JPH0654659B2 - Display tube for light source - Google Patents

Description

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

[Conventional technology]

FIG. 3 is a sectional view of a conventional display tube for a light source shown in Japanese Patent Application No. 62-256610, and FIG. 4 is an exploded perspective view thereof. In FIGS. 3 and 4, 1a is 16 pieces. A flat plate-shaped display unit having the fluorescent display unit 8; 1b, a frame forming a side surface of the fluorescent display device; 8A, an accelerating anode arranged so as to surround the fluorescent screen of the fluorescent display unit 8; Is a rear surface plate formed with the cathode 4, the second and third control electrodes 10 and 12 and the wiring electrodes 11 and 13 thereof, which is a first control electrode having an opening 15 of the light source display. The tube is assembled by providing the flat electrode 14 in the space surrounded by the frame 1b, and mounting the display portion 1a on one side of the frame 1b and the back plate 1c on the other side of the frame 1b. Here, the display unit 1a, the frame 1b, and the back plate 1c constitute a vacuum envelope.

The display portion 1a has 16 (4 rows and 4 columns) fluorescent display portions 8 formed by applying a fluorescent substance in a matrix form, and a high voltage is applied to each fluorescent display portion 8 and Emits light when colliding with. Planar electrode 1 as first control electrode
In the column 4, 16 openings (4 rows and 4 columns) 15 are formed in a matrix at positions corresponding to the respective fluorescent display sections 8.

FIG. 5 is a plan view showing an electrode structure on the back plate 1c,
In the figure, the horizontal direction is the row direction, and the vertical direction is the column direction. An exhaust port 2 is formed in the center of the back plate 1c to serve as a passage for exhausting the air inside the light source display tube. Further, four direct heating type linear cathodes 4 are formed slightly apart from the surface of the back plate 1c. When each cathode 4 is electrically heated, thermoelectrons are emitted from each cathode 4. Back plate 1c
Eight data electrodes 10, which are second control electrodes for controlling the emission of thermoelectrons from the cathode 4, are formed in 2 rows and 4 columns in a portion of the surface facing each cathode 4.
Each data electrode 10 applies a positive or negative potential with respect to the potential of the cathode 4 so that the corresponding cathode 4
Control thermionic emission from the. A third control electrode 8 for controlling the traveling direction of thermoelectrons emitted from the cathode 4 is provided on both sides of each data electrode 10 in the column direction on the surface of the back plate 1c.
The individual scanning electrodes 12 are formed in a matrix over 4 rows and 2 columns. The data electrode 10 has a smaller surface area than the scanning electrode 12. Two of the eight data electrodes 10 in the column direction are wired by four wiring electrodes 11 arranged in the column direction, and eight of the scanning electrodes 12 are two in the row direction. Wiring is performed by four wiring electrodes 13 which are orthogonal to the wiring electrodes 11, that is, arranged in the row direction. The wiring electrode 11 and the wiring electrode 13 are wired via an insulating layer so as not to contact each other. The data electrodes 10, the scanning electrodes 12, the wiring electrodes 11, and the wiring electrodes 13 are formed by printing on the surface of the substrate 1c.

Next, the operation will be described. In FIG. 5, S1 and S
2, S3 and S4 are each four scanning electrodes 12 in the row direction.
The scanning signals D1, D2, D3, and D4 applied to each of the data signals are data signals applied to two data electrodes 10 in the column direction. FIG. 6 shows these signals S1 to S4.
It shows the application timing of D1 to D4. Further, FIG. 7 shows an array of the fluorescent display portions 8 formed in a matrix on the display portion 1a, and the emission of each fluorescent display portion 8 is controlled by controlling the signals S1 to S4 and D1 to D4. It

Next, the operation of this light emission control will be described.

ON (positive) and OFF (negative) of each data electrode 10 and ON (positive) and OFF (negative) of each scan electrode 12 are controlled by the application timing of the data signal and the scan signal. There are four types of ON / OFF of the scan electrode 12 and ON / OFF of the data electrode 10 (when both the scan electrode 12 and the data electrode 10 are ON, the scan electrode 12 is ON and the data electrode 10 is ON).
Is OFF, the scan electrode 12 is OFF, the data electrode 10 is ON, and the scan electrode 12 and the data electrode 10 are both OFF). The light emitting state of the fluorescent display portion in each case will be described. 8 and 9 are schematic diagrams showing potential states in the case of these four types.

When both the scan electrode 12 and the data electrode 10 are on, the electric field in the vicinity of the heated cathode 4 becomes positive due to the electric fields of the data electrode 10 and the scan electrode 12, and thermoelectrons are emitted. The emitted thermoelectrons are deflected by the electric field of the scanning electrode 12 and accelerated by the flat electrode 14 to proceed toward the corresponding fluorescent display portion 8 and collide with the fluorescent display portion 8. Then, the thermoelectrons come into contact with the fluorescent substance, and the fluorescent display section emits light (FIG. 8).

When the scanning electrode 12 is on and the data electrode 10 is off, the data electrode 10 is formed in the vicinity of the cathode 4, so that the cathode 4 is most strongly affected by the electric field of the data electrode 10. Therefore, in this case, the electric field in the vicinity of the cathode 4 becomes negative and the thermoelectron emission from the cathode 4 is suppressed, and the fluorescent display portion 8 does not emit light (FIG. 9).

When the scan electrode 12 is off and the data electrode 10 is on, the data electrode 10 is positive, but the scan electrodes 12 formed on both sides of the data electrode 10 are negative, and the surface area of the data electrode 10 is larger than that of the scan electrode 12. Since it is small, the electric field in the vicinity of the cathode 4 becomes negative, and thermionic emission from the cathode 4 is suppressed, and the fluorescent display portion 8 does not emit light (FIG. 8).

When both the scanning electrode 12 and the data electrode 10 are off, the electric field in the vicinity of the cathode 4 becomes negative and the thermoelectron emission from the cathode 4 is suppressed, and the fluorescent display portion 8 does not emit light (9th).
Figure).

As described above, the light emission of each fluorescent display portion 8 is arbitrarily controlled by the combination of the potentials of the data electrode 10 and the scanning electrode 12. Here, since the potentials of the data electrode 10 and the scanning electrode 12 are controlled by the data signals D1 to D4 and the scanning signals S1 to S4, the presence or absence of light emission of each fluorescent display portion 8 is arbitrarily controlled by controlling these signals. Can be controlled.

[Problems to be Solved by the Invention]

Since the conventional light source display tube is constructed as described above, the high-voltage electric field of the anode 8A penetrates into the vicinity of the cathode 4 through the gap between the frame body 1b and the plane electrode 14, and is emitted from the cathode 4. There is a possibility that the electrons may reach the fluorescent display portion 8 around the display portion 1a through the gap and cause these to carelessly emit light.

The present invention has been made in view of the above, and an object thereof is to obtain a light source display tube capable of suppressing leakage of electrons emitted from the cathode to the display unit 1a side.

[Means for Solving the Problems]

In the display tube for a light source according to the present invention, the cathode, the first control electrode, the second control electrode and the third control electrode are provided on an insulating substrate which is floated from the back plate, and the first control electrode is It has a U-shaped cross section, and its edge is located near the back plate.

[Action]

The insulating substrate according to the present invention has the cathode and the second and third control electrodes on the insulating substrate, and the peripheral portion of the first control electrode passes through the side surface of the insulating substrate to reach the vicinity of the back plate. The path of the high-voltage potential soaked from the anode becomes a long path that is bent as a whole, and the high-voltage potential can be sufficiently attenuated by this long path, thereby suppressing the penetration into the vicinity of the cathode. As a result, thermoelectrons do not leak from the cathode through this path to the vicinity of the anode, and pseudo light emission is reliably prevented.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. First
The figure is a cross-sectional view showing the outline of the present invention. In FIG. 1, reference numeral 21 denotes an insulating substrate provided inside the vacuum envelope so as to float above the back plate 1c. Become. Then, on the insulating substrate 21, the cathode 4, the data electrode 10, and the scanning electrode 12 are provided in the same arrangement as in the past. 14A is a first control electrode, which forms a quadrangle as a whole, and its peripheral portion is bent to form a bent piece 14b having a U-shaped cross section. The first control electrode 14A also has the opening 13.
In addition, the edge 14b of the first control electrode is located near the rear plate 1c through the periphery of the insulating substrate 21 which has been lifted up. Although not shown in the drawing, the cathode 4 on the insulating substrate 21 and the leads of the electrodes 10, 12, and 14A are provided in the notch provided in the end edge 14b of the first control electrode 14A and in the back plate 1c. It can be taken out to the back side of the back plate 1c through a cut groove or the like. Further, the first control electrode 14A is applied with zero potential or a negative potential.

Next, the operation will be described.

Now, a voltage is applied to the cathode 4 to emit thermoelectrons therefrom, and a voltage of, for example, 8 KV is applied to the anode 8A. As a result, the high-voltage potential centering on the anode 8A and the fluorescent display 8 and the first control electrode 14A in the vacuum envelope are provided.
Distributed between and. Then, part of this high-voltage potential passes through a path passing through a minute gap between the edge 14b of the first control electrode 14A and the back plate 1c and a minute gap between the first control electrode 14a and the peripheral edge of the insulating substrate 21. After that, it tries to penetrate into the vicinity of the cathode 4. However, because this path is a long path that passes through these minute gaps and is bent,
In the middle of this, the high-voltage potential is sufficiently attenuated and almost never reaches the vicinity of the cathode 4. As a result, the electrons from the cathode 4 do not leak into the anode 8A and the fluorescent display portion 8 along this path, and there is no fear of causing the fluorescent display portion 8 to emit light carelessly. In the above embodiment, 4
The case where one cathode is associated with a pixel has been described,
As shown in FIG. 2, one pixel may be associated with two pixels, and the same effect as that of the above-described embodiment is obtained.

〔The invention's effect〕

As described above, according to the present invention, the cathode, the first control electrode, the second control electrode, and the third control electrode are provided on the insulating substrate floated from the back plate, and the first control electrode is provided. Since the cross-section is U-shaped and the peripheral edge is located near the back plate, the path from the anode to the cathode can be substantially a curved path with a minute gap. Therefore, it is possible to prevent the thermoelectrons from the cathode from leaking through this path and reaching the fluorescent display portion, and thus it is possible to reliably prevent the pseudo light emission of the fluorescent display portion other than the designated one.

[Brief description of drawings]

FIG. 1 is a sectional view showing a light source display tube according to an embodiment of the present invention, FIG. 2 is an exploded perspective view showing another embodiment of the light source display tube of the present invention, and FIG. 3 is a conventional light source display tube. FIG. 4 is a cross-sectional view showing a display tube, FIG. 4 is an exploded perspective view thereof, FIG. 5 is a plan view showing an electrode structure, FIG. 6 is a schematic view showing signal timing,
FIG. 7 is a schematic plan view of the display unit, and FIGS. 8 and 9 are schematic diagrams showing the state of potential near the cathode. 1a is a display unit, 1c is a back plate, 4 is a cathode, 8 is a fluorescent display unit, 10 is a second control electrode (data electrode), 12 is a third control electrode (scan electrode), and 14A is a first control. Electrodes, 15 are openings, and 21 is an insulating substrate. In the drawings, the same reference numerals indicate the same or corresponding parts.

Front page continuation (72) Inventor Shuji Iwata 8-1-1 Tsukaguchihonmachi, Amagasaki, Hyogo Sanryu Electric Co., Ltd. Applied Equipment Research Laboratory (72) Innovator Nobuo Terasaki 6-14 Maruo-cho, Nagasaki-shi, Nagasaki Mitsubishi (72) Inventor Yuji Kamogawa 700 Wada, Ueno-cho, Ise-shi, Mie 700 Wada, Ise Electronics Industry Co., Ltd. (72) Kazunori Tatsuda Wada 700, Ueno-cho, Ise-shi, Mie Ise Electronics Industry Within the corporation

Claims (1)

[Claims] 1. A display unit comprising 2 m rows and 2 n examples (m and n are natural numbers) arranged in a matrix, and 4 or 2 fluorescent display units at positions facing the display units. One linear cathode provided so as to correspond to each other,
A flat plate-shaped first control electrode provided between the display unit and the cathode and having 2m × 2n openings corresponding to each fluorescent display unit of the display unit, and a side of the cathode opposite to the display unit. Second control electrodes for controlling ON / OFF of thermoelectrons emitted from the cathodes at the positions corresponding to the respective cathodes, and the two second control electrodes provided corresponding to the respective cathodes. A third control electrode, which is provided on both sides of the electrode in the column direction and controls the traveling direction of electrons, and a display unit, a cathode, a first control electrode, a second control electrode, and a third control electrode, In a display tube for a light source provided with a vacuum envelope provided, an insulating substrate in which the cathode, the first control electrode, the second control electrode and the third control electrode are floated from a back plate of the vacuum envelope. Provided on the above, the first
2. The display tube for a light source, wherein the control electrode has a U-shaped cross section, and its edge is positioned near the back plate.