JPH03264921A - Automatic contrast adjusting mechanism for liquid crystal display - Google Patents

Abstract

PURPOSE:To adjust the contrast automatically by supplying a liquid crystal display with a liquid crystal driving voltage which is determined by an arithmetic part according to illuminance detected on the surface of the liquid crystal display. CONSTITUTION:A voltage supply part 15 supplies the liquid crystal display with the liquid crystal driving voltage which is determined by the arithmetic part 13 according to the illuminance detected by an illuminance detection part 11 on the surface of the liquid crystal display. The illuminance voltage generated by a solar battery 11 is converted by an A/D converting circuit 12 into an illuminance digital quantity and the arithmetic circuit 13 determines the liquid crystal driving voltage which provides the most suitable contrast for the illuminance on the surface of the liquid crystal display to generate a corresponding driving digital signal. The driving digital signal is converted by a D/A converting circuit 14 into an analog signal, which is amplified by an amplifying circuit 15 and supplied as the liquid crystal driving to the liquid crystal display. Consequently, the contrast of the liquid crystal display is held in the best state corresponding to the illuminance on the display surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal display device, and more particularly to an automatic contrast adjustment mechanism that automatically adjusts the contrast of a liquid crystal display.

[Prior Art] Conventionally, in this type of contrast adjustment mechanism for a liquid crystal display, the liquid crystal drive voltage is adjusted by manually operating a dial or the like.

[Problems to be Solved by the Invention] However, since the conventional contrast adjustment mechanism for a liquid crystal display requires manual operation of a dial, the contrast must be adjusted every time the illuminance of the liquid crystal display surface changes. The problem is that it does not.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic contrast adjustment mechanism that automatically adjusts contrast when the illuminance of a liquid crystal display surface changes.

[Means for Solving the Problems] According to the present invention, there is provided an illuminance detection unit that detects the illuminance on the surface of a liquid crystal display, and a liquid crystal drive voltage that optimizes the contrast of the liquid crystal display based on the illuminance detected by the illuminance detection unit. There is obtained an automatic contrast adjustment mechanism characterized in that it has a calculation section that determines the voltage, and a voltage supply section that supplies the liquid crystal drive voltage determined by the calculation section to the liquid crystal display.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an automatic contrast adjustment mechanism according to an embodiment of the present invention. This automatic contrast adjustment mechanism
1, an A/D conversion circuit 12, an arithmetic circuit 13, a D/A conversion circuit 14, and an amplifier circuit 15.

The solar cell 11 is disposed close to the liquid crystal display surface and generates an illuminance voltage corresponding to the illuminance of the liquid crystal display surface.

This illuminance voltage is converted into a digital amount of illuminance by the A/D conversion circuit 12 and supplied to the arithmetic circuit 13.

In response to the digital amount of illuminance, the arithmetic circuit 13 determines a liquid crystal driving voltage that provides the most appropriate contrast for the illuminance on the liquid crystal display surface, and generates a driving digital signal corresponding to this liquid crystal driving voltage.

The driving digital signal is converted into an analog signal by the D/A conversion circuit 14 and amplified by the amplifier circuit 15.

The voltage amplified by the amplifier circuit 15 is supplied to the liquid crystal display as a liquid crystal drive voltage.

[Effects of the Invention] According to the present invention, there is provided an illuminance detection section that detects the illuminance on the surface of a liquid crystal display, and an arithmetic section that determines a liquid crystal driving voltage that optimizes the contrast of the display based on the illuminance detected by the illuminance detection section. and a voltage supply unit that supplies the liquid crystal drive voltage determined by the calculation unit to the liquid crystal display, the contrast of the liquid crystal display can always be maintained at the optimum contrast depending on the illuminance of the display surface, and the contrast can be improved. This has the effect of saving you the trouble of making adjustments.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an automatic contrast adjustment mechanism for a product display according to an embodiment of the present invention. 11... Solar cell, 12... A/D conversion circuit, 13
...Arithmetic circuit, 14...D/A conversion circuit, 15...
・Amplification circuit. 15th! J

Claims (1)

[Claims] 1. An automatic contrast adjustment mechanism for a liquid crystal display that automatically adjusts the contrast of a liquid crystal display, which includes an illuminance detection section that detects the illuminance on the surface of the liquid crystal display, and an illuminance detection section that detects the illuminance of the display based on the illuminance detected by the illuminance detection section. An automatic contrast adjustment mechanism comprising: a calculation unit that determines a liquid crystal drive voltage that optimizes contrast; and a voltage supply unit that supplies the liquid crystal drive voltage determined by the calculation unit to the liquid crystal display.