JPH0619024U - Power saving electronic equipment - Google Patents

Abstract

(57) [Summary] [Purpose] A mechanism is provided to automatically turn off the power switch after the operation. [Structure] A light receiving element is arranged in the vicinity of a reflective liquid crystal display screen, the ambient light is detected by the light receiving element, and the power switch is connected so as to be ON / OFF controlled based on the result.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power-saving electronic device (particularly a desktop personal computer), and more particularly to a mechanism that can automatically turn on / off a power supply.

[0002]

[Prior art]

 In a laptop personal computer, the lid with the display device is closed to complete the operation, so even if the lid is kept while the power is on, the user does not notice that the liquid crystal display device is attached. For this reason, it is often the case that the user forgets to turn off the power inadvertently and speeds up the consumption of the liquid crystal display device or wastes power. A personal computer equipped with a liquid crystal display device with a backlight (hereinafter abbreviated as a personal computer) has a solution as shown in FIG. Immediately, when the photocoupler 31 is provided on the main body 34 side and the lid 33 is closed, the light blocking convex portion 32 provided on the lid 33 side can be inserted between the light emitting diode 31a and the light receiving element 31b of the photocoupler 31. There is. When the lid 33 is opened, the photocoupler 31 is turned on by the light from the light emitting diode 31a, and the power switch of the power supply is turned on. When the operation is completed and the lid 33 is closed, the convex portion 32 blocks the light of the photocoupler 31 and becomes the OFF state. This automatically turns off the power switch on the power supply. On the other hand, in the personal computer of the reflection type liquid crystal display device, at present, such a mechanism for automatically turning off the switch is not provided.

[0003]

[Problems to be solved by the device]

 In order to operate the photocoupler provided in the above-mentioned personal computer with a back light, it is necessary to always keep the current flowing through the light emitting diode. Therefore, it is not preferable from the viewpoint of energy saving. The present invention has been made to solve this problem, and an object thereof is to provide a power-saving mechanism for automatically turning off the power source in a personal computer of a reflective liquid crystal display device.

[0004]

[Means for Solving the Problems]

 The present invention is characterized by comprising a reflective liquid crystal display screen and a light receiving element arranged in the vicinity of the display screen, and performing ON / OFF control of a power switch of a power source by the output of the light receiving element.

[0005]

[Action]

 When the lid with the liquid crystal display screen is opened, external light enters the light receiving element provided near the liquid crystal display screen, the light receiving element is turned on, and the control circuit detects this and turns on the power switch. When the computer operation is completed, the lid with the liquid crystal display screen is closed. Light does not enter the light-receiving element provided near the liquid crystal display screen. As a result, the photoelectromotive force of the light receiving element is lost and the light receiving element is turned off. This is detected by the control circuit and the power switch is automatically turned off.

[0006]

【Example】

 Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a state in which a lid of a power-saving personal computer is opened. Reference numeral 11 is a light receiving element, 12 is a reflection type liquid crystal display screen, 13 is an operating portion, 14 is a lid, and 15 is a main body. FIG. 2 is a diagram showing a state in which the lid of the power-saving personal computer is closed. FIG. 3 is a block diagram for explaining the operation. Reference numeral 11 is a light receiving element, 22 is a photoelectromotive force detecting means, 23 is a control circuit, 24 is a power switch, 25 is a battery power source, and 26 is a personal computer circuit. The operation will be described below. As shown in FIG. 1, it is assumed that the main body 15 is operated with the lid 14 opened. At this time, the light receiving element 11 arranged in the vicinity of the reflective liquid crystal display screen 12 generates a photoelectromotive force due to illumination in the room or incidence of natural light.

This photovoltaic power is detected by a photovoltaic power detection means 22 connected to the light receiving element 11 as shown in FIG. At this time, the output of the photovoltaic detector 22 is input to the control circuit 23. The control circuit 23 maintains the power switch 24 in the ON state. That is, electric power is supplied from the battery power source 25 to the electronic circuit 26 side of the personal computer.

As shown in FIG. 2, when the operation is completed and the lid 14 is closed, light does not enter the light receiving element 11. As a result, no photoelectromotive force is generated in the light receiving element 11. This state is detected by the photovoltaic detector 22 and the detection signal is output to the control circuit 23. The control circuit 23 outputs a signal for switching the power switch 24 to the off state by this signal, the power switch 24 is automatically turned off, and the supply of power to the circuit 26 side is stopped.

Next, FIG. 4 shows an electric circuit diagram of an embodiment of a power-saving personal computer. Here, 21 is a phototransistor, 27 and 28 are transistors, 29 is a light emitting diode, and other reference numerals are the same as in FIG. Incidentally, 23a, 23b and 23c are input and output port terminals of the control circuit 23, respectively. Next, the operation will be described. When the lid 14 of the personal computer is opened, light is incident on the phototransistor 21 arranged near the liquid crystal display screen 12. The incident light turns on the phototransistor 21 and turns on the transistor 27. Therefore, the input port terminal 23a of the control circuit 23 changes from H level to L level. The control circuit 23 detects this change, changes the output port terminal 23b from the L level to the H level, turns on the transistor 27, connects the battery power supply 25 and the personal computer electronic circuit 26, and supplies electric power. State. The light emitting diode 29 may be turned on with the output port 23c set to the L level to serve as a power source display lamp.

When the operation of the personal computer is completed and the lid 14 is closed, the operation is as follows. No light enters the phototransistor 21, no current flows, and the phototransistor 21 is turned off. Therefore, the transistor 27 is also turned off, and the input port terminal 23a of the control circuit 23 changes from the L level to the H level. The control circuit 23 detects this, changes the output port terminal from the H level to the L level, turns off the transistor 28, disconnects the circuit 26 side from the battery power supply 25, and sets the output port terminal 23c to the H level. To The light emitting diode 29 is turned off.

As described above in detail, the present invention detects the ambient brightness by the light receiving element, determines whether the operation is completed, and automatically turns off the power switch. However, the liquid crystal display is never left on. Further, since the light receiving element is used as the detecting means, the power consumption is saved as compared with the case where a photo coupler or the like is used.

Further, according to the present invention, even if the use is stopped with the lid 14 left open, the power switch is automatically turned off when the surroundings become dark at night. In this case, even if the use is not stopped, if the surroundings become dark, the power is turned off, but since it is a reflective liquid crystal display, if the surroundings become dark, the liquid crystal display itself becomes invisible and the user is actually concerned. It is impossible to use a personal computer, and there is no problem even if it is automatically turned off.

[0013]

[Effect of device]

 As described above, in the reflection type liquid crystal display personal computer, the battery power switch is automatically turned on when the lid of the computer is opened by the ambient light, and the ambient light is blocked when the lid is closed. As the switch is turned off automatically, power is not wasted after the operation is completed. In addition, since it is detected only by the light receiving element and no photo coupler is used, power consumption is further saved.

[Brief description of drawings]

FIG. 1 is a view showing a state in which a lid of a power-saving personal computer of the present invention is opened.

FIG. 2 is a view showing a state in which the lid of the power-saving personal computer of the present invention is closed.

FIG. 3 is a block diagram for explaining the operation of the present invention.

FIG. 4 is an electric circuit diagram of an embodiment of the present invention.

FIG. 5 is a diagram showing a conventional personal computer.

[Explanation of symbols]

 11 light receiving element 12 reflective liquid crystal display screen 13 operation part 14 lid 22 photovoltaic detection means 23 control circuit 24 power switch

Claims (1)

[Scope of utility model registration request] 1. A light-saving device comprising: a reflective liquid crystal display screen; and a light-receiving element arranged in the vicinity of the display screen, wherein output of the light-receiving element controls ON / OFF of a power switch of a power source. Power type electronic equipment.