JPS59154884A - Video display device - Google Patents

Abstract

PURPOSE:To obtain a video display device having sufficient good response in the display of a dynamic picture by storing once a screen in a memory, comparing plural screens and detecting the movement of the displayed screen to control a display element. CONSTITUTION:A video signal applied on a line 105 is converted into a digital signal at an A/D converter 106 and stored once in a memory 108. The digital signal stored in the memory 108 is read on a line 109 with an accurate delay of time by one screen, calculated together with a signal on a line 107 at a subtractor 110, and a different between the preceding screen 109 and the present screen 107, i.e., a dynamic signal is obtained on a line 111. This dynamic signal and the video signal 107 are added at an adder 112 to operate a control switch for a display element such as electric bulb.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video display device in which a large number of display elements such as incandescent bulbs are arranged to display a multi-gradation moving image such as a preview signal.

Conventional Structure and Problems This type of large display device generally uses an incandescent light bulb as a display element. In FIG. 1, the incandescent light bulb L1. L2..."n-1"'n each forms one pixel on the screen, and a large number of incandescent light bulbs are arranged side by side, lighting is controlled according to the screen, and multi-gradation moving images are displayed. . Each of the incandescent light bulbs L1 to Ln is provided with switches 81 to Sn and switch control circuits 01 to Cn for controlling lighting, respectively. By selecting the corresponding signal (gradation) and opening/closing the switches 81-Sn, the incandescent light bulbs L1-Ln
The OPs that control the light bulbs L1 to Ln are power sources that supply power to the light bulbs through lines 103 and 104.

When displaying television images, 81~Sn is ○N10, which is opened and closed at about the field frequency or frame frequency (60 den/required or 30 den/% in the Japanese standard system).
The light emission gradation of the light bulb is controlled by changing the duty of the FF according to the gradation.

When controlling a light bulb to display a moving image using this method, there is a drawback that the response speed of the light bulb is insufficient and movement on the screen cannot be sufficiently displayed.

Figure 2 on page 3 is an extracted diagram of the circuit of the light bulb portion of Figure 1. Further, FIG. 3 shows the response characteristics of the light bulb when the duty of opening and closing the switch S is changed from time t2 to t6. Note that FIG. 3 is expressed as an average value when the duty of ○N10FF is changed. When the duty of the switch S is changed at time 0 so that the brightness becomes 100%, the brightness of the light bulb changes like 0-A-B-C, and at time t4, the brightness reaches 100% and becomes stable. When the duty of the switch S is controlled again to 0% brightness at time t6, the brightness of the light bulb starts to decrease from point D and reaches a stable state at time t7. However, at time t2, the brightness is 30%.
When A- is reached, the duty of switch S is further changed to control the brightness to 60%, and the brightness of the bulb becomes A-.
No change in B, change in A-H, 60% at time t6
reached and stabilized. When the switch S is controlled so that the brightness becomes 30% at time t6, the brightness decreases from [F] and reaches 30% at time t3, resulting in an equilibrium state. t5. The value of t8 etc. is 14
．． 17, resulting in an afterimage phenomenon when displaying a moving image.

OBJECTS OF THE INVENTION It is an object of the present invention to eliminate the drawbacks of the above-mentioned conventional devices and to provide a sufficiently responsive display in moving image display.

Structure of the Invention The present invention is configured to temporarily store a screen in a memory, detect the movement of the displayed screen by comparing a plurality of screens, and control the display element to achieve the above object. It is.

Description of examples Examples of the present invention will be described below.

For example, at time t2, a light bulb with a brightness of 30% has a brightness of 60%.
In order to change rapidly to
Perform duty control of switch S to reach 00%,
If the duty of S is controlled to stabilize at 6o% brightness at the 8 points where the brightness reaches 60% at time t3, the brightness change will be A-B-E, and the response time will change from 15-12 to t3.
- improved to t2. Figure 4 shows a signal processing circuit for controlling the switch page 5 based on this idea, and Figure 6 shows the relationship between the screen and processed waveforms when the signal processing according to Figure 4 is performed. It is something.

In FIG. 6, 105 is a line to which a video signal is added, 1
o6 is an analog-to-digital converter, 107 is a line from which a digital signal is output, 108 is a screen memory in which one or more screens are stored, 1o9 is a line to which signals read from memory 1o8 are added, and 11o is a memo IJ1.
08 is a subtracter for calculating input/output signals, 111 is a line to which the output signal of the subtracter 110 is applied, 112 is an adder, 113 is a line to which the output signal is applied, and the signal controlling the switch sl in FIG. I'm joining.

Next, the operation of this embodiment will be explained.

The video signal applied to line 105 is converted into a digital signal by analog-to-digital converter 106. line 1
The signal applied to 07 is a digital signal, but for the sake of simplicity, the screens and waveforms of analog signals are shown in FIG. It is assumed that the screen has a uniform halftone and that white circles moving from left to right exist at 107-2, 107-3, and 107-4. The analog-to-digital converted digital video signal is temporarily stored in the memo 1J10B, and then read out onto the line 109 with a delay of exactly one screen time (or multiple screen times). Screens related to the signals on line 109 are shown in FIG. The screen 107 and the screen 109 are calculated by a subtracter 110, and the line 111 shows the previous screen 109 and the current screen 10.
7 difference or motion signals can be obtained.

For example, the signal diagram C of the line 111 in FIG.
White circles 1-3 indicate changes toward white, and black circles indicate changes toward black. The motion signal of this line 111 and the video signal 10
7 is added by an adder 112 to obtain a signal for controlling the switch s1. This signal controls the switch to emphasize white for one screen time when the screen changes to white (t2 to t3 when changing from 3o% brightness to 60% brightness mentioned above)
(equivalent to controlling in the direction of 100% brightness during
In the case of a change toward black on the page, the opposite control can be performed to speed up the response.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, according to the present invention, it is possible to increase the response speed of a video display device using an element with a relatively slow response such as an incandescent light bulb, thereby displaying a moving image more accurately.

This idea can also be applied to displaying a moving image using an element with a similarly slow response speed, such as a liquid crystal.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a general video display device, FIG. 2 is a circuit diagram of its main parts, FIG. 3 is a diagram showing the response characteristics of a light bulb, and FIG. 4 is a video display device according to an embodiment of the present invention. FIG. 5 is a block diagram showing the processing status of the screen. 106...Analog-digital converter, 108
...Memory, 110...Subtractor, 112
・・・・・・Adder. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figures and S Figure 2

Claims (1)

[Claims] A converter for converting a video signal into a digital screen; a digital memory for storing digital signals of the autumnal equinox or multiple autumnal equinoxes; and a detection means for detecting movement of the screen by comparing the readout screen read from the digital memory with the current screen. 1. A video display device comprising: an output of the detection means to drive a display element in a direction to accelerate its response.