JP2010085671A - Method, device of generating discharge pattern, method of manufacturing color filter, and method of manufacturing organic functional element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of generating a discharge pattern capable of reducing unevenness by discharge variation by each nozzle and manufacturing a high quality color filter and an organic functional element in which a visual feeling of rough surface is suppressed. <P>SOLUTION: The method of generating the discharge pattern in a device for generating the discharge pattern includes: a means for holding an amount of ink to be discharged to each opening of a substrate divided into a plurality of openings by partitions in a memory as the discharge pattern; and a mechanism for discharging ink from a nozzle based on the discharge pattern upon positioning an inkjet head having the openings on the substrate and a plurality of nozzles, wherein the discharge pattern is the one regenerated by removing frequency components which make a user feel the feeling of roughness from an amplitude spectrum of the discharge pattern that an average amount of ink in an opening existing in an arbitrary region consisting of predetermined area become even. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a discharge pattern generation method and a discharge pattern generation apparatus for discharging a high-definition pattern, and relates to a method for manufacturing a color filter and a method for manufacturing an organic functional element. The present invention relates to an inkjet discharge apparatus suitable for discharging droplets.

  The substrate size of color filters is increasing year by year. Conventionally, a pigment dispersion method that repeats the photolithography process has been used, but in order to reduce the cost of the color filter, the number of processes has been reduced in recent years, and each colored layer of the color filter can be formed simultaneously. A method using an ink jet apparatus has been studied.

  As a method for producing a color filter using an inkjet apparatus, a method in which colored inks corresponding to the colors of the color filter are ejected from the nozzles of the inkjet nozzle head to the openings partitioned by the partition walls to form each colored layer is generally used. Is. At this time, the color unevenness of the color filter is reduced as the variation in the amount of ink discharged and filled in each opening is smaller, and a high-quality color filter can be manufactured.

  On the other hand, color filters tend to be miniaturized year by year due to higher resolution of image display devices and the like, and higher definition associated therewith. As the pixels of the color filter become finer, the pattern pitch to be applied by the ink jet becomes narrower. Therefore, it is necessary to control the amount of ink discharged from the ink jet nozzle head with high accuracy so as to be small and uniform. For this reason, in the manufacturing method of the color filter using an inkjet apparatus, the method of accumulating a some inkjet nozzle head and improving the resolution is examined.

  However, since the amount of ink ejected from the inkjet nozzle head varies from nozzle to nozzle, the ejection amount may vary. In particular, in the case of an ejection device aiming at high resolution in which a plurality of inkjet nozzle heads are stacked, the amount of ink ejected from one nozzle is extremely small, so the variation is relatively large. .

  In this case, even if the same number of inks are ejected from each nozzle in order to fill each opening with the same amount of ink, a difference in the final ink filling amount occurs due to the variation of each nozzle.

  As a result, the difference between the discharge amount to each partition opening (hereinafter referred to as cell) discharged by the combination of the same nozzle headset and the discharge amount in the cell formed by the combination of different nozzle headsets is visually determined for each pixel. In the meantime, it appeared as uneven color, and it was a cause of reducing the quality and yield of the color filter.

  In particular, when ink is ejected while scanning the substrate or the head in one direction, the cells formed by the combination of the same nozzle headset are arranged in a straight line. , Cell lines), streaky color unevenness occurs, and the quality of the color filter is significantly reduced.

  In order to solve such a problem, as a means for suppressing the influence of the discharge amount variation for each nozzle, for example, the discharge amount is intentionally changed for a part of the cells to be discharged by the combination of the same nozzle headset, thereby causing color unevenness. A reduction method has been proposed (Patent Document 1). According to this method, the average discharge amount per predetermined area can be made uniform by determining the number of singular cells that change the discharge amount and the change amount of the discharge amount based on the degree of color unevenness. Yes. Further, the arrangement of the singular cells for changing the discharge amount is determined by random numbers, so that the positions in the substrate are dispersed and can be prevented from being recognized as a defect when the entire substrate is observed.

  However, in the method of Patent Document 1, since a random number is used when arranging a specific cell having a discharge amount different from that of the surrounding cells, the amplitude spectrum of the discharge pattern includes a frequency component detected as noise in the human eye. Therefore, there was a problem of visually giving a rough feeling.

The known literature is described below.
JP2007-178958

  The present invention has been made in view of the above-described problems, and is capable of producing high-quality color filters and organic functional elements that can reduce color unevenness and suppress visual roughness. The challenge is to provide a method.

  According to a first aspect of the present invention, there is provided a means for holding, in a memory, an amount of ink discharged to each opening of a substrate divided into a plurality of openings by a partition, an opening on the substrate, A method for generating the discharge pattern in a discharge pattern generation apparatus comprising a mechanism for discharging ink from the nozzle based on the discharge pattern after aligning an inkjet head having a plurality of nozzles, wherein the discharge pattern is , Where f is a function for generating a discharge pattern in which the average amount of ink in an opening existing in an arbitrary area having a predetermined area is uniform, the amplitude spectrum P of the discharge pattern p generated by the function f A discharge pattern p ′ obtained from an amplitude spectrum P ′ in which a part of the frequency band in FIG. A discharge pattern generation method.

  The invention according to claim 2 of the present invention is characterized in that, in the above, the means for obtaining P ′ from the amplitude spectrum P is a low-frequency cutoff filter that blocks a low frequency of 1 cycle / mm or less. The discharge pattern generation method described.

  The invention according to claim 3 of the present invention is characterized in that, in the above, the region where the average amount of ink is uniform comprises a row of openings for discharging ink by the same nozzle. The discharge pattern generation method described.

  In the invention according to claim 4 of the present invention, in the above, the function includes an ideal ink amount for making the average amount of ink in an opening uniform in an arbitrary region having a predetermined area, and an opening in a region of interest. The discharge pattern generation method according to claim 1, wherein the discharge pattern is generated by using a difference between the average ink amounts as a weight and using the weight and a random number.

  The invention according to claim 5 of the present invention is the above-described discharge pattern generation apparatus comprising the discharge pattern generation method according to any one of claims 1 to 4.

The invention according to claim 6 of the present invention is the method for producing a color filter, wherein the colored layer is formed by the discharge pattern generation device according to claim 5.

  The invention according to a seventh aspect of the present invention is the method for producing an organic functional element, wherein the organic functional layer is formed by the ejection pattern generation device according to the fifth aspect.

  According to the discharge pattern generation method of the first aspect of the present invention, a discharge pattern in which the average amount of ink in cells existing in an arbitrary area having a predetermined area is uniform is generated, and then the generated discharge pattern is By rearranging the ejection patterns having an amplitude spectrum with little influence of noise components, it is possible to simultaneously reduce color unevenness and a rough feeling.

  According to the ejection pattern generation method according to claim 2 of the present invention, it is possible to obtain an ejection pattern from which a low frequency component of 1 cycle / mm or less, which is generally considered to give a feeling of visual roughness, is removed, and the color unevenness and the feeling of roughness are obtained. Can be reduced.

  According to the ejection pattern generation method according to claim 3 of the present invention, streak-like color unevenness generated between cells arranged in a straight line where ink is ejected by the same nozzle headset is reduced, and the feeling of roughness is reduced. can do.

  According to the discharge pattern generation method of the fourth aspect of the present invention, when generating a discharge pattern in which the average amount of ink in cells existing in an arbitrary area having a predetermined area is uniform, the discharge amount is different from the surrounding cells. Even if the cells are randomly arranged by random numbers, the feeling of roughness can be reduced by changing the amplitude spectrum.

  According to the discharge pattern generation method of the fifth aspect of the present invention, it is possible to provide a discharge pattern generation apparatus that generates and applies a discharge pattern that is homogeneous and has a less rough feeling.

  The invention according to claim 6 of the present invention makes it possible to manufacture a high-quality color filter with high definition, less color unevenness, and reduced roughness.

  The invention according to claim 7 of the present invention makes it possible to manufacture high-quality organic functional elements such as an organic EL element with less unevenness in light emission and reduced roughness.

  FIG. 1 shows an example of the overall configuration of the ejection pattern generation apparatus of the present invention. The discharge pattern generation apparatus of the present invention has a configuration having an inkjet nozzle head unit 2 in which a plurality of inkjet nozzle heads 1 in which a plurality of inkjet nozzles are arranged in combination are arranged. In order to generate a color filter, it is necessary to discharge ink of each color (for example, R, G, B) forming the colored layer, and therefore, a combination of a plurality of the above-described inkjet nozzle heads is arranged in each color. ing. The ink jet nozzle head unit moves in the main scanning direction and performs image drawing.

  The substrate table 3 is movable in the sub-scanning direction perpendicular to the main scanning direction, and is further rotatable in the θ direction. Since it can rotate in the θ direction, the partition wall of the substrate placed on the substrate mounting table and the ink jet nozzle head unit can be aligned in parallel, and image drawing can be performed by operating in the sub-scanning direction. Further, although not shown in the figure, the substrate table is provided with a suction mechanism, and the substrate placed on the substrate table can be fixed.

The ejection pattern generation apparatus of the present invention recognizes or measures position information based on at least nozzles existing in an inkjet nozzle head for ejecting ink to the opening of the partition and parameter information input in advance, and outputs the position information. Means for making the average ink amount of the openings present in an arbitrary area having a predetermined area uniform by a function, means for reducing or enhancing a part of the amplitude spectrum of the discharge pattern, and rearranging the discharge pattern And have. The parameter information is information related to the discharge pattern, for example, information that is input in advance such as the size of the substrate and the formation pattern, and information that is sequentially input such as the position of the nozzle and the substrate, and the information related to the substrate. It is.

  On the other hand, as one of image evaluation methods such as a screen, a lens, and an optical filter, MTF (Modulation Transfer Function) representing the reproducibility of the contrast and resolution of the output image of various optical members with respect to the input image is widely used. In particular, when observing an object with human eyes, it is common to use VTF (Visual Transfer Function), which is an MTF of the visual system, as one measure of whether or not it is perceived sensitively.

  FIG. 15 shows a VTF curve at an observation distance of 286 mm. From FIG. 15, the VTF curve shows a bandpass characteristic having a peak at 1 cycle / mm. Further, it has been confirmed through experiments and the like that the less the frequency component remaining when the VTF curve is multiplied by the amplitude spectrum of the image, the less the feeling of roughness with the human eye.

  On the other hand, the color unevenness with the shortest period in the color unevenness of the color filter is when light and dark are repeated between adjacent cell lines (0.5 cycle / cell) as shown in the upper part of FIG. Since the width of the opening of the color filter manufactured by the present invention is about 500 μm, 0.5 cycle / cell is 1 cycle / mm, which is the maximum frequency related to color unevenness.

  From the above, from the frequency at which the VTF curve peaks and the maximum frequency related to color unevenness, in the present invention, 1 cycle / mm or less is referred to as a low frequency component, and 0 to 1 cycle / mm is defined as a cutoff frequency. Note that the curve shifts toward a lower frequency as the observation distance increases, and the observation distance of the color filter handled in the present invention is 286 mm or more.

  The inkjet nozzle head and the nozzle for ejecting ink used in the present invention can be applied as long as they have a configuration in which a plurality of nozzles are arranged, but as shown in FIG. Use a combination of several. In this case, each phase nozzle ejects ink at different timings. For example, FIG. 2 is a schematic diagram of a cross-sectional view of the inkjet nozzle head 1, but ink is ejected from the same row of the nozzle A phase, nozzle B phase, and nozzle C phase (hereinafter referred to as A phase, B phase, and C phase). Timing is shifted in the order of A, B, C.

  In this method (hereinafter referred to as “shear wave mode”), the intervals between the nozzles, for example, the A layer to B layer and the B layer to C layer can be narrowed to obtain a high-density inkjet nozzle head. Suitable for manufacturing color filters that require pattern formation.

  The inkjet nozzle head 1 includes buffers (hereinafter referred to as line buffers) corresponding to A phase, B phase, and C phase, and the line buffers of each phase can transfer information to each other. A simple operation flow until the ink jet nozzle head discharges is shown in FIG.

  First, the A-phase line buffer receives the ejection pattern information, and starts ejection from the A-phase ink ejection port based on the information related to the A phase in the transferred information. Simultaneously with the start of ejection from the A-phase ink ejection port, ejection pattern information is transferred from the A-phase line buffer to the B-phase line buffer. After completion of ejection from the A-phase ink ejection port, the B-phase ink ejection port starts ejection based on the information regarding the B phase in the transferred ejection pattern information. Simultaneously with the start of ejection from the B-phase ink ejection port, ejection pattern information is transferred from the B-phase line buffer to the C-phase line buffer. After completion of ejection from the B-phase ink ejection port, the C-phase ink ejection port starts ejection based on the information regarding the C phase in the transferred ejection pattern information. After completion of ejection from the C-phase ink ejection port, it is determined whether or not the line counter has been ejected for a set number of times, and if the set number of ejections has not been performed, the ejection pattern information is transferred to the A-phase line buffer. Again, the A-phase ink discharge port starts to discharge based on the discharge pattern information. Thereafter, the above-described operation is repeated for the number of lines to create a desired ejection pattern.

  The above is the discharge control method in the share wave mode, but the discharge apparatus of the present invention has no problem even in other methods. Hereinafter, a case where a color filter is formed by the discharge pattern forming method of the present invention will be described as an example. However, in the case of other optical elements, for example, organic EL elements, similarly, when forming each color pixel of the light emitting layer. The present invention can be used.

  For example, an inkjet nozzle head controller 4 is connected to the ejection device as a control unit that ejects ink from the nozzles of the inkjet nozzle head based on the ejection pattern information. The inkjet nozzle head controller 4 drives the inkjet nozzle head and stores inkjet nozzle head parameter information and ejection patterns. The inkjet nozzle head parameter information is information for driving the inkjet nozzle head. In the ejection pattern information, information about ejection of a specific nozzle is stored with the position information of the inkjet nozzle head as an argument. When performing ejection, ejection pattern information is transferred from the inkjet nozzle head controller 4 to each nozzle, and drawing can be performed.

  In addition, in the inkjet nozzle head parameter information for driving the inkjet nozzle head of the inkjet nozzle head controller 4, it is preferable that an optimum voltage value parameter can be set for each inkjet nozzle head. If the drive voltages of all the ink jet nozzle heads are set to the same value, the amount of liquid droplets ejected from the ink jet nozzle heads varies depending on individual differences, so that it may not be possible to uniformly eject ink into the substrate. By making it possible to set an optimal voltage value parameter for each ink jet nozzle head, it becomes possible to control the discharge amount for each ink jet nozzle head and to adjust the discharge amount of each cell.

  The means for recognizing or measuring positional information and outputting the positional information possessed by the present invention includes a color filter size, a partition pattern pitch, a pixel pattern (such as a stripe arrangement, a cell arrangement, and a mosaic arrangement) inputted in advance. Parameters of the color filter substrate such as the information array pattern), positional information of the inkjet nozzle head and nozzles (including the positional deviation information of the head), and parameters such as the amount of movement of the substrate table of the ejection device (hereinafter, In addition, the landing position of the ink discharged from the nozzle onto the substrate is calculated from the discharge pattern information). Alternatively, an image of the substrate surface can be acquired and processed by a camera installed in the discharge device, and the ink landing position can be calculated.

  After calculating the position of the inkjet nozzle head and the nozzle with respect to the partition pattern on the substrate, whether the ink landing position is the formation position of the pixel portion (target partition opening: cell) based on this information Whether or not processing is determined by a program. Only when the landing position corresponds to the target partition opening, the nozzle is recognized as an effective nozzle, and is not ejected from a nozzle that is not.

FIG. 4 is a specific example of determining whether a nozzle is valid. Of the nozzles 5 of the inkjet nozzle head, the nozzles directly above the openings of the color filter substrate are determined to be valid, and the other nozzles are determined to be invalid, and discharge pattern information is generated. Then, according to this ejection pattern information, the nozzles of each inkjet nozzle head eject ink into the target cells. The ink discharge amount at each opening can also be expressed as the number of effective nozzle drops.

  Here, when the ejection device and the ejection method of the present invention are not used, even when the variation in the ejection amount for each cell is small in the cell line applied by the combination of the same nozzle headset, the cell lines are not separated. Since the difference in the discharge amount is larger than the difference in the discharge amount in the cell line, streak-like color unevenness along the cell line occurs, resulting in a color filter with large visually uneven color as a whole.

  Therefore, the ejection pattern generation apparatus of the present invention solves this problem by having means for increasing or decreasing the ejection amount of ink ejected from the effective nozzles to the cells, that is, the number of effective nozzle drops using random numbers. In other words, by giving a certain range of drop numbers (hereinafter referred to as the basic drop number) to a certain number of drops, the number of drops actually ejected for each cell is given a certain range so that the cell lines have arbitrary variations. Variations in the average discharge amount can be made inconspicuous, thereby reducing overall color unevenness.

  Here, the means for increasing / decreasing the number of ink drops ejected from the nozzles using a random number is to select the nozzles ejected from the above-mentioned effective nozzles, and further, the target ideal ink amount and the average ink amount of the target cell line From the difference, the number of cells whose number of drops is changed in the cell line is determined, and a discharge amount change cell is allocated in the cell line by the determined number of cells using a random number by a calculation computer. For example, for a cell line having a larger average ink amount than the ideal ink amount, the average ink amount can be made closer to the ideal ink amount by providing cells with a smaller number of drops in the cell line. However, if the number of drops in one cell increases or decreases, even if the average value of the ink amount on the cell line approaches the ideal ink amount, there is a possibility that a cell having a greatly different discharge amount from the surrounding will be recognized as a defect. is there. Therefore, it is desirable to increase or decrease the number of drops in one cell to about several drops, and to adjust the average value of the ink amount of the cell line by the number of cells whose number of drops is changed.

  By this adjustment, the average value of the ink amount of each cell line approaches the target ideal ink amount, and the arrangement of cells in which the ejection amount is changed using a random number does not cause an uneven arrangement in the cell line. As a result, the difference in the discharge amount between the cell lines due to the discharge amount variation for each nozzle is reduced, and streaky color unevenness along the cell line is reduced.

  Here, the ideal ink amount can be obtained from the target film thickness, chromaticity, luminance, and the like of the color filter to be created.

  In the above description, the adjustment method in units of cell lines has been described as one of the means for reducing streak-like unevenness, which is a typical color unevenness when a color filter is manufactured using an inkjet device. However, the unit of the area for bringing the average value of the ink amounts close to the ideal ink amount is not limited to the cell line. For example, the display area of the color filter may be divided into a plurality of rectangles.

Here, as described above, human vision has a frequency that feels rough, but in the above adjustment, a random number is used to determine the arrangement of cells for changing the number of drops, so generated ejection The amplitude spectrum of the pattern includes a frequency that makes this rough feel. In particular, a random number generated by a general computing computer is called white noise and has the same intensity in all frequency bands, and therefore contains a low-frequency component in which human vision feels most rough. Therefore, the above adjustment method reduces color unevenness, but causes a new problem of roughness.

  Therefore, in the present invention, after generating a discharge pattern that reduces color unevenness by the above method, the discharge pattern is converted into an amplitude spectrum, and a frequency component that gives a feeling of roughness is removed from the discharge pattern, and the reverse conversion is performed again to the discharge pattern. Thus, a means for obtaining a discharge pattern with reduced roughness is provided.

  Here, as a means for obtaining the amplitude spectrum of the ejection pattern, a table in which the arrangement information of the cells whose number of drops is to be changed is read into a computing computer and Fourier transformed to obtain the absolute value.

  Further, as a means for removing the frequency component that gives a feeling of roughness, an arbitrarily designed band cut-off filter and the amplitude spectrum are multiplied in the frequency space.

  The present invention can reduce the difference in discharge amount between pixels and eliminate unevenness in forming a pattern using an ink jet method, and thus can be applied to manufacturing an element using an ink jet method. Hereinafter, as an example of a method for producing an element using the present invention, a method for producing a color filter and an organic functional element will be described.

  Both the color filter and the organic functional element can be manufactured by forming a partition on a substrate and forming a pixel portion there.

  The substrate will be described below. The substrate is used as a support substrate for printed matter. For example, a known transparent substrate material such as a glass substrate, a quartz substrate, a plastic substrate, or a dry film can be used, although the type of substrate differs depending on the target optical element. Among them, the glass substrate is excellent in transparency, strength, heat resistance, and weather resistance in color filter and organic EL device applications.

  The partition will be described below. In the present invention, ink is applied to the substrate by an ink jet printing apparatus to form a color filter or an organic functional element. In order to prevent color mixing (or mixing) between different types of inks, it is preferable to form partition walls on the substrate in advance.

  The partition wall has a function of dividing the surface of the substrate into a plurality of regions and preventing color mixture of ink ejected in each of the many regions. In order to prevent color mixing, it is desirable to use a partition that exhibits a certain ink repellency. For example, a method of forming partition walls by a resin composition part containing an ink repellent agent, a method of imparting ink repellency by performing plasma treatment on the partition walls formed of a resin composition, and forming a partition wall together with a photocatalyst layer to repel the partition walls by photocatalysis. Examples thereof include a method for imparting ink properties. Moreover, in the color filter and organic EL element which comprise the display screen of a display, the contrast of a display screen can be improved by providing light-shielding property to this partition. In any case, when the partition is formed from a resin composition, it is necessary to contain a resin binder and an ink repellent as essential components.

  The partition can be formed by a known partition forming method such as a printing method or a photolithography method.

  A method for manufacturing the color filter will be described below. When forming a color filter, first, a partition wall is formed on the substrate by the method described above. A colored layer is formed by the discharge pattern forming apparatus of the present invention using colored ink. The colored ink can contain a color pigment, a solvent, and a resin binder as necessary.

  The manufacturing method of an organic functional element is demonstrated below. In the case of forming an organic EL element, an organic solar cell, or an organic semiconductor, first, a partition is formed on the substrate. The ink contains an organic light emitting material, and can be manufactured by forming an organic functional layer on a substrate by using the discharge pattern generating apparatus and the discharge method of the present invention. This ink can contain an organic light emitting material, a solvent, and a resin binder as needed. As the solvent and the resin binder, the same materials as listed in the formation of the partition walls can be used.

  The organic light emitting material will be described below. Organic light-emitting materials such as coumarin, perylene, pyran, anthrone, porphyrene, quinacridone, N, N'-dialkyl substituted quinacridone, naphthalimide, N, N'-diaryl substituted pyrrolopyrrole, iridium complex Organic light-emitting materials that are soluble in organic solvents such as those dispersed in polymers such as polystyrene, polymethyl methacrylate, polyvinyl carbazole, polyarylene-based, polyarylene vinylene-based, polyfluorene-based, etc. And a high molecular organic light emitting material.

  The discharge pattern generation method by the discharge apparatus of the present invention will be described with a specific example.

  First, the validity / invalidity of the nozzle is determined according to the ejection pattern as described above. A nozzle that ejects ink corresponding to the pixel formed in the partition opening on the substrate and formed in the pixel portion is made effective (see FIG. 4).

  Next, the number of ink drops for discharging a preset ideal ink amount (reference number of drops) is calculated and distributed as the number of drops of each effective nozzle. The ideal ink amount is calculated from the target film thickness, chromaticity, brightness, and the like.

  Here, as described above, the actual average ink amount of each cell line may deviate from the ideal ink amount due to variations in the discharge amount of each nozzle, the influence of crosstalk, and the like. Therefore, in the present invention, the number of cells for changing the number of drops in the cell line is determined from the difference between the target ideal ink amount and the average ink amount of the target cell line, and a random number is used by the computing computer, By allocating discharge amount change cells in the cell line by the determined number of cells, it is possible to bring the average ink amount close to a value close to the ideal ink amount.

  An example of generating the ejection pattern is shown below.

The difference between the ideal ink amount and the average ink amount of each cell line is
M−M (x) = k (x) (M is an ideal ink amount, M (x) is an average ink amount of each cell line, k (x) is an ideal ink amount and an average ink amount of each cell line) , X is a symbol representing each cell line).

  The k (x) can be calculated by measuring the film thickness, chromaticity, luminance and the like of each cell line.

  By comparing with the random number, it is determined whether or not the number of drops of each cell is increased / decreased by a unit drop, and this process is repeated as many times as the maximum value of the increase / decrease number of drops determined by k (x). The step of determining the increase / decrease number of the drop number is as shown in the flowcharts of FIGS. 5 and 6, for example.

  FIG. 5 is a flowchart when k (x) ≧ 0, that is, when the average ink amount is smaller than the ideal ink amount. FIG. 6 is a flowchart when k (x) <0, that is, when the average ink amount is larger than the ideal ink amount.

  First, the case of FIG. 5 will be described. The quotient when | k (x) | is divided by the unit drop amount d is m, and the remainder is n. R (j) is a function that generates a real random number from 0 to 1, y is a symbol representing each cell, and M (x, y) is the ink amount of each cell y in the cell line x.

  First, the random number is compared with | k (x) | / (m + 1) d. If the random number is smaller, the unit drop is added to the number of drops of the cell y in the cell line x. This is repeated m + 1 times, and the accumulated value is the number of drops added to the cell y. That is, in one comparison, for each cell y in the cell line x, a unit drop is added with a probability of | k (x) | / (m + 1) d, and the average ink amount M (x) of the cell line x is increased. The minutes are probabilistically close to | k (x) | / (m + 1). Therefore, by repeating this process m + 1 times, the increase in the average ink amount M (x) of the cell line x becomes a value close to k (x), and can be close to the ideal ink amount.

  Further, the case of k (x) <0 in FIG. 6 is a flow in which the process of adding the unit drop is replaced with the process of subtraction. That is, the decrease amount of the average ink amount M (x) becomes a value close to k (x), and can be close to the ideal ink amount.

  As the accuracy of the random number function used is higher, the increase / decrease value becomes closer to k (x), and the average ink amount is closer to the ideal ink amount.

  However, as described above, the amplitude spectrum of the ejection pattern generated by the above method includes a frequency component that gives a feeling of roughness. Therefore, an example of a method for removing this frequency component is shown below.

  As a result of the adjustment using the random numbers, a table in which the cell arrangement information for changing the number of drops is described as shown in FIG. The x direction of the table corresponds to the nozzle arrangement direction, and the y direction corresponds to the scanning direction of the substrate. That is, it is a set of cells in which cell rows in the y direction existing at the same x position in the table are applied by the combination of the same nozzle headset. The numbers in the table represent the number of increase / decrease drops in each cell.

  FIG. 8 shows an example of the amplitude spectrum of the ejection pattern obtained by reading the above table into a computing computer, performing Fourier transform, and taking the absolute value. In FIG. 8, the horizontal direction represents the frequency component in the x direction in FIG. 7, and the vertical direction represents the frequency component in the y direction in FIG. When the effective opening width of the cell is H, the unit conversion of the frequency in FIGS. 7 and 15 is represented by cycle / mm = (cycle / cell) / (Hmm / cell).

  Further, as a feature of the two-dimensional Fourier transform, the center portion of FIG. 8 represents a low frequency component, and becomes a high frequency component as the distance from the center portion increases. Since random numbers are used to adjust the number of drops, they have the same intensity in all directions and in all frequency bands. That is, it can be seen that a low-frequency component, which is a component that easily gives a sense of roughness to the eyes, is also included.

  Next, a method of removing a frequency component that gives a rough feeling from the amplitude spectrum will be described.

  As an example, a method of multiplying the amplitude spectrum of FIG. 8 by a low-frequency cutoff filter is conceivable in order to remove a low-frequency component that is a component that easily gives a sense of roughness to the eye. An example of the low-frequency cutoff filter is shown in FIG. As design parameters for the low-frequency cutoff filter, a horizontal filter width Hx and a vertical filter width Hy were prepared.

  By multiplying the amplitude spectrum newly obtained by multiplying the amplitude spectrum and the low-frequency cutoff filter by Fourier inverse transform, a table of ejection patterns from which low-frequency components have been removed can be obtained. This table represents cell arrangement information for changing the number of drops for reducing the feeling of roughness. However, since the amplitude spectrum is changed, the numerical value of the table obtained by inverse Fourier transform is not necessarily an integer. Therefore, it is necessary to round the table value to an integer by rounding off, etc., and change it to a value that holds as the number of nozzle drops.

  Here, by adjusting the filter widths Hx and Hy, even if the amplitude spectrum is changed, the average ink amount of the cell line greatly fluctuates, or the position of the cell for changing the number of drops in the cell line is biased. It has been found that low frequency components can be removed without doing so.

  As described above, according to the method of the present invention, it is possible to manufacture a high-quality color filter in which the color unevenness and the rough feeling are simultaneously reduced.

  Next, as Example 1, a method for producing a color filter of the present invention will be described.

  A method for forming the partition walls will be described below. As a photosensitive resin composition containing a material imparting ink repellency, a black photosensitive resin composition blended at the following composition ratio was used. As the substrate, non-alkali glass (1737: manufactured by Corning Co., Ltd.) was used, and this black photosensitive resin composition was applied thereon by spin coating, and prebaked on a hot plate at a temperature of 90 ° C. for 1 minute. A film having a thickness of 2.0 μm was formed on the substrate.

The composition of the photosensitive resin composition is cyclohexanone (boiling point 155.7 ° C.) 80 parts by weight Cresol-Novolac resin: EP4050G (manufactured by Asahi Organic Materials Co., Ltd.) 15 parts by weight Melamine resin: MW30 (Sanwa Chemical Co., Ltd.) 5 parts by weight Carbon pigment: MA-8 (manufactured by Mitsubishi Materials Corporation) 23 parts by weight Dispersant: Solsperse 5000 (manufactured by Zeneca) 1.4 parts by weight Compound having radical polymerizability: trimethylolpropane tri Acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.)
Photopolymerization initiator: Irgacure 369 (manufactured by Ciba Specialty Chemicals) 2 parts by weight Fluorine-containing compound: Modiper F-600 (manufactured by NOF Corporation, mass average molecular weight 35000) 5 parts by weight.

Subsequently, using a photomask which is a stripe pattern, an exposure process of 100 mJ / cm ² was performed with an ultrahigh pressure mercury lamp, and further a development process was performed to obtain a desired partition wall pattern. Thereafter, heat treatment was performed in a hot-air firing furnace.

  The adjustment of the color ink will be described below. 0.75 parts by weight of azobisisobutylnitrile was added to the following composition under a nitrogen atmosphere and reacted at 70 ° C. for 5 hours to obtain an acrylic copolymer resin.

The composition of the color ink composition is
Methacrylic acid 20 parts by weight Methyl methacrylate 10 parts by weight Butyl methacrylate 55 parts by weight Hydroxyethyl methacrylate 15 parts by weight Butyl lactate 300 parts by weight, so that the acrylic copolymer resin obtained is 10% by weight Dilution was performed using propylene glycol monomethyl ether acetate to obtain a diluted solution of an acrylic copolymer resin.

  Add 19.0 g of color pigment and 0.9 g of polyoxyethylene alkyl ether as a dispersant to 80.1 g of this diluted solution, and knead with three rolls to obtain red, green and blue colored varnishes. It was. As a red pigment, Pigment Red 177, Pigment Green 36 as a green pigment, and Pigment Blue 15 as a blue pigment were used.

  Propylene glycol monomethyl ether acetate is added to each colored varnish so that the pigment concentration is 12 to 15% by weight and the viscosity is 15 cps, and red, green, and blue inks are obtained. It was.

  A color filter was prepared. This will be described below. A colored layer was formed using the discharge device of the present invention shown in FIG. Here, the number of cells is 768 cells in the nozzle alignment direction and 1360 cells in the substrate transport direction. The ideal ink amount M of each cell calculated from the target chromaticity is 864 pl, which is a unit drop. The discharge amount d is 6 pl.

  First, an inspection substrate having a partition wall pattern similar to the substrate used in the color filter manufacturing method according to the present invention was prepared, and ink was discharged by generating a discharge pattern for discharging an ideal ink amount common to all cells. . Next, by measuring the luminance value of each cell of this inspection substrate, the difference between the ink amount actually ejected to each cell and the ideal ink amount was calculated. The result is shown in FIG. The discharge amount variation of the cell line in the substrate transport direction applied by the combination of the same nozzle headset was sufficiently smaller than the discharge amount variation between the cell lines, so the ink amount should be adjusted on a cell line basis. It was.

  Next, according to the flowchart shown in FIG. 5 and FIG. 6, the arrangement of the discharge amount changing cells for making the average ink amount of each cell line close to the ideal ink amount was determined. However, the maximum number of increase / decrease drops in each cell was 1 drop.

  FIG. 11 shows the difference between the ideal ink amount and the average ink amount after changing the ejection amount. Comparing FIG. 10 and FIG. 11, it can be seen that the average ink amount has come close to the ideal ink amount. FIG. 12 shows the distribution of the drop number changing cells in the cell line in the fifth column. From this, it can be seen that the cells for changing the discharge amount are arranged without deviation in the cell line.

  Next, the low-frequency component is obtained by multiplying the amplitude spectrum of the ejection pattern generated according to the flowcharts shown in FIGS. 5 and 6 by a low-frequency cutoff filter and inverse Fourier transforming the amplitude spectrum obtained thereby. A removed discharge pattern was obtained. Here, although the effective opening width of the manufactured substrate is 500 μm in the longitudinal direction (x direction), the frequency 1 cycle / mm serving as the low frequency boundary described above is cycle / mm = (cycle / cell) ÷ (Hmm / cell). ), The unit conversion is 0.5 cycle / cell. In Example 1, the width of the low-frequency cutoff filter was set to a value sufficiently larger than this, and Hx and Hy were set to 3 cycles / cell. FIG. 13 shows the result of obtaining the difference in average ink amount before and after removing the low frequency component for each cell line. From this, it can be seen that the low-frequency component can be removed without greatly changing the average ink amount. FIG. 14 shows the distribution of the drop number changing cells in the cell line of the fifth column after removing the low frequency component. From this, it can be seen that even after the low-frequency component is removed, the drop number changing cell is arranged without a large deviation in the cell line.

  The board | substrate which applied the discharge pattern produced | generated according to the flowchart shown by FIG. 5 and FIG. 6 was visually observed. As a result, a color filter with reduced color unevenness was obtained. Further, the substrates coated with the ejection patterns before and after removing the low frequency component of the amplitude spectrum were compared by visual observation. As a result, it was confirmed that the roughness was reduced by removing the low-frequency component.

  As described above, the color unevenness due to the discharge amount variation of the nozzle is reduced by adjusting the discharge amount using a random number, and the low-frequency component is removed from the amplitude spectrum of the discharge pattern to eliminate the visual roughness caused by the adjustment using the random number. As a result, it was possible to manufacture a high-quality color filter.

Schematic which shows the example of a whole block diagram of the discharge pattern production | generation apparatus of this invention. Schematic of nozzle of inkjet nozzle head in share wave mode. 6 is an ink discharge operation flowchart in a share wave mode. Schematic which selects an effective nozzle from the nozzle of an inkjet nozzle head. The flowchart which determines the increase / decrease drop number of this invention. The flowchart which determines the increase / decrease drop number of this invention. A table in which cell placement information for changing the number of drops is described. The figure showing the amplitude spectrum calculated | required from the table of FIG. An example of a low-frequency cutoff filter. The figure showing the difference of the average ink amount before adjustment by a random number, and an ideal ink amount. The figure showing the difference of the average ink amount after adjustment by a random number, and an ideal ink amount. The figure showing arrangement | positioning of the discharge amount change cell before removing a low frequency component. The figure showing the difference of the average ink amount before and behind removing a low frequency component. The figure showing arrangement | positioning of the discharge amount change cell after removing a low frequency component. The figure showing a VTF curve. The conceptual diagram showing the period of a color nonuniformity.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inkjet nozzle head 2 ... Inkjet nozzle head unit 3 ... Substrate stand 4 ... Inkjet nozzle head controller 5 ... Nozzle 6 ... Effective nozzle 7 ... Bulkhead opening

Claims (7)

Positioning means for holding the amount of ink discharged to each opening of the substrate divided into a plurality of openings by a partition as a discharge pattern in a memory and an ink jet head provided with the openings on the substrate and a plurality of nozzles In addition, a method for generating the discharge pattern in a discharge pattern generation apparatus including a mechanism for discharging ink from the nozzle based on the discharge pattern,
The discharge pattern is a discharge pattern p generated by the function f, where f is a function for generating a discharge pattern in which the average amount of ink in the openings existing in an arbitrary area having a predetermined area is uniform. A discharge pattern generation method characterized by being a discharge pattern p ′ obtained from an amplitude spectrum P ′ in which a part of the frequency band in the amplitude spectrum P is reduced or enhanced.   The ejection pattern generation method according to claim 1, wherein the means for obtaining P 'from the amplitude spectrum P is a low-frequency cutoff filter that cuts off a low frequency of 1 cycle / mm or less.   The discharge pattern generation method according to claim 1, wherein the region where the average amount of ink is uniform includes a row of openings through which ink is discharged by the same nozzle.   The function uses the difference between the ideal ink amount for making the average amount of ink in the opening portion uniform in an arbitrary area having a predetermined area and the average ink amount of the opening portion in the region of interest as a weight, and the weight and the random number. The discharge pattern generation method according to claim 1, wherein the discharge pattern generation method is a function that generates a discharge pattern by using the above.   An ejection pattern generation apparatus comprising the ejection pattern generation method according to claim 1.   A method for producing a color filter, wherein a colored layer is formed by the ejection pattern generation device according to claim 5.   An organic functional layer is formed by the discharge pattern generation device according to claim 5.

Images