JPS59110287A - Large-sized display device - Google Patents

Abstract

PURPOSE:To eliminate the need for a large-diameter lens and to improve luminance by dividing an original image into MXN parts, and sharing to display M units sectional image on N units of CRT arrayed in a matrix individually. CONSTITUTION:One lens 7 for each sectional image in each area 41 is provided between an image plane 4 and an optical fiber 51, and consequently individual sectional images are projected on the fiber 51. This fiber 51 is formed by bundling numbers of optical fibers in a plate shape. Consequently, the magnification rate of the image is set substantially and optionally by adjusting the focal length and position of the lens 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a display device, and more particularly to a large-sized display device that uses a plurality of CRTs to display images over a large area.

(b) Background of the Technology In recent years, large-sized display devices that display images on a display surface of several meters square have been increasingly used in various fields.

The need for such a display device is based on the need to enable a large number of people to view the same 5 images at the same time and to create a sense of realism. The intended effect is different from the method in which the viewer is given exclusive use.

In response to the above requirements, various types of large display devices have been proposed depending on the display content, usage environment, etc.

(C) Prior art and problems The largest display device uses incandescent light bulbs or CRTs with a diameter of several square meters as pixels, with several hundred pixels x several hundred pixels (f
There are devices in which lits are arranged in a matrix, but these are primarily intended for outdoor use and have a lower limit on display area, making them unsuitable for indoor use.

There is also a display that displays a color image by projecting light from a light emitting source (generally, three colors are provided as a light source) onto a screen, scanning the light, and modulating the brightness. The brightness of the device is relatively low;
It is necessary to darken the surroundings.

In order to solve the above problems, multiple CRTIs are arranged in a matrix as shown in Figure 1, and one image is divided and displayed among these CRTIs (hereinafter referred to as segmented image). There is one that projects this onto the screen 2.

In this type of display device, the brightness can be made relatively high (if necessary, the brightness can also be increased by providing a set of multiple CRTs for one segmented screen light), In order to form segmented images on the screen 2, a relatively large-diameter lens 3 or mirror (not shown) is required for each CRTI, which makes the device large and expensive. There were drawbacks.

(d) Object of the Invention The object of the present invention is to provide a novel large-sized display device that solves the drawbacks of the large-sized display device that projects segmented images using a plurality of CRTs.

(e) Structure of the Invention The present invention has means for dividing an original image into MXN segmented images, means for displaying M segmented images on each of N CRTs, and a lens for each segmented image. The present invention is characterized in that it is provided with means for guiding light to an imaging plane, and also provided with means for adjusting brightness in a connecting region between segmented images.

(f) Examples of the invention Embodiments of the present invention will be described below with reference to the drawings.

In the following drawings, the same parts as in the previous figures are given the same reference numerals.

As a method of avoiding the use of large-diameter lenses in the above-mentioned conventional system, as shown in FIG. 2, it is considered that an optical fiber 5 is provided between the image plane 4 of the CRTI and the screen 2 to guide the image light. It will be done.

However, the glass layer 6 in front of the image plane 4 typically has a thickness of 3 to 7 fins, and the image resolution obtainable at this surface 61 is limited to approximately twice this thickness.

That is, pixels that are closer than this resolution on the image plane 4 cannot be observed separately, and if the diameter of the optical fiber 5 is larger than this resolution, adjacent pixels cannot be observed separately. become.

In the present invention, each of the images obtained by dividing the original image into MXN pieces is called a segmented image), and the M segmented images are shared and displayed on each of the N CRTs arranged in a matrix. .

In this case, as shown in FIG. 3, one lens 7 is provided between the image plane 4 and the optical fine lens 51 for each segmented image of each area 41, and each segmented image is optically It is projected onto the fiber 51.

The optical fiber 51 is formed by bundling a large number of optical fibers into a plate shape.

According to this method, it is possible to extract pixels of each segmented image regardless of the thickness of the glass N6, and by adjusting the focal length and position of the lens 7, the magnification of the image can be substantially increased. can be set arbitrarily.

In this case, the diameter of each fiber constituting the optical fiber 51 is such that each pixel can be separated on the light incident surface of the optical fiber 51 (that is, two or more pixels are not projected onto one fiber).III All you have to do is keep it on the side.

The first advantage of the above method is that it does not require a large-diameter lens unlike the conventional method shown in FIG. 1, and the increase in device cost can be kept low.

Further, since the optical fiber 51 itself acts as a screen, there is no need to provide an independent screen. The second advantage is that the brightness can be increased by this. However, if it is necessary to widen the viewing angle of the display screen, it is sufficient to provide the outer surface (observation side) of the optical fiber 51 with appropriate light scattering properties.

According to the method of the present invention, each segmented image projected onto the optical fiber 51 is vertically and horizontally inverted with respect to the segmented image on the image plane 4.

This inversion can be corrected by an optical method such as providing a second lens, but by inverting each segmented image displayed on the image plane 4 in advance, the optical fiber 51 can be corrected. It is advantageous to make the upper projection image identical to the original image. This is MXllj
This is easily possible by controlling memory access when retrieving segmented images.

When composing segmented images onto the optical fiber 51, if the peripheral part of each segmented image is projected so as to overlap with the peripheral part of the adjacent segmented image, the joint between each segmented image becomes less noticeable, but in this case. Then, as shown in FIG.
), the brightness after composition can be made uniform.

In the figure, dl and d2 are ranges (image areas) of each segmented image on the image plane 4 that are projected onto the optical fiber 51.

Further, as is clear from FIG. 4, a blank space may be provided between each segmented image on the image plane 4.

Next, a description will be given with specific numerical examples.

FIG. 5 is a block diagram of the control system of the large-sized display device of the present invention.

In the same figure, frame memory 8 contains 51 frames for one screen.
Image signals for 2×512 pixels are stored. The image signal is divided into 16×16 segmented images by the image dividing circuit 9.

On the other hand, 4.times.4 CRTs (1) to (16) are arranged in a matrix, and 16 segmented images are assigned to each CRT as described above.

The main control circuit 10 extracts image signals for 16 segmented images from each CRT and sends them to each control circuit 11. Each control circuit 11 temporarily stores the image signal in its respective buffer memory 12, and as explained in FIG. Image signals are extracted and displayed so that the image is inverted.

In addition, when the peripheral parts of adjacent segmented images are to be overlapped on each CRT, the control circuit 11 takes out a signal including the superimposed portion as an image signal of each segmented image from the buffer memory 12, and A brightness adjustment bias signal is added to the signal.

(g) Effects of the Invention According to the present invention, a large diameter lens is not required in a large display device using a plurality of CRTs, and as a result, the depth of the device can be reduced and the cost can be reduced.

Furthermore, since a normal light-scattering screen is not necessarily required, the effect of improving brightness can also be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional large display device using multiple CRTs, and FIG. 2 is a diagram illustrating an example of guiding light from an image plane to a screen using optical fibers.
FIG. 3 is a diagram for explaining a method for extracting segmented images on each CRT in a large-sized display device according to the present invention, and FIG. 4 is a diagram for explaining the brightness adjustment in the overlapping portion between each segmented image in the method shown in FIG. 3. FIG. 5 is a block diagram of a control system of a large-sized display device according to the present invention. In the figure, 1 is a CRT, 2 is a screen, 3 is a lens, 4 is an image plane, 5 and 51 are optical fibers, 6 is a glass layer, 7 is a lens, 8 is a frame memory, 9 is an image division circuit, and 1o is a main A control circuit, 11 is a control circuit, 12 is a buffer memory, 41 is a segmented image display area, and 61 is a surface of the glass layer 6.

Claims (1)

[Claims] (1) means for dividing the original image into MXN segmented images;
(2) Means for displaying M segmented images on each of the N(Ilil CRTs) and a lens for each segmented image; A large-sized display device according to claim 1.