JPH0654658B2 - 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.

3 and 4 are a front view and a sectional view taken along line IV-IV of the basic structure of the composite type light source display tube, and FIG. 5 is an exploded perspective view of a part thereof, in which R (red) is shown. , G (green)
2 shows the case where the phosphor screens each having one of the B and blue (B) phosphors as one pixel are arranged in a matrix of 3 × 3 pixels.

In these figures, reference numeral 1 denotes 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, and an inner surface of the front panel 2 has a three-color phosphor. Each of R, G and B is applied as a unit pixel in a matrix and arranged in a matrix to form 3 × 3 pixel phosphor screens 5R, 5G and 5
A fluorescent display portion 5 made of B is formed. 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 consisting 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 section 5. 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.

Reference numeral 8 is a grid electrode group composed of row selection control grids 8 ₁ to 8 ₃ arranged between the cathode electrode group 7 and the fluorescent display portion 5, and these control grids 8 ₁ to 8 ₃ include , Electron passing holes 9 _{1 to} 9 in order to pass the electron beam 11 from the cathodes 7 _{11 to} 7 ₃₃ as a non-focused beam in the row direction corresponding to each of the fluorescent screens 5R, 5G and 5B of the fluorescent display unit 5. _Three are provided.

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. each is oppositely disposed back electrode 10 ₁ to 10 ₃ rear electrode group consisting of stripe-shaped column selection, these back electrode 10 ₁ to 10 ₃ is formed of a conductive layer such as Ag on.

Then, each of the back electrodes 10 ₁ to 10 _3, each of the cathodes 7
By applying a positive potential of the negative and 0V or several V with respect _{11-7 33} potential has become a controls the electron beam 11 to be emitted from their cathode 7 _{11-7 33.}

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 cathode 7 _11-7 on the back electrode 10 ₁ to 10 _3
When 0V or positive potential of several V is applied to the potential of ₃₃ ,
Electron beam 1 emitted from these cathodes 7 _{11 to} 7 ₃₃
1 flows toward the control grid 8 _{1-8 3.}

At this time, when the potentials of the 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 the} control grids 8 ₁ to 8 ₃ are discharged. Electron beam 1
1 cannot pass through, the electron beam 11 does not flow to the accelerating anodes 6 ₁ , 6 ₂ , ...
G and 5B do not emit light.

Then, the potentials of the control grids 8 ₁ to 8 ₃ are the cathodes 7 ₁₁ to
When the potential is positive with respect to 7 ₃₃ , these control grids 8 ₁
8 ₃ of the electron passing hole 91 _to 93 _three electron beams 11 passes each respective fluorescent screen 5R, 5G, and emit light 5B.

Therefore, the control grids 8 ₁ to 8 _{3 of} the grid electrode group 8 and the back electrodes ₁ of the back electrode group 10 arranged in a matrix corresponding to the phosphor screens 5R, 5G, and 5B described above.
Selective drive control from 0 ₁ to 10 ₃ (dynamic drive)
By doing so, the fluorescent surfaces 5R, 5
Only G and 5B can be selectively emitted.

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.
The case where the phosphor surface composed of the three-color phosphor is arranged in a matrix of 3 × 3 pixels is shown, but the present invention is not limited to this, and one phosphor constitutes 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 Patent Laid-Open No. 62-241256, the cathodes 7 _{11 to} 7 are formed by forming the electron passage portions formed in the control grids 8 ₁ to 8 ₃ into dome-shaped mesh portions. _The electrons emitted from ₃₃ can be uniformly spread and evenly applied to the phosphor screen 5, and the divergence angle of the electron beam 11 can be arbitrarily adjusted 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 light source display tube is configured as described above, since the back electrode, the cathode, the control grid, and these lead wires are provided on the back plate of the vacuum envelope, It was difficult to widen the distance and the distance between the lead wires, and there was a risk of electrical trouble.

The present invention has been proposed in view of the above, and an object thereof is to obtain a display tube for a light source with less electrical trouble.

[Means for Solving the Problems]

A display tube for a light source according to the present invention is provided with a substrate provided so as to be floated from the back plate so that a back electrode, a cathode and a control grid are mounted, and a tubular side plate provided at a joint portion between the back plate and the tubular side plate. And a lead wire which is erected in parallel with and which supports the substrate at the upper end and forms an electric path to any one of the electrodes.

[Action]

In the display tube for a light source according to the present invention, a substrate on which various electrodes such as a back electrode, a cathode and a grid electrode and lead wires of these electrodes are provided so as to be floated from a back plate of the vacuum envelope, and the back plate and the tubular side plate are From the fact that the lead wire which is provided in the junction of the above and serves as an electric path for any of the electrodes is vertically raised along the inner surface of the tubular side plate to support the substrate at the upper end portion of the lead wire, It is possible to firmly support the substrate without using a special supporting member.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First
FIG. 2 is a sectional view showing a main part of a light source display tube of the present invention,
1 is a sectional plan view taken along the line II-II in FIG.
In FIG. 2, lead wires 12 provided at least near the four corners of the vacuum envelope 1 (the illustrated example shows only one side).
Is sandwiched between the rear plate 3 of the vacuum envelope 1 and the tubular side plate 4 and is vertically raised in the vacuum envelope 1 along the inner surface of the tubular side plate. 13 is each lead wire 12
By a substrate that supported for example ceramic floated from the back plate 3, the back electrode 10 ₁ to 10 ₃ provided on the surface of the substrate 13, the cathode 7 _{11-7 33,} such as the control grid 8 _{1-8 3} The lead wire 12 as a part of the lead wire
Is used.

When the channel-shaped control grids 8 ₁ to 8 ₃ having a U-shaped cross section are mounted on the substrate 13 as in the illustrated example, the sides a and b of the control grid facing the substrate peripheral surface should surround the substrate 13. The lead wire 12 is extended to the back side, and the lead wire 12 is fixed to the extension portion a to support the substrate 13. Further, the lead wire 12 may be directly fixed to the substrate 13 and supported.

〔The invention's effect〕

As described above, according to the present invention, the lead wire sandwiched in the joint portion between the back plate and the tubular side plate of the vacuum envelope is vertically raised along the inner surface of the tubular side plate, and the upper end portion of the lead wire is raised. Since the substrate is floated above the back plate and supported and fixed, no special support member for supporting the substrate is required.
Further, since the back electrode, cathode, control grid and lead wires thereof can be provided on both sides of the substrate, it is possible to widen the electrode interval and the lead wire interval and reduce the occurrence of electrical troubles. The effect that it can be obtained is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a light source display tube according to an embodiment of the present invention, FIG. 2 is a vertical plan view taken along the line II-II of FIG. 1, and FIG. 3 is a front view of a conventional light source display tube. Fig. 4 and Fig. 3 IV
Fig. 5 is a cross-sectional view taken along line -IV, and Fig. 5 is an exploded perspective view of a part thereof. 1 is a vacuum envelope, 2 is a front panel, 3 is a back plate, 4 is a cylindrical side plate, 5R, 5G and 5B are fluorescent screens, 6 is an anode electrode, 7
Is a cathode, 8 is a grid electrode, 12 is a lead wire, and 13 is a substrate. In the drawings, the same reference numerals indicate the same or corresponding parts.

(72) Inventor Nobuo Terasaki 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Mitsubishi Electric Corporation Nagasaki Works (72) Inventor Shuji Iwata 8-1-1 Tsukaguchihonmachi, Amagasaki-shi, Hyogo Sanbishi (72) Inventor, Kazunori Tatsuda, 700, Wada, Ueno-cho, Ise-shi, Mie Prefecture, Ise Electronics Industry Co., Ltd. (72) Masaaki Kobayashi, 700, Wada, Ueno-cho, Ise-shi, Mie, Ise Electronics Industry Co., Ltd. (72) Inventor Mitsuru Masuda 700 Wada, Ueno Town, Ise City, Mie Prefecture Ise Electronics Industry Co., Ltd.

Claims (1)

[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, Further, it has an anode electrode fixed vertically to the front panel so as to surround the phosphor screen, a back electrode corresponding to the phosphor screen, a cathode for electron emission, and a control grid for controlling the flow of electrons. In a display tube for a light source, a substrate provided so as to be floated from the back plate so as to attach the back electrode, the cathode and a control grid, and a pipe provided at a joint portion between the back plate and the tubular side plate and parallel to the tubular side plate. A display tube for a light source, comprising: a lead wire which supports the substrate at an upper end portion thereof which is raised to form an electric path.