JPH08304816A - Reflecting plate for reflection type liquid crystal display device - Google Patents

Abstract

PURPOSE: To obtain such a structure of a reflecting plate of a reflection type liquid crystal display device that the use efficiency of light is improved and a reflection type liquid display device easy to see is obtd. CONSTITUTION: This reflection type liquid crystal display device is produced by disposing polarizing plates 13, 14 on both surfaces of a liquid crystal panel and further disposing a reflecting plate 11 on either surface of the panel. The liquid crystal panel consists of a pair of substrates 1, 2 each having transparent electrodes 6, 7 and orienting films 8, 9, respectively, on the inner surfaces, and a peripheral seal 15, spacer and liquid crystal material. The reflecting plate 11 consists of a metallic plate such as aluminum, a plastic plate or film of a thermoplastic resin. The surface of the reflecting plate 11 is made as a reflecting surface having a specified pitch and radius of curvature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a reflection plate of a reflection type liquid crystal display device, and more particularly to an improvement of the reflection plate for obtaining a reflection type liquid crystal display device with an improved light utilization efficiency.

[0002]

BACKGROUND ART Liquid crystal displays for office automation (OA) are roughly divided into one, a notebook type word processor and a personal computer for personal use with an emphasis on portability, and the other is a replacement for a desktop machine. It is a space-saving workstation type with excellent functions and expandability. By the way, in a personal note-type word processor or personal computer, it is necessary to satisfy the two requirements of being lightweight and being thin. In order to satisfy this condition, it is necessary to omit the backlight and drive the battery, which requires low power consumption. However, in a reflective color liquid crystal panel that does not use a backlight, there is a problem that the brightness is insufficient because the amount of light and the contrast ratio cannot be obtained by using a color filter.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to obtain a sufficient contrast ratio and brightness without using a light source from the back surface. It is an object of the present invention to provide a reflection plate for a reflection type liquid crystal display device which can be further reduced in weight, thinned and reduced in power consumption because a light source is not required.

[0004]

In order to solve the above problems, the present invention provides a liquid crystal composed of a transparent electrode, a pair of substrates each having an alignment film formed on each inner surface, a peripheral seal, a spacer and a liquid crystal material. Polarizing plates are provided on both sides of the panel,
Further, in the reflection type liquid crystal display device in which a reflection plate is provided on either one of the surfaces, the reflection plate is formed of a reflection surface having a curvature, which is a reflection plate for a reflection type liquid crystal device.

FIG. 1 is a sectional view of elements of a reflective liquid crystal display device according to an embodiment of the present invention. FIG. 2 shows the relationship of the condensed distance of the reflected light on the front surface of the panel when the radius of curvature of the reflection plate of the reflection type liquid crystal display device of the present invention is changed. The contents of the present invention will be described in detail below. As shown in FIG. 1, a color filter layer 4, an overcoat layer 5, a transparent electrode 6 and an alignment film 8 are sequentially formed inside a first glass substrate 1 having a thickness of 0.7 mm and a refractive index of 1.52. . On the other hand, the transparent electrode 7 and the alignment film 9 are provided inside the second glass substrate 2 having a thickness of 0.7 mm and a refractive index of 1.52.
Are sequentially formed. Internally processed glass substrates 1 and 2
After the alignment treatment, the sealant is applied except the portion around the glass substrate where the liquid crystal is injected, and the sealant is hardened while the spacers are scattered and the cell gap is maintained to complete the liquid crystal cell. After that, liquid crystal is injected through the injection hole and sealed, and a polarizing plate and a reflection plate are attached to complete a reflection type liquid crystal display device.
The reflector is a surface-treated metal plate such as aluminum or a plastic plate or film, and the surface of the plastic plate or film is a thin film such as aluminum formed as a reflecting surface. The curvature pitch of the reflector is matched with the pitch of the red, green, and blue color filters, and when the reflector is set on the liquid crystal panel, the alignment mark is used to align with the pitch of the color filters.

In the reflection type liquid crystal display device having the above structure, the radius of curvature of the reflection plate is 0 to 2000.
FIG. 2 shows the collection distance of the reflected light on the entire surface of the panel when it is changed in the range of mm. The refractive index of the liquid crystal used this time is 1.50, and the image plane distance in the plane through which light sequentially passes was obtained using the following formula, and finally the focal distance to the front surface of the panel was obtained. _{n 1 / S + n 2 /} S '= (n 1 -n 2) / R n 1: refractive index of the first surface, n _2: refractive index of the second surface, R: curvature of the first surface radius, S: source To the first surface, S '
: Image plane distance

[0007]

[Action] As is clear from FIG. 2, it has the curvature of the present invention.
The radius of curvature of the reflector is changed by using the reflector.
Allows the collection distance of the reflected light on the front of the panel to be set arbitrarily.
Can be set. Has a shape with a radius of curvature of 500 mm or more
By installing a reflection plate,
Incident light reaches the reflector and is reflected by the reflector.
The reflected light is at the position of 200-500mm on the front of the panel.
Collect light. In other words, near the eye position of the person watching the panel
The reflected light is condensed and a high contrast ratio can be obtained,
The display can be brightened.

[0008]

【Example】 Hereinafter, the reflective liquid crystal display device reflection plate of the present invention
An embodiment of a manufacturing method will be described in detail with reference to the drawings.
It FIG. 1 shows a reflection type liquid crystal display device using the reflection plate of the present invention.
It is an element sectional view showing one example of. First, 0.7m
m on the first and second glass substrates 1 and 2 by photolithography
An alignment mark for alignment is formed by using this.
Specifically, by sputtering or vacuum deposition on a glass substrate
100% metal film such as chromium, chromium oxide, nickel, copper
A film with a thickness of about 0Å is formed to form a shielding metal film. this
Photoresist by spinner coating on the shielding metal film
A film is formed and the alignment pattern is applied to this photoresist film.
Resist pattern for alignment by exposing and developing
Form Next, etch the parts other than the resist pattern.
After corroding with the etching solution, peel off the resist pattern and
Aligner is formed on the first and second glass substrates 1 and 2.
Is done.

Next, a metal thin film of chromium, chromium oxide or the like is formed on the first glass substrate 1 on which the alignment marks are formed by vacuum vapor deposition, sputtering, etc. and patterned by photolithography to form the black matrix 3. To do. At that time, the black matrix 3 is positioned with reference to the alignment mark. Furthermore, 4
A color filter layer 4, an overcoat layer 5, a transparent electrode 6, and an alignment film 8 having a repeating pattern of R, 4G, and 4B are sequentially formed.

Next, a transparent conductive film of indium oxide or the like is formed on the second glass substrate 2 on which the alignment marks are formed by vacuum vapor deposition, sputtering, etc., and patterned by photolithography to form a transparent electrode 7. Further, a polyimide resin is applied and dried to form the alignment film 9. Here, the color filter layer 4, the overcoat layer 5, the transparent electrodes 6 and 7, the alignment films 8 and 9, the polarizing plates 13 and 14, and the seal portion 15 are made of materials and processes used for manufacturing a general liquid crystal panel. Can be used.

As the reflector 11 of the present invention, a metal plate, a plastic plate, or a film surface-treated to have a predetermined curvature is used. As a method of obtaining a predetermined curvature shape, a method of directly machining the surface of a metal plate or a plastic plate, a method of processing the surface of a metal, a thermoplastic resin plate or a film by heat pressing using a mold, a thermoplastic resin There are various methods such as a method of surface-treating by extrusion molding, but which method can be appropriately used depending on quality and cost. In the case of a plastic plate or film, a thin metal film having a good reflection property such as aluminum is formed as a reflection film. The method of forming and processing the reflector 11 used in the present invention is not limited at all.

After the alignment processing of the alignment films 8 and 9 of the first glass substrate 1 and the second glass substrate 2 whose inner surfaces have been processed as described above, U
Apply a sealant consisting of V adhesive around the glass substrate,
Spacers are scattered, the first glass substrate 1 and the second glass substrate 2 are overlaid, and the alignment marks are used for alignment.
Ultraviolet rays are applied to cure the seal portion 15, and a liquid crystal cell in which a gap between both substrates is held by a spacer is obtained. Liquid crystal is injected into the obtained liquid crystal cell, the liquid crystal cell is sealed, a polarizing plate is attached to both surfaces of the liquid crystal cell, and then the reflection plate 11 is attached via a transparent adhesive. At this time, the curvature pitch of the reflection plate 11 and the red color,
It is necessary to match the pitch of the green and blue color filters. Here, if the reflection plate 11 is fixed in a state where the alignment mark formed on the reflection plate and the alignment mark on the second glass substrate are aligned, if the alignment marks of both glass substrates are aligned when the liquid crystal cell is formed. It is possible to match each color pitch of the color filters with the curvature pitch of the reflection plate 11. A reflective liquid crystal display device using the reflector 11 of the present invention can be manufactured by the above method.

[0013]

In the reflection type color liquid crystal display device incorporating the reflection plate 11 of the present invention, the radius of curvature is 500-12.
By using the reflection plate 11 of 00 mm, the incident light incident from the front surface and the periphery of the panel passes through the liquid crystal layer and the reflection plate 1
Since the reflected light is reflected at 1, and the reflected light is condensed at a position of 200 to 500 mm on the entire surface of the panel, a good contrast ratio and a bright display can be obtained.

[0014]

[Brief description of drawings]

FIG. 1 is an element cross-sectional view of a reflective color liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a condensed distance of reflected light on the front surface of the panel when the radius of curvature of the reflection plate of the reflection type color liquid crystal display device of the present invention is changed.

[Explanation of symbols]

 1 ... 1st glass substrate 2 ... 2nd glass substrate 3 ... black matrix 4 ... color filter layer 4R ... red color filter 4G ... green color filter 4B ... blue color filter 5 ... overcoat layer 6, 7 ... ... Transparent electrode layers 8 and 9 ... Alignment film 10 ... Liquid crystal layer 11 ... Reflector 12 ... Transparent adhesive layer 13 and 14 ... Polarizing plate 15 ... Seal part

Claims (2)

[Claims] 1. A polarizing plate is provided on both surfaces of a liquid crystal panel composed of a transparent electrode, a pair of substrates each having an alignment film formed on each inner surface, a peripheral seal, a spacer and a liquid crystal material, and one of the surfaces is further provided with a polarizing plate. A reflection type liquid crystal display device provided with a reflection plate, wherein the reflection plate is formed from a reflection surface having a curvature. 2. The reflection plate according to claim 1, which is 500 to 120.
A reflective plate for a reflective liquid crystal display device, which has a reflective surface having a radius of curvature of 0 mm.