JPS6314579A - Brightness adjusting circuit for display device - Google Patents

Abstract

PURPOSE:To prevent the fatigue of an operator by changing the brightness of a display picture correspondingly to the quantity of external light. CONSTITUTION:According to the operation of a variable resistor 1, a level adjusting circuit 6 operates to adjust the amplification degree of an amplifying circuit 5. by setting the brightness of the display picture to an environment at that time, the amplification degree of the amplifying circuit 5 is varied according to the quantity of sensing light of a photosensor 4 thereafter, and the brightness of a CRT3 is automatically adjusted according to the quantity of the external light. Accordingly, the operator can see the display picture of the brightness to his choice relatively only by adjusting the resistor 1 once.

Description

[Detailed Description of the Invention] [Summary] The brightness of characters, figures, etc. displayed on the display screen of a display device, that is, the brightness, is adjusted by an operator at any time depending on the brightness of the surrounding area where the device is installed. However, an optical sensor detects the brightness of the surrounding area and automatically adjusts the brightness according to this brightness, and also allows the operator to adjust the brightness to his or her preference.

[Industrial application field]

The present invention relates to a display device, and particularly to a display screen of a display device.
The present invention relates to a brightness adjustment circuit for a display device that automatically adjusts the brightness to suit environmental conditions.

With the development of the information society, various display devices have come to be used in information processing devices. Among these display devices, those using a cathode ray tube (CRT) are most commonly used.

By the way, the brightness of characters, figures, etc. displayed on the display screen of this CRT display device, that is, the brightness, is adjusted by the operator using a variable resistor according to the surrounding brightness and according to his own preference. When the operator is using the display screen, the amount of light entering the display screen from the surroundings changes, and if the operator continues using the display screen without noticing, the strain on the eyes increases and fatigue accumulates.

This fatigue becomes particularly noticeable when the amount of light entering from the surroundings changes gradually. Therefore, it is desirable to be able to automatically adjust the brightness in response to changes in environmental conditions.

[Conventional technology]

FIG. 3 is a block diagram showing an example of a conventional brightness adjustment circuit.

By varying the variable resistor l by the operator, CR
The T drive circuit 2 changes the voltage supplied to the cathode of the CRT 3, thereby changing the display brightness of the CRT.

[Problem that the invention seeks to solve]

Conventionally, the operator manually adjusted the variable resistor to adjust the brightness of the display screen, which required the operator to respond each time to the amount of light entering the display screen from the outside, which was cumbersome and If left untreated, there is a problem in that eye fatigue accumulates.

[Means for solving problems]

No. 111N is a block diagram of a circuit showing one embodiment of the present invention.

1 is a variable resistor in which the operator determines the reference brightness of the display screen; 2 is a CRT drive circuit; 3 is the CRT; 4 is a light sensor that detects the amount of light illuminating the display screen from the outside; 5 is the output of the light sensor 4; The amplifying circuit 6 is a level adjusting circuit that varies the reference amplification degree of the amplifying circuit 5 by the value of a variable resistor l.

The optical sensor 4 varies the reference amplification degree of the amplifier circuit 5 determined by the level adjustment circuit 6 according to the amount of light entering from the outside, changes the input signal level of the CRT drive circuit 2, and changes the voltage supplied by the CRT drive circuit 2 to the CRT 3. When the amount of external light is large, the brightness of the display screen is increased, and when the amount of external light is low, the brightness is decreased.

[Effect]

With the above configuration, the operator can use the variable resistor l
By making the level adjustment circuit 6 adjust the amplification degree of the amplifier circuit 5, the brightness of the display screen can be determined according to the environment at that time.
Since the amplification degree of the amplifier circuit 5 is varied, the brightness of the CRT 3 is automatically adjusted depending on the amount of external light.

Therefore, by adjusting the variable resistor 1 only once, the operator can maintain a display screen with a brightness that relatively suits his/her preference.

〔Example〕

In FIG. 1, an optical sensor 4 detects the amount of light entering from the outside and supplies a voltage or current corresponding to the amount of external light to an amplifier circuit 5. The amplifier circuit 5 corresponds to the magnitude of this voltage or current, and as the amount of external light increases, the input becomes larger, so it increases the output and drives the CRT drive circuit 2,
The cathode voltage of T3 is increased to increase brightness, and as the amount of external light decreases, the input becomes smaller, so the output is lowered to drive the CRT drive circuit 2, and the cathode voltage of CRT3 is lowered to lower the brightness.

The operator adjusts the variable resistor 1 and sets the reference amplification degree of the amplifier circuit 5 using the level adjustment circuit 6 so as to obtain the desired screen brightness according to the amount of external light at that time.

Therefore, once the operator adjusts the variable resistor 1,
After that, the optical sensor 4 responds to changes in the amount of external light, lowering the brightness of the display screen when the outside becomes dark, and increasing the brightness of the display screen when the outside becomes bright, so that the brightness is adjusted to suit the operator's preference. can be maintained.

FIG. 2 is a block diagram of a circuit showing another embodiment of the invention.

The setting value is entered in the memory 7 as a numerical value via the terminal A from a keyboard or the like. The D/A conversion circuit 8 converts this numerical value into an analog value and inputs it to the level adjustment circuit 6 in the same way as the value of the variable resistor 1 in FIG. The other operations are the same as those in the first M, so the explanation will be omitted.

〔Effect of the invention〕

As described above, the present invention can prevent operator fatigue because the brightness of the display screen changes in response to changes in the amount of external light that the operator is not aware of.

[Brief explanation of drawings]

Part 1 shows a block diagram of a circuit showing one embodiment of the present invention, Fig. 2 shows a block diagram of a circuit showing another embodiment of the invention, and Fig. 3 shows an example of a conventional brightness adjustment circuit. It is a block diagram. In the figure, 1 is a variable resistor, 2 is a CRT drive circuit, 3 is a CRT,
4 is a light sensor, 5 is an amplifier circuit, 6 is a level adjustment circuit, 7 is a memory,
8 is a D/A conversion circuit. Aro of the 1st line of eternal demonstration of the entrance to the sail,) 2) 1 Fig. 7 Ben S Dani no zu ≠ Otogo) Enjoy; ) Furonku g] 萬22 Conventional 4th degree training dokinu - (+1 @ Show Furonfu 2 3rd episode

Claims (1)

[Claims] A display device including a drive circuit (2) that changes the brightness of a display screen according to an input signal level, comprising: a light sensor (4) that detects the amount of external light illuminating the display screen from the outside; an amplifier circuit (5) that changes the input signal level supplied to the drive circuit (2) in accordance with the magnitude of the output of the optical sensor (4); and setting a reference amplification degree of the amplifier circuit (5). A level adjustment circuit (6) is provided, and after the operator determines the reference amplification degree of the amplification circuit (5) via the level adjustment circuit (6), the optical sensor (4) is provided with a level adjustment circuit (6).
), the brightness of the display screen is lowered as the amount of external light decreases, and the brightness of the display screen is increased as the amount of external light increases. circuit.