JPH04215235A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To form a surface supporting a light emitting body into an optimum shape and lighten the body by forming an image display surface in a panel separately from a vacuum container, and locating the image display surface in the vacuum container. CONSTITUTION:A fluorescent body 19 is formed in an electron gun 14 side of a transparent panel 12, and is housed in a vacuum container 11. With this structure, the electron beam 15 is irradiated to the light emitting body 19 to display the image on the panel 12. The panel 12 is thereby formed into the optimum shape to widen the field of view, and the wall thickness of the container 11 is thinned to be lightened.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to flattening the image display surface of a cathode ray tube and reducing the weight of the cathode ray tube.

0002

2. Description of the Related Art It is widely known that cathode ray tubes are generally vacuum vessels. A vacuum state is required for the electron gun to generate an electron beam and for the luminous body to emit light due to the collision of the electron beam. Therefore, the electron gun and the image display surface are housed within the vacuum container. FIG. 3 shows a schematic structure of a color cathode ray tube that has been most commonly used in the past. An electron beam (not shown) emitted from the electron gun 14 passes through the opening of the shadow mask 18 and collides with the light emitter 19 formed on the inner surface of the front panel glass 17, causing it to emit fluorescence. Atmospheric pressure is applied to the vacuum container, which exerts a force that crushes the container from all sides, and as the curved surface of the container approaches a flat surface, the strength of the container decreases. As shown in FIG. 5(a), a spherical container 42 is most resistant to atmospheric pressure 41, and the container can have the smallest wall thickness 43. As shown in FIG. 5B, the wall thickness 43 of the cathode ray tube container is considerably thicker than that of a spherical container due to its unique shape. Recently, as the image display surface has become more flat, the thickness 43 has become even thicker, as shown in FIG. 5(c). In the conventional television system, (a
), the aspect ratio of the image display surface 51 is approximately 3:
However, recently introduced high-definition systems have a more horizontally elongated image display screen 52 as shown in FIG. 6(b), with an aspect ratio of approximately 3:5. In such a case, as shown in FIG. 4, when the cathode ray tube is approached and viewed diagonally from the front, part of the image display surface formed on the inner surface of the front panel 17 will be in its own shadow. Therefore, the field of view 33 becomes narrow. In order to widen the field of view 33, the radius of curvature 32 of the front panel 17 may be increased to bring it closer to a flat surface. However, the radius of curvature 32
If , the thickness of the front panel 17 must be increased to withstand atmospheric pressure. As screens have become increasingly flat in recent years, the overall weight of cathode ray tubes has increased.

0003

[Problems to be Solved by the Invention] Conventional cathode ray tubes have a curved image display surface, which limits the field of view. There was a problem in that the overall weight of the container increased because the wall thickness of the container had to be increased. This invention was made to solve the above-mentioned problems, and aims to widen the field of view of images and reduce the overall weight.

0004

[Means for Solving the Problems] A cathode ray tube according to the present invention has an image display surface formed in a panel separate from the vacuum vessel, and the image display surface can be viewed directly from the outside. .

[0005]

[Operation] Since atmospheric pressure or other external stress is not applied to the panel forming the image display surface in this invention,
It is possible to create a curved surface that looks best when viewing the image from the outside, and the shape of the vacuum container can be made to be effective against atmospheric pressure, so the wall thickness of the vacuum container can be made thinner and the overall shape can be improved. Weight can be reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a transparent panel 12 is housed in a vacuum container 11, and a light emitter 19 is formed on the surface of the panel 12 on the electron gun 14 side. The electron beam 15 hits the light emitter 19 and displays an image on the panel 12. In addition, 1
8 is a shadow mask, 17 is a transparent front panel of the vacuum container, 16 is an explosion-proof band, and 13 is a deflection yoke. Figure 2
Since the panel 12 having the image display surface can be made into an optimal shape as shown in FIG. Furthermore, since the shape of the vacuum container 11 can be made into a more spherical shape that is effective against the atmospheric pressure 41, the wall thickness 43 of the vacuum container can be reduced, and as a result, the overall weight can be reduced. can. Although FIG. 1 shows an embodiment using a color cathode ray tube, the present invention can be similarly applied to a black and white cathode ray tube. If the panel 12 having the image display surface in FIG. 1 is made into a flat plate, the field of view of the image is sufficient, and the fact that the panel 12 is made into a flat plate produces advantages in manufacturing the cathode ray tube. Further, if the front panel 17 of the vacuum container 11 is subjected to anti-reflection treatment, reflection of external light can be reduced and images can be viewed reliably.

[0007]

As described above, according to the present invention, the field of view of the image can be widened and the overall weight can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an embodiment of a cathode ray tube of the present invention.

FIG. 2 is a diagram illustrating the field of view of an image of the cathode ray tube of the present invention.

FIG. 3 is a schematic cross-sectional view of a conventional cathode ray tube.

FIG. 4 is a diagram illustrating the field of view of an image of a conventional cathode ray tube.

FIG. 5 is a diagram illustrating the relationship between atmospheric pressure and the wall thickness of a vacuum container.

FIG. 6 is a diagram illustrating various shapes of the image display surface.

[Explanation of symbols]

11 Vacuum container 12 Panel 14 Electron gun 15　Electron beam 17 Front panel 18 Shadow mask 19 Luminous body 32 Radius of curvature 33 Field of view 41 Atmospheric pressure 42 Spherical container 43 Thickness 51 Image display surface with an aspect ratio of 3:4 52 Image display surface with an aspect ratio of 3:5 62 Field of view

Claims (1)

[Claims] 1. A cathode ray tube having at least an electron gun and an image display surface in a vacuum container, wherein the image display surface is formed on a panel separate from the vacuum container and placed inside the vacuum container. and the image display surface can be viewed directly from the outside.