JPH05174742A - Image display device - Google Patents

Abstract

PURPOSE:To eliminate unevenness in the chromaticity and brightness due to difference in the beam deflection width between the center of screen and periph eral zone resulting from combination of a group of control electrodes of curved structure with a vacuum vessel made from flat plate face glass. CONSTITUTION:The coating pitch (d) of a light emission layer 5 in the position at a distance (x) horizontally from the center of screen is conform to the relationship as x=L.tantheta and d=(L-r.costheta){tan(theta+tau)-tan(theta-tau)}, where L is distance of the center 1 of curvature of a curving electrode from the screen center A' on a phosphor layer 3, (r) is radius of curvature, theta is angle formed by the line tying the center 1 of curvature with the screen center A' to the line tying the center 1 of curvature with Point B' in the peripheral zone, and tau is beam deflecting angle generated by a deflecting electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a television receiver,
The present invention relates to an image display device for controlling light emission by an electron beam, which is used for a computer display or the like.

[0002]

2. Description of the Related Art In recent years, a flat panel image display device has been actively researched and developed as a display device for displaying images and characters. The applicant of the present invention has proposed, as an example thereof, the flat panel cathode ray tube described in JP-A-64-27147 and JP-A-2-33839. The former discloses the basic configuration and operation thereof, and the latter further optimizes the configuration. The internal electrode configuration diagram of the flat panel cathode ray tube shown in FIG. 3 is described in the latter of the above publication. The configuration and operation of this conventional flat panel cathode ray tube will be briefly described below.

The electron source of this cathode ray tube is a linear cathode 1.
1, a back electrode 12 placed opposite to the display screen 19 and a flat plate-shaped electron placed on the display screen 19 side across the linear cathode 11 on the opposite side of the back electrode 12. It is composed of a beam extraction electrode 13. The linear cathodes 11 are stretched in the horizontal direction, and a plurality of such linear cathodes 11 are vertically arranged at appropriate intervals.

The sheet-shaped electron beam extracted from each linear cathode 11 has an opening 13a in the electron beam extraction electrode 13.
And is split horizontally into multiple thin beams,
Heading to the beam modulating electrode 14. Each electron beam is controlled by the beam modulation electrodes 14a, 14b, 14c to the amount of passage through the aperture according to the image signal, and the vertical focusing electrode 15 and the horizontal focusing electrode 16 are controlled.
Respectively in the vertical and horizontal directions. Then, it is horizontally deflected by the horizontal deflection electrodes 17a and 17b, and further vertically deflected by the vertical deflection electrodes 18a and 18b, and finally strikes the light emitting layer on the display screen 19 to which a high voltage is applied to emit light.

Such an operation is simultaneously performed on a plurality of electron beams for each linear cathode unit, and the entire image displayed is obtained by connecting the display sections 20 emitted by each electron beam vertically and horizontally.

In the above-mentioned conventional example, there is a problem that the brightness unevenness occurs in the image due to the mechanical vibration of the linear cathode 11, and in order to solve this problem, the cathode vibration preventing structure disclosed in Japanese Patent Laid-Open No. 2-54841 is used. Was taken. That is, as shown in FIG. 4, the linear cathode 11 is stretched along a circular arc-shaped support member 23 whose surface is covered with an insulating film, and is stretched using a fixing base 24 and a spring 25. Next, due to the fact that the cathode is stretched in an arc shape, the beam extraction electrode 13 and other beam control electrode groups are also curved in an arc shape with a similar curvature, while suppressing variations in the beam current amount and an increase in deflection aberration. , A structure aimed at the effect of increasing the smoothness of the electrode surface was adopted.

On the other hand, the face glass 21 on the surface of which the display screen 19 is formed is preferably flat glass because the processing cost is the lowest, and Japanese Patent Application No. 1-5991.
As described in Japanese Patent Publication No. 3, a vacuum container having a metal dome 27 on the back side has been proposed.

Finally, as described above, the linear cathode 11
A combination of the control electrode group 26 having a curved structure, and the vacuum container in which the flat face glass 21 and the metal dome 27 are adhered to form a flat image display device as shown in FIG.

[0009]

However, in the above-mentioned structure, since the control electrode group 26 is curved in an arc shape, the face glass 21 is a flat plate shape, so that the vicinity of the center of the screen and the horizontal end portion are A difference occurs in the distance between the control electrode group 26 and the flat face glass 21 in the vicinity. Therefore, if the beams near both the center and the edge are electrostatically deflected with the same voltage, the beam deflection width at the point of landing on the flat face glass 21 will be different from each other, and the beam will be emitted at both places. We cannot find the deflection voltage condition to land right above. Therefore, there is a problem in that there is a difference in luminance or chromaticity between the center of the screen and the vicinity of the horizontal edge, which makes the screen difficult to see.

The present invention solves the above problems, and an object of the present invention is to provide an image display device capable of landing a beam right above a light emitting layer at any position on a screen.

[0011]

In order to solve the above problems, in the image display device of the present invention, the arrangement pitch between adjacent light emitting layers is set as a function of the position on the display screen corresponding to the curved curvature of the control electrode group. The phosphor layer is formed by being changed.

[0012]

With the above structure, the arrangement pitch of the light emitting layers of the phosphor is changed in accordance with the curved curvature of the control electrode group, so that the deflection width of the beam changes at each position on the screen. It can be absorbed by the change, the beam can be landed right above the light emitting layer in any part of the screen, and color unevenness and brightness unevenness due to the difference in beam deflection width can be eliminated.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image display device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of a display device for explaining how to change a coating pitch of a light emitting layer of an image display device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a control electrode group 2 curved in an arc shape.
And the radius of curvature is r. Reference numeral 3 denotes a phosphor layer formed on the inner surface of the face glass 4, and light emitting layers 5 of respective colors are applied with a guard band 6 interposed therebetween.

It has been confirmed by computer simulation that the trajectory of the electron beam emitted from the linear cathode 7 advances substantially in the normal direction of the arc of the control electrode group 2.
Therefore, the beam emitted from the point A corresponding to the center of the screen is landed at the point A'immediately above, but the beam emitted from the point B corresponding to the horizontal edge of the screen is landed at the point B'on the edge side. When the distance x between A ′ and B ′ is expressed by a function of the angle θ formed by the line connecting the curvature centers 1 and A ′ and the line connecting the curvature centers 1 and B ′, x = L · tan θ (1) Here, L is the distance between the center of curvature 1 and A '.

The coating interval, that is, the pitch, of the light emitting layer 5 at each of the points A'and B'is determined as follows. Assuming that the deflection angle of the beam is ± τ with respect to the center when a certain deflection voltage is applied to the deflection electrodes in the control electrode group 2, in the latter stage acceleration type deflection system such as the present display device. , Τ is sufficiently small, it can be considered that the beam trajectory goes straight while keeping an angle τ. Therefore, the beam landing interval d at the deflection angles ± τ at points A'and B'is represented by d = (L-r · cos θ) (tan (θ + τ) -tan (θ-τ)) (2).

As described above, at the position represented by the formula (1) from the center of the screen toward the horizontal end, if the light emitting layer 5 is formed by coating at the pitch represented by the formula (2), which position on the screen is displayed. Also in this case, the beam will land right above the light emitting layer 5. At this time, the coating widths of the light emitting layers 5 and the guard bands 6 are preferably formed to have the same coating width ratio according to the ratio of the coating widths of the light emitting layer 5 and the guard band 6 at the center of the screen. The reason is to prevent a difference in brightness between the center and the end due to the change of the ratio.

In the present embodiment, the calculation formula is shown on the assumption that the face glass has a completely flat plate shape. However, when the face glass is bent by the atmospheric pressure from the outside, the calculation according to the shape is performed. It is necessary to determine the light emitting layer pitch by a formula. Since the bending occurs not only in the horizontal direction of the screen but also in the vertical direction, for example, as shown in FIG.
The outer shape must be (a) barrel type or (b) pincushion type.

In this embodiment, the case where the control electrode is curved and formed with a constant arcuate curvature has been described, but the calculation formula is different not only when it is arcuate but also when it is curved with a smooth curve. May have the same change in the light emitting layer pitch.

In this embodiment, the light emitting layers are provided in a plurality of colors on the premise of color image display. However, the same applies to the case of monochrome display, and the arrangement of the light emitting layers is changed from horizontal to vertical. It is the same even if there is. Further, in the present embodiment, only the case where the linear cathode electron source is used is shown, but the same applies when the planar electron source is used.

[0020]

As described above, according to the present invention, by changing the coating pitch of the light emitting layer according to the curved curvature of the control electrode group, the deflection width of the beam can be changed at various points on the screen. Can be absorbed by the change in the pitch of the light emitting layer, and the beam can be landed right above the light emitting layer at any place of the screen, so that an image without color unevenness and brightness unevenness can be provided.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an image display device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a coating form of a light emitting layer in the image display device.

FIG. 3 is a perspective view showing a configuration of a flat panel image display device in a conventional example.

FIG. 4 is a schematic diagram illustrating an electrode bending structure in a conventional flat panel image display device.

FIG. 5 is a schematic diagram illustrating a structure of a vacuum container in a conventional flat panel image display device.

[Explanation of symbols]

 1 Center of Curvature 2 Control Electrode Group 3 Phosphor Layer 4 Face Glass 5 Light Emitting Layer 6 Guard Band

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Ryuichi Murai 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Satoshi Kitao 1006, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. An electron beam generating source arranged in a plurality of lines or planes, a control electrode group including an electron beam deflecting electrode, and a light emitting layer and a non-light emitting layer which emit light by bombardment of an electron beam are alternately arranged. A display screen formed in an array, the control electrode group is formed to be curved with a certain curvature, the display screen is formed on a surface having a curvature different from the curvature curvature of the control electrode group, An image display device characterized in that the adjacent arrangement pitch of the light emitting layers is formed with a change as a function of the position on the display screen, corresponding to the curvature curvature of the control electrode group. 2. The control electrode group is curved in an arc shape having a constant curvature, the display screen is formed on the surface of a flat face glass, and the arc of the control electrode group is formed from the center of the display screen. The formation pitch d of the light emitting layer at the position of the distance x in the direction is L, the radius of curvature is r, the radius of curvature is r, and the center of curvature is connected to the center point of the display screen. Assuming that the angle between the line and the line connecting the center of curvature and the point of the distance x of the display screen is θ, and the deflection angle of the beam by the deflection electrode is τ, x = L · tan θ d = (L−r · cos θ) {Tan (θ + τ) −tan (θ−
The image display device according to claim 1, wherein the image display device is formed so as to have a relationship of τ)}.