JPH0752637B2 - 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, for example, a composite type light source display tube disclosed in JP-A-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 to form a fluorescent display portion 5 including 3 × 3 pixel fluorescent screens 5R, 5G, and 5B. Here, phosphor screen 5R, 5G
The subscripts of 5B and 5B correspond to red (R), green (G) and blue (B), respectively.

Reference numeral 6 designates a plurality of accelerating anodes 6 ₁ , 6 ₂ , ... which are arranged around the respective fluorescent screens 5R, 5G and 5B of the fluorescent display section 5.
Is an anode electrode group consisting of, and these acceleration anodes 6 ₁ , 6 ₂ ,
A high voltage is applied to ... 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 in correspondence with the respective fluorescent screens 5R, 5G, 5B of the fluorescent display unit 5. 7
_{11-7 33} a pair of support 17a, each of the both ends are fixed on the rear plate 3 is supported between 17b. Here cathode 7
The 1st and 2nd subscripts of _{11 to} 7 ₃₃ are 1 to 3 respectively
It corresponds to the rows and the first to third columns.

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 composed of 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 ,
The electron beams 11 from the cathodes 7 _{11 to} 7 ₃₃ are arranged in the row direction corresponding to the respective fluorescent screens 5R, 5G and 5B of the fluorescent display portion 5.
The electron passing holes 9 _{1 to} 9 ₃ are provided to pass the beam as a non-focused beam.

10 is the back side of the cathode electrode group 7, that is, the vacuum envelope 1
On the back plate 3 forming a part of the strip display, corresponding to the respective fluorescent screens 5R, 5G and 5B of the fluorescent display section 5 and arranged in the column direction so as to be opposed to each other in a striped manner. ₁ ~ 1
This is a back electrode group consisting of 0 ₃ and these back electrodes 10 ₁ to 10 ₃
Is formed of a conductor layer such as Ag.

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

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 to 10 ₃
When a negative potential relative to the potential of but cathode 7 _{11-7 33,} because around these cathode 7 _{11-7 33} is surrounded by a negative potential, electrons from the cathode 7 _{11-7 33} control grid
8 ₁ to 8 ₃ and the accelerating anodes 6 ₁ , 6 ₂ , ... do not flow to the cut-off state.

Therefore, the addition of positive potential of 0V or several V relative to the potential of the cathode 7 _{11-7 33} to the back electrode 10 ₁ to 10 _3, the electron beam 11 emitted from the cathodes 7 _{11-7 33} control grid It flows toward 8 ₁ to 8 ₃ .

At this time, the potential of each control grid 8 ₁ to 8 ₃ is changed to the cathode.
When the potential is negative with respect to 7 _{11 to} 7 ₃₃ , these control grids are
The electron beam 11 cannot pass through the electron passage holes 9 _{1 to} 9 _{3 of} 8 ₁ to 8 ₃ and the electron beam 11 does not flow to the accelerating anodes 6 ₁ , 6 ₂ , ... The phosphor screens 5R, 5G, and 5B do not emit light.

Then, the potentials of the control grids 8 ₁ to 8 ₃ are changed to the cathodes 7 _{11 to} 7 _33.
On the other hand, when the potential is positive, the electron beams 11 pass through the electron passage holes 9 _{1 to} 9 _{3 of} these control grids 8 ₁ to 8 ₃ respectively, and each phosphor screen 5R, 5G, and 5B emits 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 which are arranged in a matrix corresponding to the phosphor screens 5R, 5G, and 5B, respectively. By selectively controlling the drive (dynamic drive),
Only the fluorescent surfaces 5R, 5G, and 5B where the two electrodes intersect can be selectively caused to emit light.

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

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 addition, in the illustrated example, the case where the phosphor surfaces made of R, G and B tricolor phosphors are arranged in a matrix of 3 × 3 pixels on the inner surface of the front panel 2 is shown, but the invention is not limited to this. In the vacuum envelope, phosphor screens each having one phosphor as one pixel are arranged in a matrix of arbitrary m × n pixels (where m and n are arbitrary integers), and a grid electrode group is arranged accordingly. The arrangement configuration of the back electrode group can be changed.

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 Patent Application No. 62-114562).

Furthermore, for example, as disclosed in JP-A-62-241256 discloses an electronic pass portion formed on the respective control grids 8 _{1-8 3} by a dome-shaped mesh portion, the cathode 7
Together can be uniformly irradiated on the phosphor screen 5 uniformly spread the electrons emitted from _{11-7 33} can be arbitrarily adjusted divergence angle of the electron beam 11 in accordance with 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 constructed as described above, as shown in FIGS. 6 and 7, a cross section U is formed on the back plate.
When the channel-shaped control grids 8 ₁ , 8 ₂ ...... are arranged, the control grids on both sides are cut in order to lead out the lead wires 12 such as the cathodes 7 ₁₁ , 7 ₁₂ ......, the back electrode 10 _1. The recess 13 must be formed.

On the other hand, the cathode 7 _11, 7 ₁₂ electrons emitted from ... tend to move on both sides of the control grid is drawn in the control grid _81, 82 the voltage applied to .... For this reason,
There is a possibility that electrons may leak from the notched concave portion 13 and pseudo light may be emitted.

The present invention has been proposed in view of the above, and an object thereof is to reliably prevent pseudo light emission due to leaked electrons.

[Means for Solving the Problems]

In the display tube for a light source according to the present invention, a substrate on which the cathode electrode group, the grid electrode group, and the back electrode group are mounted is provided so as to be floated above the back plate of the vacuum envelope, and the control grid has a channel shape with a U-shaped cross section. The end face of the U-shaped opening is brought into contact with the upper surface of the substrate and the side facing the peripheral surface of the substrate is extended to the rear surface of the substrate so as to be in close contact with the peripheral surface, and the lead wires of each electrode group penetrate the substrate. Alternatively, it is configured to be taken out from the back surface of the substrate through a notch in the peripheral surface of the substrate.

[Action]

The light source display tube according to the present invention is provided with a substrate, on the surface of which a cathode, a back electrode and the like are attached, so as to float above the back plate.
A part of a channel-shaped control grid having a U-shaped cross section provided on the substrate so as to cover the substrate is extended to the back surface of the substrate, and the lead wires such as the cathode and the back electrode penetrate the substrate or the peripheral surface of the substrate. By taking out through the notch, leaked electrons from between the control grid and the substrate can be suppressed, and pseudo light emission is surely prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. The same parts as those in FIGS. 6 and 7 are designated by the same reference numerals in FIG. 1,
In FIG. 2, reference numeral 14 denotes a ceramic substrate which is arranged so as to be floated from the back plate 3, and a cathode electrode group 7, a grid electrode group 8 and a back electrode group 10 are attached to the surface of the ceramic substrate 14. The lead wires 12 of each electrode group are used to support the ceramic substrate 14, for example.

The sides 8a and 8b of the control grids 8 ₁ to 8 ₃ forming the grid electrode group 8 facing the peripheral surface of the ceramic substrate 14 are in close contact with the peripheral surface and extend to the back surface of the ceramic substrate.

Then, the lead wires of each of the above electrode groups are led to the back surface of the ceramic substrate through the ceramic substrate or through notches (not shown) in the peripheral surface of the substrate, and the back plate 3 and the side plate 4 joined by the low melting point glass 15 are joined together. It is led out to the outside through the department. The depth of the cut is such that the lead wire 12 and the peripheral surface of the substrate are flush with each other.

〔The invention's effect〕

As described above, according to the present invention, the cross section U is formed on the upper surface of the substrate.
A control grid in the shape of a channel is brought into contact, and the side of the control grid facing the peripheral surface of the ceramic substrate is brought into close contact with the peripheral surface to extend to the back surface of the substrate, and various electrode groups mounted on the ceramic substrate are attached. Since the lead wire is configured to penetrate through the ceramic substrate or be taken out through a notch in the peripheral surface of the substrate, the electrons emitted from the cathode are attracted to the voltage applied to the control grid and move to the side of the control grid. As a result, leaked electrons flowing between the control grid and the substrate can be suppressed, and pseudo light emission can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a light source display tube according to an embodiment of the present invention, FIG. 2 is a partial perspective view thereof, FIG. 3 is a plan view of a conventional light source display tube, and FIG. Fig. 3 is a cross-sectional view taken along the line IV-IV, Fig. 5 is an exploded perspective view of a part thereof, Fig. 6 is a cross-sectional view of another conventional display tube for a light source, and Fig. 7 is a part thereof. It is a perspective view. 1 is a vacuum envelope, 5 is a fluorescent display, 5G, 5R and 5B are fluorescent screens,
6 is an anode electrode group, 6 ₁ , 6 ₂ ... Accelerating anodes, 7 is a cathode electrode group, 7 _{11 to} 7 ₃₃ is a cathode, 8 is a grid electrode group,
8 ₁ to 8 ₃ are control grids, 8a and 8b are extended sides of the control grid facing the peripheral surface of the substrate, 9 _{1 to} 9 ₃ are electron passing portions, 10 is a back electrode group, 10 ₁ to 10 ₃ are back electrodes, 11 is an unfocused beam, 12 is a lead wire, and 14 is a substrate (ceramic substrate). 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 (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 (72) Inventor Shuji Iwata 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 61-135029 (JP, A)

Claims (1)

[Claims] 1. A vacuum envelope in which a front panel is joined to a front surface of a cylindrical side plate, a back panel is joined to a back surface of the tubular side plate in an airtight manner, and an anode arranged around a fluorescent screen formed in a matrix on an inner surface of the front panel. It has an electrode group, a cathode electrode group for electron emission arranged corresponding to the phosphor screen, a grid electrode group for controlling the flow of electrons, and a back electrode group arranged on the back side of the cathode electrode group. In the light source display tube, a substrate on which the cathode electrode group, the grid electrode group and the back electrode group are mounted is provided so as to be floated from the back plate of the vacuum envelope, and the control grid is a U-shaped opening having a U-shaped channel in cross section. The end surface is brought into contact with the upper surface of the substrate, and the side facing the peripheral surface of the substrate is extended to the back surface of the substrate so as to be in close contact with the peripheral surface. Out Light source display tube, characterized by being configured so.