JPH05241512A - Display device - Google Patents

Abstract

PURPOSE:To automatically adjust luminance to optimal luminance even when the device is used in environment where illuminance is greatly changed. CONSTITUTION:In a display device displaying a picture by irradiating a LCD1 which displays the picture by using liquid crystal with a back light 2 from a back side, a sensor means 4 detects the illuminance around a screen and the luminance is automatically adjusted by using voltage value which is previously stored in a memory 6 and for realizing the optimal luminance of the LCD1 and the back light 2 corresponding to the illuminance of circumstance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying a screen by illuminating an LCD for displaying a screen using a liquid crystal from a back surface with a backlight.

[0002]

2. Description of the Related Art As shown in FIG. 3, a display device of this type is designed to display on a screen by illuminating an LCD 1 for displaying a screen using liquid crystal from its back surface with a backlight 2. The amount of light emitted is smaller than that of a normal cathode ray tube.

Therefore, since it is sensitive to the brightness of the surrounding use environment and is difficult to see in a bright place, a brightness adjusting means is provided for adjusting the brightness of each of the LCD and the backlight according to the surrounding use environment. Therefore, the user manually adjusts the brightness adjusting means according to the brightness of the surroundings and sets it in a state where it is easy to see.

[0004]

However, in such a display device, the brightness of the LCD and the backlight is adjusted by manually operating the brightness of two types of the LCD and the backlight each time the ambient illuminance changes. You have to
Further, when used in a place where the illuminance changes drastically, there is a problem that the number of adjustments increases and the original work is interrupted each time.

The present invention has been made in view of the above points, and an object thereof is a display capable of automatically adjusting the brightness to an optimum brightness even when used in an environment where the illuminance changes drastically. To provide a device.

[0006]

According to the present invention, an LCD for displaying a screen using liquid crystal is used to display the screen by illuminating the LCD from the back with a backlight, and means for adjusting the brightness of the LCD and the backlight are provided. In such a display device, a sensor means for detecting the illuminance around the screen and a memory for storing the optimum values of the brightness of the LCD and the backlight for the detected illuminance as a table are added, and the illuminance value detected by the sensor means is added. According to the above, the brightness adjusting means is controlled by referring to the table.

[0007]

In the display device of the present invention, the display device displays the screen by illuminating the LCD, which displays the screen using liquid crystal, from the back with a backlight, and the illuminance around the screen is detected by the sensor means. Is detected, and the brightness is automatically adjusted using the optimum brightness value of the LCD and the backlight stored in the memory in advance with respect to the ambient illuminance.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which 1 is an LCD for displaying a screen using a liquid crystal, 2
Illuminates the LCD 1 from the back to supplement the screen brightness,
This is to make the screen easier to see.

An optical sensor 4 is installed around the display device, detects the brightness of the surroundings, and converts it into an electric signal.

Reference numeral 5 is an A / D converter which converts an electric signal from the optical sensor 4 into a digital signal corresponding to the illuminance.

Reference numeral 6 denotes a memory, which stores a reference table of each voltage value (digital amount) applied to the LCD 1 and the backlight 2 with respect to the ambient illuminance as shown in FIG. As a result, a voltage value is output so that the LCD 1 and the backlight 2 have optimum brightness. This voltage value is set so that the LCD 1 and the backlight 2 have optimum luminance (luminance that makes the screen most visible) with respect to the ambient illuminance.

Reference numeral 7 is a D / A converter, which converts the voltage value output from the memory 6 into an analog quantity.

Reference numeral 3 denotes a brightness adjusting means, which comprises an electronic volume 31 for the LCD 1 and an electronic volume 32 for the backlight 2, and is an LC output from the D / A conversion section 7.
Voltages for D1 and backlight 2 are applied to the electronic volume 31 and the electronic volume 32, respectively,
That is, the voltage is output so that 1 and the backlight 2 have the optimum brightness. In addition, 8 is the electronic volume 3
This is a power supply supplied to the first and the second power supplies 32.

Therefore, in this embodiment, the electronic volume controls 31 and 3 in the brightness adjusting means 3 correspond to changes in the ambient illuminance.
The resistance value of 2 is changed and the LCD 1 is automatically changed.
And the brightness of the backlight 2 is adjusted to an optimum value.

[0016]

As described above, according to the display device of the present invention, in the display device for displaying the screen by illuminating the LCD, which displays the screen using the liquid crystal, from the back side with the backlight, the sensor means is provided. The illuminance around the screen is detected by the LCD against the ambient illuminance stored in the memory in advance.
Since the brightness is automatically adjusted by using the optimum brightness value of the backlight and the backlight, the display device can automatically adjust the brightness to the optimum brightness even when used in an environment where the illuminance changes drastically. Was able to provide.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a table stored in a memory according to the above.

FIG. 3 is a block diagram showing a conventional example.

[Explanation of reference numerals] 1 LCD 2 Backlight 3 Luminance adjusting means 4 Optical sensor 5 A / D converter 6 Memory 7 D / A converter 8 Power supply 31 Electronic volume 32 Electronic volume

Claims (1)

[Claims] 1. A display device in which an LCD for displaying a screen using liquid crystal is illuminated by a backlight from the back to display the screen, and a means for adjusting the brightness of the LCD and the backlight is provided. A sensor means for detecting the illuminance around the screen and a memory for storing the optimum values of the brightness of the LCD and the backlight for the detected illuminance as a table are added, and the table is referred to according to the illuminance value detected by the sensor means. Accordingly, the display device is characterized in that the brightness adjusting means is controlled.