JPH01235150A - Display tube for light source - Google Patents

Abstract

PURPOSE:To prevent the contact between an anode electrode group and the metal-back at the time of assembling and prevent the peeling off of the metal- back by applying the metal-back only on the surfaces of fluorescent faces on a front panel. CONSTITUTION:The metal-back 18 applied only on the surfaces of fluorescent faces 5G, 5R, 5B coated in a matrix shape on the inner surface of the front panel 2 of a display tube for a light source is provided. For the means to apply the metal-back only on the surfaces of phosphors, the well-known mask- deposition method is utilized, for example. An anode electrode group is assembled in direct contact with the black matrix made of a black coating member 13. The peeling off of the metal-back due to the contact with the anode electrode group at the time of assembling is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a light source display tube constituting pixels of a large screen display device, particularly a color display device.

[Conventional technology]

When a large screen display device is constructed by arranging monochromatic display tubes that utilize the light emitted by phosphors in a matrix, each element is arranged in a matrix, a space is created at the connection of each monochrome display tube, and the resolution is improved. At the same time, higher resolution also led to higher costs.

Therefore, a composite light source display tube has been proposed, for example, as disclosed in Japanese Patent Application Laid-Open No. 62-10849.

Figures 2 and 3 are a front view and a cross-sectional view along the line ■-■ showing the basic structure of this composite type light source display tube, and Figure 4 is an exploded perspective view of a part of it, and is colored R (red). , G (green)
A case is shown in which a phosphor screen in which each of the B (blue) phosphors is one pixel is arranged in a matrix of 3×3 pixels.

In these figures, reference numeral 1 denotes a vacuum envelope as a glass tube hermetically sealed by a front panel 2, a rear panel 3, and a cylindrical side panel 4. On the inner surface of the front panel 2, there is a fifth
As shown in the figure, each of the three-color phosphors R, G, and B is used as a unit pixel, and a 3×3 pixel phosphor screen 5R is coated on a coating portion 14 formed in a matrix shape with a black matrix 13.
, 5G, and 5B form a fluorescent display section 5, and a metal back 15 is applied over the entire surface of this fluorescent display section.

Here, the subscripts of phosphor screens 5R, 5G and 5B are red (
R), green (G) and blue (B), respectively.

Reference numeral 6 denotes a plurality of accelerating anodes 6□ arranged corresponding to the periphery of each fluorescent screen 5R, 5G, and 5B of the fluorescent display section 5.
, 6□, ......... A high voltage is applied to these acceleration anodes 61, 6□, ...... through the external terminal 16. It is now applied.

7 is a cathode electrode group in which cathodes 711 to 733 (not shown) for emitting electrons are arranged independently corresponding to each of the fluorescent screens 5R, 5G, and 5B of the fluorescent display section 5; 71. are supported at both ends between a pair of supports 17a and 17b fixed on the back plate 3. Here, the first cathodes 71 to 733. Second
The th subscript corresponds to the 1st to 3rd rows and the 1st to 3rd columns, respectively.

For each of the cathodes 7□1 to 733, for example, an indirectly heated type cathode in which an oxide is coated on a Ni sleeve or a direct heated type in which tungsten is coated with an oxide can be used.

Further, 8 is a grid electrode group consisting of control grids 8, to 83 for row selection arranged between this cathode electrode group 7 and the fluorescent display section 5, and these control grids 8□ to 8
．． , each of the fluorescent screens 5R, 5G and 5B of the fluorescent display section 5
Cathodes 7□, ~73 in the row direction corresponding to
Electron passing holes 91 to 9.3 allow the electron beam 11 from 3. is provided.

Reference numeral 10 indicates a column direction on the back side of the cathode electrode group 7, that is, on the back plate 3 forming a part of the vacuum envelope 1, corresponding to each of the fluorescent screens 5R, 5G, and 5B of the fluorescent display section 5. Striped row selection back electrodes 10□ to 10. are arranged opposite to each other. These back electrodes 101 to 10 are formed from a conductor layer such as Ag.

Each of the back electrodes 101 to 10. is negative and Ov or several V with respect to the potential of each cathode 7□, ~733
By applying a positive potential to those cathodes 71.
It controls the electron beam 11 emitted from the electron beams 733 to 733.

Note that 12 is a lead wire as an external terminal for drawing out each electrode of the cathode electrode group 7, the grid electrode group 8, and the back electrode group 10 from the back plate 3 to the outside.

Next, the operation will be explained. First, each back electrode 101~
10. When the potential of these cathodes 711-73. is negative with respect to the potential of cathodes 7□1-733. Since each cathode 711 to 7.3 is surrounded by a negative potential,
The electrons do not flow to the control grids 81 to 8 degrees and the accelerating anodes 61, 6□, . . . , and are in a cut-off state.

Therefore, the cathode 7 is connected to the backside electrode, ~103.
□When a positive potential of Ov or several V is applied to the potential of 1 to 7.3, these cathodes 711 to 71. The electron beam 11 emitted from the control grid 8□~8° flows toward the control grid 8□~8°.

At this time, each control grid 8□-8. When the potential of these control grids 81-8. is negative with respect to the cathodes 7□i-713. The electron beam 11 cannot pass through the electron passing holes 91 to 93 of the acceleration anode 6. ．． 6□,
. . ., the electron beam 11 does not flow, and the fluorescent screens 5R, 5G, and 5B of the fluorescent display section 5 do not emit light.

And control grids 81-8. The potential of the cathode 71
1 to 733, these control grids 8. ~8. Electron passage holes 91-9. The electron beam 11 passes through each phosphor screen 5R.

5G and 5B are emitted.

Therefore, each control grid 81 to 8 of the grid electrode group 8 arranged in a matrix corresponds to each of the phosphor screens 5R, 5G, and 5B. and each back group of the back electrode group 10 [
By selectively driving and controlling (dynamically driving) i 10 x to 103, only the phosphor screens 5R, 5G, and 5B where the circumferential electrodes intersect can be made to selectively emit light.

As mentioned above, on the inner surface of the front panel 2 constituting the vacuum envelope 1, there is a phosphor screen 5R made of three-color phosphors.

5G and 5B are arranged in a matrix of 3×3 pixels, and a cathode electrode group 7, a grid electrode group 8, and a back electrode group 10 are arranged in correspondence with each of these fluorescent screens 5R, 5G, 5B.
By providing this, it is possible to obtain a display tube for a light source that emits high-intensity light.

Therefore, when assembling a large-screen color display device using this light source display tube as one cell, the space between each pixel is narrower and the resolution can be improved compared to when a monochromatic tube with one pixel is used. With,
The number of parts and manufacturing man-hours can be reduced. Moreover, not only can the structure be simplified and cost reduced, but also the weight of the display device can be reduced.

In addition, in the illustrated example, R, G, and B are marked on the inner surface of the front panel 2.
Although the case is shown in which the 3-color phosphors are arranged in a matrix of 3 x 3 pixels, the present invention is not limited to this, and one phosphor in the vacuum envelope corresponds to one pixel. It is also possible to arrange the phosphor screen in a matrix of arbitrary mXn pixels (where m and n are arbitrary integers), and change the arrangement of the grid electrode group and the back electrode group accordingly.

In addition, each control grid of the grid electrode group 8 is made into a channel shape with a U-shaped cross section, and a shield plate made of metal that protrudes laterally is attached to each control grid, so that each control grid and the back plate are connected to each other. A display tube for a light source has been proposed (for example, Utility Model Application No. 114562/1982), in which the shield plate absorbs electrons leaking through the gap to effectively prevent false light emission on the phosphor screen due to the leaked electrons.

Further, each of the control grids 8□ to 8. By forming the electron passing portion formed in the dome-shaped mesh portion, the electrons emitted from the cathodes 711 to 733 can be uniformly spread to uniformly irradiate the phosphor screen 5. The spread angle of the electron beam 11 can be adjusted as desired.

Moreover, a light source display tube has been proposed in which the larger the curvature of the dome-shaped mesh portion, the larger the beam divergence angle, and the shorter the tube length of the display tube.

[Problem to be solved by the invention]

Since the conventional light source display tube is constructed as described above, it is possible that the metal back applied to the entire surface of the fluorescent display part may peel off due to partial contact with the anode electrode group during assembly. If it were to peel off, the metal powder would float inside the vacuum envelope and cause electrical discharge, which could adversely affect image display.

This invention has been proposed in view of the above, and an object thereof is to obtain a light source display tube in which peeling of the metal back during assembly of the anode electrode group is reduced.

[Means to solve the problem]

In the light source display tube according to the present invention, the coated portion of the phosphor screen is left in a matrix form on the inner surface of the front panel of the vacuum envelope, and a black matrix is formed using a black coated member, and the coated portion of the phosphor screen is coated on the coated portion. A metal back is applied only to the surface.

[Effect]

In the front panel of the present invention, since the metal back is applied only to the surface of the phosphor screen, there is no contact between the anode electrode group and the metal back during assembly, and no peeling of the metal back occurs.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, reference numeral 18 denotes phosphors 5G and 5R coated in a matrix on the inner surface of the front panel surface 2.

The metal back is applied only to the surface of the phosphor 5B, and as a means for applying the metal back only to the surface of the phosphor, for example, a well-known mask vapor deposition method is used.

Note that black paste, carbon, or the like is used as the black coating member that forms the black matrix 13. If black paste is used, it is possible to compensate for conductivity by applying carbon between it and the phosphor.

With the above configuration, the anode electrode group is assembled in direct contact with the black matrix formed by the black coating member 13, so there is no possibility of contact with the metal back and peeling off the metal back. In addition, since the black matrix has a strong coating strength, it does not peel off even if the anode electrode group comes into contact with it, thereby reliably preventing problems associated with peeling off of the metal back.

〔Effect of the invention〕

As described above, according to the present invention, since the metal back is applied only to the surface of the phosphor screen, there is no possibility of the metal back peeling off due to contact with the anode electrode group during assembly. As a result, inconveniences such as discharge caused by peeling off of the metal back are eliminated, and it is possible to always display a good image.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is an enlarged sectional view of the front panel of a light source display tube according to an embodiment of the present invention, FIG. 2 is a front view of a conventional light source display tube, and FIG. 3 is a front view of a conventional light source display tube. 4 is an exploded perspective view of a portion thereof, and FIG. 5 is an enlarged sectional view of the front panel thereof. 1 is a vacuum envelope, 2 is a front panel, 3 is a back plate, 4 is a cylindrical side plate, 5G, 5R, 5B are fluorescent screens, 6 is an anode electrode group,
7 is a cathode electrode group, 8 is a grid electrode group, 13 is a black matrix, 14 is a coating section, and 18 is a metal back. In addition, in FIG. 1, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 5 Figure 2 Figure 3

Claims (1)

[Claims] A vacuum envelope is formed by airtightly joining a front panel to the front side of a cylindrical side plate and a back plate to the back side, and a high voltage is applied to a phosphor screen formed in a matrix on the inner surface of the front panel, and the phosphor screen is surrounded. a light source display having an anode fixed perpendicularly to the front panel, an electron-emitting cathode disposed on the substrate side corresponding to the fluorescent screen, and a control grid for controlling the flow of electrons; In the tube, the inner surface of the front panel includes a black matrix formed by leaving the coated part of the phosphor screen in a matrix shape, a phosphor screen formed on the coated part so as to be in contact with the black matrix, and a phosphor screen formed on the coated part of the phosphor screen. A display tube for a light source characterized by comprising a metal back provided only on the surface.