JPH05343000A - Electron gun and cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide an electron gun which does not need a heater electric power source and provides electron beam with sufficient electron density and low aberration. CONSTITUTION:A cathode conductor 15, an insulating layer 16 and a gate 17 are on a susbstrate 14. An emitter 19 is formed on the cathode conductor 15 in a hole 18 formed in the insulating layer 16 and the gate 17. A first and a second electron beam converging electrodes 25, 28 are set above such FEC 20. The electron gun 12 is installed in a neck part of a glass container of a CRT. The electron beam which comes out there is deflected by a deflection electrode in a funnel part and collides against a panel part.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a CRT (Cathode Ray).
Tube (cathode ray tube), electron beam exposure apparatus, and various other electron guns that use a focused electron beam, especially field emission cathodes (FEC) as electron sources.
It relates to an electron gun using.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional general CRT. The CRT 1 is provided with a neck portion provided with an electron gun 2, a funnel portion provided with a deflection electrode 3 for deflecting an electron beam emitted from the neck portion, and a phosphor that is excited and emitted by the electron beam. And a panel portion 4 having

FIG. 7 shows an electron gun 2 used in a conventional general CRT. The electron gun 2 includes an indirectly heated cathode 5 that heats an oxide layer with a heater, an extraction electrode 6, and a focusing electrode 7.

According to the CRT constructed as described above,
The focused electron beam emitted from the electron gun 2 in the neck portion is guided to a predetermined position in the panel portion 4 by the deflection electrode 3 in the funnel portion, whereby the fluorescent screen is excited and emits light and a desired display is performed.

[0005]

The above-mentioned conventional electron gun and the CRT using the same have the following problems. (1) Since the cathode of the conventional electron gun is an indirectly heated type, it took some time from turning on the heater power supply until an electron beam was obtained.

(2) Since the life of the heater of the electron gun is short,
I couldn't make a long-life CRT. (3) An electron source that emits an electron beam with a high current density could not be obtained.

(4) The diameter of the electron generating portion of the electron gun is several mm
Since the size is so large, when the beam is converged minutely to a certain extent or less by the electron lens system, the beam shape is distorted due to the aberration and the electron density is likely to be nonuniform within the beam diameter.

The present invention is an electron gun which does not require a heater power supply and which can obtain an electron beam with sufficient electron density and small aberration.
The purpose is to provide a CRT using such an electron gun.

[0009]

An electron gun according to the present invention is provided with a field emission type cathode array group in which a plurality of field emission type cathode arrays each having an emitter and a gate are arranged, and adjacent to the field emission type cathode array group. It has a focusing electrode for the electron beam, which is provided in the same manner.

The cathode ray tube of the present invention comprises a neck portion provided with the electron gun of the present invention, a funnel portion provided with a deflection electrode for deflecting an electron beam emitted from the neck portion, and the electron beam by the electron beam. It has a panel portion coated with a phosphor that emits light.

[0011]

In the electron gun of the CRT, the electron beam emitted from the field emission type cathode of the field emission type cathode array group is
The light is focused on the focusing electrode and emitted. This electron beam
It is deflected by the deflection electrode of the funnel portion and strikes the panel portion to cause the phosphor to emit light.

[0012]

EXAMPLE A first example will be described with reference to FIGS.
This embodiment is a CRT equipped with a sealed glass container 11.
It relates to 10. That is, the electron gun 12 is provided on the elongated tubular neck portion 11a of the glass container 11, and the electron beam emitted from the neck portion 11a is deflected by the deflection electrode 3 of the funnel portion. The electron beam is emitted from the panel portion 4 provided on the inner surface of the front surface of the glass container 11.
Then, the phosphor is irradiated with this phosphor to excite and emit light, thereby displaying a desired image.

Next, the structure of the electron gun 12 will be described in detail. A substrate 14 made of an insulating material such as Si or glass is provided on the ceramic substrate 13. On the substrate 14, a Spindt-type field emission cathode 20 is provided.
A large number of (FEC20) are formed within a range of about 0.5 to 0.6 mm in diameter. That is, the cathode conductor 15 is formed of a conductive thin film on the substrate 14, and the insulating layer 16 and the gate 17 are laminated thereon. This insulating layer 1
A hole 18 is formed in the gate 6 and the gate 17 by photolithography, and the cathode conductor 15 in the hole 18 is formed.
A cone-shaped emitter 19 is formed on the top by vapor deposition. Although the emitter is a Spindt type in this embodiment, a vertical field emission emitter by etching may be used in addition to the Spindt type vapor deposition emitter, or a planar field emission emitter may be used if it has excellent directivity.

The cathode conductor 15 of the FEC 20 is connected to a cathode stem 21 provided on the ceramic substrate 13, and the cathode stem 21 is a glass container 11.
Is led out of the neck portion 11a.

A plate-shaped conductor 22 having a hole formed in the center is connected to the gate 17 of the FEC 20. Both ends of the conductor 22 penetrate the ceramic substrate 13 and
It is connected to one end of each of the two gate stems 23 protruding toward the C20 side. The other end of at least one of the gate stems 23 projects outward through the neck portion 11a of the glass container 11.

An insulating layer 24 is formed on the conductor 22 on the ceramic substrate 13, and the insulating layer 24 is formed.
A first electron beam focusing electrode 25 is provided on the above. The first electron beam focusing electrode 25 is a metal plate in which a hole 25a having a diameter of 0.5 to 0.6 mm is formed facing the FEC 20 formed on the substrate 14, and the first electron beam focusing electrode 25 and the gate 17 of the FEC 20 near the hole 25a. Distance is 0.08 ~
It is set to 0.1 mm. Both ends of the first electron beam focusing electrode 25 are supported by rod-shaped lead terminals 26, and at least one of them is led out of the glass container 11.

A second electron beam focusing electrode 28 is provided above the first electron beam focusing electrode 25 via a ceramic insulating material 27 having a thickness of 0.1 to 0.2 mm. The configuration of the second electron beam focusing electrode 28 is the same as that of the first electron beam focusing electrode 25, and at least one of the lead terminals 29 is led out of the glass container 11.

FIG. 3 is a circuit diagram for applying a voltage to each electrode in the electron gun 12. In this example, emitter 1
9 is grounded, 30 to 150 V is applied to the gate 17, 0 to 150 V is applied to the first electron beam focusing electrode 25, and 200 to 500 V is applied to the second electron beam focusing electrode 28.

FIG. 4 shows another example of a circuit diagram of the electron gun 12. Here, the gate 17 is grounded, but the potential difference applied between the electrodes is the same as in the case of FIG. In addition,
Although the electron gun 12 of this embodiment has the FEC 20 and the first and second electron beam focusing electrodes 25 and 28, third and fourth focusing electrodes may be further provided if necessary. ..

FIG. 5 shows F in the electron gun 30 of the second embodiment.
The structure of EC is shown. Although the basic electrode structure as the FEC is the same as that of the first embodiment, in this embodiment, the cathode conductor 32 or the gate 33 formed on the substrate 31 is the same as in FIG.
It is composed of a pattern as shown in. That is, in the FEC of this embodiment, a circle having a diameter of 0.5 to 0.6 mm is equal to 3
R (red) FEC array 34R divided into three fan shapes,
It is composed of an FEC array 34G for G (green) and an FEC array 34B for B (blue), and three FEC arrays 34R, G, B.
The FEC array group 34 is configured by. Further, each FEC array of the FEC array group 34 can be driven independently of each other, and each FEC array 34 of the FEC with respect to the RGB segment of the phosphor formed on the panel section 4 is driven.
R, G and B can correspond independently. The structure and circuit of the focusing electrode are the same as in the first embodiment.

In the conventional indirectly heated cathode, there are a delta electron gun in which three indirectly heated cathodes are arranged in a delta shape, and an in-line electron gun in which three inwardly heated cathodes are arranged in a line. The delta type electron gun has advantages such as excellent resolution and a small mask pitch of the shadow mask provided on the panel portion. In the present embodiment, the arrangement of each FEC array, which is an electron source, is close to that of a delta-type electron gun, and the diameter of the beam generation source is smaller than in the prior art. can get.

[0022]

According to the present invention, the following effects can be obtained. (1) Since the FEC is a cold cathode, a heater power supply is unnecessary. (2) An electron beam having a current density of 5 to 10 A / cm ² can be obtained, and the brightness of the display by the cathode ray tube can be increased.

(3) Since the electron generation region is formed by FEC, it can be formed in a small area with a diameter of 1 mm or less, for example.
Therefore, with a simple lens system, a converged electron beam with a small aberration and a uniform electron density in the beam can be obtained.

(4) Compared with the conventional indirectly heated electron gun,
You can make a thin electron gun with a simple structure and a small depth.

[Brief description of drawings]

FIG. 1 is a sectional view of an electron gun according to a first embodiment.

FIG. 2 is an enlarged cross-sectional view of the electron gun according to the first embodiment.

FIG. 3 is a circuit diagram of the electron gun in the first embodiment.

FIG. 4 is a diagram showing another mode of the circuit diagram of the electron gun in the first embodiment.

FIG. 5 is a diagram showing an FEC pattern in the electron gun of the second embodiment.

FIG. 6 is a cross-sectional view showing the structure of a general cathode ray tube.

FIG. 7 is a sectional view of a conventional electron gun.

[Explanation of symbols]

 3 Deflection Electrode 4 Panel Section 10 CRT 12, 30 Electron Gun 17 Gate 19 Emitter 20 FEC 24 First Electron Beam Focusing Electrode 28 Second Electron Beam Focusing Electrode 34R, 34G, 34B Field Emission Cathode Array 34 Field Emission Cathode Array Group

Claims (2)

[Claims] 1. A field emission type cathode array group in which a plurality of field emission type cathode arrays each having an emitter and a gate are arranged, and an electron beam focusing electrode provided adjacent to the field emission type cathode array group. Electron gun with. 2. A neck portion provided with the electron gun according to claim 1, a funnel portion provided with a deflection electrode for deflecting an electron beam emitted from the neck portion, and a phosphor emitting light by the electron beam. A cathode ray tube having a deposited panel portion.