JPH08162050A - Image display device - Google Patents

Abstract

PURPOSE: To prevent the reduction in temperature of the end part of a linear cathode by a vibration absorbing ring arranged on the linear cathode end part, and prevent the reduction in electron emission in the linear cathode and part. CONSTITUTION: This device is formed of heating wires 200 for heating a linear cathode vibration preventing ring 102 arranged on both sides of the linear cathode vibration preventing ring 102, a heating wire tensing spring 201 and a heating wire support plate 202, and the heating wire 200 is heated by applying a proper voltage to properly raise the temperature of the linear cathode vibration preventing ring 102 nipped by the heating wires 200. Thus, the reduction in temperature on both end parts of a linear cathode 2 which was caused by the heat conduction of the linear cathode vibration preventing ring 102 in the past is never caused, and the electron emitting performance in the linear cathode end part is never reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device in video equipment.

[0002]

2. Description of the Related Art Heretofore, a cathode ray tube has been mainly used as a color television image display element.
The CRT has a very long depth compared to the screen, and it was impossible to manufacture a flat-screen television receiver. Therefore, EL display elements, plasma display elements, liquid crystal display elements, and the like have been developed as flat panel display elements, but they are all insufficient in terms of performance such as brightness, contrast, and color reproducibility. Therefore, for the purpose of displaying a high-quality image similar to that of a cathode-ray tube on a flat panel device using an electron beam, the screen on the screen is divided into matrix-like sections without gaps, and the electron beam is divided into sections. 2. Description of the Related Art There is an image display apparatus that deflects and scans a phosphor to emit light to form a color television image as a whole. An example of the above-described conventional image display device will be described below with reference to the drawings.

FIG. 2 shows the configuration of a conventional image display device. In FIG. 2, 1 is a back electrode, 2 is a line cathode as an electron beam source, 3 is an electron beam extraction electrode, 4 is a signal electrode, 5 and 6 are focusing electrodes, 7 is a horizontal deflection electrode,
Reference numeral 8 is a vertical deflection electrode, and these components are housed in a glass container 9 and a smooth glass plate 10, and the inside of the container is evacuated. The line cathodes 2 are stretched in the horizontal direction so as to generate an electron flow uniformly distributed in the horizontal direction, and a plurality of such line cathodes 2 are provided in the vertical direction at appropriate intervals. These wire cathodes 2 are formed, for example, by coating an oxide cathode material on the surface of a tungsten wire.

The back electrode 1 is made of a flat plate-shaped conductive material and is provided in parallel with the line cathode 2. The extraction electrode 3 is formed of a conductive plate that faces the back electrode 1 through the line cathode 2 and has rows of through holes 11 that are provided at appropriate intervals in the horizontal direction on a horizontal line that faces each line cathode. The through hole 11 is circular in the embodiment, but may be elliptical or rectangular, or may be slit-shaped. The signal electrode 4 is the extraction electrode 3
A plurality of vertically elongated conductive plates 12 are arranged at predetermined positions at positions facing each of the through holes 11 in
Each of the conductive plates has a similar through hole 13 at a position opposed to the through hole 11 of the extraction electrode 3. The shape of the through hole 13 may be an ellipse or a rectangle, or may be an elongated slit shape in the vertical direction.

The focusing electrode 5 is formed of a conductive plate having through holes 14 at positions facing the through holes 13 of the signal electrode 4. The shape of the through hole 14 may be a circle, an ellipse, or a slit shape. The focusing electrode 6 has a slit hole 15 which is vertically connected at a position facing the through hole 14 of the focusing electrode 5. The shape of the slit hole 15 may be a round hole, an ellipse, or a rectangular shape. The horizontal deflection electrode 8 is composed of conductive plates 16 and 17 which are connected to each other at two comb-shaped end portions which are meshed with each other on the same plane at an appropriate interval.
The space 18 formed between 6 and 17 is opposed to the through slit hole 15 of the focusing electrode 6. The vertical deflection electrode 8 is
As shown in FIG. 2, the conductive plates 19 and 20 connected at the ends, that is, the two comb-shaped conductive plates 19 and 20 are in the same plane and are meshed with each other at appropriate intervals.

The screen 21 is constructed by applying a phosphor 22 that emits light when irradiated with an electron beam to the inner surface of the glass container 9 and adding a metal back layer (not shown) thereon. Further, the extraction electrode 3, the signal electrode 4, the focusing electrodes 5 and 6, the horizontal deflection electrode 7, and the vertical deflection electrode 8 described above are joined by an insulating adhesive (not shown here) to form an integrated unit. The electrode block 24 is formed.

Further, the structure of the line cathode 2 will be described with reference to FIG. FIG. 3 is a perspective view showing an end structure of the line cathode 2 of the conventional image display device. In FIG. 3, reference numeral 100 denotes a line cathode support plate, which fixes the end portion of the line cathode 2 as shown. Reference numeral 101 denotes a wire cathode tension spring that supports the wire cathode 2 with an appropriate tension.

Reference numeral 102 is a ring for vibration absorption of the linear cathode, which is fitted in the end portion of the linear cathode 2 as shown in the figure. When the linear cathode 2 vibrates, its vibration energy is generated by friction with the linear cathode support plate 100. Absorb. The ring 102 for absorbing the vibration of the wire cathode is usually fitted on both ends of the wire cathode, and is made of precision-processed ceramic or the like.

The operation of the image display device configured as described above will be briefly described with reference to FIG. 2 again.

First, the line cathode 2 is heated by flowing a heater current in order to facilitate electron emission (emission). A sheet-shaped electron beam can be emitted from the surface of the line cathode 2 by applying an appropriate voltage to the back electrode 1, the line cathode 2, and the extraction electrode 3 in a heated state. The sheet-shaped electron beam is divided into a plurality of pieces by the through hole 11 of the extraction electrode 3 and becomes a large number of electron beam streams 23. The passing amount of the electron beam flow 23 is individually adjusted by the signal electrode 4 in accordance with the image signal applied to the signal electrode 4.

Next, the electron beam passing through the signal electrode 4 is
Conductive plates 16 and 17 adjacent to the horizontal deflection electrode 7 and adjacent conductive plates 1 to the vertical deflection electrode 8 after being focused and shaped by the electrostatic lens effect of the through holes 14 and 15 of the focusing electrodes 5 and 6.
It is deflected horizontally and vertically by the potential difference applied to the electrodes 9 and 20. Further, a high voltage (for example, 10 KV) is applied to the metal back layer of the screen 21, and the electron beam is accelerated to high energy and collides with the metal back, causing the phosphor to emit light.

When a television screen is vertically and horizontally divided into a matrix to form a group of subsections 25, one electron beam separated as described above is made to correspond to each subsection. By deflecting and scanning only within each subsection, the entire screen can be displayed on the screen. Further, by controlling the RGB video signal corresponding to each pixel by the signal electrode 4, a television moving image can be reproduced.

[0013]

However, according to the above construction, since the wire cathode vibration absorbing rings 102 are arranged at both ends of the wire cathode 2 as shown in FIG. The temperature of the wire cathode near this becomes lower than that in the central portion. As a result, the electron emission (emission) capability at the end of the line cathode is reduced, which causes a problem of image quality deterioration.

In view of the above problems, it is an object of the present invention to provide an image display device which maintains the electron emission ability even at the end of the line cathode.

[0015]

In order to achieve the above object, the image display device of the present invention comprises a heating means for effectively heating a ring for vibration absorption of the line cathode arranged at the end of the line cathode. Is equipped with.

[0016]

[Function] The ring for absorbing vibration of the wire cathode at both ends of the wire cathode is heated by the heating wires arranged on both sides thereof,
The heat of the wire cathode is not dissipated, and the temperature drop at the end of the wire cathode does not occur.

Further, since the heating wires on both sides come into contact with the wire cathode vibration preventing ring when the wire cathode vibrates, the wire cathode vibration preventing effect is also improved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image display apparatus according to an embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a perspective view showing an end structure of a line cathode 2 of an image display device according to this embodiment.

The same parts as those of the conventional apparatus shown in FIGS.
Descriptions of Nos. 1, 102 and 2 are omitted here since they are the same as in the conventional example.

In FIG. 1, reference numeral 200 denotes a heating wire for heating the wire cathode vibration prevention ring 102, which is arranged on both sides of the wire cathode vibration prevention ring 102 as shown in the drawing. 20
Reference numeral 1 is a heating wire tension spring that supports the heating wire 200 with appropriate tension. A heating wire support plate 202 is located on the wire cathode support plate 100 as shown in FIG.
Position 0. The operation will be described below.

The heating wire 200 arranged at both ends of the wire cathode vibration prevention ring 102 generates heat when an appropriate voltage is applied, and the temperature of the wire cathode vibration prevention ring 102 sandwiched between the heating wires 200 is controlled. Raise it appropriately. As a result, the temperature drop at both ends of the wire cathode 2 which was conventionally caused by the heat conduction of the wire cathode vibration prevention ring 102 does not occur. As a result, the electron emission (emission) capability at the end of the line cathode does not decrease.

[0022]

As described above, according to the present invention, by providing heating wires on both sides of the wire cathode vibration prevention ring, the temperature drop at the wire cathode end portion caused by the heat conduction of the wire cathode vibration prevention ring. It is possible to provide a high-quality image display device in which the electron emission (emission) capability at the end of the line cathode does not decrease. Further, since the heating wires on both sides come into contact with the wire cathode vibration preventing ring when the wire cathode vibrates, the wire cathode vibration preventing effect can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an image display device of the present invention.

FIG. 2 is an exploded perspective view showing a configuration of a conventional image display device.

FIG. 3 is a perspective view of a main part of a conventional image display device.

[Explanation of symbols]

 2 wire cathode 24 electrode block 9 front glass container 10 back glass plate 102 wire cathode vibration absorption ring 200 heating wire

Claims (1)

[Claims] 1. A front glass container internally coated with a phosphor and a rear glass plate that closes a rear opening of the front glass container are opposed to each other, and a conductor is coated on the inner surface of the rear glass plate. Or a back electrode composed of a conductive plate arranged in parallel to the back glass plate, and the back electrode and a plurality of the back electrodes in a space sandwiched between the front glass container and the back glass plate. A line cathode, a lead electrode composed of a single or a plurality of conductive plates, a signal electrode, a single or a plurality of focusing electrodes, an electrode block formed by stacking a horizontal deflection electrode and a vertical deflection electrode back and forth, An image display device, characterized in that each of the plurality of line cathodes has a vibration absorbing ring at each end thereof, and a heating means for directly heating the vibration absorbing ring.