JPH01253147A - Display tube for light source - Google Patents

Abstract

PURPOSE:To surely prevent the leakage to the other adjacent fluorescent face by inclining a control grid located on the periphery so that electrons passing it are correctly deflected toward the corresponding fluorescent face on the periphery. CONSTITUTION:Control grids 20a and 20b are provided to surround cathodes 6a and 6b respectively, the control grid 20a on the periphery is inclined upward so that electrons passing it are deflected toward the corresponding fluorescent face on the periphery. Thermoelectrons emitted from the cathode on the periphery are deflected according to the direction of its opening and collide with only the corresponding fluorescent face on the periphery, and the leakage to the adjacent other fluorescent face 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 schematic configuration diagram showing a conventional light source display tube shown in, for example, Japanese Utility Model Application No. 62-114562. (not shown) is a glass tube as a vacuum envelope, and on the inner surface of the front panel 2 inside the glass tube 1, one phosphor is applied as a unit pixel in a matrix. 1×2 dot fluorescent screen4. ，
A fluorescent display section 4 consisting of 42 is formed. 5 is each fluorescent screen 4 of the fluorescent display section 4. , 42, an anode group consisting of frame-shaped accelerating anodes 51, 5□ arranged in correspondence with the peripheries of 42, and 6 an electron-emitting cathode corresponding to each fluorescent screen 41°48 of the fluorescent display section 4. 63, 6□ are cathode electrode groups arranged independently, and these cathodes 6, .
6. Both ends of each are supported between a pair of supports (not shown) fixed on the back plate 3.

Further, reference numeral 7 denotes a control grid 7□ for row selection, which has a plate shape and is disposed between the cathode electrode group 6 and the fluorescent display section 4.
, 72, and these control grids 7, . 72 includes each fluorescent screen 41.4 of the fluorescent display section 4.
Corresponding to □, cathodes 63 and 6□ are arranged in the row direction, respectively.
For example, a mesh-shaped electron passage section 8 is provided to pass the electron beam 11 as an unfocused beam.

Moreover, these control grids 7□, 7□ are connected to each cathode 61,
6 □, and these are back electrodes 9 for column selection. ．． 92 and are arranged facing each other. 10 is an L-shaped shield plate with an adjacent control grid? ,,? 12 electrons leaking from between
to shield.

Reference numeral 9 denotes a fluorescent screen 4 of each of the fluorescent display sections 4 on the back side of the cathode electrode group 6, that is, on the back plate 3 forming a part of the glass tube body 1.
This is a back electrode group consisting of back electrodes 91, 9□ for column selection, which are arranged facing each other in the column direction corresponding to □, 4□, and these back electrodes 91, 9□ are formed from a conductive layer such as Ag. be done. Each of the back electrodes 9□, 92 is connected to the cathodes 61, 6 by applying a negative potential and a positive potential of Ov or several V to the potential of each of the cathodes 60, 62.
The electron beam 11 emitted from the electron beam 2 is controlled.

Next, the operation of the above configuration will be explained. First, when each back electrode 91, 92 has a negative potential with respect to the potential of the cathodes 6□, 6□, these cathodes 61.6□ are surrounded by a negative potential, so that each cathode 6, . Electrons from 6g go to control grid 7□.

7 □ and the anode 51.5 □ and are in a cut-off state, the cathode 6 □
, 6□, when a positive potential of Ov or several ■ is applied, electron beams 11 emitted from these cathodes 61, 6□ flow toward control grids 71, 7□. At this time, each control grid 7,.

7□ is a negative potential with respect to the cathodes 68, 6□, these grids 7, 7. The electron beam 11 cannot pass through the electron passing section 8, and the fluorescent screens 4□, 4□ of the fluorescent display section 4 do not emit light. And each control grid 7□
, 7□ potential is cathode 6□.

These grids 7, when at a positive potential with respect to 6,.

The electron beams 11 pass through the electron passing portions 8 of 7 and 7, respectively, and cause each of the phosphor screens 41 and 4□ to emit light in sequence.

Therefore, each fluorescent screen 41, 4. each control grid 7 of the grid electrode group 7 arranged in a matrix in correspondence with;
．． 7. and each back electrode 9 of the back electrode group 9.

By selectively driving and controlling the electrodes 92, only the fluorescent screens 48 and 42 where these electrodes intersect can be made to sequentially emit light.

In addition, a plurality of light source display tubes having such a configuration are 4 (1
, are installed to constitute a large screen display device.

Therefore, it is necessary to maintain the spacing between the phosphor screens on the adjacent side of the adjacent glass tubes LA and IB equal to the spacing between the other phosphor screens, and the cathode electrode group 6, the grid electrode group 7, the back surface As shown in FIG. 3, it is necessary to easily take out the lead wires of the electrode group 9 and the lead electrodes 13 to the outside, that is, to the rear of the back plate 3.
The area where the back electrode group 9 is installed has a narrower cross-sectional area than the area where the phosphor screen is installed.

[Problem to be solved by the invention]

Since the conventional light source display tube is configured as described above, the glass tube body IA is included in the back electrode group 9.

The back electrode 9a and the control grid 7a on the side adjacent to or near the IB are connected to the corresponding fluorescent screen 4a.
It is necessary to provide the cathode 6a at a position facing the adjacent phosphor screen 4b, that is, at a position shifted toward the center of the back plate 3, rather than at the back of the screen. In addition to being guided in the direction, there is also a possibility that the light may leak into the adjacent fluorescent screen 4b, causing the fluorescent screen 4b to emit false light.

This invention was made in view of the above, and by correctly deflecting the electrons from the cathode toward the fluorescent material facing the cathode, it suppresses the decomposition and leakage of electrons in a direction other than the designated direction. To obtain a display tube for a light source that can reliably prevent inadvertent light emission from other light emitting surfaces.

[Means to solve the problem]

In the light source display tube according to the present invention, at least the control grid in the periphery has an inclination such that electrons passing through it are correctly deflected toward the phosphor screen in the periphery. It is structured as follows.

[Effect]

In this invention, the control grid in the peripheral area has an inclination so that the mesh or opening, which is the electron passage part, faces the corresponding fluorescent screen in the peripheral area.

Thermionic electrons emitted from the cathode are deflected according to the direction of the IjN port and collide only with the corresponding peripheral phosphor screen, reliably preventing leakage to other adjacent phosphor screens.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 20+i, 20b are control grids, and these control grids 20a, 20b are connected to one cathode 6a, 6, respectively.
The control grids 20a at the periphery of the control grids 20a have an inclined upper surface so that electrons passing through the control grids 20a are also deflected toward the phosphor screen 4a at the periphery.

In other words, the control grid 20a has an inclination such that the mesh or opening provided in the control grid 20a as an electron passage section faces the fluorescent screen in the peripheral portion.

Next, the operation will be explained.

Now, when the cathode electrode on the outer circumferential side generates electrons for fluorescent display, these electrons are inside the control grid 20a and do not leak outside, and moreover, a potential gradient is generated around the control grid 20a according to the inclination of the electrons. become. For this reason,
The electron passing section 8, which opens at this inclination, emits the electrons in a direction perpendicular to the inclination, and projects the electrons onto the corresponding peripheral phosphor screen 4a. For this reason, these electrons are no longer projected onto the adjacent phosphor screen 4b as in the conventional case, and therefore the light emission of each phosphor screen can be controlled to a high sugar level Jσ. Further, the other control grid 20b has the same function and operation as the conventional control grid 7b.

In addition, although the above-mentioned embodiment explained the case where the above-mentioned inclination is given only to the control grid 20a at the outermost periphery, it is also possible to give a gradually changing inclination to other control grids located inside this control grid 20a. In many cases, the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, at least the control grid in the peripheral area is configured to have an inclination, so that the electrons emitted from the cathode through the control grid in the peripheral area are
It can be accurately deflected and projected toward the target surrounding fluorescent screen.

Therefore, it is possible to prevent the electrons from leaking to other phosphor screens, and it is possible to display a good image on the entire large screen display.

[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 an enlarged sectional view of a part of a conventional light source display tube, and Fig. 3 is a conventional light source display tube. FIG. 3 is a cross-sectional view showing the flow of electrons in the display tube. IA and IB are vacuum envelopes (glass tubes), 3 is a substrate (rear plate), 4a and 4b are fluorescent display sections, and 6a. 6b is a cathode, 9 is a back electrode group, and 20a, 20b are control grids. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 3

Claims (1)

[Claims] A cathode electrode group consisting of a phosphor screen arranged in a matrix with one phosphor as a unit pixel, cathodes for electron emission arranged corresponding to these phosphor screens, and electron emission from each cathode of this cathode electrode group. a grid electrode group consisting of a channel-shaped control grid arranged in the row (or column) direction corresponding to the phosphor screen, and a substrate on the back side of the cathode electrode group, so as to control the electrons that are contains a back electrode group arranged in the column (or row) direction corresponding to each of the phosphor screens, the phosphor screen, a cathode electrode group, a grid electrode group and a back electrode group, and the back electrode In a light source display tube comprising a vacuum envelope whose installation site has a narrower cross-sectional area than the phosphor screen installation site, a control grid located at least in a peripheral area of the vacuum envelope among the grid electrode group is arranged in this display tube. 1. A display tube for a light source, characterized in that the display tube has an inclination that deflects electrons passing through the phosphor screen toward the phosphor screen in the periphery.