JPH01117251A - Image display device - Google Patents

Abstract

PURPOSE:To ensure easy focusing and deflection, and enable obtaining a large screen of small depth by dividing the screen in a vertical direction and providing a linear hot cathode, a modulation cathode, a horizontal focusing and deflection electrode and a vertical address electrode for respective screens. CONSTITUTION:The position of electron emission from a filament hot cathode 4 on a rear wall 1 is determined by a vertical address electrode 2 and the electron is modulated by a modulation electrode 3. Furthermore, the focusing and deflection of the electron in a horizontal direction are made by a horizontal focusing and deflection electrode 5. And an electron beam accelerated toward an anode 8 collides with a fluorescent material 7, thereby making the material 7 luminous. This operation is made for a plurality of hot cathodes 4 concurrently. Also, one hot cathode 4 has a capacity of about 15 picture elements horizontally and electron beams emitted from the hot cathodes 4 are concurrently deflected, thereby making luminous a fluorescent screen corresponding to one scanning line. According to the aforesaid construction, focusing and deflection can be done easily, thereby making it possible to obtain a large screen of small depth.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin, large-screen, high-definition color image display device that uses a cathodoluminescence method and has a simple structure.

[Problems to be solved by conventional technology and invention]

Among the conventional flat panel image display devices, the light emitting type includes plasma display, A, and flat panel CRT.

There are EL displays, fluorescent display tubes, etc. Among these, plasma displays have the disadvantage of high power consumption, and flat CRTs have the disadvantage that colorization is IHL, and colorization is complicated in structure. Also,
EL displays have drawbacks such as low luminous efficiency in blue, and fluorescent display tubes have low brightness when displayed in full color.

Among the above methods, the cathodoluminescence method efficiently displays clearer color images. As a flat display using cathodoluminescence method, (1
) JP-A-58-121534, (2) JP-A-53
-143648 and 53-145457,
(3) JP-A-52-52360, (4) JP-A-52-52360
6-99955, etc., but (1) tends to cause color unevenness problems when colorizing, (2), (3), (
4) had a very complicated structure.

[Means for solving problems]

This invention solves the above problems.

First, many electron sources were used to achieve planarization, the electrodes were arranged in a matrix, and electrostatic deflection was added to some parts to simplify the structure. Additionally, in order to prevent the effects of atmospheric pressure due to the larger screen, a number of supporting walls were installed between the front and back walls. Furthermore, a cathode luminescence method is used to obtain clearer color images and to reduce power consumption. In addition, by reducing the number of linear hot cathodes,
In order to further reduce power consumption and achieve higher definition, we decided to deflect and focus the electron beam.

[Effect]

This invention divides the screen vertically, and each has a linear hot cathode, a modulating horizontal focusing/deflecting electrode, and a vertical address electrode (112
5), the vertical address electrode determines the emitting position of the electrons emitted from the linear hot cathode in the vertical direction, and the modulation horizontal focusing/deflecting electrode modulates the electrons, causing them to become static in the horizontal direction. By deflecting the electricity, it is focused on a fluorescent screen and displayed as an image. Since the interior of this image display device needs to be vacuumed, a support wall is provided to maintain strength against atmospheric pressure, and the horizontal deflection range is divided by the support wall.

〔Example〕

FIG. 1 shows an image display device in an embodiment of the invention.

The position of the electrons emitted from the linear hot cathode 4 in the vertical direction of the screen is determined by the vertical address electrode 2. The electrons emitted from that position are simultaneously modulated, focused and deflected in the horizontal direction by the modulation horizontal focusing/deflecting electrode 51, accelerated toward the anode 8, and collide with the phosphor 7, causing the phosphor to emit light.

These operations are performed simultaneously on a plurality of linear hot cathodes 4. That is, one linear hot cathode has a receiver for 15 horizontal pixels, and the electron beams emitted from each linear hot cathode are simultaneously deflected to illuminate the fluorescent screen for one scanning line.

FIG. 2 shows a sectional view of this image display device. Here, detailed dimensions of this imaging device will be specifically described.

The distance between the linear hot cathode 4 and the vertical address electrode 2 is 0.1 mm.
-0.2 mm % The distance between the linear hot cathode 4 and the modulated horizontal focusing/deflecting electrode 51 is 0.5 mm to 2 mm, and the width of the modulating horizontal focusing/deflecting electrode 51 is between the linear hot cathode 4 and the modulating horizontal focusing/deflecting electrode 51
equal to or narrower than the spacing. The distance between the linear hot cathode 4 and the front wall 9 is 2 mm to 40 mm, and the pitch of the supporting wall 6 is between the linear hot cathode 4 and the front wall 9.
The width of the support wall 6 in contact with the front wall 9 is 0.1 mm to 0.3 mm, which is two to three times the distance between the front wall 9 and the front wall 9. The shape of the support wall 6 is selected to be as shown in FIG. 2 in order to increase the structural strength and spread of the electron beam. Further, as shown in FIG. 2, the anode electrode 8 is formed to extend on a part of the support wall 6 in order to prevent the support wall from being charged with unnecessary charges and to deflect the electron beam more.

In the embodiment shown in FIGS. 1 and 2, modulation, focusing, and deflection are performed by the same modulation horizontal focusing/deflecting electrode 51. However, if modulation and horizontal focusing/deflection are performed using the same electrode, the circuit becomes complicated. In order to compensate for this drawback, as shown in FIG. 3, a modulating electrode is separately provided on the back surface of the linear hot cathode, and only focusing and deflection are performed using the conventional modulating horizontal focusing and deflecting electrode.

(Problems and improvement method of linear hot cathode) In this invention,
As shown in FIGS. 1 and 2, a potential difference occurs between both ends of the linear hot cathode. Therefore, the amount of electrons emitted from the linear hot cathode varies depending on the location. There are several ways to improve this: As shown in FIG. 4, a potential difference is applied to the vertical address electrodes 2. The modulation electrodes 3 and 32 have different widths as shown in FIG. 6.
use. As shown in FIG. 7, the linear hot cathode 7 is of an indirectly heated type. As shown in FIG. 8, one linear hot cathode 4 is used for each pixel. However, each of FIGS. 3 to 8 is a partially enlarged view of FIG. 1.

When a current is passed through a linear hot cathode, thermal expansion causes the linear hot cathode to stretch and become slack. One way to improve the slack is to attach a leaf spring to one or both ends of the linear hot cathode and constantly apply tension from both ends.

(Relationship between modulation electrodes and vertical address electrodes) In FIG. 9, the modulation electrodes are eliminated and the horizontal focusing/deflection electrodes 51 are used for modulation, creating a potential difference in the vertical address electrodes 2 and eliminating the potential difference in the linear hot cathode 4. be.

In FIG. 10, the modulation electrode 3 is attached to the vertical address electrode 2 side in parallel with the linear hot cathode 4. In FIG.

In FIG. 11, the modulation electrode 3 is embedded in the vertical address electrode 2 in parallel with the linear hot cathode 4 via an insulator 11, which results in a complicated structure.

In FIG. 12, there are two modulation electrodes 3, and vertical address electrodes 2 are arranged parallel to the linear hot cathode 4 with the linear hot cathode 4 at the center.
It is attached on top of the insulator 11 with an insulator 11 interposed therebetween.

In FIG. 13, two modulation electrodes 3 are used, and a horizontal focusing deflection electrode 5 is arranged parallel to the linear hot cathode 4 with the linear hot cathode 4 as the center.
It is attached to the side surface of the housing via an insulator 11.

In FIG. 14, two modulation electrodes 3 are used, and a horizontal focusing/deflection electrode 5 is placed parallel to the linear hot cathode 4 with the linear hot cathode 4 as the center.
It is attached to the vertical address electrode side of the.

In FIG. 15, the modulation electrode 3 is sandwiched between the rear wall 1 and the vertical address electrode 2, and the modulation electrode 3 is projected from the gap between the vertical address electrodes 2.

(Correspondence between three-color phosphors and electron beams) Figure 16 shows each phosphor 71r, 72g, 73b.
This is one method of accurately applying electron beams having signals corresponding to red, green, and blue (RGB).

A phosphor 75 that emits ultraviolet rays 101 is attached to the part of the support wall 6 closest to the phosphor screen 7, and the ultraviolet rays 101 emitted by the collision of the electron beam 44 are detected by a photodetector 100 such as a photodiode or a phototransistor. , convert it into an electrical signal, and calculate R(
In this method, the timing of sending out the red) signal is controlled by an electrical signal from the light receiving element 100.

In Fig. 16, one pixel is controlled by one vertical address electrode 2, and the fluorescent screen is made up of striped phosphors applied vertically (in Fig. 17, three One pixel is controlled by one or more vertical address electrodes 2, and the fluorescent screen is horizontally coated with striped phosphors 71r, 72g, and 73b to emit electron beams 44 with corresponding signals. Guess accurately 1
There are two methods.

Next, the circuit block diagrams for displaying images are shown in Figures 18 and 19.
As shown in the figure.

First, a television signal is separated into a video signal, a horizontal synchronization signal, and a vertical synchronization signal by 200 synchronization signal separation circuits.

The video signal is separated into R and G by a color signal separation circuit 210.

B signals are sampled by a sampling circuit 215 and stored in a memory circuit 220. The data stored in this memory is controlled by a memory control circuit 225 and sent to each adder 240.

230 is a sawtooth wave generating circuit, and 235 is an inverting circuit. The sawtooth wave generated by this circuit is also sent to adder 240.

The output of adder 240 is sent to each horizontal focusing/deflecting electrode 51 for deflection, focusing, and modulation.

250 is a vertical address circuit that controls the voltage applied to each vertical address electrode.

260 is a heater power supply that supplies power to heat the linear hot cathode 4.

FIG. 19 is one of the variations 1 of FIG. 18.

The data in the memory circuit 220 is sent to the modulation electrode 3,
A sawtooth wave is sent to each horizontal focusing electrode 5.

That is, deflection and focusing are performed by the horizontal focusing/deflecting electrode 5, and modulation is performed by the variable rA electrode 3.

〔Effect of the invention〕

This invention can be expected to realize an image display device that satisfies all the effects of flatness, large screen, color, simplified structure, low power consumption, and high definition.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a part of the configuration of an image display device according to the present invention, and FIG. 2 is a partial cross-sectional view of FIG. 1. FIGS. 3 to 8 are partially enlarged views of a method of eliminating the potential difference of a linear hot cathode. 9 to 15 are perspective views showing the positional relationship between modulation electrodes and vertical address electrodes. FIGS. 16 and 17 are cross-sectional views of the interior of the image display device showing the correspondence between phosphors and electron beams. FIGS. 18 and 19 are circuit diagrams used in this invention. ■... Rear wall, 2... Vertical address electrode, 4...
Linear hot cathode, 6... Support wall, t... Fluorescent screen, 8...
- Anode, 9... Front wall, 12... Envelope, 51
...Modulation horizontal focusing deflection electrode, 91...Side wall, 3...
- Modulation electrode, 41... Heater power supply, 31... Potential gradient power supply, 32... Modulation correction electrode, 11... Insulator, 40... Heater, 42... Conductor, 43...・
Oxide linear hot cathode, 5... horizontal focusing deflection electrode, 44...
・Electron beam, 71r...Red phosphor, 72g ・
...Green phosphor, 73b...Blue phosphor, 74...
Black stripe, 75...UV phosphor, 10
0 ... Light receiving element, 101 ... Ultraviolet light, 200
... Synchronization signal separation circuit, 210 ... Color signal separation circuit, 215 ... Sampling circuit, 220 ・
... Memory circuit, 225 ... Memory control circuit, 230 ... Sawtooth wave generation circuit, 235
... Inverting circuit, 240 ... Adder, 250
...Vertical address circuit, 260 ...Heater power supply.

Claims (2)

[Claims] (1) an evacuated envelope having a front wall and a back wall that are spaced apart and substantially parallel to each other and a side wall at the end of the front wall and the back wall sandwiched between the front wall and the back wall; and a back wall having a plurality of support walls between the front wall and the back wall and forming a plurality of row vertical address electrodes separated from each other, a transparent conductive film formed facing the row vertical address electrodes, and a transparent conductive film formed facing the row vertical address electrodes; a front wall having a phosphor formed thereon; a plurality of linear hot cathodes disposed near the back wall between the two walls in a direction perpendicular to the direction of the row electrodes on the back wall; An image characterized in that plate-shaped modulated horizontal focusing/deflecting electrodes are provided on the left and right sides of the hot cathode, the surfaces of which are parallel to the linear hot cathode and parallel or inclined to the front wall. Display device. (2) A patent claim characterized by means for modulating and vertically addressing the electron beam, means for correcting the potential difference across the linear hot cathode, and means for perfecting the correspondence between the three-color phosphor and the electron beam. The image display device according to item 1.