JPS6240347Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electron gun used in an electrostatic deflection type cathode ray tube.

An example of an electron gun of an electrostatic deflection type cathode ray tube has a shape as shown in Figs. 1 and 2, where K is a cathode that emits thermoelectrons, G ₁ , G ₂ ,
G ₃ and G ₄ are the first, second, third, and fourth grids installed in front of the cathode K, and 1 and 1 are the electron guns A
The fourth grid G ₄ expands toward the tip of the
The Y deflection plates 2, 2 consist of a pair of deflection plates arranged in front of the This is an X deflection plate consisting of a pair of deflection plates arranged so as to expand toward the tip of the gun A. 3 is installed between the Y deflection plates 1, 1 and the X deflection plates 2, 2.
The XY shield electrode plate 4 is installed on the outer periphery of the XY shield electrode plate 3 and is electrically connected to a conductive layer (not shown) formed on the inner surface of the funnel part, as well as for positioning when inserting the electron gun into the neck of the cathode ray tube. 5 is the X deflection plate 2,
A rectangular cylindrical collector electrode arranged around the outer periphery of 2, 6
is a cylindrical shield electrode placed on the outer periphery of the collector electrode 5, and a correction ring 9 is provided at the front opening of the shield electrode 6 to change the electric field distribution state in front of the shield electrode 6 and to reduce deflection distortion. A mesh electrode 8 is attached via a mesh support electrode 7 formed integrally. As shown in FIG. 3, the electron gun A has a phosphor screen on the front.
It is sealed in a neck portion C of a cathode ray tube B, which has a graphite layer formed on its inner peripheral surface, and is evacuated to form a cathode ray tube.

By the way, the first, second, third, and fourth grids G ₁ , G ₂ , G ₃ , and G ₄ , the Y deflection plates 1, 1, the X deflection plates 2, 2, and the XY shield of the electron gun A of the above type Since the electrode plate 3 is fixed to support rods 10 and 10 formed of insulating members located on both sides of the electron gun A, the electrode plate 3 is relatively stable in terms of strength.
A shield electrode 6 arranged around the deflection plates 2, 2
is the bracket 1 fixed to the XY shield electrode plate 3
The shield electrode 6 is only held in position by spot welding at a few points on the electrode 1, and is weak in strength, so when it is inserted into the neck C of the cathode ray tube B into the electron gun A and positioned, the shield electrode 6 may become misaligned. As a result, there was a problem that the figures projected by the cathode ray tube A were distorted. Furthermore, if the shield electrode 6 is misaligned in this way, troubles such as the tip of the shield electrode 6 scraping off the graphite coated on the inner peripheral surface of the cathode ray tube or discharge occurring between the graphite layer and the correction ring 9 may occur. Occasionally this occurred.

This invention has been developed to improve and eliminate the above-mentioned problems, and the details of this invention will be explained below with reference to the embodiments shown in the drawings.

That is, this invention is based on a position regulating member (position regulating ring made of ceramic) whose outer periphery is in contact with the inner circumferential surface of the neck portion C of the cathode ray tube A, as shown in the dashed line in FIG. 1 and in FIG. 12 is fixed to the outer periphery of the correction ring 9 at the tip of the shield electrode 6 by suitable means such as welding. The corners of the outer peripheral surface of the position regulating ring are chamfered or curved.

In this way, the cathode ray tube B is placed on the outer periphery of the correction ring 9.
If the position regulating ring 12 is attached so that the inner circumferential surface and the outer circumferential surface of the neck portion C of The outer circumferential surface of the shield electrode 6 contacts the inner circumferential surface of the neck portion C to regulate the position of the shield electrode 6 and the correction ring 9.
Also, the correction ring 9 will not be misaligned, and various troubles caused by misalignment of the shield electrode 6 and the correction ring 9 can be prevented.

Note that the present invention is not limited to the above-mentioned embodiments; for example, as shown in FIG. It is also possible to use the metal fittings by welding and fixing them. Furthermore, the position regulating member can be fixed not only to the correction ring but also to the shield electrode, and the shield electrode in the scope of the utility model registration claims includes the correction ring.

[Brief explanation of the drawing]

Fig. 1 is a partial side sectional view of an electron gun to which this invention is applied, Fig. 2 is a front view of Fig. 1, Fig. 3 is a schematic diagram showing the state when the electron gun is inserted into a cathode ray tube, and Fig. 4 is a partial side sectional view of an electron gun to which this invention is applied.
The figure is a front view of an electron gun according to this invention, and FIG. 5 is a drawing showing another embodiment according to this invention. A... Electron gun, C... Network portion, 6... Shield electrode, 12... Position regulating member.

Claims (1)

[Scope of utility model registration request] In an electrostatic deflection cathode ray tube electron gun having a cylindrical shield electrode at the tip, a position regulating member is installed to reduce the gap between the outer circumferential surface of the shield electrode and the opposing inner circumferential surface of the neck. Characteristic electron gun.