JP2008068190A - Liquid droplet discharging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid droplet discharging method capable of dispersing the difference between discharge amounts. <P>SOLUTION: A discharge head 3 having a large number of orifices 11 linearly arranged thereto, an adherend 31 receiving the liquid droplets discharged from the orifices 11 to form dot rows, a moving means for relatively reciprocally moving the discharge head 3 and the adherend 31 are provided. The orifices 11 of the discharge head 3 are successively divided into a plurality of groups along the arranging direction of the orifices 11 so as to discharge the liquid droplets from the orifices 11 at every group. The discharge head 3 and the adherend 31 are relatively moved by the moving means so that the dot rows are formed on the adherend 31 in order different from the order of the groups of the discharge head 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a droplet discharge method for a droplet discharge device, and more particularly to an inkjet droplet discharge method.

  Since the ink jet method can eject droplets from the orifice when necessary, an arbitrary pattern can be easily formed, and since there are few solutions that are wasted and discharged, it is advantageous from the environmental viewpoint.

  As an application example of the ink jet type droplet discharge device, there is a color filter manufacturing technique for a liquid crystal display device. Since this color filter is generally manufactured by repeating many photolithography processes such as development, exposure, and etching for each of the three colors R, G, and B, many processes are required. On the other hand, when manufacturing a color filter by the ink jet method, each ink jet head is filled with inks of three colors R, G, and B, and only a necessary amount is ejected to a necessary position and cured. Can be manufactured.

  Further, in the liquid crystal display device, in order to keep the interval between the two liquid crystal substrates constant, a particulate spacer is disposed between the liquid crystal substrates. Conventionally, spacers were sprayed on the liquid crystal substrate using a spray-type spraying device, etc., but this method tends to spray the spacers non-uniformly, so that the distance between the liquid crystal substrates cannot be kept constant and the display quality deteriorates. Invite.

  In order to eliminate such disadvantages, a spacer is attached by discharging a coating liquid containing a spacer onto a liquid crystal substrate with an ink jet type droplet discharge device. According to this droplet discharge device, the spacer can be arranged at a predetermined position, and if a discharge head having a large number of orifices is used, the spacer can be disposed at a large number of designated positions at the same time. It is good.

  The following patent documents can be mentioned about the spacer application by an inkjet system.

JP-A-11-240873

  By the way, this type of droplet discharge device uses a discharge head in which a large number of orifices are arranged, but the amount of droplet discharge is reduced between the orifices, for example, between the upstream, intermediate and downstream orifices of the discharge head. There may be a difference. Therefore, when the color filter is manufactured, a difference in droplet discharge amount between the orifices appears as an ink density difference, and stripes may be formed on the display panel.

  In the case of the spacer application, the number of spacers discharged together with the liquid is almost proportional to the discharge amount, so the difference in discharge amount appears as a variation in the number of spacers, and a difference occurs in the gap when the liquid crystal substrates are bonded together. There is. This gap difference appears as color unevenness or unevenness on the display panel, leading to a deterioration in the quality of the liquid crystal display device.

  An object of the present invention is to provide a droplet discharge method capable of dispersing a difference in droplet discharge amount.

In order to achieve the above object, the first means of the present invention is as follows:
A discharge head in which a large number of orifices are arranged in a straight line;
An adherend for landing a droplet discharged from the orifice of the discharge head to form a dot row along the direction of arrangement of the orifice;
Moving means for relatively reciprocating the discharge head and the adherend along the direction in which the orifices are arranged and the direction perpendicular to the arrangement direction;
In the droplet discharge method of forming a dot row on the adherend by discharging the droplet from the orifice by relatively moving the discharge head and the adherend by the moving means,
The orifices on the ejection head are divided into a plurality of groups in order along the arrangement direction, and droplets are ejected from the orifices for each group.
The moving means relatively moves the discharge head and the adherend from the orifice so that the dot rows are formed on the adherend in an order different from the order of the groups of the discharge heads. It is characterized by discharging droplets.

The second means of the present invention is:
A discharge head in which a large number of orifices are arranged directly above;
An adherend in which a large number of dot rows that land along droplets discharged from the orifices of the discharge head and extend in the direction in which the orifices are arranged are arranged in a direction perpendicular to the direction in which the orifices are arranged;
Moving means for relatively reciprocating the discharge head and the adherend along the direction in which the orifices are arranged and the direction perpendicular to the arrangement direction;
In the droplet discharge method of forming a dot row on the adherend by discharging the droplet from the orifice by relatively moving the discharge head and the adherend by the moving means,
The orifices on the ejection head are divided into a plurality of groups along the arrangement direction, and droplets are ejected from the orifices for each group.
The dot rows are formed in an order different from the order of the groups of the ejection heads,
And the dot portion in the direction orthogonal to the arrangement direction of the adjacent dot rows is formed by different groups of the ejection heads,
The moving means relatively moves the discharge head and the adherend to discharge droplets from the orifice.

According to a third means of the present invention, in the first means or the second means,
The adherend is a liquid crystal substrate, and droplets containing spacer particles for maintaining a gap between the two liquid crystal substrates are discharged from the orifice toward the surface of the liquid crystal substrate. Is.

  The present invention is configured as described above, and the difference in the droplet discharge amount on the adherend can be dispersed, so that excellent droplet discharge is possible.

  Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 10 is a schematic configuration diagram of an entire droplet discharge apparatus according to an embodiment of the present invention, and FIG. 11 is a partially enlarged cross-sectional view of a discharge head mounted on the apparatus.

  As shown in FIG. 10, in the droplet discharge device, a substrate holder 2 holding the mother substrate 1 is installed so as to be able to reciprocate in the Y direction, and an ejection head 3 is installed above the mother substrate 1 so as to be able to reciprocate in the Z direction. Has been.

  The discharge head 3 is supported by the movement guide 4 in the X direction via the movement guide 5 in the Z direction, and is connected to a solution tank (not shown) via a flexible solution supply pipe 6. A head maintenance unit 7 is provided at the standby position of the ejection head 3.

  The discharge head 3 has a cross-sectional structure as shown in FIG. In the figure, 11 is an orifice, 12 is a pressurizing chamber, 13 is a diaphragm, 14 is a piezoelectric element, 15a and 15b are signal input terminals, 16 is a piezoelectric element fixing plate, 17 is a common coating liquid supply pipe 18 and a pressurizing chamber. 12 is a restrictor that controls the flow of the coating liquid into the pressurizing chamber 12, 18 is a common coating liquid supply pipe, 19 is a filter, 20 is an adhesive that bonds the diaphragm 13 and the piezoelectric element 14, and 21 is The restrictor plate, 22 is a pressurizing chamber plate, 23 is an orifice plate, 24 is a support plate for reinforcing the diaphragm 13, 25 is a housing, and 26 is a filter plate.

  The coating liquid in which the spacer fine particles are mixed and dispersed flows from the upstream side to the downstream side of the ejection head 3, passes through the filter 19 in the middle of the common coating liquid supply pipe 18, and then the restrictor 17, the pressure chamber 12, and the orifice. It flows in order of 11. The piezoelectric element 14 expands and contracts when a voltage is applied between the signal input terminals 15a and 15b, and returns to its original state when no voltage is applied. Due to the deformation of the piezoelectric element 14, pressure is applied to the coating liquid in the pressurizing chamber 12, and droplets containing spacer fine particles are discharged from the orifice 11.

  The discharge head 3 can move in the X direction and the Z direction along the X direction movement guide 4 and the Z direction movement guide 5 as shown in FIG. 10, and the mother substrate 1 on the substrate holder 2 can move in the Y direction. Based on a signal from a head drive control unit (not shown), a coating liquid containing spacer fine particles can be discharged to an arbitrary position on the mother substrate 1. The movement of the ejection head 3 in the X direction and the Z direction and the movement of the mother substrate 1 in the Y direction are each performed by a motor (not shown) with an encoder.

  FIG. 12 is a plan view showing the relationship between the ejection head 3 and the color filter substrate 31 for liquid crystal to which spacers are attached. The substrate 31 is formed in a plurality of sections at a predetermined interval on a large mother substrate 1 (see FIG. 10) made of a glass plate. As shown in the figure, R, G, B pixel cells 32 are regularly formed on the surface of the substrate 31. A light shielding film 33 is formed in a mesh shape so as to divide each pixel cell 32, and a spacer aggregate 34 composed of a plurality (for example, 3 to 5) of spacer fine particles is attached to the intersection of the light shielding film 33.

  While a large number of orifices 11 are formed on the discharge head 3 in a straight line with a pitch of P1, the pitch P2 of the spacer assembly 34 attached on the substrate 31 depends on the type of liquid crystal display device. 11 pitch P1 may be different. In this case, the inclination angle θ of the ejection head 3 is adjusted to match the pitch P2 of the spacer aggregate 34.

  There is a problem that a difference occurs in the discharge amount at an upstream portion, an intermediate portion, a downstream portion, or the like of the discharge head, and display quality is deteriorated based on the difference. In order to solve this problem, the present invention employs a distributed ejection system using an ejection head.

  FIG. 1 and FIG. 2 are diagrams for explaining the first embodiment. FIG. 1 is a diagram showing divided areas on the ejection head, and this embodiment shows an example in which 128 orifices are provided on a straight line on the ejection head 3, and these orifice groups are shown in FIG. As described above, the groups are equally divided into four groups A to D along the arrangement direction of the orifices, and the number of orifices in each group is 32. Orifice No. in each group Is as follows. Orifice No. As shown in the figure, reference numerals are given in order from the left side to the right side in the drawing of the ejection head 3.

Group A: Orifice No. 1-32
Group B: Orifice No. 33-64
Group C: Orifice No. 65-96
D group: Orifice No. 97-128
2 (a) and 2 (b) are diagrams for explaining a procedure for discharging a droplet from each orifice, and FIGS. (A-1) to (a-4) divide the procedure into a forward path and a return path. The diagrams shown in units of orifice groups, (b-1) to (b-4) in FIG. It is the figure shown by. In addition, the same figure (b-1)-(b-4) has shown a part of board | substrate application | coating area | region left end part.

  2A-1, the left side portion of the illustrated substrate 31 is a portion 35 of the mother substrate 1 that is disengaged from the substrate 31. Initially, the spacer assembly extends from the dislocated portion 35 to the left end portion of the substrate 31. The body 34 is applied. The X direction and the Y direction in FIG. 10A coincide with the X direction and the Y direction shown in FIG. 10, and in this embodiment, the reciprocating movement of the ejection head 3 twice in the X direction is performed. Thus, an example in which droplets are applied to a predetermined region of the substrate 31 is shown.

  Note that the alphabets “A” to “D” in FIG. 4A indicate the orifice groups shown in FIG. 1, and “1” and “2” indicate the number of reciprocations, and a dash at the upper right of the number. Those not marked with indicate coating on the forward trip, and those with a dash indicate coating on the return trip. The numbers in FIG. 4B indicate the orifice No. involved in the application. Is shown. This also applies to other embodiments described later.

  At the first start, as shown in FIG. 2 (a-1), each of the orifices (orifices No. 1 to 96) from the A group to the C group is opposed to the above-described removed portion 35, and each of the D group The ejection head 3 is arranged such that the orifice (orifices No. 97 to 128) faces a part of the left end of the substrate 31. FIG. 3 shows an arrangement state at the start of the ejection head 3 with respect to the substrate 31.

  In this state, droplets are ejected from every other odd-numbered orifice (orifice No. 1, 3,..., 127). Therefore, as shown in FIG. The spacer aggregate 34 ejected from 97, 99,... 127 is landed, and uncoated portions 36 are formed every other pixel in the Y direction. As shown in FIG. 3, the ejection head 3 is applied in every other pixel while moving in the X direction. As a result, an uncoated portion 36 is formed in every other pixel in the X direction. FIGS. 2A-1 and 2B-1 show the application state of the first outbound path.

  When the first forward application is thus completed, the ejection head 3 is moved from that position by one row in the X direction and two groups in the Y direction with respect to the substrate 31, and is indicated by a dotted arrow in FIG. In this way, the first return is performed while moving the ejection head 3 in the backward direction and applying it to the lower side of the applied pixel. 2 (a-2) and 2 (b-2) show the application state of the first return path, and as shown in FIG. 2 (b-2), the orifice No. already applied in the first outbound path is shown. 97, 99,... 127 below orifice No. Application of 33, 35,... 63 is performed.

  When the application of the first return pass is thus completed, the discharge head 3 is further moved from the position to the substrate 31 by one row in the X direction and two groups in the Y direction, and the discharge head 3 is moved in the forward direction. While moving, coating is performed every other pixel in the same manner as described above. 2 (a-3) and 2 (b-3) show the application state of the second outbound path.

  When application of the second forward path is completed in this manner, the ejection head 3 is further moved from the position to the substrate 31 by one row in the X direction and two groups in the Y direction, and the ejection head 3 is moved in the backward direction. While moving, coating is performed every other pixel in the same manner as described above. FIGS. 2A-4 and 2B-4 show the application state of the second return pass.

  When the two reciprocating movements of the ejection head 3 are completed, the application of the left end portion of the substrate 31 shown in FIG. 3 is completed. Therefore, the ejection head 3 is moved in the Y direction by the application area of the ejection head 3 (one point). (Represented by a chain line), reciprocating twice as described above. In the state of FIG. 2A-4, the non-application portion 36 remains in some places, but this non-application portion 36 is applied when the next ejection head 3 is reciprocated and is not the non-application portion 36 (described later). FIG. 4). The spacer assembly 34 is landed on the entire surface of the substrate 31 while repeating the reciprocating movement of the ejection head 3 and the movement in the Y direction corresponding to the coating area several times.

  FIG. 4 is a diagram showing the application state (part) of the substrate 31 after the application is completed in this way. As described above, when droplets are ejected while the ejection head 3 and the substrate 31 are moved relatively in the X and Y directions, as shown in FIG. 4, for example, adjacent to the area (A-2 ′) (dot portion). There are "C-2", "A-1", "C-1 '", "A-1", "C-2", "D-1", "B-1'", "D-" around 1 ”region (dot portion) is formed, and the dot portion is formed by different orifice groups, so that the difference in droplet weight (that is, the difference in the number of spacers) is randomly distributed over the entire surface of the substrate 31. Become.

  FIG. 5 is a diagram for explaining a second embodiment of the present invention. Also in this embodiment, the orifice group is equally divided into four orifice groups A to D along the arrangement direction thereof (see FIG. 1).

  FIGS. 5 (a-1) to (a-4) are diagrams showing a procedure for ejecting droplets from each orifice in units of orifice groups, and the forward path and the backward path are described together. FIG. 5B shows a part of the substrate 31 after the application is finished. It is the figure shown by. In the case of this embodiment, the coating is applied every 3 pixels in the forward path and the backward path, and when switching between the forward path and the backward path, the ejection head 3 is moved by two groups in the Y direction and by one row in the X direction with respect to the substrate 31. By repeating the reciprocating operation a number of times, a random application state as shown in FIGS. 5 (a-4) and 5 (b) is obtained.

  FIG. 6 is a diagram showing a divided region on the ejection head used in the third embodiment and the fourth embodiment of the present invention, and 128 orifices are provided on the ejection head 3 in a straight line. The orifice groups are equally divided into eight groups A to H along the arrangement direction of the orifices, and the number of orifices in each group is sixteen. Orifice No. in each group Is as follows.

Group A: Orifice No. 1-16
Group B: Orifice No. 17-32
Group C: Orifice No. 33-48
D group: Orifice No. 49-64
E group: Orifice No. 65-80
F group: Orifice No. 81-96
G group: Orifice No. 97-112
H group: Orifice No. 113-128
FIGS. 7 (a-1) to (a-4) are diagrams showing a procedure for discharging droplets at each orifice in the third embodiment of the present invention in units of orifice groups, and the forward path and the return path are described together. ing. FIG. 7B shows a part of the substrate 31 after the application is completed. It is the figure shown by. In this embodiment, every three pixels in the Y direction, that is, orifice No. For example, as shown in FIG. 113, 117... Are applied every other pixel in the forward path and the backward path, and when switching between the forward path and the backward path, the ejection heads 3 for four groups with respect to the substrate 31 in the Y direction and for one row in the X direction. By moving and repeating the reciprocating operation four times, a random application state as shown in FIG. 7 (a-4) and FIG. 7 (b) is obtained.

  FIGS. 8 (a-1) to (a-4) and FIGS. 9 (a-5) to (a-8) show the procedure for discharging droplets at each orifice in the fourth embodiment of the present invention in units of orifice groups. It is the figure shown, and the outward path and the return path are described together. FIG. 9B shows a part of the substrate 31 after the application is completed. It is the figure shown by. In this embodiment, coating is performed every 3 pixels in the Y direction, and every 3 pixels in the forward path and the backward path. When switching between the forward path and the backward path, the ejection heads 3 for the four groups in the Y direction with respect to the substrate 31 are X direction. In this way, a random application state as shown in FIG. 9 (a-8) and FIG. 9 (b) is obtained by repeating the reciprocating operation 8 times.

  The number of orifices on the discharge head, the number of group divisions, the number of reciprocations of the discharge head on the substrate, and the like are not limited to the above-described embodiment, and can be selected as appropriate. If the orifice group is divided into small sections and the number of reciprocations is increased, the difference in discharge amount due to the orifices between the groups is further dispersed, and the difference in discharge amount becomes inconspicuous.

  In the embodiment, for example, as shown in FIG. 9B, the odd-numbered orifices are used both when the ejection head is going forward and when the ejection head is going backward. Can also be used. In a plurality of reciprocating operations of the ejection head, it is possible to use odd numbered orifices for the first half of the reciprocating operation and even numbered orifices for the second half of the reciprocating operation.

  In the embodiment, the inclination angle θ of the ejection head (see FIG. 12) is relatively large and every other (first and second embodiments) or every third (third and fourth embodiment) orifices are used. If all the orifices are used for discharge with a relatively small inclination angle θ of the discharge head, the use efficiency of the discharge head can be improved and the coating time can be shortened.

  In the embodiment, the ejection head is moved in the X and Z directions and the substrate is moved in the Y direction. However, the present invention is not limited to this, and one of the ejection head and the mother substrate is orthogonal to each other. It is also possible to move in three directions of the Z direction.

  In the embodiment, the case where the coating liquid in which the solid fine particles are mixed and dispersed is described. However, the present invention is not limited to this, and the present invention is also applicable to the case where the coating liquid containing no solid fine particles is discharged.

  In the above-described embodiment, the case of manufacturing a liquid crystal display device has been described. However, the present invention is not limited to this, and can be applied to other technical fields such as the manufacture of electroluminescence.

It is a figure which shows grouping of the orifice in the discharge head used for 1st Embodiment and 2nd Embodiment of this invention. It is a figure for demonstrating the procedure of the droplet discharge which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the movement of the discharge head in each embodiment of this invention. It is the figure which showed the application state (part) of the board | substrate after application | coating is complete | finished in 1st Embodiment of this invention by the orifice group. It is a figure for demonstrating the procedure of the droplet discharge which concerns on 2nd Embodiment of this invention. It is a figure which shows grouping of the orifice in the discharge head used for 3rd Embodiment and 4th Embodiment of this invention. It is a figure for demonstrating the procedure of the droplet discharge which concerns on 3rd Embodiment of this invention. It is a figure for demonstrating the procedure of the droplet discharge which concerns on 4th Embodiment of this invention. It is a figure for demonstrating the procedure of the droplet discharge which concerns on 4th Embodiment of this invention. 1 is an overall schematic configuration diagram of a droplet discharge device according to an embodiment of the present invention. It is a partial expanded sectional view of the discharge head mounted in the droplet discharge apparatus. It is a top view which shows the relationship between the discharge head which concerns on embodiment of this invention, and the color filter substrate for liquid crystals which adheres a spacer.

Explanation of symbols

  1: Mother substrate, 2: Substrate holder, 3: Discharge head, 4: X direction moving guide, 5: Z direction moving guide, 6: Solution supply pipe, 7: Head maintenance section, 11: Orifice, 12: Pressurizing chamber , 13: diaphragm, 14: piezoelectric element, 15: signal input terminal, 16: piezoelectric element fixing plate, 17: restrictor, 18: common application liquid supply pipe, 19: filter, 20: adhesive, 21: restrictor Plate: 22: Pressurizing chamber plate, 23: Orifice plate, 24: Support plate, 25: Housing, 26: Filter plate, 31: Color filter substrate for liquid crystal, 32: Pixel cell, 33: Light shielding film, 34: Spacer assembly Body, 35: detached part, 36: uncoated part.

Claims (3)

A discharge head in which a large number of orifices are arranged in a straight line;
An adherend for landing a droplet discharged from the orifice of the discharge head to form a dot row along the direction of arrangement of the orifice;
Moving means for relatively reciprocating the discharge head and the adherend along the direction in which the orifices are arranged and the direction perpendicular to the arrangement direction;
In the droplet discharge method of forming a dot row on the adherend by discharging the droplet from the orifice by relatively moving the discharge head and the adherend by the moving means,
The orifices on the ejection head are divided into a plurality of groups in order along the arrangement direction, and droplets are ejected from the orifices for each group.
The moving means relatively moves the discharge head and the adherend from the orifice so that the dot rows are formed on the adherend in an order different from the order of the groups of the discharge heads. A droplet discharge method, wherein a droplet is discharged. A discharge head in which a large number of orifices are arranged directly above;
An adherend in which a large number of dot rows that land along droplets discharged from the orifices of the discharge head and extend in the direction in which the orifices are arranged are arranged in a direction perpendicular to the direction in which the orifices are arranged;
Moving means for relatively reciprocating the discharge head and the adherend along the direction in which the orifices are arranged and the direction perpendicular to the arrangement direction;
In the droplet discharge method of forming a dot row on the adherend by discharging the droplet from the orifice by relatively moving the discharge head and the adherend by the moving means,
The orifices on the ejection head are divided into a plurality of groups along the arrangement direction, and droplets are ejected from the orifices for each group.
The dot rows are formed in an order different from the order of the groups of the ejection heads,
And the dot portion in the direction orthogonal to the arrangement direction of the adjacent dot rows is formed by different groups of the ejection heads,
A droplet discharge method, wherein a droplet is discharged from the orifice by relatively moving the discharge head and the adherend by the moving means.   3. The droplet discharge method according to claim 1, wherein the adherend is a liquid crystal substrate, and droplets containing spacer particles for maintaining a gap between the two liquid crystal substrates are discharged from the orifice to the liquid crystal. A droplet discharge method characterized by discharging toward the surface of a substrate.

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