JPH08292740A - Burning preventive device of display - Google Patents

Abstract

PURPOSE: To make the cell burning inconspicuous by switching to other video signal input while continuously displaying a still picture on a screen such as a PDP for a prescribed time period. CONSTITUTION: Under normal condition, a mode switching section 3 is switched to an RGB signal input section 1 side and a display section 4 displays a computer generated picture. RGB signals are applied to a motion detecting section 5 and the video movement is detected by the data differences between screens. If there is no movement, a timer 6 is activated. When a prescribed time period has passed without detecting a movement, the section 3 is switched to a video signal input section 2 side. A video signal detection section 7 monitors the video signals and if there is no video, a control section 9 stops the timer timing and inhibites the switching action of the section 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sticking prevention device for a display, and more particularly to a device for preventing image sticking by switching to another signal input when a still image is displayed for a required time or longer.

[0002]

2. Description of the Related Art Plasma display panels (PDPs)
In the case of a display device such as that shown in FIG. This image sticking appears prominently when the same screen is displayed for a long time with high brightness. To prevent the image sticking on the display of a computer device, for example, the same image is displayed continuously for the required time. In some cases, the brightness of the screen is lowered, or the screen saver function is activated to switch to the display of a moving line art pattern image.

[0003]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a video signal input terminal when the display device is provided with a video signal input terminal in addition to a computer video signal input terminal. Input a moving video signal to the computer, and switch to the video signal when the video signal of the computer does not change for a long time, without displaying a dark screen or a line art pattern screen that is not comfortable to look at. The purpose is to prevent the seizure of the display.

[0004]

In order to solve the above-mentioned problems, the present invention comprises at least two video signal input sections, and the signals from the respective video signal input sections are switched by the switching section and input to the display section for display. In the display device, the motion detecting unit for detecting the motion of the image is connected to the first video signal input unit, and a timer for counting the duration of the signal without motion from the motion detecting unit is provided. It is an object of the present invention to provide an image sticking preventive device for a display, which switches to a signal from a second video signal input section via the switching section when timed.

[0005]

With the above-described structure, in the image sticking prevention apparatus for a display according to the present invention, motion is detected by calculating the video signal of the computer or the like input to the first video signal input section to detect the motion. If is not detected, the timer starts the time measurement, and if the required time is measured with no video movement, the video signal is switched to the video signal input to the second video signal input section and sent to the display section. When the video signal is not input to the second video signal input section, the switching of the video signal is prohibited, the brightness of the screen is lowered, or the video display such as a line art pattern is switched.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a display image sticking prevention apparatus according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of a main part of an embodiment of a display image sticking prevention apparatus according to the present invention. In the figure, reference numeral 1 denotes a video signal input section (RGB signal input section) for inputting digital video signals separated into red (R), green (G) and blue (B). A video signal input unit (video signal input unit) 2 inputs a video signal reproduced from an image recording medium such as a VTR, an optical disc or a compact video disc, or a television broadcast signal. Reference numeral 3 denotes a mode switching unit, which normally switches to a signal from the video signal input unit 1, and a control unit 9
Signal is switched to the signal from the video signal input section 2. Reference numeral 4 denotes a display unit, which uses a PDP as a display and displays based on a video signal from the switching unit 3. A motion detection unit 5 detects a motion of the video from the video signal input from the video signal input unit 1. Reference numeral 6 denotes a timer, which starts timing with a signal from the motion detection unit 5 and outputs a signal when the required time is counted. A video signal detection unit 7 detects the presence / absence of a video signal input from the video signal input unit 2. 8 is a discrimination unit,
The signal from the motion detector 5 or the signal from the video signal detector is discriminated. A control unit 9 controls each unit.

Next, the operation of the image sticking prevention apparatus for a display according to the present invention will be described. When this device is installed for the purpose of displaying an image from a computer device, the image signal input unit 1 receives an image signal separated into R, G, and B from the computer device, and a mode switching unit. It is input to the display unit 4 via 3, and a computer image is displayed on a screen such as a PDP. The video signal from the video signal input unit 1 is matrixed by a matrix circuit (not shown) and input to the motion detection unit 5 to detect the presence or absence of motion of the video content. Then, when there is no motion in the image, the timer 6 is started via the control unit 9 based on the signal from the motion detection unit 5, and the required time, for example, 5 minutes is counted. At the end of timing of timer 6,
A signal is sent from the control unit 9 to the mode switching unit 3 to switch to the video signal input unit 2 side. However, when the motion detection unit 5 detects the motion of the image during the time counting of the timer 6, the time counting is stopped,
clear. Also, the video signal input section 2 of the mode switching section 3
After the switching to the side, when the motion detecting section 5 detects the motion of the image, the mode is immediately switched to the image signal input section 1 side.

Further, the signal input to the video signal input section 2 is monitored by the video signal detection section 7, and the presence or absence of the video signal is detected based on the horizontal synchronizing signal and the vertical synchronizing signal. Through the control unit 9, the time counting of the timer 6 is stopped or the switching of the mode switching unit 3 to the video signal input unit 2 side is prohibited. Alternatively, a line art signal generation unit for displaying a video of a line art pattern may be provided, and the mode switching unit may be switched to a signal from the line art generation unit when the timer 6 finishes measuring time.

The motion detector 5 is constructed, for example, as shown in FIG. That is, the signal from the video signal input unit 1 is latched by the latch circuit (field memory) 11 for one screen, input to the subtraction circuit 12, and the signal of one screen next input from the video signal input unit 1 Calculate the difference. Then, the output from the subtraction circuit 12 is used as a NOR circuit (NOR gate) 13
To enter. The NOR gate 13 calculates, for example, required upper bit data (upper 5 bits when the video signal is 8 bits) of the video signal from the video signal input unit 1, and when all the bits are "0", "movement" is performed. “None” and the “H” signal is output. The reason why the lower bit is excluded from the motion judgment is to avoid an erroneous judgment when a difference occurs in the lower bit due to noise or the like.

Although not shown in the figure, when an analog video signal is input to the video signal input section 2, this signal is converted into a digital signal and applied to the mode switching section 3. In addition, a scenic background image or the like is input to the video signal input unit 2 and the background image is displayed on the screen of the display unit 4 when the image from the video signal input unit 1 becomes a still image. You may do it.

[0011]

As described above, according to the image sticking prevention device of the present invention, when the image displayed on the screen of the PDP or the like does not move for the required time, another image input, for example, Since the image is automatically switched to the background image or the like, the same cell is not lit at high brightness for a long time, so that image sticking can be made inconspicuous.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of an embodiment of an image sticking prevention device for a display according to the present invention.

FIG. 2 is a block diagram of a main part of an example of a motion detection unit.

[Explanation of symbols]

 1 Video signal input section (for RGB) 2 Video signal input section (for video signal) 3 Mode switching section 4 Display section 5 Motion detection section 6 Timer 7 Video signal detection section 8 Discrimination section 9 Control section 11 Latch circuit 12 Subtraction circuit 13 NOR circuit (NOR gate)

Claims (9)

[Claims] 1. At least two video signal input sections are provided,
In a display device in which a signal from each video signal input section is switched by a switching section and input to a display section for display, a motion detection section for detecting a motion of a video is connected to a first video signal input section, and a motion detection section Is provided with a timer for measuring the duration of the signal without movement, and when the timer measures the required time, it is switched to the signal from the second video signal input section via the switching section. 2. The switching unit is switched from the first video signal input unit when a motion is detected by the motion detection unit after switching the switching unit to the signal from the second video signal input unit. The seizure prevention device for a display according to claim 1, wherein the device is switched to a signal. 3. The image sticking prevention device for a display according to claim 1, wherein at least the first video signal input section is provided so as to input a digital video signal. 4. The first video signal input section inputs a digital video signal separated into red, green and blue, and the first video signal input section receives red, green and blue video signals. 3. An image sticking prevention device for a display according to claim 1, wherein a matrix circuit for matrixing is connected, the video signals separated into three colors and inputted are matrixed and inputted to the motion detecting section. 5. The motion detecting section, a latch circuit for latching a digital video signal from the first video signal input section, a signal from the latch circuit, and a next input from the first video signal input section. 5. A subtraction circuit for calculating the difference from the video signal to be reproduced and a NOR circuit for calculating the bits of the data from the subtraction circuit, claim 1, claim 2, claim 3 or claim 4. Seizure prevention device for display. 6. The second video signal input section is connected to a video signal detection section for detecting the presence or absence of a video signal, and when the video signal is not detected by the video signal detection section, the timer is not timed. The seizure prevention device for a display device according to claim 1, claim 2, claim 3, claim 4, or claim 5, which has been described above. 7. A video signal detection unit for detecting the presence or absence of a video signal is connected to the second video signal input unit, and when no video signal is detected by the video signal detection unit, the second video signal of the switching unit is detected.
The seizure prevention device for a display according to claim 1, claim 2, claim 3, claim 4, or claim 5, wherein switching to the video signal input section side is prohibited. 8. A brightness control section for controlling the brightness of the display section is provided, and when the video signal is not detected by the video signal detection section, the brightness control section reduces the brightness of the display section to a required brightness. The seizure preventive device for a display according to claim 6 or claim 7. 9. A line art signal generation unit for outputting a line art signal is provided, and when the video signal is not detected by the video signal detection unit, the switching unit switches to a signal from the line art signal generation unit. Claim 6
Alternatively, the image sticking prevention device of the display according to claim 7.