JP2013007916A - Liquid crystal material applying device and liquid crystal material applying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal material applying device and a liquid crystal material applying method which are capable of dropping a trace amount of a liquid crystal material with a fine pitch, and as a result, are capable of reducing gaps of a liquid crystal material layer of a liquid crystal panel.SOLUTION: The liquid crystal material applying device for applying a liquid crystal material to a substrate includes: liquid crystal material storage means 22 in which the liquid crystal material is stored; inner pressure control means 16a, 17, and 20 which is connected to the liquid crystal material storage means 20 and maintains inner pressure of the liquid crystal material storage means 22 within a prescribed range; and inkjet applying means 11 which is connected to the liquid crystal material storage means 22 and applies the liquid crystal material to the substrate. The inner pressure control means is configured to include gas supply parts 18 and 18a for supplying atmospheric air or an arbitrary gas to the liquid crystal material storage means and negative pressure supply parts 17, 17a, and 20 for supplying negative pressure to the liquid crystal material storage means.

Description

  The present invention relates to a liquid crystal material coating apparatus and a liquid crystal material coating method for coating a liquid crystal material on a substrate.

  Conventionally, a microsyringe has been used as means for dropping a liquid crystal material onto a glass plate (substrate). In this microsyringe system, the discharge amount per drop is managed in milligram units, and the dropping pitch is in millimeters. In relation to such a technique, for example, in Patent Document 1, the viscosity of the alignment film material is adjusted to a range of 5 to 13 (cp), the surface tension is adjusted to a range of 30 to 37 dyn / cm, and the initial alignment to the inkjet head is performed. When supplying a film material, or when ejection failure occurs in the inkjet head due to bubbles, bubbles inside the inkjet head are dissolved using a degassing solvent that dissolves in the alignment film material and has a degassing property. A method of forming an alignment film of a liquid crystal display element is described in which the interior of the ink jet head is replaced with the alignment film material from the degassing solvent after the removal.

Japanese Patent No. 3073493

  However, the technique described in Patent Document 1 is a technique applied to the production of an alignment film of a liquid crystal image display device, and could not be used for coating a liquid crystal material finer than before.

  The present invention has been made in view of these problems, and the liquid crystal material can be dropped at a minute and fine pitch. As a result, the liquid crystal material layer of the liquid crystal panel can be narrowed. It is an object to provide a liquid crystal material coating apparatus and a liquid crystal material coating method.

  The present invention provides a liquid crystal material coating apparatus and a liquid crystal material coating method that can drop a liquid crystal material at a minute and fine pitch, and as a result, can narrow a liquid crystal material layer of a liquid crystal panel. The solution is described below.

  The present invention is a liquid crystal material application device for applying a liquid crystal material to a substrate, wherein the liquid crystal material storage means stores the liquid crystal material, and is connected to the liquid crystal material storage means, and the internal pressure of the liquid crystal material storage means is predetermined. An internal pressure control unit that controls the liquid crystal material to be maintained within a range; and an inkjet type application unit that is connected to the liquid crystal material storage unit and applies the liquid crystal material to the substrate. The internal pressure control unit of the liquid crystal material application apparatus includes a gas supply unit that supplies air or an arbitrary gas to the liquid crystal material storage unit, and a negative pressure supply unit that supplies a negative pressure to the liquid crystal material storage unit. It is characterized by comprising.

  According to such a configuration, the pressure is maintained within a predetermined range by supplying a gas (or an arbitrary gas such as an inert gas) from the gas supply unit and supplying a negative pressure from the negative pressure supply unit. The liquid crystal material can be applied with a fine pitch, and the thickness unevenness of the liquid crystal panel and the liquid crystal material layer can be made narrow. Further, since the liquid crystal material can be discharged with a uniform pressure, the liquid crystal can be dropped in a certain amount.

  At this time, the liquid crystal material storage means is connected to a first pipe constituting the gas supply section and a second pipe constituting the negative pressure supply section, and the first pipe and the liquid crystal material. The internal pressure control means is configured such that the internal pressure is maintained by the gas flowing in this order through the inside of the storage means and the second pipe.

  According to such a configuration, the internal pressure of the liquid crystal material storage unit can be maintained with a simple configuration.

  Furthermore, the application means is an ink jet head.

  According to such a configuration, the manufacturing cost of the liquid crystal material coating apparatus can be reduced.

  Furthermore, a heating / cooling means for heating or cooling the coating means is provided.

  According to such a configuration, the physical property value such as the viscosity of the liquid crystal material can be arbitrarily managed at the nozzle portion of the head portion.

  The present invention is also a liquid crystal material application method for applying a liquid crystal material to a substrate, wherein the internal pressure of the liquid crystal material storage means storing the liquid crystal material is supplied, and the atmosphere or any gas is supplied to the liquid crystal material storage means The liquid crystal material is applied to the substrate by an ink jet type application means while being maintained within a predetermined range by a gas supply portion that performs the above operation and a negative pressure supply portion that supplies a negative pressure to the liquid crystal material storage means. .

  At this time, the liquid crystal material storage means is connected to a first pipe constituting the gas supply section and a second pipe constituting the negative pressure supply section, and the first pipe and the liquid crystal material storage means. The internal pressure is maintained by the gas flowing in this order through the interior of the pipe and the second pipe.

  Furthermore, the application means is an ink jet head.

  Then, the coating means is heated or cooled by a heating / cooling means.

  According to the present invention, a liquid crystal material coating apparatus and a liquid crystal material coating method capable of narrowing a liquid crystal material layer of a liquid crystal panel that can drop liquid crystal material with a minute amount and a fine pitch are provided. can do.

The cross-section figure of a liquid crystal image display apparatus is shown. 1 shows a system configuration diagram of a liquid crystal material application system to which a liquid crystal material application device according to an embodiment is applied. 1 is an external view of a liquid crystal material dropping apparatus to which a liquid crystal material coating apparatus according to an embodiment is applied. The schematic of the principal part of the liquid-crystal material coating device by embodiment is shown. The principal part of the liquid-crystal-material application | coating apparatus by a comparative example is shown. The comparison figure for demonstrating the difference with a comparative example and this Embodiment is shown. As for the method of injecting the liquid crystal material according to the embodiment into the gap between two glass plates, (a) shows before bonding and (b) shows after bonding. About the method of inject | pouring the liquid crystal material by a comparative example into the clearance gap between two glass plates, (a) shows before bonding and (b) shows after bonding.

  An embodiment of the present invention will be described in detail with reference to FIGS.

  First, in order to help understanding of the structure of the liquid crystal image display device manufactured by the liquid crystal material coating apparatus according to the present embodiment, a description will be given. In FIG. 1, this is a cross-sectional view simply showing the internal structure of the liquid crystal image display device 10. The configuration of the liquid crystal image display device 10 is generally composed of a polarizing filter 5, a glass substrate 4, a transparent electrode 3, an alignment film 2, a liquid crystal material 1, and a color filter 6. Note that any known configuration can be used for these components, and a detailed description thereof will be omitted.

  In the configuration of FIG. 1, when a voltage is applied to the transparent electrode 3, molecules of the liquid crystal material 1 sandwiched between the two light distribution films 2 facing each other stand up, and light from the outside strikes the color filter 6. The color becomes visible. Since the transparent electrodes 3 are arranged so as to be orthogonal to each other, a voltage can be applied by selecting an arbitrary intersection, so that drawing can be performed by selectively making the arbitrary intersection visible in the aggregate of these intersections. It becomes.

  FIG. 2 shows a system configuration diagram of a liquid crystal material coating system to which the liquid crystal material coating apparatus according to the embodiment is applied. The liquid crystal material application system 24 shown in FIG. 2 includes a control device 24A and a liquid crystal material application device 24B, and both the devices 24A and 24B are connected via a wiring section 48.

  Of the liquid crystal material application system 24, the control device 24A includes a main PC (personal computer) 30, a motor controller 31, an amplifier 32, a motor control unit 33, an inkjet controller 34, an inkjet printer PC 36, An external input interface unit 37, a temperature controller 40, and an SSR (solid state relay) 41 are included.

  Of the liquid crystal material application system 24, the liquid crystal material application device 24B includes the head 11, the heater 12, the regulator 20, the negative pressure indicator (pressure gauge) 21, the liquid crystal material tank 22, and the thermocouple 42. It is configured to include. The electronic balance 39 is used to measure the discharge amount from the head 11 and adjust the coating amount.

  Incidentally, the inkjet controller 34 and the head 11, the SSR 41 and the heater 12, and the temperature controller 40 and the thermocouple 42 are connected via the wiring part 48, respectively. Note that any of these known configurations of the liquid crystal material application system 24 can be used, and a detailed description thereof will be omitted. For simplification of illustration, a line for replenishing the liquid crystal material 1 described with reference to FIG. 4 is omitted.

  Further, the liquid crystal material application device 24B in the liquid crystal material application system 24 shown in FIG. 2 is housed in a housing as shown in FIG. 3, and the liquid crystal material 1 is dropped (applied) onto the glass substrate 4. . In FIG. 3, the liquid crystal material application device 24B is housed in a liquid crystal material dropping device 50. The liquid crystal material dropping device 50 includes a glass substrate 4 to which the liquid crystal material 1 is dropped, and a liquid crystal material. Shown are linear motors 53 and 54 for horizontally moving the tank 22 and the liquid crystal material tank 22 back and forth in the direction of the arrows in the figure. In addition to the linear motor, a linearly movable motor configuration such as a ball screw or a rack and pinion can be arbitrarily applied. The head 11 of the liquid crystal material dropping device 50 is arranged below the liquid crystal material tank 22 (that is, has a height difference), and FIG. 3 shows a case where four units are arranged in parallel. The liquid crystal material tank 22 is moved horizontally with respect to the glass substrate 4 by the linear motor 53. During this movement, the head 11 drops a predetermined amount of the liquid crystal material 1 onto the surface of the glass substrate 4. In FIG. 3, some members are omitted.

  In such a configuration, a liquid crystal panel used in a liquid crystal image display device is manufactured. In this system, the liquid crystal material 1 is dropped onto a glass substrate 4 (with the light distribution film 2 and the transparent electrode 3 disposed). Conventionally, the liquid crystal material 1 is filled into a microsyringe, The liquid crystal material 1 was dripped at a predetermined amount at the position. FIG. 4 shows a schematic view (main part enlarged view) of the liquid crystal material coating apparatus 24B of the present embodiment.

  In the liquid crystal material application device 24B shown in FIG. 4, as a configuration for applying the liquid crystal material to the substrate, the liquid crystal material storage means (liquid crystal material tank 22) for storing the liquid crystal material is connected to the liquid crystal material storage means. An internal pressure control unit that controls the internal pressure of the liquid crystal material storage unit to be maintained within a predetermined range; and an ink jet type application unit that is connected to the liquid crystal material storage unit and applies the liquid crystal material to the substrate. It is what it has.

  That is, the liquid crystal material coating apparatus 24B shown in FIG. 4 includes an inkjet head 11 (coating means), a heater 12, a heater wiring 23, valves 15, 16, 17, 18, and a pipe 16a (first piping). ), Pipe 17a (second pipe), pipe 18a, liquid crystal material tank 22 (liquid crystal material storage means), leak valve 19, regulator 20, pressure gauge 21, cooler 13 and cooling air 14 It is shown. The valves 16 and 17, the pipes 16 a and 17 a, and the regulator 20 correspond to “internal pressure control means”. Incidentally, in this embodiment, the valves 16 and 17 are ON / OFF electromagnetic valves, but may be manual ON / OFF valves, manual or electric needle valves, and the like.

  The valve 16 and the pipe 16a (first pipe) correspond to a “gas supply unit”. The valve 17, the pipe 17a (second pipe), and the regulator 20 correspond to a “negative pressure supply unit”.

  A liquid crystal material tank 22 is connected to the head 11 via a valve 15. This valve 15 controls the flow of the liquid crystal material 1 toward the head 11 side. In addition, a heater 12 is attached to the head 11 so that the head 11 can be kept warm to a desired temperature. Although not shown in FIG. 2, a cooler 13 is provided, and when it is desired to cool the head 11, the cool air 14 can be blown from the cooler 13 to the head 11 to lower the temperature. A desired temperature of the head 11 can be obtained by controlling the heater 12 and the cooler 13 in combination. For such temperature control, the optimum value is determined by the relationship of the physical properties such as temperature and viscosity of the liquid crystal material 1 ejected from the head 11. In addition, the heater 12 and the cooler 13 (that is, heating and cooling means) may be formed integrally or separately.

  In the configuration disclosed in FIG. 4, three pipes 16 a, 17 a, and 18 a are connected to the liquid crystal material tank 22. The inside of the liquid crystal material tank 22 is kept at a negative pressure by a line connected to the regulator 20 by the pipe 17a. By maintaining the negative pressure, the liquid crystal material 1 is prevented from being drawn from the head 11 due to gravity and unintentional dripping. The pipe 18 a is a line for replenishing the liquid crystal material 1 to the liquid crystal material tank 22 through the valve 18. The liquid crystal material 1 in the liquid crystal material tank 22 decreases in proportion to the application of the liquid crystal material 1 by the head 11. Due to this decrease, the internal pressure (internal pressure) of the liquid crystal material tank 22 decreases (negative pressure increases), and the pressure becomes unstable (pressure change due to so-called water head difference).

  In order to realize accurate discharge of the liquid crystal material 1, it is necessary to precisely control and manage the pressure in the liquid crystal material tank 22. For this purpose, a pipe 16 a is connected to the liquid crystal material tank 22 via the valve 16. From this pipe, air or an inert gas such as nitrogen gas is preferably supplied. That is, the internal pressure control means is configured so that the internal pressure is maintained within a predetermined range by the gas flowing through the pipe 16a, the liquid crystal material tank 22 and the pipe 17a in this order. By controlling the water head difference correction in this way, a slight change in the discharge amount of the liquid crystal material 1 is corrected, and a minute amount and precise discharge of the liquid crystal material 1 is realized. By performing such control, an inkjet head (for example, an inkjet head) that has been difficult to use in the past can be suitably used. As a result, the very small liquid crystal material 1 can be dropped (applied).

  In addition, FIG. 5 is the structure used for the liquid crystal dropping by the comparative example which does not perform water head difference correction. That is, the pipe 16a and the head 11 are not provided, but the micro syringe 25 is provided instead. In the case of this configuration, only pressure control by the regulator 20 is performed, so that there is a time lag in the control, or correction at a precise angle is difficult, and the extremely small liquid crystal material 1 cannot be dropped.

  FIG. 6 is a diagram comparing the dropping of the liquid crystal material 1 by the micro syringe method of the comparative example and the dropping of the liquid crystal material 1 by the IJ (ink jet) method using the head 11 according to the present embodiment. In the microsyringe method, the diameter of the discharge nozzle of the liquid crystal material 1 was about φ0.1 to φ1.0 mm. Therefore, the dropped liquid crystal material 1 was large and separated from each other as shown in FIG.

  On the other hand, in the IJ method according to the present embodiment, the diameter of the discharge nozzle of the liquid crystal material 1 is about φ10 μ to φ80 μm, and therefore sufficiently dense dripping can be realized with high accuracy. In the microsyringe method, unevenness 57, a collision mark 58, and a drop mark 59 are generated by bonding the glass plates after the liquid crystal material 1 is dropped, and it is difficult to realize a liquid crystal layer having a uniform thickness. On the other hand, in the IJ method according to the present embodiment, the liquid crystal layer 60 can be densely dropped as shown in FIG. it can.

  FIG. 7 is a model diagram of formation of a liquid crystal layer using the IJ method according to the present embodiment, and the liquid crystal material 1 is dropped between the glass substrates 4 as shown in FIG. When this is bonded as shown in (b), the cell gap variation can be made extremely small. Moreover, the surface of the glass substrate 4 can also be made flat.

  FIG. 8 shows a microsyringe method of a comparative example. When the liquid crystal material 1 is dripped in a large amount and the liquid crystal material 1 is sandwiched between the light distribution films 2, the cell gap varies greatly, and the liquid crystal material 1 hardly spreads. The surface of the light distribution film 2 could not be flattened.

  As described above, according to the present embodiment, the liquid crystal material can be dropped (applied) at a minute and fine pitch, and as a result, the liquid crystal material layer can be narrowed in the liquid crystal material layer. The material dropping device 50 (that is, the liquid crystal material coating device 24B) can be provided. In particular, gas flows in this order through the pipe (first pipe) 16a, the liquid crystal material tank (liquid crystal material storage means) 22 and the pipe (second pipe) 17a to reach the regulator 20 as a negative pressure source. By doing so, it is possible to suitably control the pressure (water head differential pressure). That is, the discharge of the liquid crystal material from the nozzle 11 decreases the capacity (that is, the liquid level) of the liquid crystal material tank 22, thereby changing (increasing) the negative pressure (internal pressure) of the head space in the liquid crystal material tank 22. This affects the discharge amount of the liquid crystal material 1 from the nozzle 11. This change in negative pressure can be quickly replenished by supplying gas from the pipe 16a directly connected to the head space in the tank 22, and as a result, the change in the remaining amount of the liquid crystal material 1 in the liquid crystal material tank 22 is discharged. An excellent liquid crystal material dropping device 50 (liquid crystal material coating device 24B) that is not affected by the amount can be provided.

DESCRIPTION OF SYMBOLS 1 Liquid crystal material 2 Light distribution film 3 Transparent electrode 4 Glass substrate 5 Polarizing filter 6 Color filter 10 Liquid crystal image display apparatus 11 Head 12 Heater 13 Cooler 14 Cooling air 15, 16, 17, 18 Valve 16a Pipe (1st piping)
17a Pipe (second pipe)
19 Leak valve 20 Regulator 21 Pressure gauge 22 Liquid crystal material tank (Liquid crystal material storage means)
23 Heater wiring 24 Liquid crystal material application system 24A Control device 24B Liquid crystal material application device 25 Micro syringe 30 Main PC
DESCRIPTION OF SYMBOLS 31 Motor controller 32 Amplifier 33 Motor control part 34 Inkjet controller 37 Inkjet head control unit 50 Liquid crystal material dripping apparatus 53,54 Linear motor 57 Unevenness 58 Collision trace 59 Dripping trace 60 Liquid crystal dripping trace by this Embodiment

Claims (8)

A liquid crystal material application device for applying a liquid crystal material to a substrate,
Liquid crystal material storage means for storing the liquid crystal material;
An internal pressure control means connected to the liquid crystal material storage means for controlling the internal pressure of the liquid crystal material storage means within a predetermined range;
An inkjet type application means connected to the liquid crystal material storage means and applying the liquid crystal material to the substrate;
With
The internal pressure control unit includes a gas supply unit that supplies air or an arbitrary gas to the liquid crystal material storage unit, and a negative pressure supply unit that supplies a negative pressure to the liquid crystal material storage unit. A liquid crystal material coating apparatus. The liquid crystal material storage means is connected to a first pipe constituting the gas supply section and a second pipe constituting the negative pressure supply section,
The internal pressure control means is configured such that the internal pressure is maintained by gas flowing in this order through the first pipe, the liquid crystal material storage means, and the second pipe in this order. The liquid crystal material coating apparatus according to claim 1. The liquid crystal material coating apparatus according to claim 1, wherein the coating unit is an inkjet head. The liquid crystal material coating apparatus according to claim 1, further comprising a heating / cooling unit that heats or cools the coating unit. A liquid crystal material application method for applying a liquid crystal material to a substrate,
An internal pressure of the liquid crystal material storage means in which the liquid crystal material is stored, a gas supply section for supplying air or an arbitrary gas to the liquid crystal material storage means, and a negative pressure supply section for supplying a negative pressure to the liquid crystal material storage means The liquid crystal material application method is characterized in that the liquid crystal material is applied to the substrate by an ink jet type application means while being maintained within a predetermined range. The liquid crystal material storage means is connected to a first pipe constituting the gas supply section and a second pipe constituting the negative pressure supply section,
6. The liquid crystal material application according to claim 5, wherein the internal pressure is maintained by gas flowing in this order through the first pipe, the inside of the liquid crystal material storage means, and the second pipe. Method. The liquid crystal material coating method according to claim 5, wherein the coating unit is an inkjet head. The liquid crystal material coating method according to claim 5, wherein the coating unit is heated or cooled by a heating / cooling unit.

Images