JPH01253150A - Display tube for light source - Google Patents

Abstract

PURPOSE:To surely prevent the pseudo luminescence of other portions than the specified fluorescent character display section by providing cathodes, the first control electrode, the second control electrodes, and the third control electrodes on an insulated substrate afloat from a back plate, forming the first control electrodes into a U-shaped cross section, and locating its end edge near the back plate. CONSTITUTION:Cathodes 4, the first control electrode 14A, the second second control electrodes 10, and the third control electrodes 12 are provided on an insulated substrate 21 afloat from a beck plate. The first control electrode 14A is formed into a U-shaped cross section, the end edge of the periphery is located near the beck plate. The infiltrating path of the high-voltage potential from an anode is a bent and long path as a whole, the high-voltage potential can be sufficiently attenuated, and the infiltration into the vicinity of the cathodes 4 is suppressed. As a result, thermoelectrons from the cathodes are not leaked near the anode through this path, the pseudo luminescence can be surely prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a large-screen display device, and particularly to a light source display tube constituting pixels of a color display device.

[Conventional technology]

Fig. 2 is a cross-sectional view of a conventional light source display tube shown in, for example, Japanese Patent Application No. 62-256610, and Fig. 3 is an exploded perspective view thereof. 1b is a frame forming a side surface of the fluorescent display device.

8A is an accelerating anode arranged to surround the fluorescent screen of the fluorescent display section 8; 14 is a plane electrode which is a first control electrode having 16 openings 15; and IC is a cathode 4. 2nd, 3rd
The control electrode 10.12 and its wiring electrode 11.13 are formed on the back plate, and the light source display tube is provided with a plane electrode 14 in a space surrounded by a frame 1b, and one display part 1a is arranged in a frame. It is assembled by attaching the back plate IC to one side of the frame 1b and the other side of the frame 1b. Here, the display section 1a, the frame body 1
b, the back plate 1c constitutes a vacuum envelope.

The display section 1a has 16 fluorescent display sections 8 (4 rows and 4 columns) formed by coating a fluorescent material in a matrix, and a high voltage is applied to each fluorescent display section 8, and thermionic Lights up when you collide with it. Planar electrode 1 as first control electrode
4, 16 openings 15 (4 rows and 4 columns) are formed in a matrix at positions corresponding to each fluorescent display section 8.

FIG. 4 is a plan view showing the @pole structure on the back plate 1c,
In the figure, the left-right direction is the row direction, and the up-down direction is the column direction. An exhaust port 2, which serves as a passage for exhausting the air inside the light source display tube, is formed in the medium heat of the back plate 1c. Furthermore, four directly heated linear cathodes 4 are formed slightly apart from the surface of the back plate 1c. When each cathode 4 is heated with electricity, 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 two rows and four columns on a portion of the surface facing each cathode 4.

Each data electrode 10 is connected to each corresponding cathode 4 by applying a positive or negative potential with respect to the potential of the cathode 4.
control thermionic emission from On both sides of each data electrode 10 in the column direction on the surface of the back plate 10, there are third control electrodes 8 for controlling the traveling direction of thermoelectrons emitted from the cathode 4.
The scanning electrodes 12 are formed in a matrix over four rows and two columns. Note that the data electrode 10 has a smaller surface area than the scanning electrode 12, and has eight data electrodes t.
@10 has 4 pieces arranged in the column direction, 2 pieces each in the column direction! Wired with an electrode 11, and eight scanning electrodes 1
2 is wired by four wires 2n7413 arranged perpendicularly to the wiring electrode 11, that is, in the row direction, two wires each in the row direction. The wiring electrode 11 and the wiring electrode 13 are wired via an insulating layer so that they do not melt together. These data electrodes 10, scanning electrodes 12, wiring salts t411 and wiring electrodes 13 are printed and formed on the surface of the substrate 1c.

Next, the operation will be explained. In Figure 4, SL, S2
．． S3. S4 each has four scanning electrodes 12 in the row direction.
Scanning signal applied to, Di, D2゜1)3. D4 indicates a data signal applied to two data r11 poles 10 in the column direction. FIG. 5 shows these signals S1~
S4. It shows the application timing of Di to D4. Further, FIG. 6 shows an arrangement of fluorescent display sections 8 formed in a matrix on the display section 1a, and each fluorescent display section 8 is arranged in accordance with No. 4,1 S1 to 84. Light emission is controlled by controlling Di to D4.

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

The on (positive) and off (negative) states of each data electrode 10 and the on (positive) and off (negative) states of each scan electrode 12 are controlled by the application timing of the data signal and the scan signal. There are four types of cases when the scanning electrode 12 is on and off and the data electrode 10 is on and off (when both the scanning electrode 12 and the data electrode 10 are on, when the scanning electrode 12 is on, when the data electrode t@1
0 is off, the scan electrode 12 is off, and the data electrode 10 is off.
is on, scanning electrodes 12. (when all data electrodes 10 are off) exists. The light emitting state of the fluorescent display section in each case will be explained. Figure 7.8 is a schematic diagram showing the potential states in these four cases.■ When both the scanning electrode 12 and the data electrode 10 are on, the electric field near the heated cathode 4 is the electric field of the data electrode 10 and the scanning electrode 12. becomes positive, and thermionic electrons are emitted. The emitted thermoelectrons are deflected by the electric field of the scanning type t@12 and
4, and advances towards the corresponding fluorescent display section 8.
It collides with the fluorescent display section 8. Then, the thermoelectrons come into contact with the fluorescent material, and the fluorescent display section 8 emits light (Fig. 7 (■)).

(2) When the scanning electrode 12 is on and the data electrode 10 is off Since the data electrode 10 is formed near the cathode 4, the cathode 4 is most strongly influenced by the electric field of this data electrode IO. Therefore, in this case, the electric field in the vicinity of the cathode 4 becomes negative, thermionic emission from the cathode 4 is suppressed, and the fluorescent display section 8 does not emit light (FIG. 8).

■ Scanning electrode 12 is off, data? When 1tVilO is on, the data electrode 10 is positive, but the scanning electrodes 12 formed on both sides thereof are negative, and the data voltage tf
Since i10 has a smaller surface area than scanning electrode 12, the electric field near cathode 4 becomes negative, thermionic emission from cathode 4 is suppressed, and fluorescent display section 8 does not emit light (FIG. 7 -).

■ When both the scanning electrode 12 and the data electrode 10 are off, the electric field near the cathode 4 becomes negative, thermionic emission from the cathode 4 is suppressed, and the fluorescent display section 8 does not emit light (eighth
Figure ■).

In this way, the light emission of each fluorescent display section 8 is arbitrarily controlled by the combination of the potentials of the data electrode 10 and the scanning electrode 12. Here, the potentials of the data electrodes 10 and the scanning electrodes 12 are controlled by the data signals D1 to D4 and the scanning signals 81 to S4, so by controlling these signals, it is possible to arbitrarily control whether or not each fluorescent display section 8 emits light. can be controlled.

[Problem 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 the frame 1b and the plane 1 through the gap between the pole 14 and the vicinity of the cathode 4, and is thereby emitted from the cathode 4. There is a fear that the emitted electrons may pass through the gap and reach the fluorescent display section 8 around the display section 18, causing them to emit light inadvertently.

This invention has been made in view of the above.

It is an object of the present invention to obtain a display tube for a light source that can instantly suppress leakage of electrons emitted from a cathode to a display section la side.

[Means to solve the problem]

The light source display tube according to the present invention includes a cathode, a first control tube, and a first control tube.
An electrode, a second control electrode, and a third control electrode are provided on an insulating substrate floating above the back plate, and among these, the first control electrode has a U-shaped cross section, and its edge is located near the back plate. The structure is such that the

[Effect]

The insulating substrate in this invention has a cathode on it and a second . It has a third control electrode, and the peripheral part of the first control electrode passes through the side surface of this insulating substrate and extends to the vicinity of the back plate, so that the high voltage potential from the anode penetrates into a long path that is curved as a whole. This long path can sufficiently attenuate the high voltage potential, thereby suppressing its seepage into the vicinity of the cathode.

As a result, thermoelectrons from the cathode do not leak through this path to the vicinity of the anode, thereby reliably preventing false light emission.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a cross-sectional view showing the outline of the present invention. In Figure 1, 2n is an insulating substrate provided inside the vacuum envelope so as to float above the back plate IC. Become. Then, on this insulating substrate 2n, a cathode 4, a data electrode 10. Scan electrodes 12 are provided respectively. 14A is a first control electrode, which has a rectangular shape as a whole, and its peripheral portion is bent to form a bent piece 14b having a U-shaped cross section. Note that this first control electrode 14A also has an opening 13.

Further, the edge 14b of the first control electrode is positioned near the rear panel IC, passing around the raised insulating substrate 2n. Although not shown in Figure 1, the leads of the cathode 4 and each electrode 10, 12, 14A on the insulating substrate 2n are provided in the notch provided in the edge 14b of the first control type 1414A and in the back plate IC. It can be taken out to the back side of the back plate IC through a cut groove or the like. Furthermore, zero potential or negative potential is applied to the first control electrode 14A.6 Next, the operation will be described.

Now, a voltage is applied to the cathode 4 to cause it to emit thermoelectrons, and a voltage of, for example, 8 KV is applied to the anode 8A. As a result, a high voltage potential is distributed around the anode 8A between the fluorescent display section 8 and the first jtJJ control electrode 14A within the vacuum envelope.

A part of this high voltage potential is transferred to the first control electrode 14Δ
The minute gap between the edge 14b and the back plate IC and this first
It attempts to penetrate into the vicinity of the cathode 4 through a path passing through a minute gap between the control electrode L4a and the peripheral edge of the insulating substrate 2n.

However, since this path passes through these minute gaps and is a long, winding path, the high voltage potential is sufficiently attenuated along the way and hardly reaches the vicinity of the cathode 4.

As a result, electrons from the cathode 4 will not leak into the anode 8A and the fluorescent display section 8 by following this path, and there will be no fear that the fluorescent display section 8 will emit light inadvertently6. [Effects of the Invention] 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 floating above the back plate, and the first control electrode is arranged in a cross section. Since it is made into a U-shape and the edge of the peripheral part is located near the back plate, the path from the anode to the cathode can be essentially a long bent path with a small gap. Therefore, it is possible to prevent thermoelectrons from the cathode from leaking through this path and reaching the fluorescent display section, which has the effect of reliably preventing false light emission from fluorescent display sections other than those specified.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a light source display tube according to an embodiment of the present invention, Fig. 2 is a sectional view showing a conventional light source display tube, Fig. 3 is an exploded perspective view thereof, and Fig. 4 is an electrode structure. FIG. 5 is a schematic diagram showing signal timing, FIG. 6 is a schematic plan diagram of the display section, and FIGS. 7 and 8 are schematic diagrams showing the potential state near the cathode. 1a is a display section, IC is a back plate, 4 is a cathode, 8 is a fluorescent display section, 10 is a second control electrode (data electrode), 12 is a third control electrode (scanning electrode), 14A is a first control electrode An electrode, 15 an opening, and 2n an insulating substrate. In addition, in FIG. 1, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Figure 2

Claims (1)

[Claims] A display section is formed by arranging fluorescent display sections in a matrix of 2 m rows and 2 n examples (m and n are natural numbers), and one display section for every four fluorescent display sections is arranged in a position facing the display section.
A flat plate having cathodes arranged in rows and n columns and having a linear shape in the row direction, and 2m x 2n openings provided between the display section and the cathode and corresponding to each fluorescent display section of the display section. a first control electrode, and second control electrodes arranged in m rows and 2n columns, two of which are provided in the length direction of the cathode, corresponding to each cathode, at a position on the opposite side of the display section of the cathode. , third control electrodes of 2 m rows and n columns provided corresponding to each of the cathodes and provided on both sides of the two second control electrodes in the column direction; A light source display tube comprising a vacuum envelope provided with a first control electrode, a second control electrode, and a third control electrode, the cathode, the first control electrode, the second control electrode, and the third control electrode. A control electrode is provided on an insulating substrate floating above the back plate of the vacuum envelope, and the first control electrode has a U-shaped cross section, and its edge is located near the back plate. Characteristic display tube for light source.