JPH04335318A - Information processor with liquid crystal display - Google Patents

Abstract

PURPOSE:To realize the information processor which has the liquid crystal display capable of controlling the brightness of a back light corresponding to variance in ambient brightness without any operator's judgement. CONSTITUTION:The information processor which has the liquid crystal display 4 with the back light 7 is provided with a photosensor 6 which detects the ambient brightness and outputs a level proportional to the brightness. Further, the processor is provided with a back light control circuit 5 which inputs the output of the photosensor 6 and has a previously set reference level internally. The back light 7 is turned ON under the control of the back light control circuit 5 unless the output level of the photosensor 6 reaches the reference level.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus having a liquid crystal display, and more particularly to an information processing apparatus having a liquid crystal display having a backlight in the liquid crystal display section.

0002

2. Description of the Related Art An information processing device includes a central processing unit (CPU) that performs arithmetic processing of data, a memory that stores programs and data, a keyboard that inputs data and other information, and a display that displays data and processing results. It is equipped with

Conventionally, among information processing apparatuses having this type of liquid crystal display, those having a liquid crystal display equipped with a backlight have been designed so that the operator of the information processing apparatus takes into account the brightness of the surroundings and selects the liquid crystal display or information processing apparatus. Turn on the backlight switch provided on the device body
This was done by manually turning OFF.

0004

[Problems to be Solved by the Invention] Many of the conventional information processing devices having a liquid crystal display are equipped with a backlight to make it possible to recognize the contents displayed on the liquid crystal display even in a dark place. The ON/OFF of the light was performed at the discretion of the operator using a mechanical switch or manual operation using input from a keyboard. For this reason, when the surroundings become dark, the switch must be turned on manually each time, making the operation complicated. Also, if you accidentally turn on the backlight in a bright place, you may not realize that the backlight is on.
If it remains in the ON state, it consumes a lot of power, and if the information processing device with the above-mentioned liquid crystal display is a portable device that uses an internal battery, its operating time will be shortened. There was a problem.

[0005]

[Means for Solving the Problems] An information processing device having a liquid crystal display according to the present invention is an information processing device having a liquid crystal display with a backlight. The output of the optical sensor is input, and the output level of the optical sensor is compared with the reference level, and when the output level of the optical sensor does not reach the reference level, the and a backlight control circuit that controls to turn on the light and turn off the backlight at other times.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an information processing apparatus having a liquid crystal display according to the present invention. The CPU 1 performs system control of the apparatus according to a program stored in the memory 2, and executes arithmetic processing on data input from the keyboard 3 or data stored in the memory 2. Data processing results or input data from the keyboard 3 are displayed on the liquid crystal display 4.

An optical sensor 6 is attached to the main body of the information processing device or to a location that does not interfere with the display of the liquid crystal display 4, and outputs a signal at a level proportional to the illuminance of external light. This output is applied to the backlight control circuit 5. The backlight control circuit 5 has an internal reference level, and compares the level of the output applied from the optical sensor 6 with this reference level, and turns off the backlight 7 when the output level of the optical sensor 6 does not reach the reference level. Turn on,
At other times, control is performed to turn off the backlight 7.

Further, the backlight control circuit 5 described above is provided with reference levels having a plurality of different level values, for example, a first reference level and a second reference level, and the value of the first reference level is changed to a second reference level. When the output level from the optical sensor 6 does not reach the first reference level and is equal to or higher than the second reference level, the backlight 7 is turned on at the first brightness. In addition, when the output level from the optical sensor 6 does not reach the second reference level, the backlight 7 is turned on at a second brightness that is stronger than the first brightness, and further the output level of the optical sensor 6 is set to the first reference level. If the level is above, turn backlight 7 to O.
By controlling the FF to be turned off by the backlight control circuit 5, the backlight 7 can be turned on at a brightness suitable for the surrounding brightness.

Furthermore, by providing a large number of different reference levels inside the backlight control circuit 5 described above, it is also possible to control the brightness of the backlight 7 in more stages as described above.

0010

Effects of the Invention As explained above, the information processing device having the liquid crystal display of the present invention measures the ambient brightness using the optical sensor, and controls the ON/OFF or brightness of the liquid crystal backlight using the backlight control circuit. By enabling this, there is an effect that the backlight can be turned on/off without requiring judgment by the operator of the information processing device.

[0011] Furthermore, when the surroundings are bright, it is possible to prevent the operator from accidentally turning on the backlight and wasting power.

[0012] Therefore, there is an effect that there is no possibility of wasting the battery power of a portable device having an internal battery.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an information processing device having a liquid crystal display according to the present invention.

[Explanation of symbols]

1 Central processing unit 2 Memory 4 Liquid crystal display 5 Backlight control circuit 6 Light sensor

Claims (2)

[Claims] 1. An information processing device having a liquid crystal display with a backlight, comprising: a light sensor that outputs a level proportional to surrounding brightness; and an internally predetermined reference level using the output of the light sensor as input. and compares the output level of the optical sensor with the reference level, turns on the backlight when the output level of the optical sensor does not reach the reference level, and turns off the backlight otherwise. An information processing device having a liquid crystal display, characterized in that it is equipped with a backlight control circuit that performs the following operations. 2. An information processing device having a liquid crystal display with a backlight, comprising: a light sensor that outputs a level proportional to surrounding brightness; and a light sensor that outputs a level proportional to the surrounding brightness; It has a plurality of different reference levels, and compares the output level of the optical sensor with these reference levels, and turns off the backlight when the output level of the optical sensor is equal to or higher than the maximum level of the reference levels. The apparatus further includes a backlight control circuit that controls to change the brightness of the backlight and turn it on depending on where the output level from the optical sensor is located within the area divided by the plurality of reference levels. An information processing device having a liquid crystal display characterized by: