JPH095882A - Multiple video display device - Google Patents

Abstract

PURPOSE: To provide a multiple video display device by which one sheet of video can be reproduced without mutually deviating the videos even when the projecting phase is changed and a projection tube is prevented from being burned in the case that a multi-screen is constituted. CONSTITUTION: The large-screen display device is constituted by arraying the M pieces of video projection devices 17a-17i in a horizontal direction and arraying the N pieces in a vertical direction. Then, at least one set of video projection devices out of the M×N pieces are mutually connected by cables for controlling 17j-17q. When a display position control signal is given to at least one video projection device, it is given to at least one of the other video projection device through the cables for controlling. Then, the positions of the videos displayed on the M×N pieces of video projection devices are controlled to be simultaneously moved in an identical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is effective for, for example, a projection type video projection apparatus, and more particularly to a multi video display apparatus composed of a plurality of video display apparatuses.

[0002]

2. Description of the Related Art As is well known, recently, the development and popularization of large-sized display devices have been remarkable, and there are various display means such as those using a liquid crystal or a light emitting diode. Among these, the projection type video projection device that uses a cathode ray tube is currently the main focus.

FIG. 4 shows the structure of such a projection type video projection apparatus. That is, reference numeral 11 in the figure denotes a projection type video projection apparatus main body, and three projection tubes 11a, 11b, 11 for generating images of the three primary colors of red (R), blue (B) and green (G) respectively inside the projection type video projection apparatus main body.
c is arranged. These three projection tubes 11a, 11
The image light emitted from b and 11c is emitted toward the screen 11d on the front surface of the projection type video projection apparatus main body 11. The screen 11d includes R, B, which are irradiated from the respective projection tubes 11a, 11b, 11c.
A color image can be displayed by forming the image light of G.

FIG. 5 shows details of the projection tubes 11a, 11b, 11c. Here, the projection tubes 11a, 11b,
Any one of 11c will be described. That is, reference numeral 12 in the drawing is a cathode ray tube, and the electron gun 1
2a is enclosed. The cathode ray tube 12 is coated with a phosphor 12b on the side facing the electron gun 12a side. The electron beam 12c emitted from the electron gun 12a strikes the fluorescent body 12b to cause the fluorescent body 12b to emit light. The phosphor 12b has three primary colors of red, blue and green. The above projection tubes 11a, 11b, 11c are
The R tube, B tube, and G tube are configured.

The electron beam 12c emitted from the electron gun 12a is deflected by a magnetic field directly applied from the outside by the deflection yoke 12d so that the electron beam 12c is correctly applied to the phosphor 12b. Then, the emission image 12e of the fluorescent substance 12b which is surface-emitted by the scanning of the electron beam 12c forms an image on the screen 13 located on the focal length of the projection lens 12f.

As described above, in the projection type video projection apparatus, since the size of the image is determined by the focal length of the projection lens 12f, it is relatively easy to enlarge the screen. Furthermore, in order to increase the size of the screen, a combination of multiple video projection devices is used, and a part of the video is projected on each video projection device to reconstruct one video as a whole. There is also a method.

FIG. 6 shows a display device in which a plurality of video projection devices are combined and arranged so that their respective screens are substantially on the same plane. In the figure, reference numerals 14a to 14i are screens of the respective video projection devices, on which screens one divided image is projected.
The screen 14 shows an image before being divided.

By the way, the projection type video projection apparatus, as shown in FIG.
Although the phosphor 12b is coated in b and 11c, it is impossible to avoid deterioration of the phosphor 12b. This deterioration increases as the irradiation time of the electron beam 12c increases. For example, as shown in FIG. 7A, it is assumed that the same image (showing the letter A in the figure) is always displayed on the video projection device. Then
In the area indicated by hatched lines in the figure, the irradiation amount of the electron beam 12c is always strong and the phosphor 12b emits strongly.
Since the area of No. 2 is always weak in the irradiation amount of the electron beam 12c, the phosphor 12b emits light weakly.

If such a period continues for a long time, the deterioration of the phosphor 12b in the α region becomes more remarkable than in the β region. For this reason, as shown in FIG.
When the electron beam 12c is uniformly irradiated on the entire surface, the region of α, which has always been irradiated with the electron beam 12c, has a weaker emission of the phosphor 12b than the region of β, and the region of α has an afterimage. Will be left on the screen. This phenomenon is generally called burn-in. This burn-in phenomenon is often seen in video projection devices that constantly project a still image. For example, a linear image with high brightness as seen on a bowling score display is particularly susceptible to burn-in.

Therefore, conventionally, in order to prevent the image sticking from occurring, even if the same image signal is always used, the projected phase is periodically changed little by little, or only the same phosphor 12b is used for the electron beam 12c. A video projection device has been developed to prevent the irradiation of light.

FIG. 8 shows an image displayed on the video projection device having the above-described image sticking prevention function. That is, the image 15a is displayed on the screen 15 of the video projection device. This image 15a is moving in the clockwise direction in the figure to images 15b to 15f. That is, the position of the image 15a is periodically changed.

However, in the conventional burn-in countermeasure applied to the video projection apparatus as described above, when a multi-video projection apparatus 16 is formed by combining a plurality of video projection apparatuses as shown in FIG. Since the phases of the image 16a displayed on the screen of the projection device are not the same,
A shift will occur in the divided image 16a. For this reason, there is a problem in that the original picture of a picture created by the images of its neighbors cannot be maintained normally.

[0013]

As described above, in the conventional video projection apparatus, when a plurality of video projection apparatuses are combined to form a multi-screen, if the phase of the video is arbitrarily changed, the images of neighboring comrades are displayed. Have the problem that they can't connect well.

Therefore, an object of the present invention is to reproduce a single image without causing a shift between the images even when the projected phase of the images is changed when a multi-screen is constructed.
An object of the present invention is to provide a multi-video display device capable of preventing burn-in of a projection tube.

[0015]

A multi-video display device according to the present invention has a first video display position control means for changing a video display position according to a display position control signal.
Second video display having a second video display position control means for arranging the screens side by side on the screens of the first video display device and the video display device of the first video display device. When a display position control signal is given to the device and the first video display position control means, this display position control signal is given to the second video display position control means to display an image of the first video display device. A control signal connection means for associating the second image display device with the image so that the images move simultaneously is provided.

[0016]

According to the above construction, at least one set of M × N video projection devices is connected by a control line, and a display position control signal is given to at least one video projection device. , This display position control signal is applied to at least one other video projection device via a control cable, and M ×
Since the images displayed on the N video projection devices are moved in the same direction at the same time,
The boundary with the neighboring image is continuous, and it is possible to send a smooth image that does not feel strange to the observer.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of the present invention, and shows a multi-video projection device 17 composed of individual video projection devices.
In FIG. 1, reference numerals 17a to 17i in the figure denote individual video projection devices, each of which is displaying a divided image shown by the diagonal lines in the figure. The video projection device 17a and the video projection device 17b are connected to each other by a control cable 17j, and various control signals output from the video projection device 17a are sent to the video projection device 17b via the control cable 17j. Supplied. In the same manner, the video projection devices 17c to 17i are connected by control cables 17k to 17q, respectively. Here, the multi-video projection device 17 integrated into a large screen by connecting the individual video projection devices 17a to 17i is driven based on the video projection device 17a.

On the multi-video projection device 17, a circular stationary fixed pattern shown by a diagonal line A in the figure is projected. Now, the seizure prevention process of the projection tube is working,
If the projection phase of the video projection device 17a is shifted to the upper right direction in the figure, the signal indicating the phase fluctuation change is sequentially transmitted to the video projection devices 17b to 17i via the control cables 17j to 17q. Become. That is, the video phase change signal from the video projection device 17a is sequentially transmitted to each of the video projection devices 17b to 17i, so that the image displayed on each of the video projection devices 17b to 17i shifts to the upper right direction in the figure. To be done. That is, the image displayed on the multi-video projection device 17 is displaced from the stationary fixed pattern A shown by the dotted line in FIG. 2 to the stationary fixed pattern B shown by the diagonal line in the figure. Therefore, in the multi-video projection device 17, since the boundary with the neighboring image is continuous, it is possible to display a smooth image without a sense of discomfort to the observer.

FIG. 3 shows the details of each of the video projection devices 17a to 17i. Here, any one of the video projection devices 17a to 17i will be described as a representative. That is, the video signal S1 supplied to the video input terminal 18 is supplied to the input circuit 19.
The input circuit 19 separates the input video signal S1 into an image signal component and a synchronization signal component. The sync signal component is divided into a horizontal sync signal and a vertical sync signal.

The signal S3 including the image signal component and the synchronizing signal component output from the input circuit 19 is supplied to the video signal processing circuit 21. The video signal processing circuit 21 demodulates the color signal component of the image signal component contained in the input signal S3 to generate a red, green or blue signal. The signal S4 output from the video signal processing circuit 21 is supplied to the deflection circuit 22. The deflection circuit 22 is
Based on the horizontal and vertical synchronization signals of the supplied signal S4,
Generates horizontal and vertical deflection signals. The signal S5 output from the deflection circuit 22 is a CRT (Cathode Ray Tube) 2
3 drive.

On the other hand, the control signal S6 supplied from the other device to the control input terminal 24 is supplied to the CPU 20.
The CPU 20 determines the content of the control signal S6, and based on the determination result, the input circuit 19 and the video signal processing circuit 2
1, signals S3, S4, S5 output from the deflection circuit 22
Is controlled.

Here, as a method of controlling the projected phase of the image displayed on the screen, it can be realized by correcting the convergence, changing the phase of the signal, or a combination thereof. First, the method by convergence correction is C
Based on the result determined by the PU 20, the data D1 is output to the convergence correction circuit 25. The convergence correction circuit 25, based on the input data D1,
The correction current flowing through the correction coil 26 is controlled to change the projection phase of the image displayed on the screen.

Next, the method of changing the phase of the signal is as follows.
There is a method of changing the phase of the picture portion in the video signal processing circuit 21 with reference to the horizontal synchronizing signal and the vertical synchronizing signal of the signal S3 output from the input circuit 19. That is, when the pattern is superimposed on the sync signal, the phase thereof can be controlled by the CPU 20. Therefore, the control signal S
It is possible to control the superimposing phase of the pattern by judging the contents of No. 6 and supplying the signal S2 of the judgment result to the video signal processing circuit 21.

Further, from the terminal 27, the phase control signal S7 from the CPU 20 to the next video projection device is sent.
Is output. In this way, the same phase control signal S7 is transmitted to all the multi video projection devices.

As described above, according to the above embodiment, even when a plurality of projection type video projection apparatuses are combined to form a multi-video projection apparatus,
Since the projection phase of the image can be made the same in all the devices in order to prevent the burn-in of the projection tube, there is no deviation in the images between the adjacent projection devices, and a smooth multi-image can be obtained.

In the above description, the display device is only a projection device, but the present invention is not limited to this.
It can also be applied to a large screen display device using a liquid crystal display device or a display device using a color cathode ray tube. Further, it can be applied to a combination of a liquid crystal display device and a cathode ray tube display device. Further, in the method of connecting the control cables 17j to 17q, the video projection device 17a may be connected to the video projection devices 17b to 17i at the same time.

[0027]

As described above, according to the present invention, even when the projection phase of an image is changed when a multi-screen is constructed,
It is possible to provide a multi-video display device capable of reproducing a single image without causing displacement between the images and preventing burn-in of the projection tube.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a multi-video display device according to the present invention.

FIG. 2 is a diagram for explaining the operation of a projection phase in the embodiment.

FIG. 3 is a block configuration diagram in the embodiment.

FIG. 4 is a view for explaining a conventional projection type video projection device.

FIG. 5 is a diagram showing details of the conventional projection tube.

FIG. 6 is a diagram for explaining a video output of the conventional multi-projection apparatus.

FIG. 7 is a diagram for explaining the burn-in of the phosphor of the conventional projection tube.

FIG. 8 is a diagram for explaining an example of a change in a projection phase when a conventional image sticking prevention measure is taken.

FIG. 9 is a diagram shown for explaining an output image when a multi-screen is configured by a projection device having a conventional burn-in prevention measure.

[Explanation of symbols]

11 ... Projection type video projection apparatus main body, 11a
... projection tube, 11b ... projection tube, 11c ... projection tube, 11d ...
Screen, 12 ... CRT, 12a ... Electron gun, 12
b ... Phosphor, 12c ... Electron beam, 12d ... Deflection yoke, 12e ... Emission image, 12f ... Projection lens, 13 ... Screen, 14 ... Screen, 14a ... Screen, 14b ... Screen, 1
4c ... Screen, 14d ... Screen, 14e ... Screen, 14f ... Screen, 14g ... Screen, 14h ... Screen, 14i ... Screen, 15
... screen, 15a ... video, 15b ... video, 15c ... video,
15d ... video, 15e ... video, 15f ... video, 16 ... multi-video projection device, 16a ... video, 17
... multi-video projection device, 17a ... video projection device, 17b ... video projection device, 17c ... video projection device, 17d
... video projection device, 17e ... video projection device, 17f ... video projection device, 17g ... video projection device, 17h ... video projection device, 17i ... video projection device, 17j ... control cable, 17k ... control cable, 17l ... control Cable, 17m ... control cable, 17n ... control cable, 17o ... control cable, 17q ... control cable, 18 ... video input terminal,
19 ... Input circuit, 20 ... CPU, 21 ... Video signal processing circuit, 22 ... Deflection circuit, 23 ... CRT, 24 ... Control input terminal, 25 ... Convergence correction circuit, 26 ... Correction coil, 27 ... Terminal.

Claims (4)

[Claims] 1. A first video display device having first video display position control means for changing a video display position according to a display position control signal; and screens arranged side by side on the screen of the first video display device. And a second image display device having a second image display position control means for changing the image display position by the display position control signal, and the display position control signal is given to the first image display position control means. In such a case, the display position control signal is given to the second video display position control means so that the image of the first video display device and the image of the second video display device move simultaneously. And a control signal connecting means for associating the same with a multi-video display device. 2. The first and second video display position control means and the control signal connection means are arranged such that the image of the first video display device and the image of the second video display device are in the same direction. 2. The multi-video display device according to claim 1, wherein the multi-video display device is associated so as to move to a position. 3. The same display device as the first and second image display devices has M horizontally arranged screens and N vertically arranged screens, which are arranged on substantially the same plane. 2. The multi-video display device according to claim 1, wherein the display devices are sequentially connected by the control signal connection means. 4. The multi-video display device according to claim 3, wherein the plurality of image display devices are display devices using a cathode ray tube.