KR19980014986A - Reflection type liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of manufacturing the same, wherein a protrusion is formed on a lower substrate in a reflection type LCD to replace a spacer to maintain a cell gap constant, and a cholesteric liquid crystal is mixed with a photo- Since the exposure energy is differently exposed for each of the portions scheduled to be filled with RGB in the LCD, the spiral structure of the liquid crystal in each portion has a pitch that reflects light having a wavelength corresponding to RGB. Therefore, the reflector, the retarder, Filter and the like are unnecessary, the manufacturing process is simple, the manufacturing cost can be reduced, and the cell gap can be maintained constant, so that the image quality can be improved and the reliability of the process yield and device operation can be improved.

Description

Reflection type liquid crystal display device and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective liquid crystal display (LCD) and a method of manufacturing the same, and more particularly to a reflective liquid crystal display (LCD) A filter, a polarizing plate, a phase difference plate, and a reflection plate are not required, and manufacturing cost can be reduced. By replacing the glass substrate with a spacer by forming a protrusion to etch the glass substrate, a manufacturing process is simple, Type LCD and a method of manufacturing the same.

LCD, which is a type of flat panel display, is an apparatus for changing optical anisotropy by applying an electric field to a liquid crystal having optical properties by applying an electric field to a liquid crystal having fluidity of liquid and crystal optical properties. (Cathode Ray Tube), which is low in power consumption, small in volume, large in size, and capable of high definition, is widely used.

A conventional reflective LCD will be described below.

First, the transparent phase. Transparent electrode patterns are formed on the lower substrate, and an alignment layer of a polyimide material is applied on the upper and lower substrates of the structure in order to align the liquid crystal in a predetermined direction, and rubbed to have a directionality.

Then, a seal pattern is formed on the upper or lower substrate to bond the two substrates, and the cell gap between the upper and lower substrates is filled with liquid crystal and sealed. Thereafter, the phase difference plate and the polarizing plate are attached to the upper substrate, A polarizer and a reflector are attached to complete the LCD.

A color filter for coloring an LCD is formed on the lower substrate. In the color filter, a black matrix made of a light blocking material such as chrome is formed on the lower substrate at regular intervals, A RGB pixel is formed by a method such as a silk screen printing or a photolithography after a front coating, and then a protective film made of polyimide or the like is formed on the entire surface of the structure.

In the reflection type color LCD according to the related art as described above, it is difficult to manufacture a color filter, and a transparent electrode pattern is broken due to a step difference caused by a color filter, so that the entire LCD is often defective, And the like.

Further, in order to maintain the cell gap, cylindrical or spherical spacers must be scattered, and a retardation plate or a polarizing plate must be adhered thereto. Thus, there is another problem that the manufacturing cost is high and the process yield is low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a liquid crystal display device which has a protrusion in place of a spacer on a lower substrate and has a cholesteric liquid crystal, And a reflection type LCD in which reliability of device operation can be improved because a manufacturing cost can be reduced due to the small size of the adherend.

It is another object of the present invention to provide a method of manufacturing a liquid crystal display device, which comprises the steps of: forming a projection on a lower substrate by photolithography to form a spacer, replacing the spacers and defining a pitch according to energy exposed by the cholesteric liquid crystal, The liquid crystal itself is simultaneously exposed to other energy so as to perform the role of the color filter. Thus, the manufacturing process is simple, the polarizing plate, the retarder, the color filter, and the like are unnecessary, so that the adherence is small so that the process yield and the reliability Type LCD.

1 to 6 are views showing a manufacturing process of a reflection type liquid crystal display device according to the present invention.

Description of the Related Art [0002]

10: upper substrate 11: transparent electrode

12: protective film 13: lower substrate

14: protrusion 15: yarn pattern

16: liquid crystal 20: exposure mask

21: Exposure area

According to an aspect of the present invention, there is provided a reflective LCD comprising: an upper substrate on which a transparent electrode pattern is formed; a protection film formed on an entire surface of the upper substrate; A transparent electrode formed on the lower substrate; a protective film formed on an entire surface of the lower substrate; A cholesteric liquid crystal in which a pitch is determined by exposure so as to reflect R, G, and B light respectively on a portion corresponding to RGB pixels, and a seal pattern for bonding the lower substrate to the upper and lower substrates; have.

According to another aspect of the present invention, there is provided a method of manufacturing a reflective LCD, including: forming a protrusion on a portion of a lower substrate other than a pixel, the protrusion being formed on the lower substrate; forming a transparent electrode and a protective film on the lower substrate; A step of bonding an upper substrate having a transparent electrode and a protective film on the lower substrate using an actual pattern; A step of injecting and sealing a cholesteric liquid crystal mixed with a photo-curable polymer in a cell gap between the lower substrate and the lower substrate, and a step of exposing the upper and lower substrates using an exposure mask for R, G, And a step of exposing the exposure energy corresponding to E _R E _G E _B such that the pitch of the steric liquid crystal has reflected light of _{R, G, and B} , respectively.

Hereinafter, a reflection type LCD according to the present invention and a method of manufacturing the same will be described in detail with reference to the accompanying drawings.

FIGS. 1 to 6 show a manufacturing process of a reflection type LCD according to the present invention, and FIG. 6 is a cross-sectional view of a final completed step.

First, a part of the lower substrate 13 made of a transparent material such as quartz, glass, or plastic is etched to a predetermined thickness, for example, about 2 to 10 탆, which is about the depth of a cell gap, (See FIG. 1), a transparent electrode 11 pattern made of a transparent conductive material such as ITO or SnO ₂ is formed (see FIG. 2) A protective film 12 of an insulating material is formed on the entire surface of the structure to complete the lower substrate 13. At this time, a separate alignment film may be formed on the top or bottom of the protective film (see FIG. 3).

The upper substrate 10 having the transparent electrode 11 and the protective film 12 is sealed with the seal pattern 15 on the lower substrate 13 and the cholesteric liquid crystal 16 mixed with the photo- Is filled in the cell gap and sealed. In this case, the weight ratio of the polymer to the cholesteric liquid crystal 16 is about 0 to 30% so that the orientation stability of the liquid crystal is improved and the position of the liquid crystal 16 is prevented from changing (see FIG. 4).

Thereafter, The liquid crystal 16 is exposed to ultraviolet rays using an exposure mask 20 in which an exposure region 21 for exposing a portion intended to be an R pixel in the lower substrate 10 or 13 is formed, E _R ) is a helical structure having a pitch such that the liquid crystal 16 reflects the wavelength of the R region of the visible light (see FIG. 5).

Then, the G and B pixels are also subjected to exposure with energy of E _G and E _B , respectively, to have RGB hue. When the exposure energy is increased, the helical pitch of the liquid crystal 16 is reduced, The wavelength is reduced. Therefore, if the exposure energy is E _R E _G E _B , the light reflected by each pixel has a color of RGB, so that a color LCD can be realized without a polarizing plate, a retarder, a reflector, and a color filter. Reference).

The reflective LCD according to the present invention includes an upper substrate 10 having a transparent electrode 11 and a protective film 12 and a lower substrate 13 having a protrusion 14, a transparent electrode 11 and a protective film 12, Is sealed with the seal pattern 15, and the cholesteric liquid crystal 16 mixed with the photo-curing polymer is sealed at the cell gap with a pitch at which the light of the wavelength corresponding to RGB pixels is reflected.

As described above, in the reflection type LCD according to the present invention and the method of manufacturing the same, protrusions are formed on the lower substrate in the reflection type LCD to replace the spacers to maintain a constant cell gap, and a cholesteric liquid crystal The cell gap is filled, and the exposure energy is differently applied to the predetermined angles of the LCD due to the RGB, so that the helical structure of the liquid crystal in each portion has a pitch that reflects light of a wavelength corresponding to RGB, A polarizing plate, and a color filter are not required. Therefore, the manufacturing process is simple, the manufacturing cost can be reduced, and the cell gap can be maintained constant, so that the image quality can be improved and the reliability of the process yield and device operation can be improved.

Claims (8)

An upper substrate on which a transparent electrode pattern is formed, A protective film formed on the entire surface of the upper substrate, A protrusion formed on a portion of the lower substrate other than the pixel, A transparent electrode formed on the lower substrate, A protective film formed on the entire surface of the lower substrate, The above phase. A lower substrate, The above phase. And a cholesteric liquid crystal in which the cell gap between the lower substrate is covered and the pitch is determined by exposure so as to reflect R, G.B light respectively at portions corresponding to R, G, and B pixels. The reflective liquid crystal display of claim 1, wherein the upper and lower substrates are formed of one of quartz, glass, and plastic. The reflective liquid crystal display device according to claim 1, wherein the transparent electrode is formed of ITO or SnO ₂ . The reflective liquid crystal display device according to claim 1, wherein the protruding portion is formed to have a height of 2 to 10 mu m. The reflective liquid crystal display device according to claim 1, wherein the cholesteric liquid crystal is mixed with a photo-curable polymer. The reflection type liquid crystal display device according to claim 5, wherein the photo-curable polymer is mixed with 0 to 30% by weight relative to the cholesteric liquid crystal. A step of forming protrusions on a portion of the lower substrate that is etched away from the pixel, Forming a transparent electrode and a protective film on the lower substrate, A step of joining an upper substrate having a transparent electrode and a protective film on the lower substrate using an actual pattern, Injecting a cholesteric liquid crystal mixed with a photo-curable polymer into the cell gap between the upper and lower substrates, Exposure is performed using an exposure mask for RGB that exposes a portion intended for RGB pixels on the upper and lower substrates, and the exposure energy is set to correspond to E _R E _G E _B so that the pitch of the cholesteric liquid crystal has _{R, G,} And a step of exposing the reflective liquid crystal display device. The method of manufacturing a reflective liquid crystal display device according to claim 7, wherein the step of forming the projecting portion is formed by a photolithography method.