JPH0256836A - Electron gun structure - Google Patents

Abstract

PURPOSE:To reduce the unevenness of interval between the first control electrode and an acceleration electrode and to improve the accuracy by making the acceleration electrode in a cup form, and fixing the first control electrode, a cathode support, and a cathode through a spacer of an insulator in the cup form. CONSTITUTION:An acceleration electrode 4 is made in a cup form, and the first control electrode 1 is composed to fix by an insulator spacer 7 of the form closely attached to the inner surface of the acceleration electrode 4. And the thickness of the spacer 7 is made into the size responding to the interval of the first control electrode 1 and the acceleration electrode 4. In this case, the fixation of the insulating spacer 7 and the first control electrode 1 is carried out by placing the upper side of a cathode support 2 which incorporates the cathode spacer and a cathode eyelet to the first control electrode 1, by holding the lower side with a cathode support holder 3. Consequently, an electron gun with little unevenness of interval between the first control electrode 1 and the acceleration electrode 4 and with a high accuracy can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electron gun assembly having a cathode, a current control electrode, an accelerating electrode, and the like.

[Conventional technology]

Conventionally, an electron gun assembly in which a cathode, a current control electrode, an accelerating electrode, etc. are arranged and fixed vertically on a bead glass is
As shown in the figure, a first control electrode 1 for controlling the amount of electron beam is shaped like a cup, a cathode support 2 made of a ceramic 2a and a cathode eyelet 2b attached to glass is inserted into the cup, and a cathode support presser 3 is inserted into the cup. It is fixed by welding, and furthermore, it has a structure in which four accelerating electrodes are vertically fixed to bead glass 5 which is melted at high temperature. Note that the first control electrode 1 and acceleration electrode 4 are holes 1a through which the electron beam passes.

4a.

In the electron gun assembly having the above structure, the inner surface of the cup of the first control electrode 10 and the ceramic 2a of the cathode support part 2 are welded and fixed with the cathode support presser 3 so that the inner surface of the cup of the first control electrode 10 and the ceramic 2a of the cathode support part 2 are in close contact with each other without any gaps. The support portion 2 and the first control electrode 1 may be considered to have an integral structure.

The cathode 6 is fixed by welding to the cathode support 2 having the above structure, so that it is fixed with high precision.

However, the accelerating electrode 4 is made of beet glass 5 melted at high temperature.
Since it is vertically fixed, the double feed fixing position changes depending on the melting temperature of the bead glass 5 and other conditions, and the electrode interval between the first control electric rod 1 and the accelerating electrode 4 tends to change.

[Problem to be solved by the invention]

In the conventional electron gun structure, due to the above structure, the electrode spacing between the first control electrode and the accelerating electrode 4 varies, so there is variation.
It was necessary to conduct a 100% inspection.

There is also the problem that non-standard products may be rejected and discarded.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to provide an electron gun structure in which the distance between the first control electrode and the accelerating electrode has little variation. .

[Means to solve the problem]

In the electron gun assembly according to the present invention, the accelerating electrode is shaped like a cup, and the first control electrode, the cathode support, and the cathode are fixed inside the cup via an insulating spacer.

[Effect]

In the electron gun structure according to the present invention, the accelerating electrode has a cup shape, and the first control electrode, the cathode support, and the cathode are fixed in the cup through an insulating spacer. There is little variation in the interval between
It is possible to obtain an electron gun assembly with small variations.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a cross-sectional view of an electron gun assembly according to an embodiment of the present invention, in which 4 is a cup-shaped accelerating electrode;
1 is a first control electrode, 7 is a spacer made of an insulator, 2 is a cathode support portion that integrates a cathode spacer and a cathode eye left, and 3 is the cathode support 2. First control electrode 1. This is an electrode holder that welds and fixes the spacer 7 inside the accelerating electrode 4. Further, the first control electrode 1 and the accelerating electrode 4 have holes 1a and 4a through which the electron beam passes.

Next, the effect will be explained.

In the conventional electron gun assembly, the accelerating electrode 4 was fixed to the bead glass 5 in a double-feed manner, but in the present invention, the accelerating electrode 4 has a cup shape similar to the conventional first control electrode 1. First control electrode 1
The structure is such that it is fixed by an insulating spacer 7 that is shaped to be in close contact with the inner surface of the cup-shaped accelerating electrode 4. Further, the thickness of the insulating spacer 7 is set to match the distance between the first control electrode 1 and the acceleration electrode 4.

To fix the insulating spacer 7 and the first control electrode 1, place the upper surface of the cathode support section 2, which integrates the cathode spacer and cathode eye left, against the first control electrode 1, and press the lower surface with the cathode support presser 3. do this.

In this embodiment, the distance between the first control lt pole 1 and the acceleration electrode 4 is determined only by the thickness accuracy of the insulating spacer 7, and the influence of assembly variations when melting the bead glass 5 at high temperature is zero. can.

〔Effect of the invention〕

As described above, according to the electron gun assembly according to the present invention, the first control electrode is fixed in the cup-shaped accelerating electrode via the insulating spacer, so that the first control electrode and the accelerating electrode This has the effect of obtaining highly accurate data with small variations in the distance between the two.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electron gun assembly according to an embodiment of the present invention;
FIG. 2 is a sectional view of a conventional electron gun assembly. 1... First control electrode, 2... Cathode support, 3
... Cathode support holder, 4... Acceleration electrode, 5.
...Bead glass, 6...Cathode, 7...Spacer. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) An accelerating electrode that has a hole through which the electron beam passes and at least accelerates the electron beam, a cathode electrode that is arranged in front of the first control electrode that controls the amount of electron beam, and a cathode support that holds this cathode electrode. An electron gun assembly characterized in that the acceleration electrode has a cup shape, and a first control electrode, a cathode support, and a cathode are fixed within the cup via an insulating spacer. .