JP2010234170A - Coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus for producing a color filter at a low cost that satisfies a requirement with respect to chromaticity specification equally over a large coating area without unevenness. <P>SOLUTION: A plurality of inkjet nozzles belonging to a plurality of inkjet heads are divided into a plurality (n) of groups in the longitudinal direction of the arrangement thereof. The plurality of inkjet heads are regularly arranged to form a plurality of lines of the number (n) of divisions plus 1 or greater, in the longitudinal direction of the inkjet head by shifting the position in the longitudinal direction of the arrangement of the inkjet nozzles by every division unit of the divided inkjet nozzles, to supply a coating material to the object to be coated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coating apparatus that supplies a coating material to a coating object held on a holding stage by an inkjet head having a plurality of inkjet nozzles.

  Recent progress in image display technology of information terminals is remarkable, and display devices (displays) with very high definition are manufactured and put into practical use even for large screens or small screens. Under such circumstances, there is a strong demand for a display that enables high-quality image display at low cost. There is a color filter as a key device of a display that meets such demands, and various devices have been incorporated into the color filter manufacturing method and apparatus.

  One of the development techniques for such a manufacturing method and apparatus is a conventional glass substrate in which a light-shielding portion is formed in a matrix shape by using various materials having a light-shielding function. A colorant is applied to a glass substrate or the like using a coating technique in the grid. However, in this construction method, each of the RGB three-color coloring steps is independent, and each step requires a shielding member (mask) that requires extremely high accuracy for light shielding, and is also used in terms of man-hours. There was also a problem that the manufacturing cost was high in terms of equipment and components. Instead of the current method, recently, using a coating device equipped with an inkjet head, a color filter is manufactured by supplying and applying a coloring material from the inkjet nozzle of the inkjet head onto a glass substrate or the like on which a light shielding portion is formed in a matrix. Have been proposed (see Patent Document 1 and Patent Document 2).

JP 2002-273868 Japanese Patent No. 3925525

  When applying coloring materials, etc. using an inkjet head, when applying coloring materials, etc. over a large area such as a display with a large screen, or even if the application area required for each product is small, a large amount on one substrate If it is going to produce through an application process simultaneously in parallel, as a result, it is necessary to supply a large amount of coloring materials etc. in order to apply coloring materials etc. to an effective area as a large part like a large display. In such a case, in order to efficiently complete the coating process, it is necessary to supply and apply the material to a large area (width) by a single scanning (moving) of the coating apparatus, and a plurality of inkjet heads that apply the coloring material. Must be placed in parallel. However, when a plurality of ink jet heads are simply arranged in parallel, the width of the entire developed ink jet head portion increases.

  As a method for solving this problem, Patent Document 1 discloses a method of inclining and arranging the respective inkjet heads in the arrangement and arrangement of the inkjet heads.

  In addition, in order to realize a large coating area as described above with a small number of coating steps, a single coating is performed by mounting a necessary number of inkjet heads having inkjet nozzles of a certain limited width on a moving base. A large-sized coating apparatus is required so that the operation (process) can be completed. In such a case, depending on the arrangement of a plurality of ink jet heads, adverse effects due to the arrangement, for example, variations in the coating amount due to uneven ink discharge amounts, and resultant color unevenness may occur.

  Patent Document 2 discloses a proposal for avoiding such adverse effects, and discloses that the occurrence of color unevenness can be suppressed by introducing a coating apparatus and a coating method. However, in the conventional color filter manufacturing apparatus by applying a liquid in which a plurality of inkjet heads are arranged in Patent Document 2, inkjet nozzles having a low discharge amount at both ends of the inkjet head are continuous as they are. Partially ejected / applied sections by inkjet nozzles with low application amount are continuous in the moving direction in the application sections with small amount of coloring material by ejection / application of the same inkjet nozzle, and color transmission by the corresponding coloring material Defects in color can occur linearly. If the inkjet heads are arranged and arranged in a direction perpendicular to the moving direction so as not to use the part with a low discharge amount, a large waste is generated in the arrangement space of the inkjet head, leading to an increase in the size of the apparatus. Also, it is uneconomical not to use the nozzles at both ends of all ink jet heads.

  Under these circumstances, the present inventors are working on the development of a coating method / apparatus that is applied to the coating by the current inkjet head, and as described in Patent Document 2 in the conventional inkjet head, one unit of the inkjet head is described. It was confirmed that there was a variation in the amount of colorant discharged from each inkjet nozzle of the inkjet nozzle row formed inside, and the amount of discharge from a very limited nozzle near both ends was small.

  And even if an inkjet nozzle with a small discharge amount of the coloring material that inevitably appears on the inkjet nozzle at the end of the inkjet head as in Patent Document 2, the chromaticity tolerance required for the color filter is used. It is an object of the present invention to realize a coating method and a coating apparatus that realizes within 3% by converting the color material to an allowable value of the coating amount of each color filter substrate to each pixel.

For this reason, in this invention, the said inkjet head and the said holding | maintenance stage are made relatively by the holding | maintenance stage which hold | maintains a coating target object, and the some inkjet head which has several inkjet nozzles which supply a coating material to the said coating target object. And a control means for controlling the ink jet head so as to select an ink jet nozzle for supplying a coating material to the application object.
The plurality of inkjet nozzles of the inkjet head are divided into a plurality (n) groups (blocks) in the longitudinal direction of the array, and the plurality of inkjet heads are divided into one division unit of the divided inkjet nozzles. A structure in which the position is shifted in the longitudinal direction of the arrangement of the inkjet nozzles, and the coating material is supplied to the coating object by regularly arranging at least the divided number (n) +1 or more in the longitudinal direction of the inkjet head. It was.

  Further, the control means selects an ink jet nozzle so as to make the supply amount of the coating material constant, and among the arrayed parallel ink jet heads, a portion outside the arrangement of the division number (n) th ink jet heads The inkjet head is controlled to stop the operation of the inkjet nozzle.

  Further, the control means selects an inkjet nozzle so that the supply amount of the coating material is within an allowable error range, and is outside the array of the divided number (n) -th inkjet head among the arrayed parallel inkjet heads. The inkjet head is controlled so as to stop the operation of the inkjet nozzle in this part.

  Further, an inkjet head group having a plurality of the inkjet heads, nozzle control means for changing the amount per ejection ejected from the inkjet nozzles in the inkjet head, and ejection from each inkjet nozzle in the inkjet head The apparatus further includes upper control means for controlling the nozzle control means so that the total amount per discharge is approximated to a predetermined amount for each inkjet head.

  And it updates to the measurement means which measures the quantity of the coating material supplied to the said application | coating target object from each inkjet nozzle by one operation | movement, the holding means which hold | maintains the measured quantity for each inkjet nozzle, and a holding means. A control unit that controls the inkjet head so as to select an inkjet nozzle for supplying a coating material to the coating object with reference to the stored data is provided.

With the configuration according to claim 1 as described above, a necessary number of inkjet heads having the number of inkjet nozzles corresponding to the coating amount per unit area are prepared, and the pitch density of the array required for the inkjet nozzle is set. The physical constraints to be realized, that is, the necessity to configure an inkjet nozzle that discharges a stable coating material as a reliable and durable device, should be less than the density to eliminate that constraint In addition, the inkjet nozzles in the inkjet head are divided into a plurality of groups (blocks) by determining the number of divisions (n), and the number of rows of inkjet heads arranged in parallel equal to or greater than the number of divisions (n) +1. In each division unit of the divided inkjet nozzles, the rows of the adjacent nozzles in the longitudinal direction of the arrangement of the inkjet nozzles Click by shifting the position of the jet head is regularly contiguous sequence, by operating as a control to coating apparatus the discharge of the coating material jet nozzle is selected operations of the inkjet head of each column arranged in the coating direction,
Among the plurality of inkjet nozzles arranged in the inkjet head, the difference between the ejection speeds of several nozzles at the both ends and other inkjet nozzles is about 10 to 15%. As a result, the ejection amount from the inkjet nozzles is 8%. Even if the number is small, select an inkjet nozzle to be ejected, perform ejection control with the number of ejections corresponding to the amount of coating material required for the application area, and individual areas in each part of the predetermined application area of the substrate to be applied For example, in a color filter incorporated in a liquid crystal display device, which is a typical application example, as a result, RGB transmission colors of a color filter produced by a conventional method can be accommodated. Can be kept within 3 thousandths of the allowable value of the chromaticity of the ink. Insufficient amount of coating in the area where the jet nozzles are unevenly distributed, and “white spots” with poor color riding are not concentrated, and chromaticity after coating is the same as that of conventional color filters over the entire area of the substrate ( Quality as a color filter) can be realized.

  In other words, high-quality color filters do not require manufacturing indirect members such as expensive masking members, and there is little loss of members due to peeling and removal of colored materials coated in the previous process by conventional coating methods. A coating apparatus capable of producing a color filter at a cost can be provided.

  Further, the arrangement of the inkjet head is divided into a plurality of inkjet nozzles in the inkjet head, and the divided blocks are changed to an arrangement in which the blocks are shifted one block at a time. The size of the device in the scanning direction of the coating portion equipped with the inkjet heads for three colors of RGB can be reduced, which can contribute to the realization of a small-sized coating device.

  According to the second aspect of the present invention, in addition to controlling the ink jet nozzle that averages the amount of application to the substrate while keeping the supply of the coating material constant, the ink jet heads in the number of divisions (n) rows from both ends By stopping the discharge from the ink jet nozzles of the ink jet head located outside the ink jet nozzles, the discharge of the invalid coating material is eliminated, and a preferable coating device can be obtained from the viewpoint of resource saving.

  According to the third aspect, in addition to the optimization of the discharge amount, the selection of the ink jet nozzle in the ink jet head is controlled so as to optimize the supply of the coating material so that the supply amount falls within the allowable error range. By stopping the discharge of the invalid coating material from the inkjet nozzle of the inkjet head located outside the coating range, the resource saving effect is further enhanced.

  According to the fourth aspect of the present invention, the nozzle control means for changing the ejection amount from each inkjet nozzle for each inkjet head and the ejection amount for each ejection from each inkjet nozzle for each inkjet head are controlled to a predetermined amount. By using the upper control means to distribute the variation in one discharge amount over the entire application area of the substrate, not only the chromaticity difference of only the minute area is reduced, but also the chromaticity difference of the entire area of the substrate. Can be within a predetermined range.

  According to the fifth aspect, the amount of the coating material supplied from each inkjet nozzle in one ejection operation is measured, and the measured ejection amount data is updated, stored and retained, and the inkjet nozzle is selected by referring to the data. In addition, by controlling the discharge by increasing / decreasing / finely adjusting the discharge amount, it is possible to continuously keep the application amount uniform while correcting the change in the discharge amount during operation.

  Hereinafter, embodiments of a coating apparatus of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a color filter manufacturing apparatus is described as an example.

  FIG. 1 is a perspective view showing an embodiment of a color filter manufacturing apparatus. The color filter manufacturing apparatus of this example supports a suction table 3, a coating gantry 4, a camera gantry 6 and the like on a machine base 1. The suction table 3 as a holding stage holds the glass substrate 2 by suction. In order to achieve the positioning of the glass substrate 2, the suction table 3 is rotationally driven by a driving mechanism and a guide mechanism (not shown) and in the Y direction. Driven. The application gantry 4 holds the inkjet head bar 5 and is driven in the X direction by a drive mechanism and a guide mechanism (not shown) in order to apply a coloring material to the glass substrate 2. Moreover, in order to adjust the relative position with respect to the glass substrate 2, it drives to a Z direction and a Y direction by the drive mechanism and guide mechanism which are not shown in figure.

  The camera gantry 6 holds alignment cameras 7 and 8 for alignment of the glass substrate 2 and holds a scan camera 9 that is a measuring means for detecting the coloring material supplied to the glass substrate 2. Is more preferable, and is driven in the X direction by a drive mechanism and a guide mechanism (not shown) for alignment and color material detection. Further, the alignment cameras 7 and 8 and the scan camera 9 are driven in the Y direction by a drive mechanism and a guide mechanism (not shown). The alignment cameras 7 and 8 detect marks (not shown) on the glass substrate 2, rotate the suction table 3 based on the mark detection results by the alignment cameras 7 and 8, and / or move in the Y direction. By doing so, alignment of the glass substrate 2 can be achieved. The alignment error in the X direction can be achieved by adjusting the ejection timing. Here, X and Y represent directions orthogonal to each other set to define a plane parallel to the upper surface of the glass substrate 2 held and sucked by the suction table 3, and Z is a plane defined by X and Y. The direction orthogonal to

  In addition, by adopting a two-dimensional CCD camera instead of the scan camera 9, it is possible to measure the height of the landing mark, and depending on the shape of the droplet at the time of landing obtained in advance for the coloring material to be used, The volume of the droplet can be calculated by measuring the height, and the discharge amount of the coloring material from each inkjet nozzle can be known with higher accuracy.

  The inkjet head bar 5 is formed by aligning a plurality of inkjet heads 51, and each inkjet head 51 is formed by aligning a plurality of inkjet nozzles 52 therein. The arrangement of the plurality of inkjet heads 51 is such that all the inkjet nozzles 52 arranged in one inkjet head 51 are divided into a plurality of blocks, and the arrangement of adjacent inkjet heads 51 is shifted one block at a time. The interval in the direction and the interval in the Y direction are set to be predetermined intervals.

  FIG. 2 a) is a schematic diagram showing an example of the configuration of the inkjet head bar 5. In this example, one inkjet head 51 is divided into four blocks, and a case is shown in which the application region is covered by five rows. This continuous arrangement of the inkjet heads 51 realizes the effective coating width of one inkjet head 51 by installing in parallel as many as necessary in accordance with the coating width of a coating object such as a glass substrate. The inkjet head bar 5 equipped with the inkjet head 51 group is reciprocated in the direction of the arrow X in the drawing to discharge and apply the coloring material from the inkjet nozzle 52.

  The actual discharge position of the coloring material from the ink jet nozzle 52 is the application region continuously with the array numbers (1) to (4) of the droplets surrounded by circles, which are discharged to the application region as shown in FIG. To fill. Which block of the ink-jet head 51 is responsible is controlled by discharging the ink-jet nozzle 52 based on five combinations of blocks as shown in the table of FIG. That is, the inkjet nozzle 52 of the inkjet 51 in the A row is at the position (1), the inkjet nozzle 52 of the inkjet 51 in the B row is at the position (2), the inkjet nozzle 52 of the inkjet 51 in the C row is at the position (3), The inkjet nozzle 52 of the D row inkjet 51 is located at the position (4), and the inkjet nozzle 52 of the E row inkjet 51 is located at the position (1) to (4) in each block by ejection control by a control means (not shown). Discharge and apply coloring material.

  In this example, the arrangement of the inkjet nozzles 52 formed in alignment in the inkjet head 51 of the fifth E row is shifted by one pitch for each divided block, and it is necessary to consider the production of the inkjet head 51. .

  On the other hand, the arrangement of the ejection positions of the inkjet nozzles 52 is not limited to the example shown in FIG. 2, but the (2), (3), or (4) It is also possible to form landing marks of coloring materials at positions), and a combination is set regardless of the order and arrangement of the respective inkjet heads 51, and coloring is performed at a continuously set application pitch by the arranged inkjet heads 51. It is obvious that a color filter that meets the specifications can be produced by discharging the material.

  In addition, the hatched blocks in the first to third rows are located outside the frame of the application area of the application target and need to prohibit the discharge of the coloring material, and are colored by appropriate control by the control means. Wasteful discharge of material can be avoided.

  FIG. 3 a) is a schematic view of another example showing the configuration of the inkjet head bar 5. In this example, the case where the inkjet head 51 divided into four blocks is configured to cover the application region in eight rows is shown. It is the same that the effective coating width of one inkjet head 51 is provided in parallel by the necessary number of the same in accordance with the coating width of the coating object such as a glass substrate by the continuous arrangement of the inkjet head 51 configuration. .

  As shown in FIG. 3B), the discharge position of the coloring material from the ink jet nozzle 52 is continuously filled with the array (1) to (4) of droplets discharged to the application area as in the above example. To go. Which block of the inkjet head 51 is responsible for ejection is based on eight combinations of blocks as shown in the table of FIG. That is, the inkjet nozzles 52 of the inkjet 51 in the A row and the E row are in the position (1), the inkjet nozzles 52 in the inkjet 51 in the B row and the F row are the inkjets in the ink jet 51 in the C row and the G row. The nozzle 52 ejects the coloring material to the position (3), and the inkjet nozzle 52 of the inkjet 51 in the D row and the H row ejects the coloring material to the position (4).

  Compared with the example of FIG. 2, the discharge sequence of the coloring material from the actual inkjet nozzle 52, that is, the discharge of each droplet, the inkjet nozzles 52 in the divided blocks of the inkjet heads 51 in the fifth to eighth rows. This arrangement is regular, and the arrangement of the ink jet nozzles 52 of the ink jet head 51 becomes a regular arrangement, and the production of the ink jet head 51 is not required to be taken into consideration in the special arrangement.

  As in the example of FIG. 2, the arrangement of the ejection positions of the inkjet nozzles 52 is not limited to (2 in the first row of inkjet heads 51 (A row in the example of FIG. 3)). ), (3) or (4), it is also possible to form a landing mark of the coloring material, and the ink jet heads are arranged in a combination irrespective of the order and arrangement of the rows of the ink jet heads 51. It is obvious that a color filter conforming to the specifications can be obtained by discharging the coloring material at a coating pitch set continuously by 51.

  Next, a mechanism for uniformly coating the coating area over the entire surface by the coating apparatus of the present invention will be described.

  As an embodiment of the present invention, a description will be given by applying and filling an appropriate amount of a coloring material into a pixel having a width of 180 μm and a length of 530 μm that can be used for a typical high-definition television receiver of 37 inch size.

  In this case, the arrangement density of the inkjet nozzles 52 is 1440 dpi, and the arrangement in the direction perpendicular to the coating scanning direction is the same as the arrangement of the landing marks shown in FIGS. 2b) and 3b). Position shift = application interval (pitch) is a pitch of 17.64 μm, the amount of material discharged from one inkjet nozzle 52 is 30 pl (picoliter), and a total of 1500 pl with 25 nozzles, that is, 50 to 50 from inkjet nozzles 52 This is realized by ejecting and applying the ink jet material.

  On the other hand, the present inventors now have an allowable value of chromaticity as a color filter of 3/1000 in the entire effective screen area, and an allowable value of variation in the coating amount of the coloring material that realizes the allowable value of chromaticity. The coating apparatus according to the present invention satisfying the specifications will be described with reference to a target specification of the color filter.

  Since the average diameter of droplets that have landed on the substrate is 40 μm on the basis of the measurement of the landing marks in advance of the ink jet nozzle 52, the adjacent pixel passes over the matrix-shaped light-shielding portion on which the coloring material is formed on the substrate. In order to avoid mixing in, the area outside the position of 20 μm, which is the radius value of the landing mark of the coloring material applied from the inkjet nozzle 52 to the substrate from the edge of both ends of 530 μm in length, The application is performed by discharging and applying a coloring material to the center of each pixel formed on the substrate by discharging from the inkjet nozzle 52 located between 490 μm. Therefore, from the arrangement and arrangement density of the 1440 dpi inkjet nozzles 52, the number of inkjet nozzles 52 that can discharge and apply the coloring material to one pixel area is 27.

  On the other hand, under the control of the control means, for each pixel of the entire substrate including the effective area of the color filter, a discharge command is sent to the inkjet nozzle 52 selected from the corresponding 27 inkjet nozzles 52 to discharge and apply the coloring material. Thus, the discharge control is performed so that the coloring material of 1500 pl per pixel having a size of 530 × 180 μm falls within the allowable amount of the coloring material within 3% in total. The discharge amount of the coloring material from each ink jet nozzle 52 is measured in advance by a test shot of each of the equipped ink jet heads 51 or by a test pattern inspection described later. Based on numerical values stored as data such as the diameter and volume of landing marks in test pattern application, or data obtained by measuring the ejection amount of the inkjet nozzles 52 of the respective inkjet heads 51 in advance, the numerical values and data are stored in the storage element. Selection of the inkjet nozzle 52 and control of the number of ejections are performed using numerical values stored as a data table, and the chromaticity specifications in the effective area of the color filter are satisfied.

  FIG. 4 is a graph showing the ejection speed of the inkjet nozzles 52 arranged in the width direction of the inkjet head 51 used in the present invention, and shows that the ejection speed of several nozzles at both ends is about 10 to 15% lower. It is. By confirming the correlation between the ejection speed of the inkjet head 51 shown in this graph and the ejection amount of the coloring material from the inkjet head 51, it is confirmed that the decrease in the ejection amount of the coloring material due to the lower ejection speed is a maximum of 8%. It was.

  In addition, the arrangement pitch P of the 1440 dpi inkjet nozzles 52 is 17.64 μm, but this number is one inkjet head due to restrictions on the dimensions and mechanisms of the components constituting the inkjet nozzles based on the current basic inkjet system. It may be difficult to realize, and is configured to be realized by a divided number of four-row basic inkjet heads 51. The arrangement interval of inkjet nozzles 52 formed in one inkjet head 51 is 70.56 μm at 360 dpi. It is said.

  On the other hand, since the discharge speed of the six inkjet nozzles 52 located at both ends of the 256 inkjet nozzles 52 formed on the inkjet head 51 is low and the discharge amount of the coloring material is 8% lower, the total discharge amount required per pixel From the calculation of 1500 pl, the coloring material can be applied to the pixels by 50 ejections from the inkjet nozzles 52, and when the inkjet nozzles 52 at both ends of the inkjet head 51 with a small ejection amount are applied to the applied pixels, the total ejection amount The number of discharges of the coloring material from the inkjet nozzle 52 with a small discharge amount satisfying the allowable value of 3% is within 18 shots.

  On the other hand, the worst case in which the total discharge amount from the inkjet nozzle 52 located on the pixel is small is when the inkjet nozzle 52 at the end of the inkjet head 51 is positioned in the pixel as described above. In this case, it is calculated from the length of the permissible discharge area of the coloring material and the arrangement pitch of the inkjet nozzles 52. With the value 6.95 (= 490 / 70.6), all the six inkjet nozzles 52 located at both ends of the inkjet head enter one pixel.

  From the above, it is possible to discharge and apply three color materials from the inkjet nozzle 52 with a low discharge amount arranged at the end of the inkjet head 51 under the above 18 conditions. Each of the 25 ink-jet nozzles 52 requires only two ejections and application. That is, the present invention is for a high-definition television receiver of 37 inches or more by dividing the inkjet head 51 into a plurality (n) and forming a configuration of the inkjet heads 51 having a number of divisions (n) +1 or more. In addition, it is possible to manufacture a high-definition and high-quality color filter at low cost by applying a coloring material by an inkjet method.

  In this case, since the discharge / application of the coloring material from the inkjet nozzle 52 with a small discharge amount can be accommodated in 12 shots at the maximum with respect to the allowable limit number 18, the margin (safety factor) is 1.5.

実際には、この許容吐出液滴数によって、１つのインクジェットノズル５２からの吐出数を制限し、両端に位置する吐出料の低いインクジェットノズル５２とそれ以外の他のインクジェットノズル５２の吐出数の和の数で吐出・塗布制御してカラーフィルターの仕様を満足する所要の着色材料の塗布を行う。 In addition, when a color filter with a small pixel size is required, regarding the total number of ejections allowed from the inkjet nozzle 52 with a low ejection amount, the coating amount variation of the coloring material that realizes the allowable value of chromaticity is varied. The total number of droplets J to be ejected from the inkjet nozzles 52 is lower than the other inkjet nozzles 52 near the end by an amount V (percentage value) relative to the permissible value M (percentage value). Production of a color filter that satisfies the required specifications by controlling the selection of the inkjet nozzle 52 that satisfies the following formula 1 and the number S of ejected droplets from the selected inkjet nozzle in relation to the number of droplets S Is possible.

Actually, the number of ejections from one inkjet nozzle 52 is limited by the allowable number of ejected droplets, and the sum of the ejection numbers of the inkjet nozzles 52 having low ejection charges located at both ends and the other inkjet nozzles 52 other than that. The required coloring material that satisfies the specifications of the color filter is applied by controlling the discharge and application by the number of the above.

  The ink-jet head bar 5 shown in FIGS. 2 and 3 is for applying any of red (R), green (G), and blue (B) coloring materials. An ink jet head bar for applying other coloring materials is also provided.

  FIG. 5 is a schematic block diagram showing a configuration for controlling the ink jet head bar 5 in order to select the ink jet nozzle 52. In this configuration, the scanning camera 9 that is a measurement unit and imaging data (for example, imaging data corresponding to a state in which all the inkjet nozzles 52 are operated) input by the scanning camera 9 are used as input, and coloring is discharged from each inkjet nozzle 52. Image processing device 11 that calculates X, Y coordinates of material landing marks and diameter, area, or volume of coloring material, and stores necessary data such as calculated diameter, area, or volume, and a discharge data table In order to select the inkjet nozzle 52 to be operated in consideration of the data such as the memory 12, which is the holding means to hold, the data such as the diameter, area, or volume held in the memory 12 and the data in the ejection data table, Peripherals that handle I / O interfaces that exchange data and control signals with other peripheral devices And a control unit 13 which is a control means for driving and stopping the ink jet head bar 5, including road and calculation circuit.

  Therefore, by providing this measuring means and holding means, the area, diameter, or volume held in the memory 12 can be updated every time the application operation by the ink jet head bar 5 is performed. In performing the next coating operation, it is possible to control the inkjet head bar 5 such as selecting an inkjet nozzle 52 to be operated in consideration of the latest area, diameter, or volume and issuing a discharge command.

  Note that the control device 13 receives data from the respective ink-jet nozzles 52 held in the memory 12 such as data such as the volume of the landing marks measured by discharging the coloring material from the respective ink-jet nozzles 52 and data in the discharge data table. According to the discharge amount data, the supply amount of the coloring material is determined by selecting the inkjet nozzle 52 to be discharged and the number of discharges of the droplets of the coloring material so that the supply amount of the coloring material to be landed on each pixel region 23 is constant. It is preferable to control the corresponding ink-jet head 51 and ink-jet head bar 5 in order to average over the entire coating area, and as a result, the chromaticity requirement as a color filter is satisfied.

  Alternatively, the discharge amount from each inkjet nozzle 52 held in the memory 12 such as data such as the volume obtained by measuring the landing mark from which the coloring material was discharged from each inkjet nozzle 52 or the data in the discharge data table. In order to optimize the supply amount of the coloring material to be landed on each pixel area 23, the selection of the corresponding inkjet nozzle 52 to be ejected and the ejection command of the number of droplets from the inkjet nozzle 52, etc. In order to keep the supply amount of the coloring material within the allowable error range, it is preferable to control the corresponding inkjet head 51 and inkjet head bar 5 so that the coating amount of the entire coating region is within the allowable range of chromaticity. As a result, the color filter It satisfies the chromaticity requirement.

  In the former case, the coating quality of the coloring material can be remarkably improved. Conversely, in the latter case, it is possible to achieve both the maintenance of the coating quality of the coloring material and the increase in the number of usable inkjet nozzles 52.

  Next, the operation of the color filter manufacturing apparatus having the above configuration will be described.

  FIG. 6 is a timing chart for explaining the processing of the coloring material application and the test pattern inspection.

  FIG. 7 shows a state in which six color filters CF are formed on the glass substrate 2, and a test pattern TP for each coloring material is formed in a surplus area outside the color filter CF. .

  FIG. 8 is an enlarged view of the test pattern TP forming portion, and shows the test pattern TP formed by the ink jet nozzles 52 for three colors as being inspected by the camera gantry 6. This test pattern TP is the shape of the landing mark of the coloring material discharged from each inkjet nozzle 52 on the glass substrate.

  The coloring materials are separated from each other and land in a zigzag pattern. By doing so, the test pattern TP can be inspected by the scan camera 9 of the camera gantry 6, and the diameter, area, or volume of the ink landing mark is measured as necessary together with the X and Y coordinates of the ink landing mark. . Then, when an improper ink landing mark shape or ejection failure such as non-landing is detected, necessary countermeasures (color filter production interruption, ink jet head 51 replacement, etc.) are immediately taken as described later. It is possible to minimize the production of defective products.

  Since the landing marks are staggered, the spacing between the coloring materials is large, and there is room for image processing at the time of measurement, so that the inspection accuracy can be increased.

  FIG. 9 is a flowchart for explaining an example of the test pattern inspection process. Note that the timing chart of FIG. 6 does not show processing based on the flowchart of FIG.

  The test pattern inspection process will be described with reference to FIG.

  In step SP1, after the test glass substrate is carried into the suction table 3 by a carry-in robot (not shown) or the like, in step SP2, rough positioning of the test glass substrate is achieved by external shape regulating means (not shown). In step SP3, the test glass substrate is sucked by the suction table 3. Thereafter, in step SP4, the camera gantry 6 is moved forward. In step SP5, the alignment mark of the test glass substrate is detected, and the Y direction is detected. Positioning and alignment in the direction of θ (rotation around the Z axis) are achieved, and in step SP6, the camera gantry 6 is moved backward.

  Next, in step SP7, the coating gantry 4 is moved forward / backward, and the X coordinate value of the coating gantry 4 is output. In step SP8, the coating gantry 4 reaches the test pattern coating position based on the X coordinate value. If the test pattern application position has not been reached, the process of step SP7 is performed again.

  If it is determined in step SP8 that the application gantry 4 has reached the test pattern application position, the movement of the application gantry 4 is stopped in step SP9, and the liquid of the coloring material is discharged from all the inkjet nozzles 52 of the inkjet head bar 5. In step SP10, the application gantry 4 is moved back and stopped at the standby position.

Next, a flow for imaging and inspecting the test pattern (TP) is entered. Here, in step SP11, the camera gantry 6 is moved forward, and in step SP12, it is determined whether or not the camera gantry 6 has reached the test pattern inspection position. judge.
If the test pattern inspection position has not been reached, step SP11 is performed again.

  If it is determined in step SP12 that the camera gantry 6 has reached the test pattern inspection position, the camera gantry 6 is stopped in step SP13, and the scan camera 9 is moved in the Y direction in step SP14 to perform the test. The test pattern is imaged to the end while detecting the pattern, and then the scan camera 9 is returned to the Y direction.

  After the processing of step SP14, in step SP15, the camera gantry 6 is moved backward and stopped at the standby position to finish the “test pattern (TP) imaging flow”, and in step SP16, the suction of the glass substrate 2 is released, Discharge and end a series of processing.

  In parallel with the processing in step SP15 and step SP16, in step SP17, the detection signal from the scan camera 9 is image-processed, and the X, Y coordinates and the diameter, area and / or volume of the landing mark of the coloring material are measured. In step SP18, the coordinate position information detected from the coloring material landing mark of the test pattern is input, and in step SP19, the position information (coordinate values) of all the pixels on the glass substrate 2 is input in step SP20. In step SP21, the data table is calculated / created. In step SP22, the calculation result is stored in the ejection data table, and a series of processing such as image processing and measurement / calculation is completed.

  Next, an example of the color filter manufacturing process will be described with reference to the color filter manufacturing flowchart shown in FIG.

  In order to realize efficient operation of the apparatus, the application gantry can be reciprocated once with respect to the required application area so that the application operation is completed with a single stroke from the predetermined start position of the application gantry. It is desirable to set the width of the effective inkjet head nozzle.

  In step SP1, after the glass substrate 2 is carried into the suction table 3 by a carrying robot (not shown) or the like, in step SP2, the rough positioning of the glass substrate 2 is achieved by outer shape regulating means (not shown). In step SP3, the glass substrate 2 is sucked by the suction table 3, and then in step SP4, the camera gantry 6 is moved forward. In step SP5, the alignment mark of the glass substrate 2 is detected, and the Y direction, θ ( The alignment of the glass substrate 2 is achieved by positioning in the theta direction, and the camera gantry 6 is moved back in step SP6.

  In step SP7, it is determined whether the application is the forward pass application or the return pass application.

  If it is determined in step SP7 that the forward application is performed, in step SP8, the application gantry 4 is moved forward, and the X coordinate value of the application gantry 4 is output. If it is determined, the coating gantry 4 is moved back in step SP9.

  When the process at step SP8 or the process at step SP9 is performed, it is determined at step SP10 whether or not the application has been performed up to the end of the application region.

  If it is determined in step SP10 that the application has not been performed until the end of the application region, in step SP11, the X coordinate output signal of the application gantry 4 and the discharge data table are compared, and in step SP12, the X coordinate is It is determined whether or not the discharge data matches. If the X coordinate and the discharge data match, in step SP13, a droplet of the coloring material is discharged by the inkjet nozzle 52. The process returns to step SP7.

  The color material droplet discharge operation in step SP13 will be described.

  As described with reference to FIG. 2, among the inkjet heads 51 arranged at both ends of the plurality of rows of inkjet heads 51 arranged on the inkjet bar 5, the number of blocks divided from the outermost side (n). The hatched blocks in the first row to the third row, which are blocks outside the inkjet head 51 in the second row, are located outside the frame of the application region of the application target and need to inhibit the discharge of the coloring material. With appropriate control, the ink jet nozzle 52 located in this portion is stopped from being ejected by the control device 13 and can avoid wasteful ejection of the coloring material.

  For the other ink-jet nozzles 52, the control device 13 retains the data such as the volume measured for the landing marks discharged from the respective ink-jet nozzles 52 and the data stored in the memory 12 such as the data in the discharge data table. Depending on the discharge amount data from the inkjet nozzles 52, the selection of the inkjet nozzles 52 to be discharged and the number of droplets of the coloring material to be discharged so as to make the supply amount of the coloring material to be landed on each pixel region 23 constant. In order to average the supply amount of the coloring material over the entire coating region, the corresponding inkjet head 51 and inkjet head bar 5 are controlled, and as a result, the ejection operation is controlled so as to satisfy the chromaticity requirements as a color filter.

  Alternatively, each inkjet nozzle held in the memory 12 such as data such as a volume obtained by measuring the landing mark from which the coloring material is ejected from each inkjet nozzle 52 by the control device 13 or data in the ejection data table. With the aim of optimizing the supply amount of the coloring material to be landed on each pixel area 23 based on the ejection amount data from 52, the selection of the corresponding inkjet nozzle 52 to be ejected and the number of droplets from that inkjet nozzle 52 It is preferable to control the corresponding inkjet head 51 and inkjet head bar 5 so that the coating amount of the entire coating region is within the allowable range of chromaticity so that the supply amount of the coloring material is within the allowable error range by the discharge command of As a result, the colorant to meet the demands of chromaticity as a color filter It controls the ejection operation of the droplets.

  Subsequently, in step SP10, it is determined whether application has been performed to the end based on the X coordinate value.

  If it is determined in step SP12 that the X coordinate does not match the ejection data, or if the process in step SP13 is performed, the process returns to step SP7 to determine the return path.

  If it is determined in step SP10 that the application has been performed up to the end, it is determined in step SP14 whether or not the application is the first time in the forward path. If the application is the first time in the forward path, the application is performed in step SP15. The gantry 4 is moved to the test pattern application position, and a test pattern is formed by the inkjet head bar 5 in step SP16. Specifically, the ink jet head bar 5 is moved in the X direction, the ink jet nozzles 52 that perform the ejection operation are selected from the ink jet nozzles 52 of all the ink jet heads 51, and the coloring material is ejected and applied, thereby staggering. A test pattern is formed.

  If it is determined in step SP14 that it is not the first application of the outward path, or if the process of step SP16 is performed, whether or not a predetermined number of times of application for applying the entire application region has been performed in step SP17. Determine.

If it is determined in step SP17 that the number of times of application has not reached the predetermined number, in step SP18, the application gantry 4 is stopped, the inkjet head bar 5 is moved in the Y direction, and the determination in step SP7 is performed again.
The movement distance in the Y direction is determined by the effective application width of the inkjet head 52 according to the specifications of the inkjet head bar 5, and the application area is completed evenly by scanning the entire width of the application area evenly.

  If it is determined in step SP17 that the predetermined number of times of application has been performed, the application process is terminated in step SP19, and in step SP20, all obtained in the “TP imaging flow” described with reference to FIG. From the image of the landing mark of the coloring material discharged from the inkjet nozzle 52, it is determined whether or not the ejection failure of each inkjet nozzle 52 exceeds the number allowed in the range of the target pixel unit in the application region.

  As a result of the determination, if the occurrence density of the ejection failure of the inkjet head 52 exceeding the allowable range is confirmed, the process proceeds to the cleaning flow, and if within the allowable range, the suction of the glass substrate 2 by the suction table 3 is performed in step SP21. Is released, and the glass substrate 2 is unloaded by an unillustrated unloading robot or the like, and the series of processes is finished as it is.

  On the other hand, if it is determined that the return path is determined in step 7, the application completion process in step SP19 is performed through the “TP imaging flow” described in FIG. 9 in parallel with the return path movement of the application gantry in step SP9. Move.

  In the above-described example, the embodiment in which the application gantry 4 is moved in the X direction with respect to the suction table 2 has been described. However, the application gantry 4 may be fixed and the suction table 3 may be moved. It is.

In the above embodiment, the ink jet nozzle 52 is selected so that the total application amount for the pixels on the color filter is made closer to the required application amount, and per discharge discharged from the ink jet nozzle 52. There is no change in the amount of.
However, nozzle control means (not shown) for providing an inkjet head bar 5 having a plurality of inkjet heads 51 in the coating gantry 4 and changing the amount per ejection discharged from the inkjet nozzles 52 in the inkjet head 51; The upper control means (not shown) controls the control means of the ink jet nozzle 52 so that the total amount per discharge discharged from each ink jet nozzle 52 in the ink jet head 51 approaches a predetermined amount for each ink jet head 51. It is preferable to further include

  For example, the nozzle control means changes the discharge amount per discharge by changing the drive voltage applied to the inkjet nozzle 52.

  The upper control means inputs, for example, the discharge amount non-uniformity data obtained by the scan camera 9 and the like, and the total discharge amount per discharge of each ink jet nozzle 52 in the ink jet head 51 (of the ink jet head 51). The operation command to the control means of each inkjet nozzle 52 is performed so that the discharge amount per discharge) approaches the target discharge amount.

In this case, the coating amount can be adjusted for each inkjet head 51. More specifically, even when a specific inkjet head 51 is affected by the viscosity of the ink and the discharge amount becomes low, an operation command for each nozzle control unit is set by the host control unit, and the nozzle control unit sets the inkjet nozzle. By changing the drive voltage applied to the nozzle 52, it is possible to suppress variations in the discharge amount with the other inkjet heads 51.
The inkjet nozzles 52 in the inkjet head 51 naturally have minute variations in the inner inkjet nozzles 52 except for the number of inkjet nozzles 52 at both ends of the inkjet head 51 where stable ejection can be expected. Can be dealt with by the above-described embodiment.

  As described above, an application example for manufacturing a color filter used in a liquid crystal display device or the like has been described as a typical application example of a coating apparatus. However, this apparatus is a device for applying a coloring material or a coating material to other planar members. Of course, it can be applied without any trouble.

Perspective perspective view of an embodiment of a coating apparatus Example of nozzle arrangement of inkjet head bar Other examples of inkjet head bar nozzle arrangement Graph showing discharge speed for each inkjet nozzle Block diagram of the controller that selects and discharges inkjet nozzles Timing chart of coating operation and coating pattern inspection process The figure of the state which applied six color filters and a test pattern on the substrate Partial enlarged view of the test pattern formation section Sample flow chart of test pattern inspection process Example of color filter manufacturing process flowchart Schematic of nozzle arrangement example of inkjet head bar

Explanation of symbols

2 Glass substrate 3 Suction table 5 Inkjet head bar 9 Scan camera 11 Image processing device 12 Memory 13 Control device 51 Inkjet head 52 Inkjet nozzle

Claims (5)

The inkjet head and the holding stage are moved relative to each other by a holding stage for holding the application object and a plurality of inkjet heads having a plurality of inkjet nozzles for supplying a coating material to the application object. A coating device comprising a control means for controlling the inkjet head to select an inkjet nozzle for supplying a coating material to an object,
The plurality of inkjet nozzles of the inkjet head are divided into a plurality of (n) groups in the longitudinal direction of the array, and the plurality of inkjet heads are divided into one division unit of the divided inkjet nozzles. In the longitudinal direction of the inkjet head, the coating material is supplied to the coating object by regularly arranging in at least the divided number (n) +1 or more in the longitudinal direction of the inkjet head. Application device to do.   The control means selects an ink jet nozzle to make the supply amount of the coating material constant, and out of the arrayed parallel ink jet heads, the ink jet of the portion outside the array of the (n) -th divided ink jet heads The coating apparatus according to claim 1, wherein the inkjet head is controlled to stop the operation of the nozzle.   The control means selects an inkjet nozzle so that the supply amount of the coating material is within an allowable error range, and among the arrayed parallel inkjet heads, a portion outside the array from the division number (n) th inkjet head The coating apparatus according to claim 1, wherein the inkjet head is controlled to stop the operation of the inkjet nozzle.   An inkjet head group having a plurality of inkjet heads, nozzle control means for changing the amount per ejection ejected from the inkjet nozzles in the inkjet head, and ejection 1 ejected from each inkjet nozzle in the inkjet head The coating apparatus according to any one of claims 1 to 3, further comprising a higher-level control unit that controls the nozzle control unit so that a total amount per rotation approaches a predetermined amount for each inkjet head.   Measuring means for measuring the amount of the coating material supplied to the application object from each inkjet nozzle in one operation, holding means for holding the measured amount for each inkjet nozzle, and updating / saving in the holding means 5. The apparatus according to claim 1, further comprising: a control unit that controls the inkjet head so as to select an inkjet nozzle for supplying a coating material to the application target with reference to the held data. The coating device described

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