JP4864405B2 - Ferroelectric liquid crystal display device - Google Patents

Description

  The present invention relates to a ferroelectric liquid crystal display element.

  Conventionally, in a ferroelectric liquid crystal display device, the peripheral portions of a pair of substrates are sealed with a sealing material, and a ferroelectric liquid crystal is injected between the substrates through an injection port provided in the sealing material, and then sealed in the injection port. A configuration in which a stopper is applied and sealed is known. FIG. 3 is an enlarged view of the vicinity of the injection port of a ferroelectric liquid crystal display device according to the prior art. When the X-axis and Y-axis are installed on the side of the display pixel 3 as shown in the figure, the peripheral sealing material 2 is formed parallel to the X-axis and Y-axis, and the injection port 1 is in the X-axis direction or Y-axis direction. Generally, it is formed in the Y-axis direction in the figure.

  In the above conventional configuration, when a bistable ferroelectric liquid crystal is used as a display device, the longitudinal direction of the liquid crystal molecules is parallel to the X-axis or Y-axis of the substrate plane at least in one optically stable state. In general, alignment control is generally performed. In this case, the alignment control direction of the alignment film is often required to be inclined with respect to the XY axis of the substrate plane. Ferroelectric liquid crystals have a layer structure between narrow substrates on which alignment control films are formed. When the orientation is controlled so that the longitudinal direction of the ferroelectric liquid crystal molecules is parallel to the X axis or Y axis of the substrate plane, the liquid crystal layer direction is inclined with respect to the XY axis of the substrate plane. In the case of a ferroelectric liquid crystal display element having a layer structure, a specific layer structure defect occurs due to a slight stress, which causes a display defect. The layer structure defect is likely to occur in the vicinity.

As a technique for solving the above problem, a ferroelectric liquid crystal display device in which a ferroelectric liquid crystal is sandwiched between a pair of substrates is provided for injecting a ferroelectric liquid crystal into the ferroelectric liquid crystal display device. A technique for orienting ferroelectric liquid crystal so that a layer extending from the intersection of the inlet and the layer of the injected ferroelectric liquid crystal does not intersect the display parting inner region is disclosed. (For example, Patent Document 1)
JP-A-5-188379

  The technique disclosed in Patent Document 1 is not a technique for preventing the occurrence of a layer structure defect. Therefore, when the layer structure defect spreads, the layer structure defect enters the display parting. In addition, the layer extending from the intersection of the injection port provided for injecting the ferroelectric liquid crystal into the ferroelectric liquid crystal display device and the layer of the injected ferroelectric liquid crystal does not intersect the display parting area. Therefore, an unnecessary part is required outside the parting.

In order to solve the above-described problem, the ferroelectric liquid crystal display element of the present invention includes at least a pair of substrates on which an alignment control film is formed and a ferroelectric liquid crystal partially including a peripheral portion of the pair of substrates. A layered structure of the ferroelectric liquid crystal , comprising: a sealing member which is provided with an injection port for injection, a ferroelectric liquid crystal injected from the injection port, and a sealing material for sealing the injection port there a ferroelectric liquid crystal display element Ru is formed in a direction perpendicular to the alignment control direction of the alignment layer, one side of the protruding portion of said injection port, the inclination with respect to the XY axis of the substrate plane of the substrate and the said alignment control film ferroelectric liquid crystal display device in the alignment control direction that are substantially perpendicular to the.

At least a pair of substrates on which an alignment control film is formed, a seal member for bonding by providing an injection port for injecting ferroelectric liquid crystal in a part of the periphery of the pair of substrates, and injection from the injection port A ferroelectric liquid crystal and a sealing material for sealing the injection port, and the ferroelectric liquid crystal layer structure is formed in a direction perpendicular to the alignment control direction of the alignment control film A ferroelectric liquid crystal display, wherein one side of the projection of the injection port is inclined with respect to an XY axis of a substrate plane of the substrate and substantially parallel to an alignment control direction of the alignment control film. Element.

At least a pair of substrates on which an alignment control film is formed, a seal member for bonding by providing an injection port for injecting ferroelectric liquid crystal in a part of the periphery of the pair of substrates, and injection from the injection port A ferroelectric liquid crystal and a sealing material for sealing the injection port, and the ferroelectric liquid crystal layer structure is formed in a direction perpendicular to the alignment control direction of the alignment control film In the liquid crystal display element, one side of the protrusion of the injection port is inclined with respect to the XY axis of the substrate plane of the substrate and is substantially orthogonal to the alignment control direction of the alignment control film, and the protrusion of the injection port The ferroelectric liquid crystal display element in which the other side of the portion is inclined with respect to the XY axis of the substrate plane of the substrate and is substantially parallel to the alignment control direction of the alignment control film.

  According to the first aspect of the present invention, it is possible to suppress the occurrence of layer structure defects near the inlet. According to the invention of claim 2, it is possible to further suppress the occurrence of layer structure defects. According to the invention of claim 3, a general optical configuration of a polarizing plate in which the stretching axis of the polarizing plate is parallel to the X axis or Y axis of the substrate plane can be used.

  A feature of the embodiment of the present invention is that the liquid crystal layer of the ferroelectric liquid crystal is arranged so that the longitudinal direction of the liquid crystal molecules coincides with one of the XY axes of the substrate plane in one stable state of the bistable ferroelectric liquid crystal. The alignment film is processed in such a manner that one side of the protrusion of the injection port is parallel to the layer direction of the liquid crystal layer and the other side is orthogonal to the layer direction of the liquid crystal layer. There is in point.

  FIG. 1 is an enlarged view of the vicinity of an injection port of a ferroelectric liquid crystal display device according to the present invention, and schematically shows a ferroelectric liquid crystal layer structure. FIG. 2 is a cross-sectional view of a ferroelectric liquid crystal display element. The ferroelectric liquid crystal display element according to the present invention will be described with reference to FIG. Here, a reflective ferroelectric liquid crystal display element having the reflective pixel electrode 8 on the base substrate 13 is exemplified, but it is of course applicable to a transmissive ferroelectric liquid crystal display element using glass or the like as the base substrate.

  This reflective ferroelectric liquid crystal display element is provided with a base substrate 13 on one side and a counter substrate 14 on the other side with a liquid crystal layer 12 interposed therebetween.

  The base substrate 13 is formed with a reflective pixel electrode 8 having a thickness of several thousand と す る mainly composed of aluminum or the like on a circuit substrate 7 having active elements, and an alignment film 9 is formed thereon. Yes. The counter substrate 14 uses a glass substrate as the insulating substrate 11, the transparent electrode 10 is formed on the entire surface thereof, and the alignment film 9 is formed thereon.

  Regarding the formation of the alignment films 9 and 9, an organic film such as polyimide is formed by a method such as spin coating. When the field sequential is adopted using the ferroelectric liquid crystal 12, the high-speed response of the ferroelectric liquid crystal 12 is made more effective (voltage drop is reduced), and the visible light transmittance is not lowered as much as possible. The thickness of the film 9 is preferably small, but if the film thickness is too small, the orientation of the ferroelectric liquid crystal 12 is adversely affected. Considering these, the film thickness is about 200 mm.

  Thereafter, in order to align the ferroelectric liquid crystal molecules, the alignment films 9 and 9 are rubbed with a cotton cloth or the like. Further, the base substrate 13 and the counter substrate 14 are arranged on the side where the alignment film 9 is formed. These surfaces are opposed to each other, and are bonded together through a sealing material 2 in which a spacer ball is mixed and formed with an inlet shape as shown in FIG. In order to create a bistable state of the liquid crystal molecules and to make the high-speed response of the ferroelectric liquid crystal 12 more effective (increase the execution voltage), the diameter of the spacer ball is set to 1.0 μm or less.

  Thereafter, the ferroelectric liquid crystal 12 is injected from the injection port into the space formed between the substrates 13 and 14 by vacuum injection, and the injection port is sealed. Thus, the reflection type ferroelectric liquid crystal display element shown in FIG. 2 is completed.

  As for the shape of the inlet 1 portion of the sealing material 2, for example, as shown in FIG. 1, the cone angle is 40 °, the tilt angle is ± 20 °, and the liquid crystal layer 6 is formed in a direction perpendicular to the alignment control direction 5. When the bistable ferroelectric liquid crystal 12 is controlled so that the longitudinal direction of the liquid crystal molecules of the bistable ferroelectric liquid crystal 12 is parallel to the X axis of the substrate in one stable state, The orientation control direction 5 is a direction inclined by 20 ° from the X axis of the substrate. At this time, the shape of the inlet 1 is inclined by 70 ° from one side of the X axis of the substrate, and the other side is inclined by 20 ° from the X axis of the substrate.

FIG. 2 is an enlarged view of the vicinity of an injection port of a ferroelectric liquid crystal display device according to the present invention, and further schematically shows a ferroelectric liquid crystal layer structure. Cross section of ferroelectric liquid crystal display device Enlarged view of the vicinity of the injection port of a conventional ferroelectric liquid crystal display device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inlet 2 Seal material 3 Display pixel 4 Cone of ferroelectric liquid crystal molecule 5 Orientation control direction 6 Liquid crystal layer direction 7 Circuit board 8 Reflection pixel electrode 9 Orientation film 10 Transparent electrode 11 Insulating substrate 12 Liquid crystal layer 13 Base substrate 14 Opposite substrate

Claims (3)

  At least a pair of substrates on which an alignment control film is formed, a seal member for bonding by providing an injection port for injecting ferroelectric liquid crystal in a part of the periphery of the pair of substrates, and injection from the injection port A ferroelectric liquid crystal and a sealing material for sealing the injection port, and the ferroelectric liquid crystal layer structure is formed in a direction perpendicular to the alignment control direction of the alignment control film In the liquid crystal display element, one side of the protrusion of the injection port is inclined with respect to the XY axis of the substrate plane of the substrate and substantially orthogonal to the alignment control direction of the alignment control film. A ferroelectric liquid crystal display element. At least a pair of substrates on which an alignment control film is formed, a seal member for bonding by providing an injection port for injecting ferroelectric liquid crystal in a part of the periphery of the pair of substrates, and injection from the injection port A ferroelectric liquid crystal and a sealing material for sealing the injection port, and the ferroelectric liquid crystal layer structure is formed in a direction perpendicular to the alignment control direction of the alignment control film In the liquid crystal display element, one side of the protruding portion of the injection port is inclined with respect to an XY axis of a substrate plane of the substrate and substantially parallel to an alignment control direction of the alignment control film. Ferroelectric liquid crystal display element. At least a pair of substrates on which an alignment control film is formed, a seal member for bonding by providing an injection port for injecting ferroelectric liquid crystal in a part of the periphery of the pair of substrates, and injection from the injection port A ferroelectric liquid crystal and a sealing material for sealing the injection port, and the ferroelectric liquid crystal layer structure is formed in a direction perpendicular to the alignment control direction of the alignment control film In the liquid crystal display element, one side of the protrusion of the injection port is inclined with respect to the XY axis of the substrate plane of the substrate and is substantially orthogonal to the alignment control direction of the alignment control film, and the protrusion of the injection port The ferroelectric liquid crystal display element, wherein the other side of the portion is inclined with respect to the XY axis of the substrate plane of the substrate and substantially parallel to the alignment control direction of the alignment control film.

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