JP2005262744A - Inkjet head, method for regulating position of line-type inkjet nozzle, method for regulating position of inkjet nozzle unit and alignment layer forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet head whose nozzle pitch can be narrowed. <P>SOLUTION: In the inkjet head 1, "n" line-type inkjet nozzles 2 which are nozzles 4 for discharging a liquid material arranged in a single line, are juxtaposed in such a way that the position of the nozzle 4 is deviated by 1/n pitch of a nozzle pitch P1. Thus the inkjet head 1 is set in such a state that the nozzles 4 are arranged at a nozzle pitch equal to 1/n of one line-type inkjet nozzle 2. The discharge timing of the liquid material by the inkjet head 1 can be regulated for every line-type inkjet nozzle 2. Consequently, it is possible to simply regulate the dot pitch in fine coating or coarse coating. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an inkjet head.

  In recent years, when printing is performed with ink on a print medium such as paper, when forming an alignment film or applying UV ink on a substrate (transparent substrate) such as a liquid crystal display, or on a substrate of an organic EL display In the case of applying a color filter, a so-called ink jet method using an ink jet head has been widely adopted.

  For example, Japanese Patent No. 3073493 discloses an apparatus including a line-type inkjet nozzle in which nozzles are arranged in a row. Further, as shown in FIGS. 5 to 7, this patent also discloses that the arrangement of the line-type inkjet nozzles is devised to improve the processing speed of applying the liquid material (Patent Document 1).

Japanese Laid-Open Patent Publication No. 9-138410 discloses an inkjet head that forms a uniform film thickness, in which nozzles are arranged in a plurality of rows and columns in a predetermined area, and nozzles in arbitrary rows are arranged in adjacent rows. Inkjet nozzles are disclosed that are offset by a half pitch with respect to the nozzle array. The publication also discloses that a line-type inkjet nozzle in which nozzles for discharging a liquid material are arranged in series is applied while moving in a zigzag manner to form a uniform film thickness (Patent Document 2). .
Japanese Patent No. 3073493 (FIGS. 5 to 7) JP-A-9-138410 (FIGS. 1, 4, and 5)

  In order to finely apply the liquid material, it is necessary to narrow the nozzle pitch disposed in the inkjet head. However, there is a physical limit to narrowing the nozzle pitch. For this reason, there is a limit to narrowing the nozzle pitch in the area-type inkjet nozzle described in Patent Document 2. In addition, the method of coating while moving the line-type inkjet nozzle in a zigzag manner has a slow processing speed because the movement of the inkjet nozzle is complicated. Further, when the inkjet nozzle is moved in a complicated manner, the flight of the droplet is likely to be bent, and it becomes difficult to control the landing position of the droplet with high accuracy.

  An inkjet head according to an embodiment of the present invention includes n line-type inkjet nozzles in which nozzles for discharging a liquid material are arranged in a row, and the nozzle positions are shifted from each other by 1 / n pitch of the nozzle pitch in parallel. It is arranged.

  An ink jet head according to another aspect of the present invention includes n line type ink jet nozzles in which nozzles for discharging a liquid material are arranged in series by shifting the nozzle positions by 1 / n pitch of the nozzle pitch. The ink jet nozzle units arranged in parallel are arranged in series with staggered staggered positions in the direction in which the nozzles of the line type ink jet nozzle are arranged.

  The method for adjusting the position of the line-type inkjet nozzles arranged in parallel in the inkjet head according to one embodiment described above, for example, based on an image obtained by photographing each line-type inkjet nozzle arranged in parallel with a camera, The position may be adjusted to a predetermined position where the line-type inkjet nozzle is to be attached.

  In addition, the position adjustment method of the inkjet nozzle unit of the inkjet head according to another embodiment is, for example, aligned with the reference plane of the mounting shaft formed in a straight line as a reference plane serving as a reference for the inkjet nozzle unit mounting position, An ink jet nozzle unit may be attached.

  According to this ink jet head, n line type ink jet nozzles in which nozzles for discharging a liquid material are arranged in a row are arranged in parallel by shifting the nozzle positions by 1 / n pitch of the nozzle pitch. Therefore, the nozzle pitch can be made narrower than the physical limit that can make the nozzle pitch narrow for the entire inkjet head. In addition, since the line-type inkjet nozzles are combined, the dot pitch can be adjusted by adjusting the discharge timing of each line-type inkjet nozzle, and adjustment from fine coating to rough coating can be easily performed.

  Moreover, according to the position adjustment method of the line-type inkjet nozzle according to the present invention, the line-type inkjet nozzles are arranged at positions where the line-type inkjet nozzles should be attached based on images obtained by photographing the line-type inkjet nozzles arranged in parallel with the camera. Since the adjustment is performed, the position of the line-type inkjet nozzle can be adjusted with high accuracy.

  Further, according to the position adjustment method of the inkjet nozzle unit according to the present invention, the mounting shaft formed with the reference plane that is a reference for the mounting position of the inkjet nozzle unit is used, and each inkjet nozzle unit is placed on the reference plane of the mounting shaft. Align and install. The reference plane of the mounting shaft is one plane, and it is relatively easy to ensure the accuracy of the straightness and flatness. For this reason, the accuracy of the reference surface to which the ink jet nozzle unit is attached can be secured relatively easily, so that the ink jet nozzle unit can be accurately adjusted in position and attached.

  These ink jet heads are suitable as, for example, an ink jet head for an alignment film forming apparatus because the nozzle pitch can be narrowed and the dot pitch can be easily adjusted.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of an inkjet head, a line-type inkjet nozzle position adjusting method, and an inkjet nozzle unit position adjusting method according to the invention will be described with reference to the drawings.

  As shown in FIG. 1, the inkjet head 1 according to this embodiment includes two line-type inkjet nozzles 2a and 2b and a housing 3 to which the line-type inkjet nozzles 2a and 2b are attached.

  The line-type inkjet nozzles 2a and 2b are configured by arranging nozzles 4 for discharging a liquid material in a line at a predetermined interval. Since the line-type inkjet nozzles 2a and 2b are simultaneously molded with the nozzle 4 during molding, the shape and position of each nozzle 4 can be accurately manufactured. The line-type inkjet nozzles 2a and 2b are supplied with a liquid material from a liquid material supply unit (not shown) to each nozzle 4, and are predetermined based on an injection command signal from a control device (not shown). The liquid material is discharged at the timing. Accordingly, the line-type inkjet nozzles 2a and 2b can discharge the liquid material to each nozzle 4 at the same timing, or can discharge the liquid material from only some selected nozzles 4.

  As shown in FIG. 1, the inkjet head 1 includes two line-type inkjet nozzles 2a and 2b in a housing 3, and the nozzles 4 are displaced from each other by a half pitch (1 / 2P1) of the nozzle pitch P1. They are arranged in parallel. It is extremely important for the inkjet head 1 to accurately adjust the relative positional relationship between the two line-type inkjet nozzles 2a and 2b.

  In this embodiment, as shown in FIG. 2, when the line type inkjet nozzle 2 is attached to the housing 3, the CCD camera 12 (image capture) is placed on the housing 3 at a position facing the nozzle attachment surface 5. Apparatus, camera), and the positions of the nozzles 4 of the line-type inkjet nozzles 2a and 2b are aligned based on the image of the CCD camera 12.

  For example, as shown in FIG. 2, the work space 10 for assembling the inkjet head 1 includes a housing fixing unit 11 that fixes the housing 3, a CCD camera 12, and a control unit 13 that controls the movement of the CCD camera 12. And. In FIG. 2, 15 is a storage unit, 16 is a movement operation unit, and 17 is a monitor that displays an image captured by the CCD camera 12.

  The housing fixing portion 11 is configured to fix the nozzle mounting surface 5 of the housing 3 facing downward. The CCD camera 12 is disposed so as to move in parallel with the nozzle mounting surface 5 while facing the nozzle mounting surface 5 of the housing 3 fixed to the housing fixing portion 11. For example, the CCD camera 12 may be installed on an XY table 14 that can be precisely adjusted so that the position of the CCD camera 12 can be adjusted with high accuracy relative to the nozzle mounting surface 5.

  Further, the control unit 13 sets XY coordinates with an arbitrarily selected part of the housing 3 as a reference position, and position coordinates (x1, y1), ( .., x2, y2), (x3, y3), (x4, y4)... and a moving operation unit 16 for moving the CCD camera 12 according to the position coordinates stored in the storage unit 15. It has. The moving operation of the CCD camera 12 may be performed using a computer so that the CCD camera 12 moves accurately.

  In this embodiment, the storage unit 15 sets the XY coordinates with the upper right corner 18 of the housing 3 in FIG. 1 as the reference position (0, 0) of the housing 3, and sets the left and right ends of each line-type inkjet nozzle 2a, 2b. The position coordinates (x1, y1), (x2, y2), (x3, y3) and (x4, y4) of the nozzles 4a1, 4a2, 4b1, 4b2 are stored.

  Next, an example of the position adjustment of the line-type inkjet nozzles 2a and 2b using the work space 10 in which the above-described assembly operation of the inkjet head 1 is performed will be described.

  In the position adjustment of the line type ink jet nozzles 2a and 2b, first, the line type ink jet nozzles 2a and 2b are installed at a predetermined mounting position of the nozzle mounting surface 5 of the housing 3 without accurately adjusting the position. In this embodiment, the housing 3 is attached to the work space 10 with the nozzle attachment surface 5 facing downward, and the line-type inkjet nozzles 2a, 2b are not dropped from the nozzle attachment surface 5, and the position is fine. Temporarily fixed in a state where adjustment is possible.

  The position adjustment of the line type ink jet nozzles 2a and 2b is performed by adjusting the position coordinates (x1, y1), (no. x2, y2), (x3, y3), and (x4, y4).

  In this embodiment, in an image projected on the monitor 17, a mark m (for example, a cross mark) indicating the photographing center is displayed at the center of the image so as to be superimposed on the image photographed by the CCD camera 12. ing.

  The CCD camera 12 is moved to a position where the photographing center of the CCD camera 12 and the reference position of the housing 3 (in this embodiment, the upper right corner 18 of the housing 3 as shown in FIG. 1) overlap. Then, while viewing the image of the CCD camera 12 that has captured the region s 1 including the reference position 18 of the housing 3, the XY table 14 so that the mark m indicating the imaging center of the CCD camera 12 overlaps the reference position 18 of the housing 3. To move the CCD camera 12. Whether the reference position 18 of the housing 3 coincides with the mark m indicating the photographing center of the CCD camera 12 is recognized by, for example, image processing by a computer, and the reference position 18 of the housing 3 is recognized. May be determined by the computer to match the mark m indicating the photographing center of the CCD camera 12.

  The position where the photographing center of the CCD camera 12 is aligned with the reference position of the housing 3 in this way is set as the coordinate origin of the XY table 14. In this embodiment, the upper right corner of the housing 3 is the reference position 18 of the housing 3, and the XY coordinates are taken with reference to this position. The reference position 18 of the housing 3 is an arbitrary position on the nozzle mounting surface 5 of the housing 3. Can be set to position.

  Next, the control unit 13 moves the CCD camera 12 based on the position coordinates of the nozzles 4 of the line-type inkjet nozzles 2 a and 2 b stored in the storage unit 15.

  In this embodiment, based on the nozzle position coordinate data stored in the storage unit 15, the CCD camera 12 is moved to the position (x1, y1) where the right end nozzle 4a1 of the line-type inkjet nozzle 2a should be. At this time, the mark m indicating the photographing center of the CCD camera 12 indicates the position (x1, y1) where the right end nozzle 4a1 of the line-type inkjet nozzle 2a should be. Then, the CCD camera 12 moved in this way is fixed, and the right end nozzle 4a1 of the line-type inkjet nozzle 2a appropriately installed at a predetermined mounting position of the housing 3 is reflected in the image. The position of the line-type inkjet nozzle 2a is adjusted so that the center of the right end nozzle 4a1 of the inkjet nozzle 2a is aligned with the center of the mark m indicating the photographing center of the CCD camera 12.

  In this embodiment, the circular shape of the nozzle 4a1 is recognized by the image recognition means, and the center position of the nozzle 4a1 is calculated. Then, while looking at the monitor 17, the position of the line-type inkjet nozzle 2 appropriately placed at a predetermined mounting position of the housing 3 so that the center position of the nozzle 4a1 is aligned with the center of the mark m indicating the photographing center of the CCD camera 12. Make fine adjustments. In addition, the coordinates of the center position of the nozzle 4a1 in the XY coordinate system based on the reference position 18 of the housing 3 are calculated, the coordinates of the center position of the nozzle 4a1 are displayed on the monitor 17, and the coordinate value displayed on the monitor 17 is displayed. While viewing, the position of the line-type inkjet nozzle 2 may be finely adjusted so that the coordinates of the center position of the nozzle 4a1 coincide with the position (x1, y1) where the center of the nozzle 4a1 should be.

  Thereby, the center of the nozzle 4a1 at the right end of the line-type inkjet nozzle 2a can be adjusted to the position (x1, y1) that should exist. The position of the nozzle 4a2 at the left end of the line-type inkjet nozzle 2a is also adjusted in the same manner.

  The line-type inkjet nozzle 2 a is fixed to the housing 3 by adjusting the positions of the nozzles 4 a 1, 4 a 2 at the left and right ends (x 1, y 1) (x 2, y 2) at the same time. For this reason, for example, using two CCD cameras 12, the nozzles 4a1 and 4a2 at the left and right ends of the line-type inkjet nozzle 2a may be simultaneously photographed to adjust the position of the line-type inkjet nozzle 2a.

  Similarly, in the other line-type inkjet nozzle 2b, the positions of the nozzles 4b1 and 4b2 at the left and right ends are adjusted to the positions (x3, y3) and (x4, y4) that should be present at the same time, Install with high accuracy.

  In this way, the two line-type inkjet nozzles 2a and 2b can be arranged in parallel by accurately shifting the position of the nozzle 4 from each other by a half pitch (1/2 pitch) of the nozzle pitch P1. The ink jet head 1 in which the line type ink jet nozzles 2 are arranged in this way is equivalent to a state in which the nozzles 4 are arranged for every half nozzle pitch (1 / 2P1) of one line type ink jet nozzle 2 as a whole. Therefore, when the nozzle pitch P1 of the line-type inkjet nozzle 2 is narrowed to the limit, the inkjet head 1 can set the nozzle pitch to a further half as a whole.

  In addition, the inkjet head 1 can adjust the discharge timing of the liquid material for each line-type inkjet nozzle 2. Thereby, adjustment of dot pitch, such as fine application and rough application, can be easily performed. For example, if the liquid material is discharged from only one line-type inkjet nozzle 2, the nozzle pitch of the entire inkjet head 1 becomes the nozzle pitch P1 of one line-type inkjet nozzle 2a. If the liquid material is discharged from the two line-type ink jet nozzles 2a and 2b at a predetermined timing, the liquid material can be discharged with a narrow nozzle pitch (1 / 2p1) as a whole of the ink jet head 1.

  As described above, in the above-described embodiment, two line-type inkjet nozzles 2 in which the nozzles 4 for discharging the liquid material are arranged in a row are shifted in parallel by shifting the position of the nozzle 4 by 1/2 the nozzle pitch P1. Although the disposed inkjet head 1 has been described, the number n of the line-type inkjet nozzles 2 disposed in parallel can be arbitrarily increased.

  For example, although not shown, if the three line-type inkjet nozzles 2 are arranged in parallel by shifting the positions of the nozzles 4 by 1/3 of the nozzle pitch P1, the nozzle pitch of the entire inkjet head is reduced. The nozzle pitch P1 of the line-type inkjet nozzle 2 can be reduced to 1/3. Further, when the four line-type inkjet nozzles 2 are arranged in parallel by shifting the position of the nozzle 4 by 1/4 pitch of the nozzle pitch P1, the nozzle pitch of the entire inkjet head is changed to the line-type inkjet nozzle 2. The nozzle pitch P1 can be reduced to 1/4. Similarly, when n line-type inkjet nozzles 2 are arranged in parallel by shifting the positions of the nozzles 4 by 1 / n pitch of the nozzle pitch P1, the nozzle pitch of the entire inkjet head is changed to the line-type inkjet nozzle. 1 / n of the nozzle pitch P1 of 2.

  As the number n of line-type inkjet nozzles 2 arranged in parallel is increased, the nozzle pitch of the entire inkjet head can be reduced. However, as the number n of the line-type inkjet nozzles 2 arranged in parallel is increased, the distance between the leading line-type inkjet nozzle and the rear-line-type inkjet nozzles of the line-type inkjet nozzles 2 arranged in parallel increases. For this reason, in applications where there is a problem of poor fusion of the discharged liquid material (for example, for forming an alignment film), the number of line-type inkjet nozzles arranged in parallel to such an extent that such problems do not occur It is good to adjust n. At present, in these applications, it is considered appropriate that the number n of line-type inkjet nozzles assembled in parallel is within 4 or 5.

  Next, an inkjet head constituted by assembling the inkjet head 1 in which the line-type inkjet nozzles 2 are combined in parallel as a single inkjet nozzle unit as described above will be described.

  As shown in FIG. 3, the inkjet head 20 is configured so that the left and right ends of the liquid material ejection region j of the inkjet nozzle unit 1 are continuous with the liquid material ejection region j of the adjacent inkjet nozzle unit 1. The nozzle units 1 are arranged in series.

  In this embodiment, as shown in FIG. 4, the inkjet nozzle units 1 are alternately arranged in a staggered pattern on both sides of the mounting shaft 21 in the width direction of the mounting shaft 21. A reference plane 22 is formed on one side surface (the upper side surface in FIG. 4) of the mounting shaft 21. The reference plane 22 ensures a required flatness in order to arrange the inkjet nozzle unit 1 with high accuracy. In this embodiment, the reference flat surface 22 has a flatness of ± 5 μm as a whole, and also has a flatness of ± 1 μm / 160 mm even when viewed locally. A screw hole 23 for attaching the inkjet nozzle unit 1 (a T-shaped adapter 24 described later of the inkjet nozzle unit 1) is formed on the lower surface of the attachment shaft 21 at a predetermined interval in the longitudinal direction.

  As shown in FIGS. 4 and 5, the inkjet nozzle unit 1 is attached to the attachment shaft 21 via an adapter 24 having a substantially T-shaped planar shape on the upper surface. The adapter 24 is molded with extremely high accuracy. In the inkjet nozzle unit 1, the line-type inkjet nozzle 2 is disposed below the portion 24 b extending laterally of the T-shaped adapter 24 and along the portion 24 b extending laterally of the T-shaped adapter 24. Install. The inkjet nozzle unit 1 is accurately attached to a predetermined position with respect to the T-shaped adapter 24. In this embodiment, the adapter 24 is attached to the attachment shaft 21, and then the inkjet nozzle unit is attached to the adapter 24. Normally, when removing the ink jet nozzle unit, the adapter 24 remains attached to the attachment shaft 21 and only the ink jet nozzle unit 1 can be removed from the adapter 24.

  As shown in FIGS. 4 and 5, the adapter 24 includes a groove 25 that is attached to the attachment shaft 21 at the center of a vertically extending portion 24 a. On both side surfaces 26, 27 in the longitudinal direction of the groove 25, the same degree of flatness as the reference flat surface 22 of the mounting shaft 21 is secured. On the bottom surface of the groove 25, a screw hole 28 for mounting a screw corresponding to the screw hole 23 of the mounting shaft 21 is formed. The screw hole 28 forms a hole having a large diameter relative to the diameter of the screw to be mounted so that the relative positional relationship between the mounting shaft 21 and the adapter 24 can be finely adjusted. Further, on both sides of the groove 25, screw holes 29 and 30 for mounting screws (not shown) for pressing the side surface (26 or 27) of the adapter 24 against the reference plane 22 are provided in the vertical direction.

  When the adapter 24 is attached to the attachment shaft 21, as shown in FIG. 5, the groove 24 of the adapter 24 is fitted into the lower surface 31 of the attachment shaft 21, and a portion 24a extending vertically of the T-shaped adapter 24 is It is attached to the attachment shaft 21 so as to be orthogonal to 21. Each adapter 24 is aligned with the reference plane 22 of the mounting shaft 21 and fixed to the mounting shaft 21 as shown in FIG.

  In this embodiment, one side surface (26 or 27) of the groove 25 of the T-shaped adapter 24 is pressed against the reference plane 22 of the mounting shaft 21 in advance, and the adapter 24 is accurately attached to the mounting shaft 21. The attachment accuracy of the inkjet nozzle unit 1 to the attachment shaft 21 is ensured by attaching the inkjet nozzle unit 1 to the adapter 24 with high accuracy.

  The adapter 24 is attached by, for example, mounting the groove 25 of the T-shaped adapter 24 on the lower surface 31 of the mounting shaft 21, attaching screws 32 and 33 from the lower surface of the adapter 24, and attaching the adapter 24 to the mounting shaft 21. Lightly fix to (temporarily fix). A screw (not shown) is attached to the screw hole (29 or 30) on the side surface (26 or 27) of the groove 25 on the side surface 34 opposite to the reference plane 22 of the mounting shaft 21, and this screw is screwed together. The tip of the screw is pressed against the side surface 34 of the mounting shaft 21. Accordingly, the side surface (27 or 26) of the groove 25 and the reference plane 22 are brought into contact with each other on the reference plane 22 side of the mounting shaft 21 so that the T-shaped adapter 24 is accurately perpendicular to the mounting shaft 21 and the screw 32 , 33 to fix the adapter 24 to the mounting shaft 21. As a result, the adapter 24 can be fixed to the mounting shaft 21 in a state where the portion 24 a extending vertically of the T-shaped adapter 24 is accurately orthogonal to the mounting shaft 21.

  More specifically, in the adapter 24 shown in FIG. 5, of the side surfaces 26 and 27 of the groove 25, the side surface 26 on the distal end side of the portion 24 a extending vertically in the T-shape is the reference plane 22 of the mounting shaft 21. Opposite. In this case, the tip of a screw (not shown) screwed into the screw hole 30 on the left side in the drawing is pressed against the side surface 34 of the attachment shaft 21 so that the right side 26 in the drawing becomes the reference of the attachment shaft 21. It is in contact with the plane 22.

  Although illustration is omitted, of the side surfaces 26 and 27 of the groove 25 of the adapter 24, the side surface 27 on the proximal end side of the portion 24 a extending vertically in the T shape faces the reference plane 22 of the mounting shaft 21. In the case (in the opposite case of FIG. 5), a screw is screwed into the screw hole 29 on the distal end side, the distal end of the screw is pressed against the side surface 34 of the mounting shaft 21, and the side surface 27 on the proximal end side of the adapter 24. May be pressed against the reference plane 22 of the mounting shaft 21.

  As described above, in this embodiment, the reference plane 22 is formed on one side surface of the mounting shaft 21, and all the adapters 24 are attached to the reference plane 22. In this way, if the flatness of the reference flat surface 22 of the mounting shaft 21 is ensured with high accuracy, all the adapters 24 can be mounted with high accuracy, so that the mounting accuracy of the adapters 24 can be easily secured.

  Next, a method for attaching the inkjet nozzle unit 1 to the adapter 24 attached to the attachment shaft 21 with high accuracy in this way will be described. When the inkjet nozzle unit 1 is attached to the adapter 24, it is required to ensure a high degree of attachment accuracy, similar to the attachment of the adapter 24 described above.

  In this embodiment, the inkjet nozzle unit 1 is attached to a lower portion of a portion 24b that extends to the side of the adapter 24 to be attached. The lower surface 41 and the side surface 42 of the extended part 24b are processed with high accuracy.

  Specifically, the side surface 42 of the portion 24 b that extends to the side of the adapter 24 is formed so as to be parallel to the side surfaces 26 and 27 of the groove 25 of the adapter 24, and the side 24 of the portion 24 b that extends to the side of the adapter 24. The lower surface 41 is formed with high accuracy so as to extend at right angles to the side surface 42 of the laterally extending portion 24b. Further, the lower surface 41 and the side surface 42 of the portion 24 b extending to the side of the adapter 24 are formed with a flatness comparable to the reference plane of the mounting shaft 21.

  Further, as shown in FIG. 5, the housing 3 ′ of the inkjet nozzle unit 1 has a mounting wall portion 44 that rises vertically at the side edge of the upper portion of the housing 3 ′ (surface opposite to the nozzle mounting surface 5). The side surface 45 on the inner side of the mounting wall portion 44 and the upper surface 46 of the housing 3 ′ are processed with high accuracy.

  Specifically, the inner side surface 45 of the mounting wall portion 44 is formed so as to extend at a right angle to the upper surface 46 of the housing 3 ′, and the inner side surface 45 of the mounting wall portion 44 and the housing 3 ′. The upper surface 46 is formed with the same degree of flatness as the reference plane 22.

  When attaching the inkjet nozzle unit 1 to the adapter 24, first, as shown in FIG. 5, first, the upper surface of the housing 3 ′ of the inkjet nozzle unit 1 is placed on the lower surface 41 and the side surface 42 of the portion 24b extending laterally of the adapter 24. 46 and the inner side surface 45 of the mounting wall portion 44 are pressed against each other. Next, the housing 3 ′ of the inkjet nozzle unit 1 is lightly fixed to the adapter 24 with screws 47 and 48 attached to a portion 24 b extending to the side of the adapter 24 (temporary fixing).

  Next, the side surface 45 of the mounting wall portion 44 is lightly tightened with the screws 49 attached from the outside to the mounting wall portion 44 of the housing 3 ′ so that the side surface 42 of the portion 24 b extending to the side of the adapter 24 abuts. Then, while adjusting the horizontal position of the housing 3 ′ with respect to the adapter 24, the screws 47, 48 and 49 are alternately tightened to fix the inkjet nozzle unit 1 to the adapter 24. Thus, in this embodiment, the upper surface 46 of the housing 3 ′ and the lower surface 41 of the portion 24 b extending laterally of the adapter 24, and the side surface 45 inside the mounting wall portion 44 and laterally extending of the adapter 24 are extended. By fixing the housing 3 ′ of the inkjet nozzle unit 1 with the side surfaces 42 of the portions 24 b pressed against each other, the mounting accuracy of the inkjet nozzle unit 1 with respect to the adapter 24 is ensured.

  According to the attachment method of the inkjet nozzle unit 1 according to this embodiment, when removing the inkjet nozzle unit 1, normally, only the inkjet nozzle unit 1 is removed from the adapter 24 with the adapter 24 attached to the attachment shaft 21. be able to. And when attaching the inkjet nozzle unit 1 to the adapter 24, if the screws 47, 48, 49 are alternately tightened to fix the inkjet nozzle unit 1 to the adapter 24 as described above, the inkjet nozzle unit 1 can be attached with high accuracy. Can do. Accordingly, the ink jet nozzle unit 1 can be easily attached and detached.

  Next, adjustment of the gap g (see FIG. 6) between the inkjet nozzle unit 1 and the object 51 to which the liquid material is applied will be described. If the gap g is too large, flight bending tends to occur, and if it is too narrow, the liquid pool accumulated on the lower surface of the inkjet nozzle unit 1 comes into contact with the coating object 51. For this reason, the lower limit of the gap g is 0.5 mm or more (more preferably 0.7 mm or more), and the upper limit of the gap g is adjusted to a predetermined value of 1.2 mm or less (more preferably 1.0 or less).

  In this embodiment, as shown in FIG. 6, the gap g is adjusted by placing a substrate 52 (glass substrate) on the upper surface of the coating object 51 so that the end portion protrudes from the coating object 51. Further, the length measuring device 53 is disposed so as to face the surface of the inkjet nozzle unit 1 on which the nozzle 4 is disposed. In this embodiment, an optical length measuring device (laser length measuring device) is used as the length measuring device 53 so that distance measurement can be accurately performed. Then, the distance measuring device 53 measures the distance L1 between the length measuring device 53 and the nozzle surface of the inkjet nozzle unit 1. Next, the substrate 52 placed on the coating object 51 is caused to enter the length measuring device 53, and the distance L2 between the length measuring device 53 and the lower surface of the substrate 52 is measured. A gap g between the nozzle surface of the line-type inkjet nozzle 2 and the upper surface of the coating object 51 is calculated as a difference between the distance L1 and the distance L2 (g = L1-L2). And it is good to adjust the height of the attachment shaft 21 which attached the inkjet nozzle unit 1 so that the measured gap g may become a predetermined gap value.

  As a result, the gap g can be adjusted with high accuracy, the landing position of the liquid material discharged from each nozzle 4 of the inkjet nozzle unit 1 can be easily controlled, and the liquid puddle can adhere to the object to be coated. Can be prevented.

  As described above, according to the ink jet head 20, the line type ink jet nozzle 2 in which the nozzles 4 for discharging the liquid material are arranged in a line, the position of the nozzle 4 is 1 / n pitch of the nozzle pitch P1, Since the inkjet heads 1 arranged in parallel and shifted from each other are used as the inkjet nozzle unit, the nozzle pitch of the line-type inkjet nozzle 2 can be reduced as a whole. In addition, the inkjet head 20 can adjust the discharge timing of the liquid material for each line-type inkjet nozzle 2 of each inkjet nozzle unit 1. Thereby, adjustment of dot pitch can be performed and adjustment from fine coating to rough coating can be easily performed.

  And as above-mentioned, by attaching the some inkjet nozzle unit 1 to the attachment shaft 21 with sufficient precision, the area | region which can apply | coat a liquid material at once can be ensured, and the speed of a process can be improved.

  The ink jet head 20 according to this embodiment has a mounting shaft 21 when the liquid material discharged from the ink jet head 20 is an alignment film material, and an object to be applied with the alignment film material is a liquid crystal element substrate, for example. The inkjet nozzle unit 1 can be disposed such that the length corresponding to the width of the liquid crystal element substrate is secured and the inkjet nozzle unit 1 faces the entire width of the liquid crystal element substrate.

  Thereby, when apply | coating alignment film material to a liquid crystal element substrate, it can apply | coat at once, the film thickness of alignment film material can be made uniform, and the speed of a process can be improved. As described above, this inkjet head is configured by combining an inkjet head in which line-type inkjet nozzles are combined in parallel into a single inkjet nozzle unit, which is assembled in series, and it is easy to adjust the nozzle pitch and dot pitch. In addition, by arranging the inkjet nozzle units in series in the required length, the liquid material can be uniformly applied, and the processing speed is fast. Therefore, it is particularly suitable as an inkjet head for an alignment film forming apparatus that needs to ensure uniformity of film thickness by fusing the applied liquid material without unevenness.

  As mentioned above, although the inkjet head which concerns on one Embodiment of this invention was demonstrated, this invention is not limited to embodiment mentioned above. For example, various changes can be made to the shapes of the constituent members such as the housing 3, the attachment shaft 21, and the adapter 24, and the mutual attachment structure between the constituent members.

FIG. 2 is a bottom view illustrating the configuration of the inkjet head according to the embodiment of the invention. It is a figure which shows the attachment process of the line type inkjet nozzle of the inkjet head which concerns on one Embodiment of this invention. The top view which shows the arrangement | positioning position of the inkjet nozzle unit of the inkjet head which concerns on other embodiment of this invention. The top view which shows the attachment structure (position adjustment) of the inkjet nozzle unit of the inkjet head which concerns on other embodiment of this invention. It is an AA side end view of FIG. The side view which shows the attachment structure (height adjustment) of the inkjet nozzle unit of the inkjet head which concerns on other embodiment of this invention.

Explanation of symbols

1 Inkjet head (inkjet nozzle unit)
2 Line-type inkjet nozzle 3 Housing 4 Nozzle 5 Nozzle mounting surface 10 Work space 11 Housing fixing part 12 Camera 13 Control part 14 Table 15 Storage part 16 Moving operation part 17 Monitor 18 Reference position 20 Inkjet head (Inkjet nozzle units are arranged in series) Form)
21 Mounting shaft 22 Reference plane 23 Screw hole 24 Adapter 24a Adapter extended part 24b Adapter extended part 25 Groove 26, 27 Side face 28 Screw hole 29, 30 Screw hole 31 Lower surface 32 of the attachment shaft, 33 Screw 34 Side surface of mounting shaft (side surface opposite to the reference plane)
41 Lower surface 42 of the portion extending laterally of the adapter 42 Side surface 44 of the portion extending laterally of the adapter Mounting wall portion 45 Side surface of the inner side of the mounting wall portion 46 Upper surface 47, 48, 49 of the screw Screw 51 Object 52 Substrate 53 Measuring instrument g Gap j Ejection area P1 Nozzle pitch

Claims (9)

  An inkjet head in which n line-type inkjet nozzles in which nozzles for discharging a liquid material are arranged in a row are arranged in parallel by shifting the nozzle positions by 1 / n pitch of the nozzle pitch.   Line-type inkjet nozzles in which nozzles for discharging a liquid material are arranged in a line, and nozzle units in which n nozzle positions are shifted from each other by 1 / n pitch of the nozzle pitch, are arranged in parallel. Inkjet heads arranged in series with staggered staggered positions in the direction in which the nozzles are arranged.   The ink jet head according to claim 2, comprising an attachment shaft in which a reference plane serving as a reference for an ink jet nozzle unit attachment position is formed in a straight line, and attaching each ink jet nozzle unit in alignment with the reference plane of the attachment shaft. An inkjet head characterized by the above. A position adjustment method for line-type inkjet nozzles arranged in parallel with the inkjet head according to claim 1,
A method for adjusting the position of a line-type inkjet nozzle, characterized in that the line-type inkjet nozzle is adjusted to a position where the line-type inkjet nozzle is to be attached based on an image taken by a camera of each line-type inkjet nozzle arranged in parallel.   A line-type inkjet nozzle is displayed by displaying a mark at a position where an arbitrarily selected portion of the line-type inkjet nozzle is located on the image photographed by the camera and aligning the selected portion of the line-type inkjet nozzle with the mark. The position adjustment method for a line-type inkjet nozzle according to claim 4, wherein the position is adjusted to a position to be attached. The position adjustment method of the inkjet nozzle unit of the inkjet head according to claim 2,
An inkjet nozzle characterized by using an attachment shaft on which a reference plane serving as a reference for the attachment position of the inkjet nozzle unit is formed and aligning and attaching each of the inkjet nozzle units to the reference plane of the attachment shaft. Unit position adjustment method. A first distance measuring step of disposing a length measuring device facing the ink jet nozzle and measuring a distance between the ink jet nozzle and the length measuring device;
A second distance measuring step of placing a substrate on an object to be coated, causing the substrate to face the length measuring device, and measuring a distance between the substrate and the length measuring device;
The distance between the ink jet nozzle and the length measuring device measured in the first distance measuring step;
A gap calculation method for calculating a gap between an inkjet nozzle and an object to be coated from a difference between the distance between the substrate and the length measuring device measured in the second distance measurement step.   A position adjustment method for an ink jet nozzle, wherein the distance between the ink jet nozzle and the coating object is adjusted based on the gap between the ink jet nozzle and the coating object calculated by the gap calculation method.   An alignment film forming apparatus comprising the inkjet head according to claim 1.