JPH041351B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display device having a CRT screen and a liquid crystal screen.

[Conventional technology]

Since the liquid crystal itself is not a light emitting body, conventional display devices using liquid crystals either provide a light source for the liquid crystal display and illuminate from the front surface of the liquid crystal and display the reflected light, or illuminate from the back side of the liquid crystal. It was displayed by the transmitted light.

[Problem that the invention seeks to solve]

However, by providing a light source for liquid crystal display, the display device becomes complicated and space is required for the light source, making it difficult to miniaturize the display device. In particular, when a liquid crystal screen is installed together with other devices such as a CRT, the above problems become even more serious.

An object of the present invention is to provide a display device that does not require a light source for liquid crystal display in a display device that includes a CRT screen and a liquid crystal screen.

[Means to solve the problem]

First, the principle of the present invention will be explained.

As shown in FIG. 5, generally, the effective screen 1 of a CRT is formed at the center of the raster screen 2 on the panel 3, and the peripheral area 2a of the raster screen 2 is used as the effective screen 1 because image distortion is likely to occur. is not used. Therefore, in the present invention, the peripheral area 2 of the raster screen 2
This increases the brightness of the CRT and uses it as a light source to illuminate the LCD screen attached to the CRT.

A display device according to the present invention is a display device having a CRT screen and a liquid crystal screen, and is characterized in that the liquid crystal screen is illuminated using the periphery of the raster screen of the CRT as a light source.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a screen of a display device according to an embodiment of the present invention, and FIG. 2 is a cross section of FIG. 1.
It is a sectional view at XX. The light guide plate 4 is made of acrylic material or the like and is installed on the CRT panel 3 so that one side of the diagonally cut cross section overlaps the peripheral part 2a of the raster screen 2. It is installed on the light guide plate 4.

Next, the operation of this embodiment will be explained with reference to FIG.

FIG. 3 is an enlarged view of the junction Y between the CRT screen and the liquid crystal screen in FIG. 2. The brightness of the peripheral area 2a of the raster screen 2 is set high in advance by a control device (not shown) in the CRT, and a high-energy electron beam is irradiated onto the fluorescent surface 6 of the peripheral area 2a of the raster screen 2. , light is emitted from the fluorescent surface 6. After passing through the panel 3, this light enters the light guide plate 4, is reflected by the oblique cut surface 4a, and travels inside the light guide plate 4. Further, this light is diffusely reflected at various parts of the light guide plate 4 due to impurities in the material from which the light guide plate 4 is made or due to non-uniformity of the material, and enters the liquid crystal 5 .

In this way, the liquid crystal 5 is illuminated from the back surface using the peripheral portion 2a of the CRT raster screen 2 as a light source.

FIG. 4 shows another embodiment.

A liquid crystal screen is provided between two CRTs, and a light guide plate 14 is installed so as to span the panels 13 and 23 of the two CRTs, and a liquid crystal 15 is further installed on top of the light guide plate 14. In addition, panels 13 and 2
The cross section of both ends of the light guide plate 4 to be joined to the light guide plate 4 is cut diagonally as shown in Fig. 3, so that both CRTs
Since the periphery of the raster screen is used as a light source, the brightness of the surface of the liquid crystal 15 is made uniform, and a higher quality liquid crystal image can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a liquid crystal image can be obtained without providing a light source for liquid crystal display in a display device in which a CRT screen and a liquid crystal screen are provided together. Furthermore, by suppressing the peripheral area of the CRT raster screen using software processing in a microcomputer circuit, it is possible to change the colors on the same LCD screen.It is also possible to create a partial color distribution on the LCD screen.
It is possible to control the shading of the LCD image.In addition to the effect of adding movement to the LCD screen by controlling the color and shading, it also makes use of the peripheral area of the raster screen, which was the unnecessary part of conventional CRTs. can be used.

[Brief explanation of drawings]

FIG. 1 is a plan view of a screen of a display device according to an embodiment of the present invention, and FIG. 2 is a cross section of FIG. 1.
Cross-sectional view at XX, Figure 3 is the joint Y in Figure 2
An enlarged view of , Figure 4 is another example, Figure 5 is a CRT
It is an explanatory diagram of a screen. 1... Valid screen, 2... Raster screen, 2a...
Peripheral part, 3, 13, 23...Panel, 4, 14...
...Light guide plate, 5, 15... Liquid crystal, 6... Fluorescent surface.

Claims (1)

[Claims] 1. A display device having a CRT screen and a liquid crystal screen, wherein the liquid crystal screen is illuminated using a peripheral area of a raster screen of the CRT as a light source.