JPS62237429A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To reduce the size of a liquid crystal display element by using a solar battery in place of a reflective plate of said element so that the solar battery can be utilized in the area of the liquid crystal display element as well. CONSTITUTION:A liquid crystal 5 sandwiched by a glass plate 3 and a glass plate 4 is disposed between a polarizing plate 1 and a polarizing plate 2 and the solar battery 10 is placed in the lowermost part. Incident light 9 arrives at the solar battery 10 and the element looks bright with the light reflected by the solar battery 10 when a voltage is not impressed between a transparent electrode 7 and a transparent electrode 8 attached to the glass plates. Electricity is generated by the light absorbed by the solar battery and can be used as a driving power source. The area part of a display pattern is shielded of light and the light does not arrive at the solar battery 10 when the voltage is impressed, but the light arrives similarly at the other part and electric power is generated. The need for separately providing areas to the liquid crystal display element and the solar battery is thereby eliminated and the reduction of the size is attained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid crystal display element.

[Conventional technology]

The basic structure of a conventional liquid crystal display element is described in Nikkei Electronics, August 26, 1985, pages 169-188 and January 2, 1984, pages 121-122. As shown in FIG. 6, the basic configuration of a reflective liquid crystal display element is that a liquid crystal 5 is placed between a polarizing plate 1 and a polarizing plate 20, sandwiched between a glass plate 3 and a glass plate 4, and a reflective plate 6 is placed at the bottom. is placed. When no voltage is applied between the transparent electrode 7 and the transparent electrode 8 attached to the glass plate, the incident light 9 reaches the reflection plate 6, and the reflected light is bright (visible).

When a voltage is applied, the liquid crystal loses its optical rotation in the area where the voltage is applied, so the light is blocked by the polarizing plate and becomes dark (visible).

[Problem that the invention seeks to solve]

As described above, in the conventional technology, as shown in FIG. 7, it is necessary to provide separate spaces for the liquid crystal display element and the solar cell 10, which poses a problem in miniaturizing the device.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a liquid crystal display element that is a reflective type liquid crystal display element operated by a solar cell and is miniaturized.

[Means for solving problems]

The above object is achieved by using a solar cell instead of a reflective plate of a liquid crystal display element.

[Effect]

The liquid crystal display element displays nine characters and figures based on the contrast of the reflection of illumination light, and some percentage of the total incident light reaches the reflector and is reflected back out.

At this time, a portion of the light reaching the reflecting plate is converted into electricity by a solar cell and used as a driving power source, thereby making it possible to obtain a miniaturized liquid crystal display element.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. A liquid crystal 5 sandwiched between a glass plate 3 and a glass plate 4 is disposed between a polarizing plate 1 and a polarizing plate 20. A solar cell 1o is placed at the bottom. When no voltage is applied between the transparent electrode 7 and the transparent electrode 80 attached to the glass plate, the incident light 9 reaches the solar cell 1o and is reflected by the solar cell 10, making it appear bright.

Additionally, electricity is generated from the light absorbed by the solar cells, which can be used as a driving power source. When a voltage is applied, light is blocked in the area of the display pattern and does not reach the solar cell 10, but light reaches other areas in the same way and generates electric power. By doing so, there is no need to provide separate areas for the liquid crystal display element and the solar cell, and miniaturization can be achieved. FIG. 2 is an example of a calculator that is constructed in this manner, thereby reducing the area occupied by the solar cell and reducing the size of the calculator.

Further, FIG. 3 shows another embodiment of the present invention. This example is an example in which a semi-transparent mirror 11 with a transmittance of about 50% and a solar cell 10 are installed in the solar cell part in FIG. 1. By doing so, the brightness of the background light of the liquid crystal display element can be ensured. This reflectance is not necessarily limited to 50%, and may be appropriately set depending on the electromotive force of the solar cell and the required contrast ratio of the liquid crystal. Furthermore, if a diffuser plate such as frosted glass having an appropriate light transmittance is used instead of a semi-transmissive mirror, the directionality of background light illumination will be eliminated and the visibility will be even better.

Further, FIG. 4 shows another embodiment of the present invention. This is an example in which a solar cell 1o having a partially reflective film 12 on its surface is used instead of the solar cell in FIG. 1. By doing this, an independent semi-transmissive mirror is not required, the number of parts can be reduced, and a constant amount of reflected light can be ensured.

Further, FIG. 5 shows another embodiment of the present invention. In place of the solar cell shown in FIG. 1, a diffusion surface 13 made of, for example, frosted glass is provided on the surface, which scatters and reflects an appropriate amount of incident light and absorbs the remaining light as electromotive force. This is an example in which a solar cell 10 having the following structure is used. By doing this, only the solar cells are used, and the directionality of the background light is eliminated, resulting in even better visibility.

〔Effect of the invention〕

As explained above, according to the present invention, the area of the liquid crystal display element can also be used for solar cells, which reduces the area required and enables miniaturization compared to the conventional technology that requires separate areas for both. effective.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional structural diagram showing one embodiment of a reflective liquid crystal display element with a solar cell according to the present invention, FIG. 2 is an external view of a calculator using this, and FIGS. Cross-sectional structural diagram showing another example of a reflective liquid crystal display element with a battery, No. 6
The figure is a cross-sectional structural diagram showing a conventional reflective liquid crystal display element.
FIG. 7 is an external view of a calculator using the liquid crystal display element shown in FIG. 1.2...Polarizing plate 3,4...Glass plate 5.
...Liquid crystal 6...Reflector plate 7.8...Transparent electrode 9...Incoming light 10...Solar cell
11... Semi-transmissive mirror 12... Partial reflection J[13.
・・Diffusion surface〆−＼t、゛+92 Agent Patent attorney Masaru Ogawa 12 Figure S Figure,, l/ II II
4゜II If II Rock 40 Atsushi Mu Diagram Series Half Wa Hard

Claims (1)

[Scope of Claims] 1. A liquid crystal display element having a sandwich structure of a polarizing plate, a glass plate, a transparent electrode, and a liquid crystal, characterized in that a solar cell is disposed on the back side. 2. The liquid crystal display element according to claim 1, characterized in that a semitransparent mirror or film is disposed on the solar cell. 3. The liquid crystal display element according to claim 1, characterized in that a light diffusing plate having an appropriate light transmittance is disposed on the solar cell. 4. The liquid crystal display element according to claim 1, wherein the surface of the solar cell is a light diffusing surface.