JPH01241741A - Image display device - Google Patents

Abstract

PURPOSE:To make it possible to always maintain the initial image quality of a display device by providing a transparent film or glass plate on the outside surface of the face portion of a glass envelope, in which components of an image display element are sealed, so as to close contact to the surface or to have an air layer on the surface. CONSTITUTION:When an image display device is operated, heat is generated in line cathodes 2a-2b in the inner portion of the image display element 44 and in the metal backed layer of the rear surface of the face portion, and the pitch of the through holes of the horizontal electron beam is enlarged by the thermal expansion of the component electrodes. By the air layer constructed with a glass plate 41 and side plates 42a, 42b on the face portion of the image display element 44, the heat radiation through the said face portion is decreased so as that the temperature of the whole face portion fan be made nearly equal to that of the inner portion of the said element 44. As the thermal expansion coefficients of the glass envelope and the component electrodes are made to be nearly equal, the thermal expansion of these components can be made to be nearly equal to eliminate the deviation between the respective pitches of the through holes of the beam and the phosphor in the horizontal direction. Thereby the initial image quality can be always maintained even if the image display element 44 is thermally expanded or contracted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention generates an electron beam for each division when a screen on a screen is vertically divided into a plurality of divisions, and generates an electron beam for each division. The present invention relates to an apparatus for displaying a plurality of lines by vertically deflecting a beam to display a television image as a whole.

Conventional technology Conventionally, cathode ray tubes have been mainly used as display elements for displaying color television images, but conventional cathode ray tubes have a very long depth compared to the screen size, making it difficult to use in thin television receivers. It was impossible to create. Recently, EL display elements, plasma display devices, liquid crystal display elements, etc. have been developed as flat display elements, but all of them are insufficient in terms of performance such as brightness, contrast, and color display, and are not put into practical use. It has not yet reached the point where it will be done.

Therefore, the present applicant proposed a new display device in Japanese Patent Application No. 56-20618 (Japanese Unexamined Patent Publication No. 57-135590) to achieve a flat display device using electron beams.

This generates an electron beam for each section when the screen on NuClean is divided vertically into multiple sections, and displays multiple lines by deflecting each electron beam vertically for each section. However, it displays a television image as a whole.

Without further ado, one basic configuration of the image display element used here will be explained with reference to FIG. 2. This display element consists of, in order from the rear to the front, a back electrode 1, a line cathode 2 as a beam source, a vertical focusing electrode 3.3', a vertical deflection electrode 4, a beam current control electrode 6, a horizontal focusing electrode 6, a horizontal A deflection electrode 7, a beam acceleration electrode 8, and a screen 9 are arranged, and these are housed inside a flat glass pulp (not shown) that is evacuated. A line cathode 2 serving as a beam source is stretched horizontally so as to generate an electron beam distributed linearly in the horizontal direction.
There are multiple lines in the vertical direction at appropriate intervals (in the figure, there are 2
(Only four of the two are shown). In this example, it is assumed that 15 are provided. Let's call them 2i~2yo. These wire cathodes 2 are constructed by coating the surface of a tungsten wire with a thickness of 10 to 20 .mu.da with an oxide cathode material for thermionic emission. These line cathodes 2A to 2Y are heated so as to generate a thermionic electron beam by passing an electric current through them, and as will be described later, the electron beams are generated sequentially for a certain period of time starting from the line cathode 2I. controlled to emit.

The back electrode 1 suppresses generation of electron beams from line cathodes other than the line cathode controlled to emit electron beams for a certain period of time, and pushes out the generated electron beams only in the forward direction. act.

This back electrode 1 may be formed by a coating film of a conductive material adhered to the inner surface of the rear wall of the glass pulp. Instead of the back electrode 1 and linear cathode 2, a planar electron beam emitting cathode may be used.

The vertical focusing electrode 3 is a conductive electrode 11 having a horizontally long slit 10 facing each of the line cathodes 2a to 2yo, and collects the electron beam emitted from the line cathode 2 into the slit.
10 and vertically focused.

Electron beams for one horizontal line (360 pixels) are taken out at the same time.

In the figure, only one section in the horizontal direction is shown. The slit 10 may be provided with crosspieces at appropriate intervals in the middle, or at smaller intervals in the horizontal direction (
The through holes may be substantially configured as slits by a row of a large number of through holes provided at intervals of almost touching each other. The vertical focusing electrode 3' is also similar.

A plurality of vertical deflection electrodes 4 are arranged horizontally at intermediate positions of the slits 10, and conductors 13, 13' are provided on the upper and lower surfaces of the insulating substrate 12, respectively.
It consists of a set of Then, a vertical deflection voltage is applied between the opposing conductors 13 and 13' to deflect the electron beam in the vertical direction. In this embodiment, one wire cathode 2 is formed by a pair of conductors 13 and 13'.
The electron beam is deflected vertically to a position corresponding to 16 lines.

The 16 vertical deflection electrodes 4 constitute 15 pairs of conductors corresponding to each of the 15 line cathodes 2.
In the end, the electron beam is deflected so as to draw 240 horizontal lines on the screen 9.

Next, the control electrodes 6 are composed of conductive electrodes 15 each having a vertically long slit 14, and a plurality of conductive electrodes 15 are arranged in parallel in the horizontal direction at a predetermined interval. In this example 1
Eighty conductive electrodes 15a to 15n for control electrodes are provided. (Only 9 lines are shown in the figure). This control electrode 5
Each divides the electron beam into two picture elements in the horizontal direction and extracts the electron beam, and controls the amount of electron beam passing therethrough in accordance with the video signal for displaying each picture element. Therefore, if 180 conductive electrodes 15a to 15n for the control electrode 5 are provided, 360 picture elements can be displayed per horizontal line. In order to display images in color, each picture element is R, G,
Display is performed using phosphors of three colors B, and RlG and B video signals for two picture elements are sequentially applied to each control electrode 5. In addition, 180 conductive electrodes 15a to 15n for the control electrode 5
180 sets of video signals for one line (two picture elements per set) are simultaneously applied to each of the lines, and the video for each line is displayed at one time.

The horizontal focusing electrode 6 is composed of a conductive electrode 17 having a plurality of vertically long slits 16 (180 slits) facing the slits 14 of the control electrode 5, and collects electrons for each picture element divided in the horizontal direction. Each beam is focused horizontally into a narrow electron beam.

The horizontal deflection electrode 7 includes a plurality of conductive electrodes 18 arranged vertically on both sides of the slit 16,
18', each electrode 18, 18
Six levels of horizontal deflection voltage are applied to ', which deflects the electron beam for each picture element in the horizontal direction, and sequentially irradiates the two sets of R, G, and H phosphors on Nuclean 9. to make it emit light.

In this embodiment, the deflection range is two picture elements wide for each electron beam.

The acceleration electrode 8 is composed of a plurality of conductive electrodes 19 provided horizontally at the same position as the vertical deflection electrode 4,
The electron beam is accelerated to collide with the screen 9 with sufficient energy.

Nuclean 9 is constructed by coating the back surface of a glass plate 21 with a phosphor 20 that emits light when irradiated with an electron beam, and adding a metal back layer (not shown).

The phosphors 20 are provided with two pairs of phosphors of three colors R9G and B for each slit 14 of the control electrode 5, that is, for each horizontally divided electron beam. It is applied in vertical stripes. In FIG. 2, the broken lines drawn on the screen 9 indicate divisions in the vertical direction that are displayed corresponding to each of the plurality of line cathodes 2, and the two-dot chain lines correspond to each of the plurality of control electrodes 5. Indicates the horizontal division displayed. As shown in the enlarged view in FIG. 3, one section partitioned by these two has R, G, and B phosphors 20 for two pixels in the horizontal direction, and 16 lines in the vertical direction. It has a width of 1
The size of one section is, for example, 1 mm in the horizontal direction,
The vertical direction is 9 mm.

Note that in FIG. 2, the length in the horizontal direction is greatly expanded relative to the length in the vertical direction for clarity.

Furthermore, in this example, for one control electrode 5, that is, for one electron beam, only one pair of R, G, and B phosphors 20 are provided for two picture elements; A picture element or three or more picture elements may be provided, and in that case, the control electrode 5 has R, G,
A B video signal is sequentially applied, and horizontal deflection is performed in synchronization with the B video signal.

The phosphor 20 is applied directly to the inner surface of the face portion of the glass container of the present image display device.

Problems to be Solved by the Invention However, in the above configuration, the glass container enclosing the components of the image display element is in direct contact with the outside air, so the temperature rise during operation of the image display device may affect the internal components. Comparatively less. As a result, there is a difference in expansion and contraction due to heat, resulting in a misalignment between the horizontal landing pitch of the electron beam and the pitch of the phosphor, resulting in a problem of deterioration of image quality.

In view of the above problems, the present invention provides an image display device that can always maintain the initial image quality even if the temperature of the image display device changes.

Means for Solving the Problems In order to solve the above problems, the image display device of the present invention includes:
A transparent film or glass plate is glued to the outer surface of the face of the glass container that encloses the components of the image display element, or a groove is formed to create a layer of air.

Effect of the present invention With the above-described configuration, by increasing the heat retention of the face portion of the glass container, the value of thermal expansion and contraction of the glass can be brought close to the value of the constituent elements inside the glass container, and the electrodes and horizontal electron It is possible to eliminate the relative deviation between the beam passing hole and the pitch and the horizontal pitch of the phosphor coated on the inner surface of the face of the glass container. Therefore, even if the temperature of the image display device changes, the initial image quality can always be maintained.

Embodiment Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to drawing C1. FIG. 1 shows a side view of an image display device according to an embodiment of the present invention.

In Figure 1, 41 is a transparent glass plate, 42i, 42
0 is a side plate for creating an air layer, 43 is a cabinet,
Reference numeral 44 denotes a conventional image display device in which the components shown in FIG. 2 are sealed inside a glass container. The transparent glass plate 41 is installed so as to face the face of the image display element 44, and an air layer is formed between the side plates 42 and 420 and the face of the image display element 44.

The operation of the image display device configured as described above will be explained below with reference to FIGS. 1 and 2. When the image display device is operated, heat is generated in the line cathodes 2-20 inside the image display element 44 and the metal back layer on the back of the face part, and the constituent electrodes thermally expand, allowing the electron beam to pass in the horizontal direction. The pitch of the holes increases. On the other hand, the image display element 44 is
By forming an air layer in the face portion, heat emission from the face portion is reduced, and the temperature of the entire face portion becomes approximately the same as the temperature inside the image display element 44. Since the temperature coefficients of the glass container and the constituent electrodes are almost the same, they exhibit the same thermal expansion value, and there is no pitch deviation between the electron beam passage hole and the phosphor in the horizontal direction.

As described above, according to this embodiment, by providing the glass plate 41 to create an air layer on the outer surface of the glass container face portion of the image display element 44, even if the image display element 44 expands and contracts due to heat, the initial state is always maintained. Image quality can be maintained.

In the above embodiment, the glass plate 41 was installed to form an air layer to achieve the intended purpose, but it is also possible to adhere a transparent film or a transparent glass plate directly to the outer surface of the face portion. It is also possible to obtain similar effects.

Effects of the Invention As described above, according to the present invention, by adhering a transparent film or glass plate to the outer surface of the face portion of the glass container in which the image display element components are sealed, or by arranging it in a structure that creates an air layer. Even if the temperature of the image display device changes, the thermal expansion and contraction values of the glass container face portion of the image display element and the internal constituent electrodes can be made the same, and the initial image quality can always be maintained.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of an image display device according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of an image display element used in a conventional image display device, and FIG. 3 is an exploded perspective view of the image display device. It is an enlarged view of a light surface. 41...Glass plate, 42i, 420...
- Side plate, 44... Image display element. Name of agent: Patent attorney Toshio Nakao and 1 other person 41
...-Glass 4-? A, 42 kukur+accumulation Fig. 3＼ 1 horizontal section

Claims (1)

[Claims] a screen coated with a phosphor that emits light when irradiated with an electron beam; an electron beam source that generates an electron beam for each vertical section of a side surface of the screen that is divided into a plurality of vertical sections; separation means for separating the electron beam generated by the electron beam source into each horizontal section and irradiating the screen; a beam flow control electrode that controls the amount of light emitted from each pixel on the screen by controlling the amount of electron beams separated into the horizontal sections irradiated onto the screen; , a focusing electrode for controlling the size of light emitted by the electron beam on the phosphor surface in each picture element, a back electrode for controlling the amount of electron beam from the electron beam source, the screen, the electron beam source, the separating means, and A glass container enclosing each electrode is provided, and the phosphor is directly applied to the inner surface of the face of the glass container to form a screen, and a transparent film or glass plate is adhered to the outer surface of the face, or air is An image display device that creates layers.