JPH04362917A - Lcd device - Google Patents

Abstract

PURPOSE:To prolong the useful time of portable machinery using an LCD device as a display device without increasing the capacity of a battery. CONSTITUTION:A battery 5 for driving a transmission type LCD panel 1 and a solar cell 2 generating electric power with light passed through the panel 1 and functioning as the auxiliary power source of the battery 5 and a charger for the battery 5 are fitted.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LCD (liquid crystal display) device used, for example, in a notebook computer.

0003

2. Description of the Related Art In recent years, LCD devices have been used as display devices for portable devices such as notebook computers and electronic notebooks. Since these portable devices are battery-powered, their usage time is limited, and as a means to extend their usage time, efforts are being made to reduce the power consumption of their main circuits. However, the amount of power consumption of the LCD device affects the usage time, and there is a limit to how long the usage time can be extended.

0004

[Problems to be Solved by the Invention] Portable devices such as electronic notebooks that use an LCD device as a display device have a limited usage time due to the power consumption of the LCD device. For this reason, there is a desire for longer usage times, and one possible solution is to increase the capacity of the battery.
There is a problem in that increasing the capacity of a battery leads to an increase in the size of the portable device.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an LCD device that can extend the usage time of a portable device or the like without increasing the capacity of the battery.

[Configuration of the invention]

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a transmissive LCD panel, a battery for driving the LCD panel, and a battery that generates electricity using light transmitted through the LCD panel to assist the battery. The gist is that the device includes a power source and a solar cell that functions to charge the battery.

[0008]

[Operation] In the above configuration, the power generated by the solar cell is LC
When the power consumption is lower than the power consumption of the D panel, the solar cell functions as an auxiliary power source for the battery, and the battery and the solar cell cooperate to supply power to the LCD panel.

[0009] When the power generated by the solar cell exceeds the power consumed by the LCD panel, the solar cell supplies power to the LCD panel and charges the battery.

Furthermore, when the LCD panel is off and the voltage generated by the solar cell exceeds the voltage of the battery, the power generated by the solar cell is used to charge the battery.

[0011] This makes it possible to extend the usage time of portable equipment, etc. that uses the LCD device as a display device, without increasing the capacity of the battery.

0012

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

FIGS. 1 and 2 are diagrams showing a first embodiment of the present invention.

First, the configuration of the LCD device will be explained using FIG. 1. In the figure, 1 is a transmissive LCD panel, and on the back side there are a solar cell 2 and a side light tube 3.
and a reflecting plate 4 are provided. Since the LCD panel 1 transmits light except for parts such as characters for display, in normal use, even if the solar cell 2 is placed on the back side of the LCD panel 1, the natural light transmitted through the LCD panel 1 will cause the solar cell 2 to pass through. It is quite possible to obtain the required power generation from Also,
Backlight light emitted from the sidelight tube 3 reaches the LCD panel 1 directly and after being reflected by the reflection plate 4, allowing the user to recognize displayed characters and the like.

Reference numeral 5 denotes a battery, and its output line is connected via a power switch 6 to an LCD panel 1 and a main body circuit 7 of a portable device or the like that uses the LCD device as a display device. Further, an output line of the solar cell 2 is connected to the battery side of the power switch 6 via an overcharge prevention device 8 and a diode 9.

Next, the operation of the LCD device configured as described above will be explained using FIG. 2. Power is generated from the solar cell 2 using natural light transmitted through the LCD panel 1. When the power switch 6 is turned on, the main body circuit 7 is activated and the LCD
The required display is performed from panel 1. At this time, if the power generated by the solar cell 2 is lower than the power consumption of the LCD panel 1 and the main circuit 7, the solar cell 2 functions as an auxiliary power source for the battery 5, and the battery 5 and the solar cell 2 cooperate to Power is supplied to the panel 1 and main body circuit 7 (FIG. 2(a)). At this time, due to the action of the diode 9, the voltage of the battery 5 is not applied to the solar cell 2 side.

When the power switch 6 is in the ON state, if the power generated by the solar cell 2 exceeds the power consumption of the LCD panel 1 and the main circuit 7, the solar cell 2 supplies power to the LCD panel 1 and the main circuit 7. and charging of the battery 5 is performed (FIG. 2(b)).

Furthermore, when the power switch 6 is OFF, the main circuit 7 and the LCD panel 1 are inactive, and the voltage generated by the solar cell 2 exceeds the voltage of the battery 5,
The power generated by the solar cell 2 is used to charge the battery 5 (FIG. 2(c)). At this time, overcharging of the battery 5 is prevented by the overcharging prevention device 8.

[0019] Due to the above action, the capacity of the battery 5 can be increased;
As a result, the portable device can be used for a longer period of time without increasing the size of the device.

FIGS. 3 and 4 show a second embodiment of the present invention.

In this embodiment, as shown in FIG. 3, the arrangement of the sidelight tube in the first embodiment is omitted;
Instead, a semi-transparent plate 10 is disposed between the LCD panel 1 and the solar cell 2.

Natural light passes through the LCD panel 1, reaches the semi-transparent plate 10, and is separated into transmitted light and reflected light. this house,
The reflected light passes through the LCD panel 1 from the back side and allows the user to recognize displayed characters and the like. On the other hand, the light transmitted through the semi-transparent plate 10 reaches the solar cells and generates electricity.

The function of the solar cell 2 as an auxiliary power source for the battery 5 and the function of charging the battery 5 are almost the same as those of the first embodiment (FIGS. 4(a), 4(b),
(c)).

[0024]

[Effects of the Invention] As explained above, according to the present invention,
The LCD device can be used as a display device without increasing the capacity of the battery because it is equipped with a solar cell that generates electricity using the light that passes through the LCD panel and functions as an auxiliary power source for the drive battery and for charging the battery. It is possible to extend the usage time of portable devices, etc.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a first embodiment of an LCD device according to the present invention.

FIG. 2 is a diagram for explaining the operation of the first embodiment.

FIG. 3 is a configuration diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the second embodiment.

[Explanation of symbols]

1 LCD panel 2. Solar cells 5 Battery

Claims (1)

[Claims] 1. A transmissive LCD panel, a battery that drives the LCD panel, and a solar cell that generates electricity using light transmitted through the LCD panel and functions as an auxiliary power source for the battery and for charging the battery. An LCD device characterized by: