JPH07129142A - Brightness control device - Google Patents

Abstract

(57) [Summary] [Purpose] To change the brightness of digital image data at high speed. [Structure] A constant storage means 2 for storing a constant for performing an arithmetic operation on an input image signal, and an arithmetic means 1 for performing an arithmetic operation on an input image signal using an arithmetic constant output from the constant storage means 2 are stored. High-speed brightness control is realized by multiplying the input signal with a constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brightness control device for a digital image display device.

[0002]

2. Description of the Related Art In recent years, with the widespread use of digital control for display devices and the like, it has been required to change the brightness at high speed.

An example of such a conventional brightness control device will be described below with reference to the drawings.

FIG. 2 is a block diagram of a conventional brightness control device. In FIG. 2, 21 is a CPU, 22 is a frame memory for storing image data output from the CPU 21, and 23 is a display device for displaying image data output from the frame memory 22.

In the brightness control device configured as described above, when a certain image is displayed and the brightness is changed to ½, the CPU 21 has the brightness of ½ of that of the frame memory 22. The data is written, and the frame memory 22 outputs the image data having a half luminance to the display device 23 according to the written data, and the display device 23
As a result, the display is performed with half the brightness.

[0006]

However, in the above structure, when controlling the luminance, it is necessary to rewrite the image data in the entire frame memory area, so that the luminance is controlled at high speed. Had a problem that it was difficult.

In view of the above-mentioned conventional problems, it is an object of the present invention to provide a brightness control device for changing brightness of digital data at high speed.

[0008]

According to the present invention, an image storage means for storing an input image signal, a constant storage means for storing a constant for performing an operation on image data, and an output of the constant storage means. A brightness control device is provided with a calculation means for performing a calculation for changing the brightness on an image signal output from the image storage means using a calculation constant and outputting the changed image data.

[0009]

According to the present invention, with the above-mentioned structure, the input image signal is stored in the image storing means, and the constant for storing the image data is stored in the constant storing means. Using the arithmetic constant output from the constant storage means, the image signal output from the image storage means is operated to change the brightness and the changed image data is output. As a result, the brightness can be adjusted at high speed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a brightness control device according to an embodiment of the present invention. In FIG. 1, 2 is a constant storage means (device) storing constants, 3 is a constant output,
Further, a CPU for outputting image data, 4 is a frame memory for storing the image data, 1 is a calculation means (device) for changing the brightness of the image data by a constant, and 5 is a display device for displaying the image data whose brightness is changed. is there.

The operation of the brightness control device configured as described above will be described below with reference to FIG.

Certain image data is output from the CPU 3 to the frame memory 4. The image data is output from the frame memory 4 to the display device 5 via the calculation means. The display device 5 displays an image according to the image data.

When the brightness is changed to ½, the CPU 3 stores the constant 0.5 in the constant storage means 2. Therefore, the arithmetic means 1 inputs the constant 0.5 stored in the constant storage means 2. The calculation means 1 calculates the input image data by using the constant 0.5 as a multiplication constant, converts the calculated image data into a luminance of ½, and outputs the image data with the luminance changed. The display device 5 is
The changed image is displayed.

Therefore, the CPU 3 does not need to change the image data written in the frame memory 4.

As a result, it is possible to realize brightness control at high speed for digital data.

In this embodiment, the calculating means is a multiplier, but other calculating means for changing the brightness may be used.

Further, although the constant storing means of the present invention stores the constant sent from the CPU 3 in the above embodiment, the present invention is not limited to this, and the constant may be stored by other setting means. Absent.

Further, in the above embodiment, the brightness change is 0.
It was 5, but of course other changes are acceptable.

Further, the arithmetic means can be realized by software using a computer, or can be realized by using a dedicated hardware circuit having each function thereof.

[0021]

As is apparent from the above description,
The present invention uses the image storage means for storing an input image signal, the constant storage means for storing a constant for performing an operation on image data, and the operation constant output by the constant storage means. Since the image signal output from the device is provided with an operation unit for performing an operation for changing the brightness and outputting the changed image data,
Brightness can be controlled at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram of a brightness control device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional brightness control device.

[Explanation of symbols]

 1 computing means 2 constant storage means 3 CPU 4 frame memory 5 display device

Claims (1)

[Claims] 1. An image storage means for storing an input image signal, a constant storage means for storing a constant for performing an operation on image data, and an operation constant output from the constant storage means for storing the image. A brightness control device comprising: a calculation means for performing a calculation for changing the brightness of an image signal output from the means, and outputting the changed image data.