JPH07105850A - Manufacture of flat image display device - Google Patents

Abstract

PURPOSE:To solve the problem of a high voltage leak by the contamination of the inner wall of a front glass vessel, and reproduce an image of good quality in an image display device used for various image equipments. CONSTITUTION:Taking, as a ground voltage (0 V), the voltage of an electrode block 24 formed of a back plate 1 integrated into a rear glass vessel 10, plurally laid linear cathodes 2, and each electrode, a plus high pulse voltage is applied to a screen consisting of a metal back layer formed on a front glass vessel 9 for a fixed time. A tube internal discharge is caused thereby, and a foreign material on the inner wall of the front glass vessel is removed by its electric shock. The unnecessary leak current on the screen is removed by the removal of the foreign material on the inner wall of the front glass vessel 9, and an image of good quality can be reproduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing 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. However, a cathode ray tube has a very large depth compared to a screen, and it is not possible to manufacture a thin television receiver. It was possible.
Therefore, EL display elements, plasma display elements, liquid crystal display elements, etc. 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. An image display device has been developed which deflects and scans the 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.

First, FIG. 4 shows the structure of a conventional image display device. In FIG. 4, 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 is a first focusing electrode, 6 is a second focusing electrode,
Reference numeral 7 is a horizontal deflection electrode, and 8 is a vertical deflection electrode. These components are housed in a front glass container 9 and a rear glass container 10 to create a vacuum inside the container.

The line cathodes 2 are horizontally stretched so as to generate an electron flow having a substantially uniform current density distribution in the horizontal direction, and a plurality of line cathodes 2 are vertically arranged at appropriate intervals (4 in this embodiment). Only books are shown.) Provided. These line 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 electron beam extraction electrode 3 is formed of a conductive plate that faces the back electrode 1 through the line cathode 2 and has a row of through holes 11 that are provided at appropriate intervals in the horizontal direction on a horizontal line that faces each line cathode. The signal electrode 4 is composed of a row of vertically elongated conductive plates 12 which are arranged at a position facing each other in the horizontal direction in the electron beam extraction electrode 3 in the horizontal direction with a predetermined interval therebetween. In the electron beam extraction electrode 3, a similar through hole 1 is formed at a position opposite to the through hole 11 of the electron beam extraction electrode 3.
Have three. The first focusing electrode 5 is made of a conductive plate having through holes 14 at positions facing the through holes 13 of the signal electrode 4. The second focusing electrode 6 has a slit hole 1 vertically connected to a position facing the through hole 14 of the first focusing electrode 5.
Have five.

The horizontal deflection electrode 6 is composed of two conductive plates 16 and 17 which are connected to each other at appropriate intervals on the same plane by comb-shaped ends, and the horizontal deflection electrodes 16 and 17 are connected to each other. The space 18 formed therebetween faces the through slit hole 15 of the second focusing electrode 6. The vertical deflection electrode 8 has a structure in which conductive plates connected at their ends, that is, two comb-shaped conductive plates are meshed with each other on the same plane at appropriate intervals, as shown in FIGS. For the beam 23, the lower conductive plate 19 and the upper conductive plate 20 form a pair of vertical deflection electrodes. The screen 25 is configured by applying a phosphor 21 that emits light when irradiated with an electron beam to the inner surface of the front glass container 9 and adding a metal back layer (not shown) thereon. Further, the electron beam 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 together by an insulating adhesive (not shown) to form an integral body. The electrode block 24 is formed. In addition, the linear cathode 2 is attached to the back electrode 1 at appropriate intervals using an attachment member (not shown) and the electrode block 24 is insulated and fixed to form an integral electrode unit. ing. In addition, this electrode unit is provided on a fixed base (not shown) fixed to the rear glass container 10 with appropriate intervals using, for example, screws, and the rear glass container 1
It is fixed so that it is parallel to 0.

The operation of the image display device configured as described above will be described. First, the voltage V
1. A voltage V2 higher than V1 is applied to the electron beam extraction electrode 3. Further, if an appropriate voltage V0 satisfying V1 <V0 <V2 is applied to the line cathode 2 to heat the line cathode and emit electrons, the electric field on the surface of the line cathode 2 becomes positive and the electron flow is emitted. It is accelerated toward the electron beam extraction electrode 3.
Further, for example, if a voltage V0 satisfying V0> V2 is applied to the line cathode 2, the electric field on the surface of the line cathode 2 becomes negative and the emission of electrons can be suppressed. Therefore, by individually controlling the voltage of the line cathodes, the line cathodes 2 are repeated so as to sequentially emit an electron beam from the upper side for a fixed time, and each line cathode has a uniform current density distribution in the horizontal direction. It is possible to generate a sheet-shaped electron beam. The above-mentioned sheet-shaped electron beam is horizontally divided into a plurality of through-holes 11 of the electron-beam extraction electrode 3, and further reaches a through-hole 13 of the signal electrode 4 as a large number of electron beam rows 23. , At this time, set the voltage V3 of the signal electrode 4 to V3> V
If it is 0, the electron beam passes, and if V3 <V0, the electron beam loses kinetic energy and cannot pass.
Therefore, by controlling V3 with time, the electron beam passage amount is adjusted for each electron beam according to the video signal for displaying the picture element. The electron beam that has passed through the signal electrode 4 then reaches the first focusing electrode 5 and the second focusing electrode 6,
After being focused by the electrostatic lens effect of the through hole 14 and the slit hole 15, the adjacent conductive plates 16 and 1 of the horizontal deflection electrode 7 are arranged.
Electrostatic deflection is performed horizontally and vertically by a potential difference (referred to as a deflection voltage) applied between the conductive plates 19 and 20 adjacent to each other and between the vertical deflection electrodes 8. Further, a high voltage (for example, 13 kV) is applied to the metal back layer of the screen 25, the electron beam is accelerated to high energy and collides with the metal back, causing the phosphor 21 to emit light.

When a high voltage is applied to the metal back layer, a high voltage terminal (not shown here) is used. The high voltage terminal is attached to the front glass container 9 at a high temperature by an insulating adhesive. ing.

When the 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, and the electron beam is divided into two sections. By deflecting and scanning only within each subsection, the entire screen can be displayed on the screen. Further, by controlling the RGB video signals corresponding to the respective picture elements with the signal electrode voltage over time as described above, a television moving image can be reproduced.

[0009]

However, in the above structure, a high voltage is applied to the metal back layer due to insufficient cleaning or contamination due to foreign matter adhered to the inner wall of the front glass container in the parts stage or in the manufacturing process. At this time, the current leaks along the inner wall of the front glass container, so that the set voltage cannot be secured, and the current causes the inner wall of the front glass container to emit light.

The present invention solves the above problems, and an object of the present invention is to provide a method of manufacturing a high-quality image display device by eliminating contamination by foreign matters inside the front glass container.

[0011]

To achieve this object, in the manufacturing process, a spark is applied between the screen and other electrode groups by applying a high voltage pulse voltage sufficiently higher than that during normal operation of the image display device. Foreign matter in the glass container is removed by (forced high-pressure discharge in the tube).

[0012]

By this means, foreign matter on the inner wall of the front glass container is removed by the action of the potential difference between the inner surface of the front glass container and the other electrode groups, and unnecessary leak current of the screen is reduced, causing deterioration of image quality. It is possible to reproduce a high quality image without any trouble.

[0013]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the manner of sparking of the image display device according to the first embodiment of the present invention. In FIG. 1, 1 is a back electrode, 2 is a line cathode, 24 is an electrode block, 21 is a scoon, 9 is a front glass container,
10 is a rear glass container. FIG. 3 is a waveform of the sparking voltage applied to the image display device.

Sparking of the image display device configured as described above will be described with reference to FIGS. First, in order to spark the image display device, the voltages of the back electrode 1, the line cathode 2 and the electrode block 24 are set to the ground level (0V). And, as the sparking voltage,
Screen 21 with metal back on front glass container 9
A positive high voltage pulse voltage is applied to. An example of the waveform of the high voltage pulse voltage applied at this time is shown in FIG. In this way, by applying a high voltage (for example, several tens of kV) for a certain period of time, a high potential difference can be obtained among the metal-backed screen 21, the back electrode 1, the linear cathode 2 and the electrode block 24, and The foreign matter on the inner wall of the front glass container is removed by the electric shock caused by the high-voltage discharge.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a sectional view showing the manner of sparking of the image display device according to the second embodiment of the present invention. In FIG. 2, 1 is a back electrode, 24 is an electrode block composed of a line cathode and each electrode, 9 is a front glass container, 10 is a rear glass container, and 26 is a heater for heating the front glass container. FIG. 3 is a waveform of the sparking voltage of the image display device.

Sparking of the image display device configured as described above will be described with reference to FIGS. The basic sparking method for the image display device is the same as that in the first embodiment. At this time, at the time of sparking, the front glass container heating heater 26 heats the front glass container 9 to an arbitrary temperature. As a result, the inner wall of the front glass container is activated and the sparking effect of the image display device is increased. Therefore, the foreign matter on the inner wall of the front glass container 9 can be removed more efficiently.

Although the voltage of the back electrode 1, the line cathode 2 and the electrode block 24 is set to the ground level (0 V) here, in order to secure a higher potential difference, the negative high voltage pulse voltage is changed to the positive high voltage pulse voltage. It goes without saying that the same effect can be obtained by applying the signals in synchronization.

Further, although the sparking voltage is the high voltage pulse voltage here, it is also effective as a method of combining the high voltage DC voltage or the high voltage pulse voltage and the high voltage DC voltage.

Further, although the pulse width and the pulse interval of the high voltage pulse voltage are shown in FIG. 3, any time may be used.

In the embodiment, the metal back layer formed on the front glass container 9 is used as the plus side, the back electrode 1 and the line cathode 2 are provided.
Although the voltage of the electrode block 24 and the voltage of the electrode block 24 are set to the negative side, the reverse application method may be used.

[0023]

As described above, according to the present invention, by applying a voltage higher than that during the operation of the image display device to the screen, foreign matter on the inner wall of the front glass container is removed by the action of electric shock. It is possible to realize an image display device that reduces unnecessary leak current of the screen and reproduces a high quality image.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state of sparking according to a first embodiment of an image display device of the present invention.

FIG. 2 is a sectional view showing a state of sparking of a second embodiment of the same device.

FIG. 3 is a waveform diagram of the sparking voltage of the same embodiment.

FIG. 4 is an exploded perspective view showing the basic configuration of the image display device.

[Explanation of symbols]

 1 Rear Electrode 2 Wire Cathode 9 Front Glass Container 10 Rear Glass Container 21 Screen 24 Electrode Block 26 Heating Heater

Claims (2)

[Claims] 1. A screen in which a phosphor is applied to the inner surface of a front glass container and which is metal-backed, a flat back electrode integrated with a rear glass container, and a space sandwiched between the back electrode and the screen. , Line cathode, electron beam extraction electrode, signal electrode, focusing electrode, horizontal deflection electrode,
In the flat panel image display device including the vertical deflection electrodes, the front glass container that stores them in a vacuum state, and the rear glass container, a high-voltage pulse voltage is applied between the screen and other electrode groups. A method for manufacturing a flat panel image display device, characterized in that a foreign matter removing process on an inner wall of the glass container is performed by sparking. 2. When removing foreign matter by sparking,
The method for manufacturing a flat panel image display device according to claim 1, wherein heating is performed.