JPH11296100A - Device with liquid crystal display - Google Patents

Abstract

(57) [Problem] To provide a large power supply and downsizing in a device including a liquid crystal display element and using a solar cell as a power supply. A liquid crystal display comprising a power supply unit including a solar cell panel and a liquid crystal display unit including a transmissive liquid crystal display panel, wherein the liquid crystal display panels are stacked so as to cover at least a part of the solar cell panel. A device comprising a part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to various devices having a liquid crystal display.

[0002]

2. Description of the Related Art Liquid crystal display panels are used in various fields of equipment. Devices equipped with a liquid crystal display panel require a power supply for driving them. In fields where miniaturization and weight reduction are required, for example, card-like calculators and financial cards, solar cells are used as power supplies for liquid crystal display panels, as described in JP-A-9-31921. Often.

When a solar cell is provided, as described in the publication, it is common to arrange a liquid crystal display panel and a solar cell panel in a two-dimensional manner. But,
When the liquid crystal display panel and the solar cell panel are two-dimensionally arranged, it is difficult to reduce the projected area of the device. Particularly, in a high-performance device or a device having a large liquid crystal display element, the power consumption increases. Therefore, miniaturization is not possible because a large area solar cell panel is required.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus having a liquid crystal display element and using a solar cell as a power supply.
An object of the present invention is to make it possible to supply a large amount of power and to reduce the size.

[0005]

The above object is achieved by the following (1).
This is achieved by any one of the configurations (1) to (3). (1) A liquid crystal display unit including a power supply unit including a solar cell panel and a liquid crystal display unit including a transmissive liquid crystal display panel, wherein the liquid crystal display panel is stacked so as to cover at least a part of the solar cell panel. An apparatus comprising: (2) The device including the liquid crystal display unit according to the above (1), wherein only a part of the solar cell panel is covered by the liquid crystal display panel. (3) The device including the liquid crystal display unit according to (1) or (2), wherein the power supply unit has a power storage unit.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially cutaway perspective view showing an example of the structure of a main part of a device having a liquid crystal display unit of the present invention (hereinafter, may be simply referred to as a device). The device of the present invention includes a liquid crystal display panel 2 and a solar cell panel 3 in which a plurality of solar cells are two-dimensionally arranged.

The liquid crystal display panel used in the present invention is of a transmission type and does not have a reflection plate. In the present invention, a solar cell panel is provided on the back surface of the liquid crystal display panel, and the surface of the solar cell panel is used as a reflector to function similarly to a reflective liquid crystal display panel. Therefore, the selection of the optical properties of the liquid crystal, the display mode, the optical design of the liquid crystal display panel (the configuration of the polarizing plate, etc.) may be determined based on the configuration of the conventional reflective liquid crystal display panel.
In the present invention, it is preferable to increase the light transmittance of the liquid crystal display panel as much as possible in order to suppress a decrease in the amount of light reaching the solar cell panel. As the liquid crystal display panel capable of increasing the light transmittance, for example, a panel using polymer dispersed liquid crystal is preferable. A polymer-dispersed liquid crystal has a structure in which fine particles composed of liquid crystal molecules are dispersed in a polymer. In a polymer-dispersed liquid crystal, when no voltage is applied, light scattering occurs due to the difference in the refractive index between the liquid crystal molecule and the polymer.
No incident light is transmitted. On the other hand, when a voltage is applied, the refractive index of the liquid crystal changes, and the liquid crystal becomes transparent when the refractive index becomes equal to that of the polymer. When a polymer-dispersed liquid crystal is applied to the present invention, reflected light from the surface of the solar cell panel is emitted when a voltage is applied, so that a negative liquid crystal display panel is usually obtained. However, a positive-type liquid crystal display panel can be obtained by appropriately selecting and combining the type of solar cell panel and the type of liquid crystal. Since the polymer-dispersed liquid crystal does not require a polarizing plate, the light transmittance can be significantly increased. The liquid crystal display panel used in the present invention preferably has a light transmittance of about 80% or more.

The basic structure of the solar cell panel used in the present invention may be the same as a conventionally known solar cell panel. That is, for example, a lower electrode layer made of aluminum or the like, a Si layer having a PIN junction, a transparent electrode layer made of ITO (indium tin oxide) or the like are laminated on a base made of glass, resin, or the like. A layer in which a buffer adhesive layer made of a hot melt adhesive or the like and a protective film made of resin may be used. In the solar cell panel used in the present invention, the protective film may not be provided.

It is preferable that the device of the present invention is provided with a power storage means for holding the power obtained by the solar cell. By providing the power storage means, the device can be used at night, in rainy weather, in a dark place, or the like. In addition, it can cope with a case where a large amount of electric power is required temporarily. As the power storage means, a normal power storage element such as a secondary battery or a capacitor and a charging circuit thereof can be used. However, in order not to hinder the effects of the present invention, a structure in which a sheet-like power storage element is provided on the back surface of the solar cell panel is preferable. FIG. 1 shows an example of this configuration. In FIG. 1, a sheet-like power storage element 4 composed of, for example, a polymer secondary battery or a supercapacitor is provided on the back surface of the solar cell panel 3. The charging circuit may be a conventional one. When a super capacitor is provided, for example, a charging circuit as shown in FIG. 4 is provided. When a secondary battery is provided, a charging circuit as shown in FIG. May be provided.

The device of the present invention for laminating a liquid crystal display panel and a solar cell panel can use a larger solar cell panel when the dimensions are the same, as compared with a conventional device in which both panels are two-dimensionally arranged. Also, a larger liquid crystal display panel can be used. Therefore, the present invention is suitable for a device that easily consumes a large amount of information and a large amount of display information, such as a high-function device or a multifunction device having a plurality of functions. In addition, if the power supply and the display area are equivalent to those of a conventional device, the device can be downsized, which is particularly suitable for a portable device. Next, an example in which the present invention is applied to such an apparatus will be described.

FIG. 2 shows a GPS (Global Positioning System).
This is an example in which the present invention is applied to a portable type position search and display device using the same. FIG. 2 shows a liquid crystal display panel 2 for displaying a map and a current position pointer thereon,
An operation panel 6 of the PS receiver is shown, and further,
A part of the solar cell panel 3 is shown alongside the liquid crystal display panel. The solar cell panel 3 extends to the back of the liquid crystal display panel 2 as shown by a broken line in the figure. In this device, the liquid crystal display panel 2 does not cover the entire surface of the solar cell panel 3. Negative-type liquid crystal display panels have little translucency when no voltage is applied.Therefore, if the liquid crystal display panel is configured to cover the entire surface of the solar cell panel, the negative type liquid crystal display panel has no power storage means or the power storage means is completely discharged. If it has, the power becomes insufficient or the power cannot be supplied at the time of starting the device, and the start becomes difficult or impossible. Therefore, when a negative-type liquid crystal display panel is used, a part of the solar cell panel is exposed as shown in FIG. 2 so that a required amount of power can be secured without driving the liquid crystal display panel. Is preferred. However, in order to secure a space for mounting various modules such as a GPS receiver, a configuration in which the solar cell panel is completely covered by the liquid crystal display panel may be adopted. In this case, both panels do not need to have the same dimensions, and the solar cell panel may have a smaller area. For example, a large-area liquid crystal display panel is provided over almost the entire front of the device,
A configuration in which a solar cell panel and various circuits are arranged side by side on the back surface may be adopted.

FIG. 3 shows a portable multifunction device in which a GPS receiver and a mobile communication device are integrated, and a large-area liquid crystal display panel 2 capable of simultaneously displaying both information is provided on the front of the device. And an operation panel 6 for operating both. The present invention is particularly effective because such a multifunction device consumes a large amount of power and requires a large area for both the liquid crystal display panel and the operation panel.
In FIG. 3, the dimensions of the solar cell panel 3 are assumed to be equivalent to the dimensions of the liquid crystal display panel 2.

The present invention is not limited to a GPS receiver and a mobile communication device, but includes, for example, a device mounted with various functional modules such as a radio receiver, a TV receiver, and various sensors such as an ultraviolet sensor, and two types of these devices. The present invention is also preferably applied to a multifunction device equipped with the above.

The liquid crystal display panel in the device of the present invention comprises:
Since it is used as a reflective liquid crystal display panel with a solar cell panel surface as a reflector, it is suitable for outdoor use during the daytime.However, if necessary, a backlight is provided on the liquid crystal display panel, and a normal transmission type liquid crystal display panel is used. You can use it in the same way as. Although the backlight consumes a large amount of power, the device of the present invention can supply a large amount of power, so that the backlight can be easily driven. When a backlight is provided in a normal liquid crystal display panel, a diffusion plate is provided on the back surface of the liquid crystal layer.In the present invention, in order to prevent a decrease in light transmittance due to the diffusion plate, no diffusion plate is provided, and the solar cell panel surface and It is preferable to irradiate the back surface of the liquid crystal layer directly from the side.

[0015]

According to the device of the present invention for stacking a liquid crystal display panel and a solar cell panel, a larger solar cell panel can be used when the dimensions are the same as compared with a conventional device in which both panels are two-dimensionally arranged. And a larger liquid crystal display panel can be used. Therefore, high-performance devices,
It is suitable for a device such as a multifunction device having a plurality of functions, in which power consumption is likely to increase and the amount of display information is likely to increase. In addition, since the power generation is large, it is easy to design the charging circuit to be driven simultaneously during use of the device, and a device excellent in usability can be easily realized. Also, if the power supply and display area are equivalent to the conventional device,
Since it is possible to reduce the size, it is particularly suitable for portable devices.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a main part of an apparatus of the present invention.

FIG. 2 is a perspective view showing a configuration example of the device of the present invention.

FIG. 3 is a perspective view showing a configuration example of the device of the present invention.

FIG. 4 is a circuit diagram showing an example of a charging circuit used in the device of the present invention.

FIG. 5 is a circuit diagram showing an example of a charging circuit used in the device of the present invention.

[Explanation of symbols]

 Reference Signs List 2 liquid crystal display panel 3 solar cell panel 4 sheet-like power storage element 6 operation panel 11 solar cell 12 backflow prevention diode 13 supercapacitor 14 charging circuit control unit 15 smoothing circuit 16 secondary battery 17 protection diode

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Kazuyuki Ito 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Ryoji Sunami 1-13-1 Nihonbashi, Chuo-ku, Tokyo Within DK Co., Ltd. (72) Inventor Hiroshi Sakai 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Takashi Dozeki 3-2-1, Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone (72) Inventor Junzo Yamada 3-2-1-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (3)

[Claims] 1. A liquid crystal comprising: a power supply unit including a solar cell panel; and a liquid crystal display unit including a transmissive liquid crystal display panel, wherein the liquid crystal display panel is stacked so as to cover at least a part of the solar cell panel. An apparatus including a display unit. 2. The device according to claim 1, wherein only a part of the solar cell panel is covered by the liquid crystal display panel. 3. The device according to claim 1, wherein the power supply unit includes a power storage unit.