JPH02310523A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE:To reduce the weight and thickness of the liquid crystal display panel by interposing a liquid crystal between transparent film substrates having heat resistance to constitute a cell, providing a phase film and polarizing plate on the display side of the cell and providing a polarizing plate and reflecting plate or flat plate luminous body on the non-display side. CONSTITUTION:The STN liquid crystal cell is constituted by using the transparent film substrates 11, 11' having the heat resistance in place of using glass substrates, then by sticking the polarizing plates 15, 15' to both sides. Further, the thickness and weight are additionally reduced if the film of the type integral with the polarizing plate formed by crimping a polarizer between heat resistant films is used as a substrate 18 and is used after transparent electrodes 12, 12' are directly formed thereon. In addition, the higher efficiency is obtd. as the stage for sticking the polarizing plates 15, 15' is eliminated. The film phase plate 16 constituted by laminating films in such a manner as to obtain the same optical characteristics in place of the cell formed by injecting the liquid crystal between glass substrates may also be used as the phase plate. A plastic type EL lamp may be used to reduce the thickness as a back lighting 17 as well. The respective layers are omitted in this way and the reduction in the thickness and weight is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid crystal display panel that displays black and white or color.

2. Description of the Related Art A liquid crystal display panel capable of providing a black and white display with high contrast generally has a structure as shown in FIG. That is, a glass substrate 1 provided with transparent electrodes 2, 2',
The periphery of 1' is fixed with a sealant 3 at a constant gap so that the electrodes face each other, and a liquid crystal (STN liquid crystal) 4 having a twist angle of 180 to 200 is interposed inside. Next, a liquid crystal cell (referred to as a phase plate or compensation cell) in which a liquid crystal 6 twisted in the opposite direction is interposed between glass plates 6 and 6'.
are formed, and both are superimposed and polarizing plates 7, 7' are provided on both sides. Further, in order to provide uniform illumination from behind, a lamp house is provided in which a lamp 9 such as a cold cathode tube or a hot cathode tube and a reflector plate 10 are combined with a diffuser plate 8 interposed therebetween. With this configuration, the coloration peculiar to STN liquid crystal cells is compensated for and a black and white display can be obtained.

When displaying in color, a color filter layer is provided between the electrode and the substrate. Furthermore, in order to reduce cost and weight, film phase plates have recently been used which can achieve the same effects as compensation cells using a film layer.

Problems to be Solved by the Invention In the configuration shown in Figure 6, a glass plate with a thickness of 1.1 m is generally used for the large panel from the viewpoint of strength, and both the STN liquid crystal cell and the phase plate cell have a thickness of about 2.6 m. It becomes thick. Furthermore, since the illumination tube has a diameter of several meters, and about 20 square meters is the minimum required to obtain uniform illumination, the total thickness is about 26 square meters. Therefore, even if the phase plate is made into a film, there will be no big difference, and performance such as black-and-white and contrast will be improved, but the characteristics of liquid crystals such as light weight and thinness will be lost, which will also pose a practical problem.

The present invention aims to significantly reduce the weight and thickness of the device by taking advantage of the advantages of this method and structure.

Means for Solving the Problems Therefore, the present invention uses STN instead of using a glass substrate.
A liquid crystal cell is constructed using a heat-resistant transparent film substrate, and then polarizing plates are attached to both sides. Furthermore, if a polarizer-integrated film in which a polarizer is sandwiched between heat-resistant films is used as a substrate, and transparent electrodes are directly formed on this film, it can be made thinner and lighter, and the process of attaching a polarizer can be omitted, making it more efficient. . Regarding the phase plate, instead of a cell in which liquid crystal is injected between glass substrates, a film phase plate formed by laminating films so as to obtain the same optical characteristics may be used. A phase plate integrated with a polarizing plate in which a polarizer is sandwiched within the phase plate is also effective. Next, if you want to colorize it, just like with conventional glass color liquid crystal cells, print and dye it.
A color filter layer may be formed on the transparent electrode, between the transparent electrode and the substrate, on the substrate, etc. by a method such as coloring or electrodeposition, and the same effect as in the case of black and white can be obtained.

Next, since back lighting requires the most thickness, it is also replaced with a surface light source such as KL. A cold cathode tube using a plate cell is also effective, but a plastic type ML lamp may be used to significantly reduce the thickness.

Function As explained above, a film substrate is used instead of a glass substrate, which is the main constituent material of conventional liquid crystals, and each function,
For example, by integrating polarization properties, light refraction properties, etc., and improving the heat resistance of these substrate materials, it is possible to directly construct transparent electrodes on top of them and omit necessary constituent layers, making it even thinner and lighter. It becomes possible. In particular, the lighting part, which was large and heavy in the conventional configuration, has been made flat, and by simply combining, compounding, and even integrating these parts, the overall thickness is 2 to 3 inches, about 1/1 of the conventional thickness. It is possible to

Embodiment (Embodiment 1) FIG. 1 is a cross-sectional view showing an embodiment of the present invention. First, a heat-resistant transparent film substrate 11.11', for example, a
A striped transparent electrode 12°12' was formed on one side of a 00 μm polyether sulfone (PKS) using indium oxide (hereinafter referred to as ITO), and these electrodes were placed facing each other in a matrix pattern, and a twist angle of 240° was formed. ST
An N type liquid crystal 14 is sandwiched and its peripheral portion is fixed with a sealant 13 to form a cell. Polarizing plates 15 and 1 are placed on both sides of this
When 5' is pasted, a yellowish display is obtained. Therefore, there is a gap of 150 μm between the polarizing plate 16 on the display side and the cell.
By interposing the film phase plate 16 and optically compensating for this coloration, a black and white display can be obtained.

In this case, the puncture lighting 17 is a flat plate cold cathode tube or a K
If you use an L lamp, the phase cell and liquid crystal cell will each be 0-
5 rtan or less, backlight 2 to 2.5 Fllf
F1 rank will be R, A thickness will be about 3 fights. In the conventional structure as shown in FIG. 6, the thickness is approximately 20 to 25 ml, as described above.

(Example 2) An example will be shown below in which, based on the configuration of Example 1, further thinning and simplification were realized by compositely integrating functional films such as a substrate, a polarizing plate, and a phase plate.

Figure 2 shows a 100 μm thick P as the substrate on the back lighting side.
This is a case in which an ITO electrode 12' is directly formed on a heat-resistant polarizing plate-integrated film substrate 18 constructed by sandwiching a polarizing element film between two ES films. Figure 3 shows P
A heat-resistant film phase plate 19 is obtained by making a film phase plate using ES, and the film substrate 11 is omitted by directly forming the ITO electrode 12 thereon. FIG. 4 shows a case in which a thermostatic film substrate 20 of a polarizing plate/phase plate integrated type, in which a polarizing plate is also integrally held on the display side of the film phase plate 19, is used.

When colorizing these, the transparent electrode 12' on the illumination side
Color filters are printed, dyed, etc. on the top or between the transparent electrode 12' and the film substrate 11' or the film substrate 18.
It can be easily obtained by forming by a general method such as electrodeposition. In this case, it is sufficient to provide a smooth layer as required in the conventional manner.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a film substrate is used instead of a glass substrate in a conventional two-layer monochrome liquid crystal cell (STN type), and a polarizing plate and a phase plate are used as the substrate.

By combining the functional parts of the lighting as necessary and integrating them into a composite structure, the structure is simplified and the manufacturing process is significantly reduced, and the structure is thinner by omitting each layer.

This made it possible to reduce the weight. For example, the thickness of the conventional 25 cabinets is about 1/1o, 2.5 to 3. The effect is particularly remarkable in portable zero-meter devices because it can be made to the order of Orrrm.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views showing a liquid crystal display panel according to an embodiment of the present invention, and FIG. 6 is a cross-sectional view of a conventional liquid crystal display panel. 11.11'...Transparent substrate, 12, 12'.
......Transparent electrode, 13...Sealing agent, 14
......Liquid crystal, 15°16'...Polarizing plate,
16... Film phase plate, 17... Back illumination, 18... Film substrate integrated with polarizing plate, 19... Film phase plate, 2Q... ...
・Film substrate with integrated polarizing plate and 9 phase plates. Name of agent: Patent attorney Shigetaka Awano (1 person)
u'----Film base/Z, /Z'-near agony IL tumor 14°-blasphemy/S, 15'-・°Ibian Ra 已 handling 16...-Fishim 411g non-tile 17°゛- Back tragic figure 1

Claims (5)

[Claims] (1) A cell is constructed by placing transparent electrodes of a desired pattern on a heat-resistant transparent film substrate facing each other and interposing a liquid crystal between the substrates, and a phase film and a polarizing plate are provided on the display side of the cell. , a liquid crystal display panel equipped with a polarizing plate and a reflector or a flat light emitter on the non-display side. (2) The liquid crystal display panel according to claim 1, wherein the display side is constructed by providing a polarizing plate on a substrate in which a phase film is sandwiched within a heat-resistant transparent film. (3) The liquid crystal display panel according to claim 1, wherein the non-display side is formed by sandwiching a polarizing element or a polarizing element and a reflective plate within a heat-resistant transparent film; (4) The liquid crystal display panel according to claim 1, wherein the display side uses a substrate in which a phase film and a polarizing element are stacked and sandwiched within a heat-resistant transparent film. (5) The liquid crystal display panel according to claim 1, further comprising a color filter provided with a smooth layer on the transparent electrode of the film substrate on the non-display side or between the substrate and the transparent electrode.