JPH0831307B2 - Image display device - Google Patents

Description

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

Conventional example configuration and its problems Conventionally, a cathode ray tube has been mainly used as a display element for displaying a color television image, but the conventional cathode ray tube has a very long depth as compared with the screen, and a thin television. It was impossible to make a John receiver. In addition, EL display devices, plasma display devices, liquid crystal display devices, etc. have recently been developed as flat plate display devices, but they are all insufficient in terms of performance such as brightness, contrast and color reproducibility of color display. It has not been put to practical use. Therefore, for the purpose of achieving a device capable of displaying a color television image on a flat panel display device using an electron beam, the screen on the screen is divided into a plurality of sections in the vertical direction and each section is divided into a plurality of sections. The electron beam is deflected in the vertical direction to display multiple lines, and it is further divided into multiple sections in the horizontal direction, and R, G, B
Etc. by sequentially emitting fluorescent substances such as R, G, B, etc., and controlling the irradiation amount of the electron beam to the fluorescent substances such as R, G, B, etc. by a color video signal to display a television image as a whole. Is. A conventional image display device has a rear electrode 1, a line cathode 2 as an electron beam source, vertical focusing electrodes 3, 3 ', and a vertical deflection electrode in this order from the rear to the front, as shown in the specific structure of FIG. An electrode 4, an electron beam flow control electrode 5, a horizontal focusing electrode 6, a horizontal deflection electrode 7, an electron beam accelerating electrode 8 and glass containers 9 and 22 are arranged and configured, and the components are housed in the glass container. Use a vacuum.
A linear cathode 2 as an electron beam source is horizontally stretched so as to generate an electron beam linearly distributed in the horizontal direction, and a plurality of such linear cathodes 2 are vertically arranged at appropriate intervals ( Only four of 2a to 2d are shown here). In this embodiment, it is assumed that 15 pieces are provided and the numbers are 2a to 2yo. These wire cathodes are, for example,
An oxide cathode material is applied on the surface of a 20 μφ tungsten wire. Then, as will be described later, the electron beam is controlled so as to emit an electron beam sequentially from the upper line cathode 2a at regular intervals. The back electrode 1 creates an electric potential with the vertical focusing electrode 3 which will be described later, and generates an electron beam from a line cathode 2 other than the line cathode 2 which is controlled to emit the electron beam for a certain period of time. And suppresses the generated electron beam and pushes out the generated electron beam only in the forward direction. The back electrode 1 may be formed by a coating film of a conductive material attached to the inner surface of the rear wall of the glass bulb.
Instead of the back electrode 1 and the line cathode 2, a planar electron beam emitting cathode may be used. The vertical focusing electrode 3 is a conductive plate 11 having a horizontally long slit facing each of the line cathodes 2a to 2yo. The electron beam emitted from the line cathode 2 is taken out through the slit 10 and is in the vertical direction. Focus on. The slits 10 may be provided with crosspieces at appropriate intervals in the middle, or may be substantially slits in the case of a large number of through holes provided side by side at a small horizontal interval (an interval at which they are almost in contact). It may have been done. The vertical focusing electrode 3'is also the same. A plurality of vertical deflection electrodes 4 are horizontally arranged at intermediate positions of the slits 10, and conductors 13, 1 are provided on the upper and lower surfaces of the insulating substrate 12, respectively.
3'is provided. Then, a vertical deflection voltage is applied between the conductors 13 and 13 'which face each other,
Deflection the electron beam vertically. In this configuration example, an electron beam from one hot cathode 2 is vertically deflected to a position of 16 lines by a pair of conductors 13 and 13 '. Then, the 16 vertical deflection electrodes 4 form 15 pairs of conductors corresponding to the 15 line cathodes 2, respectively, and finally the electron beam is deflected so as to draw 240 horizontal lines on the screen 21. . Next, the control electrode 5 is composed of a conductor 15 having slits 14 each long in the vertical direction,
A plurality of pieces are arranged side by side in the horizontal direction at a predetermined interval. In this configuration example, 320 control electrode conductive plates 15a to 15n are provided (only 10 are shown in the figure). Each of the control electrodes 5 separates and takes out the electron beam in the horizontal direction for each picture element, and controls the passing amount according to a video signal for displaying each picture element. Therefore, if 320 control electrodes 5 are provided, 320 per horizontal line
The picture element can be displayed. Also, in order to display the image in color, each picture element is to be displayed in a three-color phosphor of R, G, B, and each control electrode 5 receives each of the R, G, B image signals. Added sequentially. Also, 320 lines of video signals for one line are simultaneously applied to 320 control electrodes 5, and one line of video is displayed at one time. The horizontal focusing electrode 6 is the control electrode 5
Vertically long multiples (320 facing each other)
This is composed of a conductive plate 17 having a slit 16), and horizontally focuses the electron beams for each picture element divided in the horizontal direction into a narrow electron beam. The horizontal electrode 7 is composed of a plurality of conductive plates 18 arranged vertically in the middle position of each of the slits 16, and a horizontal deflection voltage is applied between each of the horizontal electrodes 7 for each picture element. Each of the electron beams is deflected in the horizontal direction, and the R, G, and B phosphors are sequentially irradiated on the screen to emit light. The deflection range is the width of one picture element for each electron beam in this embodiment. The accelerating electrode 8 is composed of a plurality of conductive plates 19 horizontally provided at the same position as the vertical deflection electrode 4, and accelerates the electron beam so that the electron beam impinges on the screen with sufficient energy. It also serves to deflect vertically. The screen 21 has a glass container 9 in which a fluorescent body 20 that is emitted by irradiation of an electron beam is used.
Is applied to the back surface of the above, and a metal back layer (not shown) is added. The fluorescent body 20 is one of the control electrodes 5.
For each of the slits 14, that is, for each electron beam divided in the horizontal direction, one pair of R, G, B fluorescent colors of three colors is provided, and stripes are arranged in the vertical direction. It is applied in a shape. In FIG. 1, the broken lines drawn on the screen 21 indicate the vertical divisions corresponding to the plurality of line cathodes 2, and the two-dot chain lines correspond to the plurality of control electrodes 5, respectively. Shows the horizontal division. In one section divided by these two, the second
As shown in the enlarged view of the figure, in the horizontal direction, R, G, and
There is a B phosphor 20, which has a width of 16 lines in the vertical direction. The size of one section is, for example, in the horizontal direction.
1mm, vertical 16mm. In addition, in FIG.
Note that the horizontal length is drawn much larger than the vertical length for clarity. Further, in this embodiment, only one pair of R, G, B phosphors 20 for one control electrode 5, that is, one electron beam, is provided, but two or more picture elements are provided. However, in that case, the R, G, and B video signals for two or more picture elements are sequentially applied to the control electrode 5, and horizontal deflection is performed in synchronization therewith. However, in the above structure, the conductive plate 19 of the accelerating electrode 8 is a thin plate stretched horizontally in the structure as shown in FIG. Then, as shown in FIG. 3, in the blanking period (FIG. 3- (1) A) for each field of the screen, ripples are added to the high voltage potential applied to the acceleration electrode 8 as shown in FIG. 3- (2). As a result, a periodic Coulomb force is generated between the horizontal deflection electrode 7 and the acceleration electrode 8, and this Coulomb force causes the suspended acceleration electrode 8 to vibrate, and the frequency of this Coulomb force (= TV When the natural frequency of the accelerating electrode 8 is close to an integral multiple of the screen field switching frequency of 60 Hz in John, the vibration is gradually amplified and becomes a large vibration as shown in FIG. As shown in FIG. 4), it has a big defect that the landing of the electron beam in the vertical direction on the screen 21 is disturbed.

OBJECT OF THE INVENTION In view of the above-mentioned drawbacks, the present invention prevents vibration of an accelerating electrode,
An image display device intended to prevent disturbance of vertical landing, and to provide a highly reliable image display device.

According to the present invention, there are provided a plurality of linear hot cathodes, electrode means for extracting an electron beam from the linear hot cathodes, electron beam control electrode means composed of a plurality of electrodes, and for deflecting the electron beam. In an image display device having a transparent glass container, the electrode means for accelerating the electron beam, the electrode means for accelerating the electron beam, and the display means coated with a phosphor that emits light when the electron beam collides with the electron beam. In order to prevent vibration due to high-voltage ripple or external vibration, mechanical force dampers are provided at both ends of the electrode means for doing so.

Description of Embodiments An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a method of constructing an accelerating electrode and a power supply unit in an embodiment of the present invention. As shown in FIG. 4, the accelerating electrode 8 includes a metal block 30 and a thin metal plate (in the embodiment, a metal thin plate is used).
1mm) is stretched. The thin plate 8 is a metal block 30
Is positioned at a shaded portion 29 of the above, and is spot-welded to the metal block 30 at the end of the shaded portion. A DC high voltage 27 is added to this accelerating electrode 8, but since this high voltage potential is a potential integrated with the anode 21, the moment the electron beam reaches the anode, it is between the anode and the high voltage power supply 27. A voltage of several hundred V, which is the product of the protective resistance 25 provided and the electron beam amount, is added to the high voltage potential of DC,
It becomes a ripple and draws a periodic potential curve as shown in (2) of FIG. Originally, a large Coulomb force is exerted between the horizontal deflection electrode 7 and the accelerating electrode 8 due to the large potential difference, and the above-mentioned periodic potential is slightly above the Coulomb force + periodic Coulomb force. Will give power. This periodic Coulomb force causes the thin plate-shaped accelerating electrode 8 to gradually vibrate. When the natural frequency of the string-shaped accelerating electrode 8 is close to an integral multiple of 60 as described above, it resonates and a large vibration occurs. As shown in FIG. 3- (4), the raster that should be straight in the horizontal direction bends like a dotted line and a uniform screen cannot be obtained. Therefore, in the present invention, in order to prevent the vibration even when the periodic Coulomb force acts, the vibration is forcibly damped by the frictional force. Specifically, as described above, the accelerating electrode 8 is pressed against the plane of the metal block oblique line portion 29, and only the end portion is spot-welded, so that the accelerating electrode 8 vibrates as much as possible due to the periodic Coulomb force. After starting, the frictional force acts between the acceleration electrode 8 and the shaded portion 29, and the vibration is immediately stopped.
Further, in order to increase the effect of the forced damping, as shown by 23 in FIG. 4, the fixed accelerating electrode is pressed against the shaded portion 29 by a spring from above. This made it possible to obtain a very high damping effect.

As described above, in the present invention, by providing the forced dampers at both ends of the accelerating electrode, it is possible to eliminate the vibration of the accelerating electrode and obtain a highly stable image quality.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an image display element used in an image display device, FIG. 2 is an enlarged plan view of a screen, FIG. 3 (a) is an explanatory view of scanning lines, and FIG. 3 (b) is an accelerating electrode. Fig. 3 (c) is a diagram showing a state of vibration of the accelerating electrode, Fig. 3 (d) is a diagram showing an abnormal raster, and Fig. 4 is an embodiment of the present invention. Explanatory drawing. 1 ... Rear electrode, 21 ... Screen, 9,22 ... Glass container, A ... Scan line retrace period, B ... Scan line, C
... 1 field period, D ... retrace period, E ... high-voltage potential applied to the accelerating electrode, F ... time axis, G, H, I, J ... one scanning line.

Claims (1)

[Claims] 1. A plurality of linear hot cathodes, electrode means for extracting an electron beam from the linear hot cathodes, electron beam control electrode means composed of a plurality of electrodes, and electrodes for deflecting the electron beam. An image display device comprising: a transparent glass container; a means, an electrode means for accelerating the electron beam, and a display means coated with a phosphor that emits light when the electron beam collides with the electron beam. An image display device, characterized in that mechanical forcing dampers are provided at both ends of the electrode means to prevent vibration due to high-voltage ripple or external vibration.