JPS62195984A - Projector - Google Patents

Abstract

PURPOSE:To prevent a splice from being noticed as a whole by overlapping adjacent video parts in the splice of the video parts obtained from plural video lights, smoothly changing and controlling the brightness level of the video parts constituting the overlapped part in a gradual manner toward the end of the video part. CONSTITUTION:The video information DSa-DSd of a controller 52 is controlled and the signal level of the signal impressed to the signal line L1 of a transistor 52 for driving a pixel 51 constituting the respective liquid crystal cells of liquid crystal plates 1-4 is changed. Then, the brightness level of the respective video parts 31-34 of the overlapping parts 41-45 is controlled so as to change smoothly, linearly, for instance. For instance, in the vicinity of the overlapping part 41, the brightness level of the video part 31 drops linearly from the brightness level of 100% to that of 0% with progressing from the end part (a) of the vertical video part 32 to the end part (b) of the video part 31. In this manner, the video based on the video information DS having the even brightness level as a whole is displayed on a screen 6.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a projector, and particularly to a projector that displays one image as a whole by projecting image light obtained from a plurality of transmissive liquid crystal panels onto a screen in a matrix form. The present invention is suitable for application to a projector such as the above.

B. Summary of the Invention The present invention provides a projector that displays a single image as a whole by projecting a plurality of image lights obtained from a plurality of liquid crystal panels onto a single screen in a matrix, and the joints between the respective image parts. , so that adjacent video parts are superimposed on each other, and the brightness level of the overlapping part and the video part changes smoothly,
The aim is to display an image that does not seem to have any seams as a whole.

C. Prior Art Conventionally, there have been various video display devices in which a single display screen is formed using a single liquid crystal plate, which is composed of a matrix of liquid crystal cells whose transmittance changes depending on the applied voltage. Proposed.

However, it has been difficult to create a so-called liquid crystal plate with high pixel density, in which many liquid crystal cells are formed on one liquid crystal substrate, and furthermore, it has been difficult to increase the size of the liquid crystal plate.

In addition to this, there is a problem with LCD panels in general that when the viewer's viewpoint moves, the contrast of the image displayed on the LCD panel changes rapidly, which is the so-called narrow viewing angle. The video display device used is usually used for small-sized video display with a screen size of several inches or less so that this effect can be ignored in practice.

On the other hand, for large screens of 20 inches or more,
In consideration of these problems, a projection type projector using a plurality of liquid crystal panels 1 to 4 as shown in FIG. 4, for example, has been proposed.

In other words, 5 represents the projector as a whole, and screen portions 61 to 6 are formed by dividing the transparent screen 6 into four parts.
On the optical axis passing through the center position of 4, light is supplied to liquid crystal plates 1 to 4, and image light L A + to LA is supplied to the liquid crystal plates 1 to 4.
4 and the corresponding screen portions 61 to 6.
Optical systems 7 to IO are provided for projecting images onto 4.

Each optical system 7 to 10 has the same configuration, for example, for optical system 7, screen portion 6. and the liquid crystal plate 1 between the light source 11
is arranged, and the light emitted from the light source 11 is condensed and transmitted to the liquid crystal plate 1 by a condenser lens 12 and a Fresnel lens 13. In this way, an image light LA+ is formed on the liquid crystal plate 1, with each liquid crystal cell as one pixel, and this image light LA passes through the field lens 14 to the screen portion 6. It is designed to be projected on.

Similarly, an image LA of the liquid crystal plate 2 formed by the optical system 8 is projected onto the screen portion 6b, an image light LA3 of the liquid crystal plate 3 formed by the optical system 9 is projected onto the screen portion 6C, and further Image light LA4 of the liquid crystal plate 4 formed by the optical system 10 is projected onto the screen portion 64.

The projector 5 uses a circuit configuration as shown in FIG.
An image consisting of Ds is displayed on a screen 6.

That is, the controller 21 receives the video information DS and controls the screen portion 6. of the screen 6. The video information qDS of the video portion displayed on the screen is outputted to the liquid crystal panel l via the pass line 22. Similarly, screen portion 6. ~6J
Video information 'taps corresponding to the video part displayed in ~
DSa is outputted to the liquid crystal panels 2 to 4 via the pass line 22.

The liquid crystal panels 1 to 4 have built-in drive circuits and control circuits, and display video information DS obtained via the pass line 22.
, ~D Sa A transparent image is formed with each liquid crystal cell as one pixel.

In the above configuration, each of the screen portions 6a to 6G of the screen 6 has video information of the liquid crystal panels 1 to 4, respectively. QD
S, ~D A video corresponding to a is displayed. Video information i
DS, to D S a are the screen portions 6 . Since the video information corresponding to the video portions displayed in .about.6d is assigned, the video images on the liquid crystal panels 1-4 come to display each video portion of the video information DS.

Thus, when the user looks at the screen 6 from the direction of the arrow X behind the screen 6 (FIG. 4), the user can view the video of the video information DS as a large-sized display video with a large number of pixels and a wide viewing angle. be able to.

D Problems to be Solved by the Invention However, for example, depending on the digit 1 of the liquid crystal panels 1 to 4, as shown in FIG. In some cases, they do not match and a slight gap 35 is created in the horizontal direction, for example.

In this case, for example, even when a bright image is displayed as a whole, the gap 35 is displayed black, and the image portions 31 to 3
There was a problem in that the seams of 4 were conspicuous and resulted in an unsightly image.

Conversely, if a portion 36 slightly overlaps the image portions 31 to 34 in the vertical direction, for example, this portion 36 will be displayed brighter than the other portions, resulting in an unsightly image where the seam is displayed brightly. There was a problem with putting it away.

One way to make such seams 35 and 36 less noticeable is to completely match the video parts 31 to 34 so that the screen 6
Although it would be possible to make the brightness continuous at the top, there is a problem in that it requires delicate adjustment work that is extremely complicated and requires skill.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a projector in which changes in brightness that occur at the joints of image parts are made inconspicuous in the overall displayed image.

E Means for Solving Problems In order to solve these problems, the present invention uses a plurality of image lights LA obtained from a plurality of liquid crystal plates 1.2.3.4.
, , LAz , LA3 , LA4 onto one screen 6 in a matrix form to display one image as a whole. In the projector 5 , a plurality of image lights LA+ , LAz , LA
:+, Video part 31.32.3 obtained from LA4
3. At the seam of 34, adjacent video portions 3■, 32.
33 and 34 are superimposed, and in the superimposed parts 41 to 45, the brightness levels of the video parts 31 to 34 constituting the superimposed parts 41 to 45 are changed to the video parts 31 to 34.
By controlling the image to change smoothly toward the end of the video image 34, the brightness level of the overlapping portions 41 to 45 is corrected to be less noticeable compared to the brightness levels of other video portions.

In the F action superimposed parts 41 to 45, the video parts 31 to 3
If the brightness level of 4 is made to change smoothly as it goes to the edge of the video part, the overlapping parts 41 to 4
5 and the brightness levels of the video parts 31 to 34 change continuously and smoothly.

In this way, the brightness level of the image on the screen 6 changes continuously and smoothly before and after the seam, so it is possible to obtain a natural image in which the seam is not noticeable.

G example An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, the video portion 3 on the screen 6 in FIG.
The structure is otherwise the same as that shown in FIG. 4, except that the display portions 1 to 34 are changed so that portions 41 to 45 that always overlap each other occur at the seam portions.

In practice, this can be achieved by adjusting the relative positions of the components of the liquid crystal panels 1-4 or the optical systems 7-10 shown in FIG.

Furthermore, in accordance with the change in the display portions of the video portions 31 to 34 described above, for example, the output timing of the controller 21 shown in FIG. The parts 31 to 34 display the same image to prevent different images from being displayed in duplicate.

Furthermore, the video information (UDS,
~DS, for example, as shown in FIG. As shown in FIG. 3, by changing the
For example, the brightness of the image should be changed linearly and smoothly.

That is, for example, before and after the overlapping part 41, the brightness level of the video part 31 is vertically from the end a of the video part 32 to the end of the video part 31 (accordingly, the brightness level of the video part 31 is 10).
The brightness level decreases linearly from 0% brightness level to 0% brightness level.

Conversely, the brightness level of the video portion 32 increases linearly from the 0% brightness level to the 100% brightness level from the end to the end.

In the overlapping portion 42, the video portion 3 is
The brightness level of the video part 33 decreases as one goes from the end a of the video part 2 to the end of the video part 33.
brightness level increases.

Similarly, in the overlapping portion 43.44, the brightness level of the adjacent video portions 31 to 34 is changed in the horizontal or vertical direction as described above, and as a result, the brightness level before and after the overlapping portion 43.44 is changed. A smoothly changing image can now be obtained on the screen 6.

Thus, even in the superimposed portion 45, each video portion 3
1 to 34, the brightness level changes in the horizontal and vertical directions as shown in FIG. 3.

In the above configuration, the video parts 31 to 34 (FIG. 1) obtained on the screen 6 are the overlapping parts 41 to 34 (FIG. 1).
45, the brightness level decreases toward the edges of the video portions 31-34.

That is, in the overlapping portion 41, as shown in FIG. 3, when the brightness level of the video portion 31 decreases linearly from a 100% brightness level to a 0% brightness level,
On the other hand, the brightness level of the video portion 32 increases linearly from the 0% brightness level to the 100% brightness level.

Therefore, in the overlapped portion 41, the overlapped portion 4
100% brightness is now maintained over the entire surface of image area 4I, and image areas 31 and 3 before and after the overlapping area 4I
It becomes equal to the brightness level of 2.

Similarly, in the overlapping parts 42 to 45, 100% brightness is maintained over the entire surface of the overlapping parts 42 to 45, which is equal to the brightness level of the video parts 31 to 34 before and after the overlapping parts 42 to 45. Become.

In this way, an image based on the image information iDs having a uniform brightness level as a whole is displayed on the screen 6.

According to the above configuration, the image obtained on the screen 6 can be maintained at a brightness level of 100% for both the joint portion and other portions, so that the display can be performed on a large screen where the seam of the video portion is not noticeable. Obtainable.

Further, according to the above embodiment, the overlapping portions 41 to 45
Since the brightness level of the video parts 31 to 34 constituting this is gradually and smoothly reduced, for example, the video parts 31 to 34 move and the size of the overlapping parts 41 to 45 increases. Even when the brightness changes, the resulting change in brightness level at the seam is extremely small.

Therefore, the adjustment work for positioning the respective video parts 31 to 34, which is complicated and requires skill, as in the conventional art, can be made more efficient.

In the above embodiment, the light sources 11 were provided for each of the liquid crystal plates 1 to 4, but instead of this, for example, after dividing the light from one light source into four, the liquid crystal plates 1
You may add it to 4. Furthermore, for example, two light sources may be provided, and each emitted light may be divided into two and applied to the liquid crystal plates 1 to 4.

Further, in the above-described embodiment, the overlapping portions 41 to
The video information gDs output from the controller 21 controls the brightness level 3B of the video portion 45.

Although the signal level of the signal applied to the signal line L1 of the liquid crystal cell is changed by controlling ~D S a, instead of this, the one-word level of the signal applied to the scanning line L2 is controlled. You can do it like this.

In the above-described embodiment, a projector is described in which two liquid crystal panels are arranged horizontally and two vertically (four in total), but the present invention is not limited to this, and the present invention is not limited to this,
The present invention can be widely applied to i3 type projectors using a plurality of liquid crystal plates, such as a total of nine liquid crystal plates.

Further, in the present invention, each of the liquid crystal panels 1 to 4 is connected to a video portion 31.
The present invention can be applied not only to the case of projecting images from 1 to 34, but also to a color projector using a plurality of sets of three liquid crystal plates, for example.

Further, in the above embodiment, the brightness level of the video portion changes linearly from the 100% brightness level to the 0% brightness level, but this is not necessarily the case.
For example, the same effect can be obtained by reducing the brightness level smoothly so as to draw a gentle curve so that the brightness level changes smoothly in the video portion and the overlapping portion.

H Effects of the Invention As described above, the present invention provides a projector using a transmissive liquid crystal panel that has a large screen, has a large number of pixels, and can display images with a wide viewing angle without noticeable seams in the image area. can be obtained easily.

[Brief explanation of drawings]

FIG. 1 is a linear plan view showing the displayed image of the projector according to the present invention, FIG. 2 is a linear plan view showing the liquid crystal cells of the liquid crystal panel, and FIG. 3 is the brightness of the joints of each image part of the projector according to the present invention. FIG. 4 is a route diagram showing the changes, FIG. 4 is a route perspective view showing the configuration of a projector, FIG. 5 is a block diagram of the projector, and FIG. 6 is a route plan view showing a display image of a conventional projector. 1-4...Liquid crystal board, 5...Projector, 6...Screen, 7-10...
Optical system, 20... Receiving section, 21... Controller, 31-34... Video portion, 41-
45...Overlapping part.

Claims (1)

[Scope of Claims] A projector configured to display one image as a whole by projecting a plurality of image lights obtained from a plurality of transmissive liquid crystal plates onto one screen in a matrix, Adjacent video parts are overlapped at the seam of the video parts obtained from the video light of A projector characterized in that the brightness level of the overlapping portion is corrected so as to be less noticeable compared to the brightness level of other video portions by controlling the brightness level to change smoothly.