JP3706264B2 - Projection type multi-screen display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a projection display device that combines a plurality of screens.
[0002]
[Prior art]
Conventionally, as a method for realizing an ultra-high-definition projection display, there is a method (hereinafter referred to as a multi-screen method) in which a screen is divided into a plurality of small blocks and each uses a projection device. FIG. 1 shows an example of the multi-screen method. In this figure, three projection devices 2 are depicted, but since they are actually arranged vertically and horizontally, 2 × 3 or 3 × 3 projection devices 2 are stacked. These emitted lights 3 are combined on the screen 1 to form one screen. If one projection device is 1000 × 1000 pixels and each 3 × 3 is arranged, 3000 × 3000 pixels are obtained, and an ultra-high-definition display is realized.
[0003]
[Problems to be solved by the invention]
As described above, an ultra-high-definition display can be realized by the multi-screen method, but the joint of the screen of each projection apparatus 2 becomes an image quality disturbance. This is because subtle brightness and color differences between the projection apparatuses, a minute positional shift, and a joint line generated on the screen become very conspicuous.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide a projection type multi-screen display device capable of realizing an ultra-high-definition display in which the above-mentioned joint problem is eliminated.
[0005]
[Means for Solving the Problems]
To achieve this object, a projection multi-screen display device according to the present invention is a display device that displays a single screen by combining a plurality of projection display elements, and a first projection display element that has low resolution and high brightness. A plurality of second projection display elements having higher resolution and lower brightness than the first projection display element are spatially arranged, and the projection light from the first projection display element and the second projection display element It is configured to obtain a high-resolution screen by superimposing the projection light from the projection display element on the screen.
Here, the first projection display element is a low-resolution single-panel liquid crystal light valve, and the second projection display element has a smaller area than the liquid crystal light valve of the first projection display element. In addition, a liquid crystal light valve with higher resolution is preferable.
[0006]
The display device may further comprise means for separating the input video signal into a low resolution signal component comprising a low frequency component and a high resolution signal component comprising a high frequency component, and the low resolution Means for supplying a signal component to the first projection display element and means for supplying the high resolution signal component to the second projection display element.
[0007]
Here, the separating means reduces the minimum value among the input video signals corresponding to each of the plurality of pixels of the second projection display element corresponding to each pixel of the first projection display element. A minimum value output circuit for outputting as a resolution signal component; a subtracting circuit for subtracting the output of the minimum value output circuit from the input video signal; and the high-level supply to the second projection display element from the output of the subtracting circuit. It is preferable to include a scan conversion circuit that generates a video signal composed of resolution signal components.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Prior to that, the principle of the present invention will be described with reference to FIG.
In addition to the projection device 2 used in FIG. 1, a high-intensity projection device 4 is used, for example, as shown in FIG. This uses 3 × 4 normal projection devices 2 and one high-intensity projection device 4, and the high-intensity projection device 4 projects the entire screen as shown in the side view of FIG. .
[0009]
An input signal of each projection apparatus will be described. For convenience, it is assumed that the high-intensity projector 4 has the same number of pixels as the projector 2. Further, for the sake of explanation, it is assumed that the number of pixels of the projection device 2 is 1000 × 1000. At this time, since the resolution of the entire screen is 4000 × 3000 and the high-intensity projection device 4 is 1000 × 1000, one pixel of the high-intensity projection device 4 occupies the area of 4 × 3 pixels of the projection device 2 on the screen. become.
[0010]
Next, signal processing will be described. Basically, the input video signal has various frequency components, and the low frequency component is projected by the high luminance projection device 4 and the remaining high frequency components are projected by the plurality of projection devices 2. . However, for example, as shown in FIG. 3, the input video signal 5 is simply obtained through the low-frequency passing circuit 6 to obtain the video signal 9 for the high-intensity projection device 4, and the difference between it and the input video signal 5 through the subtraction circuit 7. In the method of creating the video signal 10 for the projection apparatus 2 by using the scan conversion circuit 8, the following problems occur.
[0011]
The input video signal is 4000 × 3000 pixels in the example of FIG. 2, the video signal 9 for the high-intensity projection device 4 is 1000 × 1000 pixels, and the input of the scan conversion circuit 8 is 4000 × 3000 pixels. 8 generates a signal 10 to be divided into small screens and sent to each projector 2.
For example, in the configuration shown in FIG. 3, if the input video signal 5 is shown in FIG. 4A, the signals shown in FIGS. 4B and 4C (the output of the circuit 6 and the output of the circuit 7 respectively) are obtained. However, as shown in the figure, in FIG. 4C, a negative component is generated. When a negative component occurs in FIG. 4C, the video signal 10 for the projection apparatus 2 (FIG. 4D) also includes a negative component, but since there is no negative light, it cannot be accurately reproduced. It becomes.
[0012]
Therefore, in the present invention, a minimum value output circuit 11 is used in place of the low frequency pass circuit 6 as shown in FIG. This is because the smallest value among the input video signals 5 corresponding to each of the plurality of pixels of the low-intensity projector 2 corresponding to each pixel of the high-intensity projector 4 is the signal of the corresponding pixel of the high-intensity projector 4. When this is used, the signal 10 sent to the projection apparatus 2 as shown in FIG. 6 does not have a negative component, so that it can be accurately reproduced.
[0013]
A configuration example of the minimum value output circuit 11 is shown in FIG. This example is used when an output signal of 1000 × 1000 pixels is created from an input of 4000 × 3000 pixels, as in the above example. The input video signal 5 is combined with the 1-pixel delay circuit 12 and the 1-scan line delay circuit 13 to extract video signals for 4 pixels × 3 scan lines, and is compared by the comparison circuit 14 to output a minimum value. A hold circuit 15 is provided for holding time of 4 pixels × 3 scanning lines to 1000 × 1000 pixels. The hold circuit 15 holds a signal for the time of 4 pixels in the horizontal direction and 3 scanning lines in the vertical direction. For this reason, the clock 16 is sent to the holding circuit 15 every 4 pixels in the horizontal direction and every 3 scanning lines in the vertical direction. It is done. That is, the hold circuit 15 takes out the output signal of the comparison circuit 14 for every four pixels and holds it for that period. This operation is performed for every three scanning lines and the hold signal of the scanning line for which the operation has been performed is divided into three scanning lines. The time axis is extended to obtain an output signal of 1000 × 1000 pixels.
The configuration example of the first embodiment according to the display device of the present invention is shown in FIG. 2 already illustrated, and the configuration block diagram of the video signal processing circuit in FIG. 2 is FIG.
[0014]
An example of the configuration of the second embodiment of the present invention is shown in FIG. This is an example in which two liquid crystal light valves are used. Since this figure is for monochrome, three systems are prepared for each color in the same way. In FIG. 8, a low resolution liquid crystal light valve 17 and a high resolution liquid crystal light valve 18 are used. The output light obtained by irradiating the readout light 21 polarized by the polarizing plate 25, that is, the high resolution output light 22 and the low resolution output light 23 are synthesized by the half mirror 19 and passed through the polarizing plate 25. The final output light 24 is obtained from the projection lens 20. As shown in FIG. 9, each liquid crystal light valve has a single low resolution liquid crystal light valve 17, but the high resolution liquid crystal light valve 18 is a combination of a plurality of small area liquid crystal light valves 26.
[0015]
An example of the configuration of the third embodiment of the present invention is shown in FIG. This has a plurality of high resolution liquid crystal light valves 18, in this example, two high resolution liquid crystal light valves 27 and a high resolution liquid crystal light valve 28, and is synthesized by a half mirror 19. A configuration example of each high-resolution liquid crystal light valve is shown in FIG. By dividing in this way, a region necessary for wiring of the small area liquid crystal light valve 26 can be secured with a margin.
[0016]
Although the present invention has been described above with reference to some embodiments, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the invention described in the claims. It will be self-evident.
[0017]
【The invention's effect】
According to the present invention, a high-brightness projection display element that covers the entire screen at a lower resolution and a plurality of projection-type display elements that have a higher resolution and a lower brightness (since a single unit cannot cover the entire screen, Providing a projection type multi-screen display that is used side by side. Accordingly, it is possible to realize a projection type multi-screen display with high brightness and high resolution in which the brightness is uniform over the entire screen and the joints of the screen are not noticeable.
[Brief description of the drawings]
FIG. 1 shows a configuration example of a conventional projection type multi-screen display.
FIG. 2A shows an arrangement example of the projection apparatus according to the first embodiment of the present invention, and FIG. 2B similarly shows the relationship between the projection apparatus and the screen.
FIG. 3 shows an example of a video signal processing circuit in a projection type multi-screen display.
4 is a diagram for explaining the results of the processing circuit shown in FIG. 3, where (a) is the input signal waveform of the input video signal 5, (b) is the output signal waveform of the low frequency pass circuit 6, and (c). Represents the output signal waveform of the subtracting circuit 7, and (d) represents the output signal waveform of the scanning conversion circuit 8.
FIG. 5 shows a configuration example of a video signal processing circuit according to the first embodiment of the present invention.
6 is a diagram for explaining the results of the processing circuit shown in FIG. 5, where (a) is the input signal waveform of the input video signal 5, (b) is the output signal waveform of the minimum value output circuit 11, and (c) is the output signal waveform. The output signal waveform of the subtracting circuit 7 and (d) show the output signal waveform of the scanning conversion circuit 8, respectively.
FIG. 7 shows a configuration example of a minimum value output circuit according to the first embodiment of the present invention.
FIG. 8 shows a configuration example of a second embodiment of the present invention.
9 shows the configuration of the liquid crystal light valve used in the configuration shown in FIG. 8. FIG. 9A shows a single low-resolution liquid crystal light valve 17 and FIG. 9B shows a plurality of high-resolution liquid crystal light valves 26 having a small area. Each of the combined high resolution liquid crystal light valves 18 is shown.
FIG. 10 shows a configuration example of a third embodiment of the present invention.
11 is a configuration of a liquid crystal light valve used in the configuration shown in FIG. 10, and (a) and (b) are two types of high resolution liquid crystal light valves in which a plurality of small area high resolution liquid crystal light valves 26 are combined ( a) 27 and (b) 28 are shown respectively.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Screen 2 Projection apparatus 3 Output light 4 High-intensity projection apparatus 5 Input video signal 6 Low frequency pass circuit 7 Subtraction circuit 8 Scan conversion circuit 9 Signal 10 for high-intensity projection apparatus 4 Signal 11 for projection apparatus 2 Minimum value output Circuit 12 1 pixel delay circuit 13 1 scanning line delay circuit 14 comparison circuit 15 hold circuit 16 hold circuit clock 17 low resolution liquid crystal light valve 18 high resolution liquid crystal light valve 19 half mirror 20 projection lens 21 readout light 22 high resolution output light 23 Low resolution output light 24 Output light 25 Polarizing plate 26 Small area liquid crystal light valve 27 High resolution liquid crystal light valve (a)
28 High-resolution liquid crystal light valve (b)

Claims (4)

In a display device that displays a single screen by combining a plurality of projection type display elements, a first projection type display element having a low resolution and a high luminance, and a higher resolution and a lower luminance than the first projection type display element. A plurality of the second projection display elements are spatially arranged, and the projection light by the first projection display element and the projection light by the second projection display element are superimposed on the screen, A projection type multi-screen display device characterized by being configured to obtain a high-resolution screen. 2. The display device according to claim 1, wherein the first projection display element is a low-resolution single-panel liquid crystal light valve, and the second projection display element is a liquid crystal of the first projection display element. A projection type multi-screen display device characterized by being a liquid crystal light valve having a smaller area and higher resolution than the light valve. 3. The display device according to claim 1, wherein the display device further separates an input video signal into a low resolution signal component composed of a low frequency component and a high resolution signal component composed of a high frequency component; A projection type multi-screen display apparatus comprising: means for supplying a signal component to the first projection type display element; and means for supplying the high resolution signal component to the second projection type display element. . 4. The display device according to claim 3, wherein the separating means includes an input video signal corresponding to each of a plurality of pixels of the second projection display element corresponding to each pixel of the first projection display element. Among them, a minimum value output circuit for outputting a minimum value as the low-resolution signal component, a subtraction circuit for subtracting the output of the minimum value output circuit from the input video signal, and the second projection type from the output of the subtraction circuit A projection type multi-screen display device comprising: a scan conversion circuit for generating a video signal composed of the high-resolution signal component supplied to the display element.

Images