JPH01253148A - Display tube for light source - Google Patents

Abstract

PURPOSE:To uniformly and efficiently radiate unfocused beams on fluorescent faces by installing an accelerating anode in front of a fluorescent character display section as a flat shadow mask plate having multiple window holes passing unfocused beams. CONSTITUTION:An accelerating anode 21 is installed in front of a fluorescent character display section 5 as a flat shadow mask plate provided with multiple window holes 22 passing unfocused beams. When electrons are emitted from one of cathodes 711-733, unfocused beams of electrons pass one of the corresponding control grids 81-83 and pass the corresponding window hole 22 and are applied with the electric field with high voltage and accelerated and radiated to the preset fluorescent faces 5R, 5G, and 5B. In this case, the anode 21 is formed in a flat plate shape as a whole, the potential gradient for the unfocused beams is made wholly uniform, thus the unfocused beams are prevented from being converged only on one part of the anode 21. The unfocused beams are efficiently radiated to fluorescent faces 5R, 5G, and 5B respectively.

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 as one pixel, a space is created at the connection part of each monochrome display tube, making it difficult to improve the resolution. Higher resolution has sometimes 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, 1 is a vacuum envelope as a glass tube hermetically sealed by a front panel 2, a back plate; 3 and a cylindrical side plate 4; The fluorescent display section 5 is formed by coating and arranging the pixels R, G, and H in a matrix in the form of a matrix, with each of the pixels R, G, and H serving as a middle-rank pixel. Here, the subscripts of -m light surfaces 5R, 5G and 5B are red (R)
, corresponding to green (Ci) and blue (B), respectively.

Reference numeral 6 designates an anode electrode group consisting of a plurality of skirt-shaped accelerating anodes 611621 disposed around the phosphor screens 5R, 5G, and 5B of the phosphor display section 5, respectively. Acceleration anode 61,6□.

A high voltage is applied to . . . through an external terminal 16.

Reference numeral 7 indicates cathodes 71□ to 71.7 for electron emission corresponding to each of the fluorescent screens 5R, 5G, and 5r3 of the fluorescent display section 5. (not shown)
are cathode m pole groups arranged independently,
These cathodes 711-71. is the back plate 3 on both ends of each
It is supported between a pair of supports 17a and 17b fixed above. Here, the cathode 70. ~74. 1st. The second subscript corresponds to the first to third rows and the first to third columns, respectively.

For each of the cathodes 7□l 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, reference numeral 8 denotes a control grid 8 for row selection arranged between the cathode fit 4 group 7 and the fluorescent display section 5. As shown in FIG. 4, these control grids 81-8. , cathodes 711 to 77 . are arranged in the row direction corresponding to each of the fluorescent screens 5R, 5G, and 5B of the fluorescent display section 5, respectively. More electron beam 11
Hole 9 for electrons to pass through as a non-focused beam. ~9
．． 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. This is a back electrode group consisting of striped column selection back electrodes 101 to 103, as shown in FIG. 4, which are arranged opposite to each other, respectively. 103 is formed from a conductor layer such as Ag.

And each of the back molds 1410, -10. are each cathode 7□ to 71. negative and Ov or a few V for the potential of
By applying a positive potential to the cathodes 7,
The electron beam emitted from ~7°]1 is controlled.

Note that L2 is a lead wire serving 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 IO from the back plate 3 to the outside.

Next, the operation will be explained. First, each back flit4i
When 10□ to 103 have a negative potential with respect to the potential of cathodes 7□1 to 73J, each cathode 73 is surrounded by negative potential.
．． Electrons from ~7JJ are transferred to the control grid 8. ~8° and accelerating anode 6. ．． 62. It doesn't flow to...
It becomes a cutoff state.

Therefore, the back electrode 10. ~10. cathode 711
~71. When a positive potential of Ov or several V is applied to the potential of , it is released from these cathodes 7 it~7 J, l. Daughter beams 11 flow towards control grids 81-83.

At this time, each control grid 81-8. When the potential is negative with respect to the cathodes 71 to 733.

Electron passage holes 9, ~9 of these control grids 8□~83
3, the electron beam 11 cannot pass through the accelerating anode 6.
．． 62. . . ., 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 grid 8□~8. The potential of the cathode 71
．． 7:13, these control grids 8. ~81 holes for electron passage9. ~9. The electron beam 11 passes through each phosphor screen 5R.

5G and 5B are emitted.

Therefore, each control grid 8. of the grid electrode group 8 arranged in a matrix corresponds to each of the phosphor screens 5R, 5G, and 5B. By selectively driving and controlling (dynamically driving) the back electrodes 10□ to 103 of the back electrode group 10, only the phosphor screens 5R, 5G, and 5B where these two tttti intersect are selectively emitted. can be done.

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

5(3, and 5B) are arranged in a 3×3 pixel matrix, and a cathode electrode group 7, a grid electrode group 8, and a back electrode group 10 are provided corresponding to each of these phosphor screens 5R, 5G, 5B. A high-intensity light source display tube 1j) can be produced.

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 the cost can be reduced, but also the weight of one display device can be reduced.

In the illustrated example, the inner surface of the front panel 2 has 12. A phosphor surface consisting of G and B three-color phosphors is 3 x 3 pixels of 71
Although the case where the phosphor is arranged in a helical shape is shown, the present invention is not limited to this, and the phosphor screen in which one phosphor is arranged in a vacuum envelope as one pixel can be arranged in arbitrary mXn pixels (however, m,
It is also possible to arrange them in a matrix (n is an arbitrary integer) and change the arrangement of the grid electrode group and the back electrode group accordingly.

[Problem to be solved by the invention]

Since the conventional light source display tube is constructed as described above, the cathode 71. Electrons emitted from each of the acceleration anodes 61, 6. When accelerated by..., a part of the skirt concentrates on the sharp tip of these skirts and generates electric discharge at the sharp tip, which causes the phosphor screen 5R to
.

The present invention has been made in view of the above, and an object of the present invention is to obtain a display tube for a light source that can uniformly and efficiently irradiate a phosphor screen with an unfocused beam while preventing the formation of sharp parts in the accelerating anode.

[Means to solve the problem]

In the light source display tube according to the present invention, an accelerating anode is installed in front of a fluorescent display section with a flat shadow mask plate provided with a plurality of window holes through which unfocused beams pass.

[Effect]

The accelerating anode in this invention is located between the fluorescent display section and the control grid and has a flat plate shape, and there is no sharp part where electrons tend to concentrate when the unfocused beam passes through the window hole. The electron beam does not cause any discharge phenomenon, and therefore acts to uniformly and efficiently irradiate the phosphor screen of the phosphor display with an unfocused beam (electron beam).

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 21 is an accelerating anode, which is connected to each of the cathodes 7, □ to 74 . It is made of a shadow mask plate provided with a plurality of window holes 22 through which the non-bundled beams from the cathodes 711 to 7Jj are transmitted. Further, this acceleration anode 21 is connected to each of the fluorescent screens 5R, 5G, 5B and the control lids 8, . . .
8. This is provided between each fluorescent screen 5I2, 5G,
511 and an aluminum film (not shown) provided on the inner surface of the front panel 2 for electron reflection.

Next, the operation will be explained.

Now, when electrons are emitted from any one of the cathodes 7□, ~7, and 3, the unfocused beam of electrons passes through the corresponding window hole 22 through one of the corresponding control grids 8, ~81. When passing through the window hole 22, the light is accelerated by a high-voltage electric field, and is irradiated onto predetermined fluorescent screens 5R, 50, and 5B. In this case, since the accelerating anode 21 has a flat plate shape as a whole, the potential gradient for the unfocused beam becomes uniform over the entire surface, so that the unfocused beam does not converge on only a part of the accelerating anode 21. Therefore, the unfocused beam efficiently irradiates each phosphor screen of 5R95G and 5B. As a result, the image obtained by the color display device as a whole can be displayed clearly and brightly.

Note that the window hole 22 can be arbitrarily selected to have a round shape, a rectangular shape, or the like.

〔Effect of the invention〕

As described above, according to the present invention, in front of the fluorescent display section,
Since the plate-shaped accelerating anode is provided with a window hole through which the unfocused beam from the cathode passes through while accelerating, it is possible to prevent the unfocused beam from concentrating on a part of the accelerating anode. The irradiation efficiency of the unfocused beam onto the phosphor screen can be greatly improved, and as a result, there is an effect that good image display can be performed in a large screen display device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a light source display tube according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a conventional light source display tube.
The figure is a cross-sectional view taken along tn-ma in FIG. 2, and FIG. 4 is an exploded perspective view of a part thereof. 1 is the vacuum envelope, 2 is the front panel, and 3 is the back plate. 4 is a cylindrical side plate, 5 is a fluorescent display section, 5G, 5R, and 5B are fluorescent screens, 21 is an acceleration anode, and 22 is a window hole. In addition, in FIG. 1, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 21 = Addition ts122: Takukan 2ViA Figure 3 Figure 4

Claims (1)

[Claims] a vacuum envelope in which a front panel is airtightly joined to the front surface of a cylindrical side plate and a back panel is airtightly bonded to the back surface; a fluorescent display section formed by arranging fluorescent screens in a matrix on the inner surface of the front panel; In a light source display tube having an accelerating anode disposed around a surface and accelerating a non-focused beam that causes the fluorescent screen to emit light, the accelerating anode is provided in front of the fluorescent display section and the non-focused beam A display tube for a light source, characterized by having a flat shadow mask plate having a plurality of window holes through which beams pass.