JPH0425728Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention consists of a liquid crystal cell that uses a solar cell as a power source, and a light source arranged behind the back of the liquid crystal cell to illuminate the liquid crystal cell and the solar cell. The present invention relates to a transmission type liquid crystal display device.

(Prior Art) Conventionally, illumination light is irradiated onto a solar cell and the solar cell is used as a power source for a liquid crystal display device.
Japanese Unexamined Patent Publication No. 58-220171 and Unexamined Japanese Patent Application No. 59-75281 are known. Since LCD devices always require illumination light, when trying to store solar cells and light sources in a case, the solar cells are placed on the opposite side of the liquid crystal cell 22 across the light source 20, as shown in FIG. 24 had to be placed.

(Problems to be Solved by the Invention) Due to this configuration, the light from the light source is dispersed in the direction of the liquid crystal cell and the direction of the solar cell, resulting in poor efficiency from the light source. Therefore, it is necessary to increase the area of the solar cell, and a predetermined distance is required from the light source to the liquid crystal cell or the solar cell, resulting in a problem that the space of the liquid crystal display device itself becomes large.

(Means for solving the problem) The present invention aims to efficiently use the light from the light source and to reduce the space of the liquid crystal display device. In a liquid crystal display device comprising a liquid crystal cell, a light source disposed behind the back surface of the liquid crystal cell, and a solar cell that uses light from the light source as a power source for the liquid crystal cell, the solar cell is connected to the liquid crystal cell. The liquid crystal cell is arranged on the back side of the cell and has a through hole in the display pattern portion of the liquid crystal cell.

(Example) An example of the present invention will be described below based on the drawings.
FIG. 1 is an exploded perspective view of a main part of a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of the liquid crystal display device of FIG.

2 are predetermined display patterns 2a and 2b, such as a twisted nematic type or a guest host type, for displaying various display patterns such as numbers, letters, pictures, etc.
This liquid crystal cell 2 has the following characteristics:
A solar cell 6, which will be described later, is used as a power source. A light source 4 connected to an external power source is placed behind the back of the liquid crystal cell 2, and the light emitted from the light source 4 toward the liquid crystal cell 2 corresponds to display patterns 2a and 2b on the liquid crystal cell 2. It is configured so that the light passes through the liquid crystal part and toward the front. Here, it is assumed that the amount of light from the light source 4 is always constant. 6 is a solar cell arranged on the back side of the liquid crystal cell 2 and has through holes 6a and 6b;
a, 6b are display patterns 2a, 2b of the liquid crystal cell 2
That is, the solar cell 6 is provided with a through hole that can display only a desired display portion of the liquid crystal cell 2.

Therefore, when the light source 4 is turned on, the solar cell 6 exchanges the light from the light source 4 into electrical energy to drive the liquid crystal cell 2, and at the same time, the light from the light source 4 is transmitted through the through holes 6a and 6b of the solar cell 6. The light passes through the liquid crystal cell 2 and illuminates the display patterns 2a and 2b of the liquid crystal cell 2, so that various display patterns of the liquid crystal cell 2 can be displayed. Further, since the reflective plate 8 is provided so that the light from the light source 4 is not leaked to the outside, the light from the light source 4 is effectively irradiated onto the liquid crystal cell 2 and the solar cell 6.

In addition, a filter such as a transparent plastic plate is placed on the back side of the solar cell 6, and the through hole 6 of the solar cell 6 is
It is also possible to display the liquid crystal cell 2 in color by coloring the portions corresponding to a and 6b, that is, the portions of the liquid crystal cell 2 corresponding to the display patterns 2a and 2b, in arbitrary colors. Since the solar cell 6 absorbs light, the light from the light source 4 does not pass through the holes 6a and 6b of the solar cell 6. For example, the colored part of the filter is passed through the hole 6 of the solar cell 6.
Even if the area is made somewhat larger than the areas of a and 6b, there is no need to provide a light shielding plate in front of the filter as in the conventional case. In other words, the solar cell 6 functions as a light shielding plate, and this can be said even when a filter is not provided.

Since the light from the light source 4 is always constant, the solar cell 6 only needs to have an area large enough to drive the liquid crystal cell 2. For example, if the power required to drive the liquid crystal cell is small, or if When the area of the solar cell is sufficient for part of the area other than the display pattern of the liquid crystal cell, such as when the light is strong, a through hole is provided in the part corresponding to the display pattern of the liquid crystal cell, and a part of the light shielding area is covered with a through hole. Needless to say, a structure may be adopted in which a light shielding plate provided with a solar cell is arranged on the back side of the liquid crystal cell.

Further, in this embodiment, the solar cell 6 is arranged on the back surface of the liquid crystal cell 2, but the solar cell may be directly deposited on a portion of the liquid crystal cell other than the display pattern.

(Effects of the invention) According to the invention, since the solar cell is placed between the light source and the liquid crystal cell, the light from the light source only needs to be irradiated in one direction, and the light from the light source can be used efficiently. In addition, since the distance between the light source and the liquid crystal display device can be set so that the light source can uniformly illuminate the liquid crystal cell, the distance between the light sources can be half that of the conventional one, and there is no need to take up a large space as in the conventional one. Furthermore, since solar cells do not allow the light emitted from the light source to pass through the liquid crystal cell in front of the solar cell, it provides a light-shielding effect to the liquid crystal cell. The contrast between the displayed portion of the cell and other portions can be made clear.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of essential parts of a liquid crystal display device according to the present invention. FIG. 2 is a sectional view of a main part of the liquid crystal display device of FIG. 1. FIG. 3 is a sectional view of a conventional example. 2...Liquid crystal cell, 2a, 2b...Display pattern, 4...Light source, 6...Solar cell, 6a, 6b...
...through hole.

Claims (1)

[Scope of utility model registration request] a liquid crystal cell having a display pattern for displaying characters, etc.; a light source disposed behind the back surface of the liquid crystal cell;
A liquid crystal display device comprising: a solar cell that uses light from the light source to power the liquid crystal cell;
A transmission type liquid crystal display device, wherein the solar cell is arranged on the back side of the liquid crystal cell, and a through hole is provided in a display pattern portion of the liquid crystal cell.