JPS6237852A - Image display device - Google Patents

Abstract

PURPOSE:To make a high-definition image with no color phase irregularity at the ends of a faceplate and extend the effective imaging area of the faceplate, by providing a display means made of stripes of fluorescent substances applied at prescribed unequal intervals at both the ends of the faceplate. CONSTITUTION:At the central portion (continuously extending from the right of the drawing and therefore not shown therein) of a faceplate, fluorescent substances 34 are applied in stripes at equal intervals corresponding to those of the slits of a horizontal convergence electrode 28. However, near a metal frame 31, the fluorescent substances 34 are applied in stripes at prescribed unequal intervals corresponding to the changes of electron beam spots 35, so that the spots are made in the centers of the stripes of the fluorescent substances even if electron beams are curved by a voltage impressed on the metal frame. As a result, a color phase irregularity is prevented, and the effective imaging area of the faceplate is extended.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an image display device in video equipment.

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 much longer depth than the screen, making it difficult to manufacture thin television receivers. It was impossible to do so.

Furthermore, performance such as flat panel display contrast and color reproducibility is insufficient, and it has not yet been put to practical use. Therefore, electron beams are used to display color television images on flat panel displays. In order to achieve a device that can display images on a screen, the screen on the screen is vertically divided into multiple sections, and the electron beam is vertically deflected for each of the three sections. The line is further divided horizontally into a plurality of sections, and each section is made to sequentially emit phosphors such as R-G-B. A television image is displayed as a whole by controlling the amount of electron beam irradiated onto the screen using a color video signal. An example of a conventional image display element will be described below with reference to the drawings. FIG. 2, FIG. 3, and FIG. 4 show conventional image display elements. In FIG. 2, from the rear to the front, 1 is a back electrode, 2 is a linear hot cathode as an electron beam source, 3a and 3b are vertical focusing electrodes,
4/'i vertical deflection electrode, 5 a current beam control electrode, 6a and 6b horizontal focusing electrodes 7 a horizontal deflection electrode, 8 an electron beam accelerating electrode, and glass containers 9 and 22. Then, the components are housed in the glass container 22 and evacuated. The operation of the image display device configured as described above will be described below. First, two aS poles serving as electron beam sources are stretched horizontally so as to generate electron beams distributed linearly in the horizontal direction, and a plurality of such two line cathodes are arranged vertically at appropriate intervals. There are books (only four books 2-2 are shown here). In this example, 15
The wire cathodes 2, which are assumed to be provided herein, are constructed by coating an oxide cathode material on the surface of, for example, a tungsten wire with a diameter of 10 to 2 μm. Then, as will be described later, the electron beams are controlled to be emitted sequentially from the upper line cathode 2 for a fixed period of time. The back electrode 1 suppresses the generation of electron beams from other line cathodes 2 other than the line cathode 2 which is controlled to emit electron beams for a certain period of time, which will be described later, and directs the generated electron beams only in the forward direction. It has the effect of pushing out. The 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 bulb. Further, instead of the back electrode 1 and the linear cathode 2, a planar electron beam emitting cathode may be used. The vertical focusing electrode 3 is a conductive plate 11 having horizontally long slits 1o facing each of the line cathodes 2a to 2yo, and collects the electron beam emitted from the line cathode 2 through the slits 10. Extend and focus vertically. The slit 1o may be provided with crosspieces at appropriate intervals in the middle, or may be a row of through holes arranged horizontally at small intervals (nearly touching intervals). It may be configured with slits.

The vertical focusing electrode 3b is also similar. Vertical deflection electrode 4
A plurality of slits 10 are arranged horizontally at intermediate positions of the slits 10, and each
2, conductors 13a and 13b are provided on the upper and lower surfaces thereof. Then, a vertical deflection voltage is applied between the opposing conductors 13a and 13b to deflect the electron beam in the vertical direction. In this configuration example, the pair of conductors 1aa and 13b deflects the electron beam from one line cathode 2 to positions corresponding to 16 lines in the vertical direction.

Then, the 16 vertical deflection electrodes 4 constitute 15 pairs of conductors corresponding to each of the 15 line cathodes 2, and in the end, the electron beam is drawn so as to draw 240 horizontal lines on 6 pages on the screen 21. to deflect. Next, the electron beam flow control electrodes 5 are composed of conductive plates 16 each having a vertically long slit 14, and a plurality of the electron beam flow control electrodes 5 are arranged in parallel in the horizontal direction at a predetermined interval. In this configuration example, 320 control electrode conductive plates 15
a to 15n are provided (only 10 are shown in the figure).

Each of the electron beam flow control electrodes 5 divides the electron beam horizontally into one picture element and extracts the electron beam, and
The amount of passage is controlled according to the video signal for displaying each picture element. Therefore, if 32,020 electron beam flow control electrodes 6 are provided, 320 pixels can be displayed per horizontal line. In addition, in order to display images in color, each picture element is displayed with phosphors of three colors, R and Q-B, and each electron beam flow control electrode 5 is
Each video signal is added sequentially. Furthermore, 320 sets of video signals for one line are simultaneously applied to the 320 electron beam flow control electrodes 6, so that one line of video is displayed at one time. The horizontal focusing electrode 6 is 7 bases.

It is composed of a conductive plate 17 having a plurality of vertically long slits 16 (320 slits 16) facing the slits 14 of the electron beam flow control electrode 5, and controls the electron beam for each pixel divided in the horizontal direction. Each is focused horizontally into a fine beam of electrons. The horizontal deflection electrode 7 is composed of a plurality of conductive plates 18 arranged vertically in the middle of each of the slits 16, and a horizontal deflection voltage is applied between each of the conductive plates 18, so that a horizontal deflection voltage is applied to each pixel. The electron beams are each deflected horizontally and R-G on the screen 21.
- Each of the phosphors B is sequentially irradiated to emit light.

In this embodiment, the deflection range is the width of one picture element for each electron beam. The acceleration electrode 8 includes a plurality of conductive wires 1 provided horizontally at the same position as the vertical deflection electrode 4.
9, which accelerates the electron beam so that it collides with the screen 21 with sufficient energy. The screen 21 includes a phosphor 2 that emits light when irradiated with an electron beam.
0 is applied to the back surface of the glass container 9, and a metal bank layer (not shown) is added. Fluorescent material 2
For each slit 14 of the electron beam flow control electrode 6, that is, for each horizontally divided electron beam, one pair of phosphors of three colors R, G, and B is provided. It is applied in vertical stripes.

In FIG. 3, broken lines drawn on the screen 21 indicate divisions in the vertical direction corresponding to the plurality of line cathodes 2, and two-dot chain lines indicate the divisions in the vertical direction corresponding to the plurality of line cathodes 2. The horizontal divisions displayed corresponding to each are shown. As shown in the enlarged view in Figure 3, one section partitioned by these two has R-G for one pixel in the horizontal direction.
-B phosphor 20, which has a width of 16 lines in the vertical direction. Note that in the figure, A is one section in the vertical direction, and B is one section in the horizontal direction. The size of one section is, for example, 1111 m in the horizontal direction and 16 m in the vertical direction.
It is fi. Also, please note that in FIG. 3, the horizontal length is greatly expanded relative to the vertical direction for clarity. In this embodiment, only one pair of R-G-Bcr) phosphors 20 is provided for each picture element for one 9-page electron beam flow control electrode 6, that is, for one electron beam. Of course, two or more picture elements may be provided, and in that case, the electron beam flow control electrode 6 sequentially separates R, G, and B video signals for two or more picture elements.
Horizontal deflection is performed in synchronization with this.

Problems to be Solved by the Invention However, when a voltage is applied to each electrode in the above configuration, a Coulomb force is generated between the accelerating electrode 8 to which a particularly high voltage is applied and the horizontal focusing electrode 6b on the low voltage side. Occur. The horizontal focusing electrode 6b is connected to the vertical focusing electrode sb, the vertical deflection electrode 4, the electron beam flow control electrode 6, the horizontal focusing electrode 6a, and the horizontal deflection electrode 7 through a coupling spacer (not shown) made of a metal material coated with glass on both sides. Since the accelerating electrode 8 has a high rigidity and is bonded to the horizontal focusing electrode eb, the deformation caused by the Coulomb force can be ignored. However, since the accelerating electrode 8 has a small rigidity, it is pulled toward the horizontal focusing electrode eb by the Coulomb force, causing deflection. 10. In order to avoid negative effects on the image quality, as shown in FIG. method. However, when such an electrode holding method is used, as shown in FIG. 5, which is a horizontal cross-sectional view near the metal frame 23 in FIG.
As shown in the figure, the same high voltage is applied all the time, the equipotential line 24 is curved near the metal frame 23, the electric field is distorted, and the electron beam trajectory 25 is bent in the direction of the metal frame. Although the electron beams pass through the through holes of the horizontal focusing electrode 6b at equal pitches in the horizontal direction, the distance between adjacent electron beams is smaller than that of the metal frame 2.
The closer it gets to 3, the bigger it gets. As a result, as shown in the lower part of FIG. 6, the pitch of the phosphor stripes 26 applied at equal intervals and the pitch of the electron beam spots 27 are
There was a problem in that misalignment occurred near the metal frame, causing color unevenness.

11.-: In view of the above-mentioned problems, the present invention provides an image display device that has a high-quality image without color unevenness at the edge of the screen and realizes expansion of the effective screen.

Means for Solving the Problems In order to solve the above problems, the image display device of the present invention includes:
Changes in the electron beam trajectory in the vicinity of the metal frame are predicted by numerical analysis simulation, and the phosphor stripes are set at unequal pitches to correspond to the landing points of the electron beam on the screen.

Function The present invention uses, as a display means, phosphor stripes bent toward the metal frame at the edge of the screen and arranged at uneven pitches corresponding to the electron beams landing at uneven pitches on the screen. Both electron beams form a spot at the center of the phosphor, thereby preventing color unevenness.

Embodiment Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to the drawings. The overall configuration of this example is as follows:
It features a phosphor coated on a power ζ screen 21 similar to that shown in FIG. FIG. 1 shows a horizontal sectional view of the vicinity of a metal frame of an image display device according to an embodiment of the present invention. At the bottom of FIG. 1 is added a diagram showing the relationship between the phosphor Pif and the electron beam spot. In FIG. 1, 28 is a horizontal focusing electrode, 29 is an accelerating electrode, 3o is a screen, 31 is a metal frame, 32 is an equipotential line, 33 is an electron beam trajectory, 34 is a phosphor stripe on the screen, and 35 is on a screen. Shows the spot of the electron beam. The image display device configured as above will be explained below by comparing FIG. 1 and FIG. 6. In FIG. 1 and FIG. 6, since the electrode configuration in the horizontal cross-sectional view and the driving voltage of each electrode are the same, the equipotential lines 32 and 24 and the electron beam trajectory 3
3.25 also have similar shapes. Therefore, even on the screen, the pitch of the electron beam (35.27) becomes wider as it approaches the metal frame 13 in both FIGS. 1 and 5. In the conventional embodiment shown in FIG. 6, since the phosphor 26 was applied over the entire screen at equal intervals, the pitch of the electron beam spot 27 becomes misaligned as it approaches the metal frame 23, as shown in the figure. However, color unevenness occurred as a result of one spot irradiating two adjacent phosphors.

On the other hand, in the embodiment of the present invention shown in FIG. 1, the pitch of the phosphors in the central part of the screen (not shown) that continues to the right of the drawing is the same as the slit pitch of the horizontal focusing electrode 28, as in FIG. (In the vicinity of the metal frame 31, the forces are arranged at equal intervals corresponding to Electron beam spots 36 are formed at each center of the light body, making it possible to prevent color unevenness from occurring.

Next, a method for determining the pitch variable when designing this unequal pitch phosphor will be described. This may be measured by actually making a prototype, but it is also effective to calculate by performing a numerical analysis simulation of the electric field and electron beam trajectory. For example, the equipotential lines and electron beam trajectories shown in FIGS. 1 and 6 are both created based on three-dimensional simulation using the boundary element method, and their calculation accuracy is high. In this example, to summarize the calculation results, the electron passing coordinate at the horizontal focusing electrode taken in the horizontal direction with the inner surface of the metal frame as a reference is x1. Similarly, when the electron landing coordinate on the screen is y, y = x-A
exp(-Bx) ・・・・・・・・・・・・・・・
・・・・・・・・・(11A, B: In equation (1), which has been found to be an approximate constant and is an important design index, when I is increased, it becomes obvious that y 4 z ・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・(2), and in the center of the screen far enough away from the metal frame,
It is clear that the phosphors can be designed at equal pitches without considering the effect of distortion of the electric field.

Effects of the Invention As described above, the present invention provides display means consisting of striped phosphors coated at predetermined uneven pitches at both ends of the image, thereby achieving high quality images with no color unevenness at the edges of the screen. Images can be provided and the effective screen can be expanded.

[Brief explanation of drawings]

FIG. 1 is a horizontal sectional view at the edge of the screen of an image display device according to an embodiment of the present invention, and a plan view showing the relationship between a phosphor and a spot, and FIG. 2 is an image display of a conventional image display device and an embodiment of the present invention. FIG. 3 is an exploded perspective view showing the basic configuration of the device, FIG. 3 is a plan view showing the phosphor of the image display device, and FIG. 4 shows the accelerating electrode of the conventional and one embodiment of the present invention and a frame for supporting and fixing the accelerating electrode. The perspective view and FIG. 6 are a horizontal sectional view at the edge of the screen of a conventional image display device and a plan view showing the relationship between a phosphor and a spot. 28...Horizontal focusing electrode, 29...Accelerating electrode, 30...Screen, 34...
Fluorescent stripes. 30-11 Sugusoso J4--One pull-Busy 1 toss dry life ``Negative'' body again try 7゜Figure 3Figure 4

Claims (1)

[Claims] A vertical conductive plate consisting of a plurality of linear hot cathodes and a conductive plate located parallel to the linear hot cathodes and having a horizontally long slit that vertically focuses the electron beam emitted from the linear hot cathodes. a focusing electrode, a vertical deflection electrode consisting of a plurality of pairs of conductive plates for vertically deflecting the electron beam, an electron beam flow control electrode consisting of a conductive plate having a plurality of vertically long slits, and the electron beam a horizontal focusing electrode made of a conductive plate having a plurality of vertically long slits to focus the electron beam in the horizontal direction; and a horizontal deflection electrode made of a conductive plate having a plurality of vertically long slits to deflect the electron beam in the horizontal direction. , an accelerating electrode consisting of a plurality of conductive wires provided in the horizontal direction, and a flat plate coated with a plurality of vertically long striped phosphors that emit light upon collision with the electron beam at predetermined uneven pitches in the horizontal direction. An image display device that has a screen made of glass inside a transparent vacuum container.