JPH01235152A - Display tube for light source - Google Patents

Abstract

PURPOSE:To prevent electric troubles caused by a getter film by providing a substrate afloat from the back plate of a vacuum envelope, fitting various electrode groups such as a back electrode group, a cathode electrode group and a grid electrode group on the surface of the substrate, end providing a getter on the back of the substrate. CONSTITUTION:A back electric group 10, a cathode electrode group 7 and a channel-shaped grid electrode group with a U-shaped cross section are fitted on the surface of a ceramic substrate 18 provided afloat from the back plate 3 of a vacuum envelope 1, for example. Lead wires 12 of individual electrode groups are guided to the back of the substrate through the substrate 18 or through notches on the periphery of the substrate and guided to the outside through the connection section between the back plate 13 and a cylindrical side plate 14 connected by low-melting point glass 15. When a getter 19 fitted to the back of the substrate 13 to face the back plate 3 via a fitting plate 20 is flashed, a getter film 21 is formed on the back plate, but distances from various electrode groups provided on the surface of the substrate are not decreased, the occurrence of electric troubles caused by the getter film 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 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 3 and 4 are a front view showing the basic structure of this composite light source display tube, a sectional view taken along the line IV-mV, and Figure 5.
The figure is an exploded perspective view of a part of the screen, and the phosphor screen is arranged in a matrix of 3 x 3 pixels, with one pixel for each of the R (red), G (green), and B (blue) phosphors. The following shows the case where the array is arranged as follows.

In these figures, 1 is a vacuum envelope as a glass tube hermetically sealed by a front panel 2, a back panel 3, and a cylindrical side panel 4, and the inner surface of the front panel 2 is coated with three-color phosphor. Each of R, G, and B is coated and arranged in a matrix as a unit pixel, and fluorescent screens 5R, 5G, and 5 of 3×3 pixels are formed.
A fluorescent display section 5 made of B is formed. Here, the subscripts of the phosphor screens 5R, 5G, and 5B correspond to red (R), green (G), and blue (B), respectively.

Reference numeral 6 denotes a plurality of acceleration anodes 61 disposed corresponding to the periphery of each of the fluorescent screens 5R, 5G, and 5B of the fluorescent display section 5.
This is an anode electrode group consisting of 162+... A high voltage is applied to these acceleration anodes 62, 6□, . . . through an external terminal 16, and as shown in FIG. A getter 13 is attached to the accelerating anode facing the cylindrical side plate 4, and a getter film 14 is formed on the inner surface of the cylindrical side plate 4 by the flash of the getter 13.

Reference numeral 7 designates a cathode electrode group in which electron-emitting cathodes 7□1 to 733 (not shown) are arranged independently corresponding to each of the fluorescent screens 5R, 5G, and 5B of the fluorescent display section 5, and these cathodes 711-71. are supported at both ends between a pair of supports 17a and 17b fixed on the back plate 3. Here, the first one of the cathodes 7.1 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 711 to 733, for example, an indirectly heated type cathode formed by coating an oxide on a Ni sleeve or a directly heated type cathode formed by coating tungsten 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 the cathode electrode group 7 and the fluorescent display section 5, and these control grids 8. ~8
．． , each of the fluorescent screens 5R, 5G and 5B of the fluorescent display section 5
Cathodes 711-7, 711-7, respectively 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. This is a back electrode group consisting of striped back electrodes 101 to 103 for column selection, which are arranged facing each other, and these back electrodes 101 to 10 are formed from a conductive layer such as Ag.

Then, each of the back electrodes 10□ to 10. is negative and Ov or number ■ for the potential of each cathode 7□1 to 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 10, ~
10. is a negative potential with respect to the potential of the cathodes 711-733, these cathodes 7□1-733 are surrounded by a negative potential, so that each cathode 711-7,3
The electrons do not flow to the control grids 81 to 83 and the acceleration anodes 60, 6□, . . . , and are in a cut-off state.

Therefore, the back electrodes 101 to 10. to cathode 7□1
~73. When a positive potential of Q■ or several V is applied to the potential of the control grid 8. Flows towards ~83.

At this time, each control grid 8. ~8. When the potential of is negative with respect to the cathodes 711 to 733, the electron beam 11 cannot pass through the electron passing holes 9□ to 93 of these control grids 8□ to 83, and the acceleration anodes 61, 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.

Then, the potential of the control grids 8□ to 83 is the cathode 7□
, ~733, these control grids 8□~8. Electron passing holes 9□~9. The electron beam 11 passes through each phosphor screen 5R.

5G and 5B are emitted.

Therefore, each of the control grids 8□-8. and each back surface of the back electrode group 10? I
i-pole 101-10. By selectively driving and controlling (dynamic driving), only the phosphor screens 5R, 5G, and 5B where the picture 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 m x n 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 81 to 8. By making the electron passing portions formed in the dome-shaped mesh portions, the cathodes 71□ to 73. The electron beam 11 can be uniformly spread to uniformly irradiate the phosphor screen 5, and the spread angle of the electron beam 11 can be arbitrarily adjusted according to the curvature of the dome-shaped mesh portion.

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, when the getter attached to the anode electrode is flashed facing the side plate of the vacuum envelope, a getter film is formed over a wide area on the inner surface of the side plate. The distance between this getter film and the control grid formed on the back plate is so close that there is a risk of electrical problems such as short circuits or discharge occurring between the two.

The present invention has been proposed in view of the above, and an object of the present invention is to obtain a display tube for a light source that is free from the fear of electrical travel caused by a getter film.

[Means to solve the problem]

In the light source display tube according to the present invention, a substrate on which a cathode electrode group, a grid electrode group, and a back electrode group are attached is provided floating above the back plate of a vacuum envelope, and a getter is provided on the back side of this substrate facing the back plate. It was established.

[Effect]

In the light source display tube of the present invention, a getter is provided on the back surface of the substrate, which is placed above the back surface of the vacuum envelope, and faces the back surface, so that the flash of the getter spreads the getter film over a wide area on the back surface. Even if a getter film is formed, the distance between this getter film and each electrode group provided on the substrate does not become close, and there is no risk of electrical troubles caused by the getter film.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a part of the display tube for a light source according to the present invention. In FIG. A back electrode group 1°, a cathode group 7, and a channel-shaped grid electrode group 8 having a U-shaped cross section are attached to the surface of the electrode 18. The lead wires 12 of each electrode group pass through the substrate 18 or are guided to the back surface of the substrate through a notch on the circumferential surface of the substrate, and are passed through the joint between the back plate 3 and the cylindrical side plate 4, which are joined with the low melting point glass 15. Extracted to the outside. Therefore,
The board 18 is supported floating on the back plate by the lead wires 12 without using any special mounting members. A getter 19 is attached to the back surface of the substrate 13, facing the back plate 3, via a plate 20.

With the above configuration, when the getter 19 is flashed,
Although the getter film 21 is formed on the back plate, the distance between the getter film 21 and the various electrode groups provided on the substrate surface is not shortened, and no electrical trouble occurs.

In addition to attaching the getter 19 directly to the back of the board, as shown in FIG. 2, a U-shaped barrier 22 is attached to the back of the board.
By providing the getter 19 inside this thin part 22, it is possible to suppress the spread of the getter film 21,
Electrical troubles caused by the getter film 21 can be more reliably prevented.

〔Effect of the invention〕

As described above, according to the present invention, a substrate is provided floating above the back plate of the vacuum envelope, and various electrode groups such as a back electrode group, a cathode electrode group, and a grid electrode group are attached to the surface of this substrate. Since the getter is provided on the back surface of the substrate, a getter film is formed on the back plate by flashing the getter, and electrical troubles caused by this getter film can be reliably prevented. Therefore, the getter can be sufficiently burned, and the getter can sufficiently increase the degree of vacuum in the vacuum envelope and improve reliability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a part of a light source display tube according to an embodiment of the present invention, and FIG. 2 is a perspective view showing how the getter is installed.
Fig. 3 is a front view of a conventional light source display tube, Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3, Fig. 5 is an exploded perspective view of a part thereof, and Fig. 6 is Fig. 4. FIG. 1 is a vacuum envelope, 2 is a front panel, 3 is a back plate, 4 is a side plate, 5R, 5G, 5B are fluorescent screens, 6 is an anode 7ti14.
7 is a cathode, 8 is a grid electrode, 18 is a substrate, 19 is a getter, and 21 is a getter film. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masu Oiwa Yube 1
Figure 6 Figure 3 5R, 5G, 58: Fluorescent image Figure 4 Figure 8: /7'' / η1 Figure 5

Claims (1)

[Claims] A vacuum envelope is formed by airtightly bonding a front panel to the front of a cylindrical side plate and a back plate to the back, and a high voltage is applied to a phosphor screen formed on the inner surface of the front panel, and the phosphor screen is surrounded by a vacuum envelope. In a display tube for a light source, the display tube has an anode fixed perpendicularly to the front panel, an electron-emitting cathode disposed corresponding to the phosphor screen, a grid electrode for controlling the flow of electrons, and a back electrode. , a substrate having the electron-emitting cathode, the grid electrode, and the back electrode attached to the surface and floating above the back plate; and a getter provided on the back side of the substrate to form a getter film on the back plate. A display tube for a light source characterized by: