KR970007536B1 - Doming preventing system in image apparatus - Google Patents

Abstract

None.

Description

Anti-Doming Device of Video Equipment

FIG. 1 is a block diagram for explaining the phenomenon of the doming of a conventional television.

Figure 2 is a circuit diagram for explaining the anti-doming of the television vision of the present invention.

* Real names of symbols on the main parts of the drawings

1: Image processor 2: Image signal generator

3: display part 4: anti-doming part

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to anti-doming of an imaging device, and more particularly, to an anti-doming device for an imaging device that removes bleeding and white bleeding due to excessive contrast level.

In general, color means a color intensity, brightness means brightness, and contrast means contrast in a young device such as a television.

In the prior art, as shown in FIG. 1, an image processor 1 for generating color signals Red, Green, and Blue signals corresponding to color, bright, and contrast signals according to key manipulation of a key matrix and a cock signal of the image processor 1 are provided. It is composed of an image signal generator 2 for driving the cathode of the cathode ray tube (3).

In the prior art configured as described above, the image processing unit 1 receives color, bright and contrast signals by a user to generate each color signal, and the image signal generating unit 2 is applied to each cathode of the cathode ray tube 3. Apply the respective signal.

At this time, since each electron gun emits an electron beam, the electron beam is interlaced by horizontal and vertical synchronous, and thus a desired image appears on the screen.

However, in such a conventional technique, when the contrast level is excessive, doming and white bleeding occur in the image on the screen, resulting in deterioration of image quality.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional drawback, and an object of the present invention is to provide an anti-doming apparatus for an imaging apparatus capable of realizing a clear image at all times regardless of contrast level.

A feature of the present invention for achieving the above object is an image processor for outputting a video signal of the contrast is adjusted in response to the contrast level control signal; An image signal generator for driving a cathode ray tube in response to an image signal of the image processor; A first transistor configured between a cathode ray tube and the image signal generator and inverting and amplifying an image signal applied to the cathode ray tube from the image signal generator; An integrating resistor and capacitor for integrating the output signal of the first transistor; And a second transistor for applying a contrast control signal corresponding to the level of the signal integrated by the resistor and the capacitor to the image processor.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a circuit diagram of the present invention, in which color and bright signals, which are controlled by a user (i.e., by key manipulation of key metrics of an image device), are applied to the image processing unit 1 in the same manner as in the related art.

However, the contrast signal is configured to be applied from the doming circuit 4, which will be described later, unlike the conventional art. The image signal output from the image processor 1 is applied to the image signal generator 2, and the image signal generator 2 corresponds to the color signal of the image processor 1 and drives the cathode of the cathode ray tube 3. Let's go.

At this time, a domming circuit 4 is formed between the image processor 1 and the cathode of the cathode ray tube 3 as shown.

As shown, the doming circuit 4 supplies the voltage distribution resistors R3 and R4 for dividing the voltage level of the image signal applied to the cathode from the image signal generator 2 to the cathode. The voltage divided by the resistors R3 and R4 is configured to be inverted and amplified through the transistor Ql.

The voltage inverted and amplified by the transistor Q1 is applied to the integrating circuit through the zener diode ZDl. That is, when the inverted amplifier voltage of the transistor Ql is equal to or higher than the breakdown voltage of the zener diode ZD1, it is integrated through the integrating circuit composed of the resistor R61 and the capacitor C1.

The output voltage of the transistor Ql integrated in the integrating circuit can be said to mean the contrast level (inverted state) of the image signal, and the output of the integrating circuit can be called the average level of the inverted contrast level of the image signal. have.

The transistor Q2 is driven by this average level, and the collector side of the transistor Q2 is connected to the image processor 1, and the image signal processor 1 is applied to the emitter side of the transistor Q2. If the contrast of the video signal is controlled in accordance with the (contrast control signal), the video signal can output a video signal with a constant contrast.

As described above, according to the present invention, when the contrast amount of the image signal generator 2 is excessive, the contrast of the image processor 1 is automatically reduced so that the contrast is always kept stable, thereby eliminating the doubling and white bleeding. It is effective.

Claims (1)

An image processor 1 for outputting an image signal of which contrast is adjusted in response to the contrast level control signal; An image signal generator (2) for driving the cathode ray tube (3) in response to the image signal of the image processor (1); A first transistor configured between the cathode ray tube 3 and the image signal generator 2 and inverting and amplifying an image signal applied from the image signal generator 2 to the cathode ray tube 3; Q1) and; An integration resistor (R61) and a capacitor (C1) for integrating the output signal of the first transistor (Q1): the contrast control signal corresponding to the level of the signal integrated by the resistor (R61) and the capacitor (C1). And a second transistor (Q2) for applying to the image processor (1).