string in (e), the complement target is represented by 1, and 0 indicates that it is not the complement target.

Here, circular shift is a method of circulating the overflowing bits during bit shift processing. For example, when bit shifting to the upper bit side, the value of the most significant bit is moved to the lower bit, and the value of the lower bit is moved to the lower bit. When bit shifting is performed, the value of the least significant bit is moved to the most significant bit, thereby eliminating data that is erased due to overflow due to bit shifting.

(f) is to perform a bit-by-bit OR of the data of the non-complementable pixel generated in (c) and the data of the complementary pixel generated in (e) by the pixel calculation process after the complementary process in step 506. 2 shows the process of generating pixel data after completion of the interpolation process (that is, a bit string indicating a position that can be interpolated by the interpolation nozzle in (e)). In the bit string of (f), when complementation is performed, a 1 indicates a location where the complement cannot be performed, and a 0 indicates a location where the complementation is possible. If the interpolation process has failed, the bit string of the pixel after the interpolation process generated in (f) is the same bit string as the bit string generated in (c).

(g) is performed by performing a bit-by-bit AND of the data of the non-complementable pixel generated in (c) and the data of the complementation destination pixel generated in (e) by the completion failure pixel calculation process in step 507. , shows the process of generating data for pixels that fail to be complemented. Here, when all of the complement target pixels shown in (d) are complemented, the value of (g) becomes all bits 0. Here, as shown in (g), the third bit is 1, indicating that the complementation is not complete. Note that in the bit string (g), 1 indicates a failure in which complementation could not be performed. 0 indicates a part with no problem.

(h), (i), and (j) are second-stage verification calculations for searching for complementary nozzles.

In (h), by circularly shifting the data of the completion failure pixel generated in (g) by 1 bit to the left by the completion destination pixel calculation process in step 505, the completion destination pixel that is different from the data in (e) is obtained. It shows the process of generating data. That is, through this process, the complementary candidate nozzle is changed. In the bit string (h), the complement destination is indicated by 1. 0 is a part that is not complemented.

(i) is to perform a bit-by-bit OR of the data of the pixel after the interpolation process generated in (f) and the data of the interpolation destination pixel generated in (h) by the pixel calculation process after the interpolation process in step 506. 2 shows the process of generating pixel data after completion of the interpolation process (that is, a bit string indicating a position that can be interpolated by the interpolation nozzle in (h)). In the bit string of (i), when the complementation process is performed, a 1 indicates that the complement cannot be performed, and a 0 indicates a location that can be complemented. If the interpolation process has failed, the bit string of the pixel after the interpolation process generated in (i) is the same bit string as the bit string generated in (c).

(j) is the data of the completion failure pixel by performing a bitwise AND of the completion processing pixel calculated in (f) and the completion target pixel calculated in (h) by the completion failure pixel calculation processing in step 507. It shows the process of generating . Here, if all the pixels to be complemented shown in (d) are complemented, the value of (j) will be all bits 0, but the pixel whose completion failed in (j) will not be complemented because the 0th bit is 1. It shows that it is not completed. Note that in the bit string (j), after the completion processing, 1 indicates a failure in which the completion was not possible. 0 indicates a part with no problem. In this case, there is a 1 in the 4th bit, so it is a failure.

(k), (l), and (m) are the third-stage verification calculations for searching for complementary nozzles.

(k) is obtained by circularly shifting the data of the completion failure pixel generated in (j) by 1 bit to the left by the completion destination pixel calculation process in step 505. It shows the process of generating data.

(l) is to perform a bit-by-bit OR of the data of the pixel after the interpolation process generated in (i) and the data of the interpolation target pixel generated in (k) by the pixel calculation process after the interpolation process in step 506. This shows the process of generating pixel data after the interpolation process (that is, a bit string indicating a position that can be interpolated by the interpolation nozzle (k)).

(m) is obtained by performing a bit-by-bit AND of the pixel data after the interpolation process generated in (i) and the data of the interpolation destination pixel generated in (k) by the interpolation failure pixel calculation process in step 507. , shows the process of generating data for pixels that fail to be complemented. Here, if all the pixels to be complemented shown in (d) are complemented, the value of (j) will be all bits 0, but the completion failure pixel in (m) is complete because all bits are 0. It shows things.

(n) is the information obtained by logically inverting the pixel data after the complementary process generated in (l) and the data of the non-ejectable pixels obtained in (b) by the ejection impossible pixel exclusion process in step 509. This shows a process of generating excluded pixel data that does not use non-ejection pixels by performing an AND operation.

The excluded pixel data generated in step (n) becomes the final ejection data for ejecting the required amount of ejection into the cell using only the ejection nozzles without using non-ejecting nozzles. Then, when printing is executed, the inkjet printing apparatus U uses this final ejection data to cause each nozzle of the inkjet head 102 to eject droplets. Note that in the embodiment of FIG. 8, the first nozzle is used to complement the pixel at address 2 that requires ejection from the print data.

From the above, in the control configuration of this embodiment, non-ejection complementation can be realized by a combination of simple logical operations and bit shift processing. As described above, according to the method for controlling an inkjet printing apparatus according to the present invention, it is possible to execute the complementary process using simple logic, and it is possible to perform the complementary process using hardware.
In addition, in the control configuration of the present embodiment, even if the position of a non-ejecting nozzle among the nozzle rows of the inkjet head 102 is changed, the non-ejecting nozzle can be compensated for without regenerating and transferring print data. It is possible. That is, according to the control configuration of this embodiment, it is possible to continue printing even if the position of the non-ejection nozzle is changed.

Note that the circular shift amount used in (e), (h), and (k) is a process of shifting one bit at a time to the upper bit in the above explanation, but if the complementation destination pixel is the initial complementation target pixel position. It is sufficient if all pixels in the cell can be covered except for. For example, if you want to complement a non-ejecting nozzle with as many nearby nozzles as possible, one possible method is to gradually expand the number of target nozzles while checking to see if there are any ejection nozzles on the left and right adjacent positions of the non-ejecting nozzle. In this case, the third bit becomes 1 by circularly shifting 1 bit to the upper bit in the first stage complementary pixel acquisition process in (e), and the lower one in the second stage complementary pixel acquisition process in (h). By circularly shifting 2 bits to the bit, the 1st bit becomes 1, and in the third stage complementation destination pixel acquisition process of (k), by circularly shifting 3 bits to the upper bit, the 0th bit becomes 1, and the initial Since all pixels in the cell other than the position can be covered, the shift amount may be given in this way.

In addition, in FIG. 8, both the post-complementation pixel calculation process in step 506 and the complementation failure pixel calculation process in step 507 are performed, and at the complementation destination candidate nozzle determined in the completion destination pixel calculation process in step 505, A mode is shown in which a process is performed to determine whether or not it is possible to complement a non-ejecting nozzle. However, whether or not it is possible to complement the non-ejection nozzle with the complement destination candidate nozzle determined in the complement destination pixel calculation process in step 505 is determined by the pixel calculation process after the complement process in step 506 or the completion failure pixel in step 507. It is possible to determine whether only one of the calculation processes is performed. From this point of view, the present invention may be configured to perform only either the post-completion processing pixel calculation process in step 506 or the complementation failure pixel calculation process in step 507.

By using the ejection pattern generation method and the ejection pattern generation device of the present invention, it becomes possible to perform complementary processing for non-ejection nozzles with simple logic, so for example, print image data can be changed in response to changes in the nozzle status of the inkjet printing device U. can be done quickly. Moreover, it is therefore useful for use in a droplet discharge type printing apparatus for coating and forming an organic light emitting material in the manufacture of organic EL display panels, for example.

U Inkjet printing device 101 Printing target substrate (display panel)
101a Cells formed on the substrate to be printed 102 Inkjet head 102a Nozzle holes of the inkjet head 103 Print data generation section 103a Print data generation section 103b Data transmission section 103c Cell pattern data 103d Cell arrangement data 103e Non-discharging nozzle data 104 Inkjet head Control section 104a Data reception section 104b Print data holding memory 104c Position detection section 104d Print timing generation section 104e Drive signal generation section 104f Drive signal selection section 104g Non-ejection nozzle complement section 104h Cell arrangement holding memory 104i Non-ejection nozzle holding memory 201 Print data Reading process 202 Print data generation process 203 Ejection failure complement process 204 Transfer process 205 Print process 206 Ejection failure complement process & printing 207 Ejection failure nozzle transfer process 501 Ejection required pixel acquisition process 502 Ejection impossible pixel acquisition process 503 Complement impossible pixel calculation Process 504 Complement target pixel calculation process 505 Complement target pixel calculation process 506 Pixel calculation process after complementation process 507 Completion failure pixel calculation process 508 Repeat count determination process 509 Unejectable pixel exclusion process 601 When one droplet is placed in the print scanning direction Droplet arrangement in the cell 602 Arrangement of pixels required for ejection on memory when one droplet is arranged in the printing scanning direction 603 Droplet arrangement in the cell when two droplets are arranged in the printing scanning direction 604 Two droplets in the printing scanning direction Arrangement of pixels requiring ejection on the memory when arranged 605 Arrangement of droplets in the cell when 3 droplets are arranged in the printing scanning direction 606 Arrangement of pixels requiring ejection on the memory when 3 droplets are arranged in the printing scanning direction 701 Inkjet head Arrangement of non-ejecting nozzles on the top 702 Arrangement of non-ejecting nozzles in the cell when one droplet is placed in the print scanning direction 703 Arrangement of pixels that cannot eject on memory when one droplet is arranged in the printing scanning direction 704 In the printing scanning direction Arrangement of non-ejectable nozzles in the cell when 2 droplets are placed 705 Arrangement of pixels that cannot be ejected on memory when 2 droplets are arranged in the print scanning direction 706 Arrangement of non-ejectable nozzles in the cell when 3 droplets are arranged in the print scan direction Ejection nozzle arrangement 707 Arrangement of pixels that cannot be ejected on memory when 3 droplets are arranged in the print scanning direction

Claims (5)

A method of controlling an inkjet printing device having a plurality of nozzles and configured to be able to apply ink to each separate cell of a display panel using the plurality of nozzles, the method comprising:
A first step (a) of acquiring data related to a first bit string in which each of the nozzles that require ejection and the nozzles that do not need ejection among the plurality of nozzles is expressed in units of 1 bit from the print data holding memory;
a second step (b) of acquiring data related to a second bit string in which each of the ejection nozzle and the ejection failure nozzle among the plurality of nozzles is expressed in units of 1 bit from the ejection failure nozzle holding memory;
a third step (c) of generating a third bit string by bitwise OR of the first bit string and the second bit string;
a fourth step (d) of generating a fourth bit string by bit-wise logical AND of the first bit string and the second bit string;
updating the fourth bit string so as to shift a bit related to the complementation destination candidate nozzle specified in the fourth bit string and changing the complementation destination candidate nozzle to another nozzle among the plurality of nozzles; 5 step (e) and
a sixth step (f, g) of generating a fifth bit string by bitwise OR or AND of the third bit string and the fourth bit string;
including;
The fifth step (e) and the sixth step (f, g) are repeatedly executed in this order, and the fifth bit string generated in the sixth step ( f, g) is used to complement the non-ejecting nozzle. If it is shown that it is possible, selecting the complementation destination candidate nozzle set at that time as a nozzle to complement the non-ejection nozzle;
A method of controlling an inkjet printing device. When repeatedly performing the fifth step (e) and the sixth step (f, g), each time the fifth step (e) Shift one bit at a time,
A method for controlling an inkjet printing apparatus according to claim 1. a print data reading step of reading a cell arrangement, which is an arrangement position of the cells provided in a display panel to be printed, and a cell pattern, which is an ink ejection pattern in the cells;
a print data generation step of generating print data based on the cell arrangement and the cell pattern in the main body of the inkjet printing device;
a transfer step of transferring the print data from the main body side to an inkjet head control unit;
a printing step of applying ink into the cells of the display panel using the plurality of nozzles while moving the plurality of nozzles relative to the display panel,
In the printing step, the first step (a) to the sixth step (f, g) are performed to apply ink using the plurality of nozzles while supplementing the non-discharging nozzle.
A method for controlling an inkjet printing apparatus according to claim 1 or 2. When the inkjet head control unit receives another data indicating the position of the non-ejecting nozzle among the plurality of nozzles from the main body side,
In the printing process, the first process (a) to the sixth process (f, g) are performed using the print data that has already been received and the other data to compensate for the non-ejecting nozzle. applying ink using the plurality of nozzles while performing
The method for controlling an inkjet printing apparatus according to claim 3. An inkjet printing device having a plurality of nozzles and configured to be able to apply ink to each cell of a display panel using the plurality of nozzles,
A first step (a) of acquiring data related to a first bit string in which each of the nozzles that require ejection and the nozzles that do not need ejection among the plurality of nozzles is expressed in units of 1 bit from the print data holding memory;
a second step (b) of acquiring data related to a second bit string in which each of the ejection nozzle and the ejection failure nozzle among the plurality of nozzles is expressed in units of 1 bit from the ejection failure nozzle holding memory;
a third step (c) of generating a third bit string by bitwise OR of the first bit string and the second bit string;
a fourth step (d) of generating a fourth bit string by bit-wise logical AND of the first bit string and the second bit string;
updating the fourth bit string so as to shift a bit related to the complementation destination candidate nozzle specified in the fourth bit string and changing the complementation destination candidate nozzle to another nozzle among the plurality of nozzles; 5 step (e) and
a sixth step (f, g) of generating a fifth bit string by bitwise OR or AND of the third bit string and the fourth bit string;
Equipped with a control device that executes
The control device repeatedly executes the fifth step (e) and the sixth step (f, g) in this order so that the fifth bit string generated in the sixth step ( f, g) is When it is indicated that the ejection nozzle can be complemented, selecting the complementation destination candidate nozzle set at that time as the nozzle for complementing the non-ejection nozzle;
Inkjet printing equipment.

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