JPH0642362B2 - Display tube for light source - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a light source display tube which constitutes a pixel of a large-screen display device, particularly a color display device.

[Conventional technology]

When a large-screen display device is constructed by arranging single-color display tubes utilizing the light emission of the phosphor as one pixel in a matrix, there is a space at the connection portion of each single-color display tube, and it is difficult to improve the resolution. Higher resolution may result in higher cost.

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

2 and 3 are a front view and a sectional view taken along line III-III of the basic structure of the composite type light source display tube, and FIG. 4 is an exploded perspective view of a part thereof, in which R (red) is shown. , G (green) and B (blue) phosphors are arranged in a matrix of 3 × 3 pixels with the number of pixels being the phosphor screen having each pixel as one pixel.

In these figures, 1 is a vacuum envelope as a glass tube which is hermetically sealed by a front panel 2, a back plate 3 and a tubular side plate 4. The inner surface of the front panel 2 has a fifth
As shown in the drawing, each of the three-color phosphors R, G, and B is used as a unit pixel, and a phosphor screen 5 of 3 × 3 pixels coated on a coating portion 14 formed in a matrix with a black matrix 13 is formed.
A fluorescent display portion 5 is formed by R, 5G and 5B, and a metal back 15 is applied to the entire surface of this fluorescent display portion. Here, the suffixes of the phosphor screens 5R, 5G and 5B correspond to red (R), green (G) and blue (B), respectively.

Reference numeral 6 denotes an anode electrode group composed of a plurality of accelerating anodes 6 ₁ , 6 ₂ , ... Arranged correspondingly around the respective fluorescent screens 5R, 5G and 5B of the fluorescent display unit 5, and these accelerating electrodes are A high voltage is applied to the anodes 6 ₁ , 6 ₂ , ... Via the external terminal 16.

Reference numeral 7 denotes a cathode electrode group in which electron emission cathodes 7 _{11 to} 7 ₃₃ (not shown) are independently arranged corresponding to the respective fluorescent screens 5R, 5G, 5B of the fluorescent display section 5. Both ends of 7 _{11 to} 7 ₃₃ are supported between a pair of supports 17 a and 17 b fixed on the back plate 3. Here, the first and second subscripts of the cathodes 7 _{11 to} 7 ₃₃ correspond to the 1st to 3rd rows and the 1st to 3rd columns, respectively.

Note that the cathodes 7 _{11-7 33,} for example, a straight thermal which was coated an oxide indirectly heated or tungsten was coated with oxide on the Ni sleeve can be used.

Further, 8 is a grid electrode group including control grids 8 ₁ to 8 ₃ for row selection arranged between the cathode electrode group 7 and the fluorescent display portion 5, and these control grids 8 ₁ to 8
₃ includes fluorescent screens 5R, 5G and 5B of the fluorescent display unit 5.
Correspondingly, electron passing holes 9 _{1 to} 9 ₃ are provided in the row direction to pass the electron beams 11 from the cathodes 7 _{11 to} 7 ₃₃ as non-focused beams, respectively.

Reference numeral 10 denotes the rear surface side of the cathode electrode group 7, that is, on the rear plate 3 forming a part of the vacuum envelope 1, in the column direction corresponding to the respective fluorescent screens 5R, 5G and 5B of the fluorescent display portion 5. Is a back electrode group including back electrodes 10 ₁ to 10 ₃ for column selection in stripes, which are arranged to face each other. The back electrodes 10 ₁ to 10 ₃ are formed of a conductor layer of Ag or the like.

Then, each of the back electrodes ₁₀ 1 to 10 _3, by applying a positive potential of the negative and 0V or several V relative to the potential of the cathode 7 _{11-7 33,} which cathode 7 _{11-7 33}
The electron beam 11 emitted from is controlled.

Reference numeral 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.

Next, the operation will be described. First, the back electrode ₁₀ 1 -
10 When ₃ is a negative potential with respect to the potential of the cathode 7 _{11-7 33,} because around these cathode 7 _{11-7 33} is surrounded by a negative potential, electrons are controlled from the cathode 7 _{11-7 33} grid ₈ 1-8 ₃ and acceleration anode _{6 1, 6} 2,
It does not flow to ……… and is in a cut-off state.

Therefore, the cathodes 7 ₁₁ to the rear electrodes 10 ₁ to 10 ₃
When applying a positive potential of 0V or several V with respect 7 ₃₃ potential, electrons flow beam 11 emitted from the cathodes 7 _{11-7 33} toward the control grid ₈ 1-8 _3.

At this time, when the potentials of the respective control grids 8 ₁ to 8 ₃ are negative with respect to the cathodes 7 _{11 to} 7 ₃₃ , the electron passage holes 9 _{1 to} 9 _{3 of} these control grids 8 ₁ to 8 ₃ are used. The electron beam 11 cannot pass therethrough, and the acceleration anodes 6 ₁ , 6 ₂ , ...
The electron beam 11 does not flow to the ... And the fluorescent screens 5R, 5G, and 5B of the fluorescent display unit 5 do not emit light.

Then, the potentials of the control grids 8 ₁ to 8 ₃ are set to the cathode 7 ₁₁
When the potential is positive with respect to ~ 7 ₃₃ , these control grids 8
_The electron beam 11 is emitted from the electron passage holes 9 _{1 to} 9 _{3 of 1} to 8 _3.
Respectively pass through and cause each of the fluorescent surfaces 5R, 5G, and 5B to emit light.

Therefore, the control grids 8 ₁ to 8 _{3 of} the grid electrode group 8 and the back electrodes 10 ₁ to 10 _{3 of the} back electrode group 10 arranged in a matrix corresponding to the phosphor screens 5R, 5G, and 5B are respectively provided. By selectively driving and controlling (dynamically driving) the fluorescent screen 5 where the two electrodes intersect.
Only R, 5G, and 5B can selectively emit light.

As described above, the phosphor screens 5R, 5G, and 5B made of phosphors of three colors are arranged in a matrix of 3 × 3 pixels on the inner surface of the front panel 2 which constitutes the vacuum envelope 1, and each of these phosphor screens is arranged. Cathode electrode group 7 corresponding to 5R, 5G, and 5B
By providing the grid electrode group 8 and the back electrode group 10, it is possible to obtain a display tube for a light source that emits light with high brightness.

Therefore, when assembling a large-screen color display device using this light source display tube as one cell, the space between each pixel becomes narrower than that in the case where a single color tube with one pixel is used, and the resolution can be improved. ,
The number of parts and the number of manufacturing steps can be reduced. Further, not only the structure can be simplified and the cost can be reduced, but also the weight of the display device can be reduced.

In the illustrated example, R, G and B are formed on the inner surface of the front panel 2.
Although the case where the phosphor screens composed of the three-color phosphors are arranged in a matrix of 3 × 3 pixels is shown, the invention is not limited to this, and one phosphor is defined as one pixel in the vacuum envelope. It is also possible to arrange the phosphor screens in a matrix of arbitrary m × n pixels (where m and n are arbitrary integers) and change the arrangement configuration of the grid electrode group and the back electrode group accordingly.

Further, each control grid of the grid electrode group 8 is formed into a channel shape having a U-shaped cross section, and a shield plate made of metal protruding laterally is attached to each of the control grids. There has been proposed a light source display tube in which electrons leaking from a gap are absorbed by the shield plate to effectively prevent pseudo light emission of a fluorescent screen due to leaking electrons (for example, Japanese Utility Model Application No. 62-114562).

Further, as disclosed in, for example, Japanese Unexamined Patent Publication No. 62-241256, the cathodes 7 _{11 to} 7 ₃₃ are formed by forming the electron passage portions formed in the control grids 8 ₁ to 8 ₃ into dome-shaped mesh portions. It is possible to uniformly spread the electrons emitted from the phosphor screen 5 and evenly irradiate the phosphor screen 5, and it is possible to arbitrarily adjust the spread angle of the electron beam 11 according to the curvature of the dome-shaped mesh portion.

Moreover, there has been proposed a light source display tube in which the divergence angle of the beam increases as the curvature of the dome-shaped mesh portion increases, and the tube length of the display tube can be shortened.

[Problems to be Solved by the Invention]

Since the conventional display tube for a light source is configured as described above, it is considered that the metal back applied to the entire surface of the fluorescent display part is peeled off due to partial contact of the anode electrode group during assembly. If it is peeled off, the metal powder may float in the vacuum envelope and cause discharge, which may adversely affect the image display.

The present 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 a metal back during assembly of an anode electrode group is reduced.

[Means for Solving the Problems]

The light source display tube according to the present invention is such that a black matrix is formed on the inner surface of the front panel of the vacuum envelope by a black coating member while leaving the coating portion of the fluorescent surface in a matrix shape, and the coating of the fluorescent surface on the coating portion is performed. A metal back is applied only to the surface.

[Action]

In the front panel according to the present invention, the metal back is applied only to the surface of the phosphor screen, so that the anode back is not in contact with the metal back at the time of assembly and the metal back is not peeled off.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, reference numeral 18 denotes a metal back applied only to the surface of the phosphors 5G, 5R, 5B applied in a matrix on the inner surface of the front panel surface 2, and thus the metal back is applied only to the phosphor surface. As a means, for example, a well-known mask vapor deposition method is used.

A black paste, carbon, or the like is used as the black coating member that forms the black matrix 13. When the black paste is used, carbon can be applied between the phosphor and the phosphor to compensate the conductivity.

With the above configuration, since the anode electrode group is directly abutted on the black matrix by the black coating member 13 to be assembled, it is not necessary to come into contact with the metal back and peel off the metal back. Further, since the black matrix has a high coating strength, it does not peel off even if the anode electrode group comes into contact with it, so that the inconvenience associated with peeling of the metal back is surely prevented.

〔The invention's effect〕

As described above, according to the present invention, since the metal back is applied only to the surface of the phosphor screen, the metal back is not peeled off due to contact with the anode electrode group during assembly. As a result, there is no inconvenience such as electric discharge due to the peeling of the metal back, and there is an effect that a good image can be always displayed. Further, a conductive black matrix such as carbon is formed by leaving the coating portion of the phosphor screen in a matrix shape, or a non-conductive black matrix of black paste is formed, and between the non-conductive black matrix and the phosphor screen. It is made by applying carbon etc. to obtain conductivity,
This has the effect of ensuring electrical continuity between the metal backs divided into a matrix.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a 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 along line III-III in FIG. Transverse view, 4th
FIG. 5 is an exploded perspective view of a part thereof, and FIG. 5 is an enlarged sectional view of the front panel. 1 is a vacuum envelope, 2 is a front panel, 3 is a back plate, 4 is a cylindrical side plate, 5G, 5R and 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 portion, and 18 is a metal back. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Kobayashi 700 Wada, Ueno Town, Ise City, Mie Prefecture Ise Electronics Industry Co., Ltd. (72) Mitsuru Masuda 700 Wada, Ueno Town, Ise City, Mie Prefecture Ise Electronics Industry Incorporated (72) Inventor Zenichiro Hara 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Mitsubishi Electric Corporation Nagasaki Works (72) Inventor Nobuo Terasaki 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Mitsubishi Electric Corporation Nagasaki Seisakusho (72) Inventor Shuji Iwata 8-1-1 Tsukaguchihonmachi, Amagasaki City, Hyogo Sanyo Electric Co., Ltd. Applied Equipment Research Laboratory (56) Reference JP-A-62-188129 (JP, A) JP-A-SHO 58-133752 (JP, A)

Claims (2)

[Claims] 1. A vacuum envelope in which a front panel is joined to the front surface of a cylindrical side plate and a back panel is joined to the back surface in an airtight manner, and a high voltage is applied to a fluorescent screen formed in a matrix on the inner surface of the front panel. An anode electrode fixed vertically to the front panel so as to surround the phosphor screen, an electron emission cathode arranged on the substrate side corresponding to the phosphor screen, and a control grid for controlling the flow of electrons. In the display tube for a light source, the inner surface of the front panel has a black matrix of electrodes formed by leaving the coating portion of the fluorescent surface in a matrix, and the fluorescent light applied to the coating portion so as to contact the black matrix. And a metal back provided only on the surface of the phosphor screen. 2. A vacuum envelope in which a front panel is joined to the front surface of a tubular side plate and a back plate is joined to the back surface in an airtight manner, and a high voltage is applied to a fluorescent screen formed in a matrix on the inner surface of the front panel. An anode electrode fixed vertically to the front panel so as to surround the phosphor screen, an electron emission cathode arranged on the substrate side corresponding to the phosphor screen, and a control grid for controlling the flow of electrons. In the display tube for a light source, the inner surface of the front panel is applied to the non-conductive black matrix formed by leaving the coating portion of the phosphor screen in a matrix and the coating portion so as to be in contact with the black matrix. For a light source, comprising: a fluorescent screen, a metal back provided only on the surface of the fluorescent screen, and a conductive member provided between the black matrix and the fluorescent screen.示管.