JP2931500B2 - Electron gun - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun for a cathode ray tube, and more particularly to an electron gun having a highly accurate structure when downsized.

[0002]

2. Description of the Related Art As shown in FIG. 2, a control having a beam transmission hole in the center at a predetermined distance in front of a cathode structure 14 comprising a cathode material 19, a heater 20, a cathode sleeve 21, a strap 22, and a holder 18. A grid 15 is directly embedded in an insulating support bar 16 made of glass. The cathode assembly 14 has one end a of a fixing piece 17 attached to the outer peripheral portion of the holder 18, and the other end a ′ of the fixing piece 17 is connected to the insulating support rod 1.
6 buried and supported. Further, an acceleration grid 23 is provided at a predetermined distance in front of the control grid on an outer peripheral portion thereof.
4, one end b is attached, and the other end b 'is buried in an insulating support bar 16 and supported and fixed.

[0003]

The insulating support rod made of glass has a poor impact resistance, so that cracks or breakage are apt to occur. However, it is difficult to secure a sufficient holding strength, and cracks may be generated even if it is buried too deeply. In addition, heat treatment is required to bury the fixed piece, and distortion during the heat treatment is likely to remain, and the positional accuracy of the electron gun is reduced due to the difference in the thermal expansion and contraction rate between the constituent members of the electron gun and the glass. There was a problem.

[0004] It is an object of the present invention to obtain an electron gun supporting structure having high positional accuracy and high mounting accuracy when an electron gun is completed.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a brazing material is applied to the inner wall of the center hole using an insulating member (insulating ceramic) having a hole in the center, and a cathode assembly is formed in the center hole. Insert and glue. Further, using a control grid having a cylindrical beam transmission hole, a brazing material is applied to the outer wall of the insulating member to which the above-described cathode structure is fixed, and is adhered and fixed in the control grid via a spacer.

[0006] The control grid and the acceleration grid having the above configuration are fixed to the inner diameter of a pipe-shaped insulating member (insulating ceramic) in which a spacer is integrally formed. At that time,
The beam transmission holes of the control grating and the acceleration grating are opposed to each other, and are press-fitted and fixed via a spacer portion integrally formed inside the pipe-shaped insulating member.

[0007]

FIG. 1 is a sectional view of an embodiment of the present invention, and is a partial view of an electron gun. Reference numeral 7 denotes a metal container which contains a cathode material 6 and has a lid portion 5 having a large number of holes for emitting electrons. The metal container 7 is welded to a cathode sleeve 8 including a heater 11. 10 is a strap,
One end of the strap 10 is welded and fixed to the upper end of the holder 9 and the other end is fixed to the lower end of the cathode sleeve 8 to form a cathode assembly. The brazing material 12 is applied to the inner wall of the central hole of the insulating ceramic 4, the above-mentioned cathode structure is inserted, and heat treatment is performed for fixing. Next, the height from the upper surface of the insulating ceramic 4 to the upper part of the lid part 5 is measured, and the spacer 3 is selected so that the control grid 1 and the upper part of the lid 5 are at a predetermined interval. Then, a brazing material 12 ′ is applied to the outer wall of the insulating ceramic 4 to which the cathode structure is fixed, and the brazing material 12 ′ is inserted into the control grid 1 via the spacer 3, and is heat-fixed.

Reference numeral 13 denotes a pipe-shaped insulating member, and reference numeral 2 denotes an acceleration grating. The outer shapes of the control grid 1 and the acceleration grid 2 are positioned and fixed by the inner diameter of the pipe-shaped insulating member 13. The opposing surfaces of the control grid 1 and the acceleration grid 2 are pipe-shaped insulating members 1
3 are positioned at predetermined intervals by a spacer 13 'integrally formed.

[0009]

As described above, the present invention has the following advantages.

[0010] The structure of the cathode assembly is simplified since it is merely inserted into the central hole of the insulating member and fixed. Also, the manufacturing process is facilitated, and workability is improved.

[0011] Since it is constituted by using a ceramic member and a cylindrical control grid without using an insulating support rod made of glass, it is excellent in impact resistance. Also, thermal distortion and thermal expansion and contraction are reduced due to the characteristics of the ceramic.

One pipe-shaped insulating member has a function of fixing the control grid and the acceleration grid, and positions the control grid and the acceleration grid according to the outer shape. Therefore, a transmission hole is accurately formed in the outer shape of the control grid and the acceleration grid. If this is done, there will be no displacement of the beam transmission hole and higher accuracy will be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional electron gun component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control lattice 2 Acceleration lattice 3 Spacer 4 Insulating member 5 Lid 6 Cathode substance 7 Metal layer container 8 Cathode sleeve 9 Holder 10 Strap 11 Heater 12 12 'Row material 13 Pipe-shaped insulating member 14 Cathode structure 15 Control lattice 16 Insulating support rod 17 Fixing piece 18 Holder 19 Cathode material 20 Heater 21 Cathode sleeve 22 Strap 23 Acceleration grating 24 Fixing piece

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) H01J 29/48-29/51 H01J 9/02-9/18

Claims (1)

(57) [Claims] 1. An electron gun comprising a cathode assembly, an insulating member having a hole in the center, a control grid, an acceleration grid, and a pipe-shaped insulating member integrally formed with a spacer. The cathode structure is inserted and fixed in the central hole of the insulating member, and the fixed cathode structure and the insulating member are positioned and fixed in the control grid using a spacer. An electron gun which is press-fitted and fixed via a part.