JPS60136131A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent the contact failure of a contact spring that applies voltage to a shadow mask due to resonance by preventing said contact spring and an inner shield from making direct contact. CONSTITUTION:A contact spring 6 that touches a graphite film 8 on the inner wall surface of the funnel 2 of a cathode-ray tube is welded and fixed to the frame 5 of a shadow mask 3 and high voltage is applied to the mask 3, then an inner shiled 7 arranged along the inner wall surface of the funnel 2 is semi-fixed to the frame 5 using a hooking spring. In this case, a recess 7a is formed on the frame 5 side, that makes contact to the spring 6, of the shield 7 and a recess 7b is formed at a section corresponding to the folding section of the spring 6. As a result, since the spring 6 and the shield 7 do not make direct contact, the contact failure of the spring 6 to the graphite film 8 caused by the oscillation of the shield 7 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cathode ray tube, and particularly to the structure of an inner shield provided within a bulb.

[Background of the invention]

This type of inner shield is generally formed into a shape almost the same as the funnel part by press molding a thin plate, for example, a stainless steel plate, and the large diameter part Ill is fixedly arranged on the shadow mask frame, and the small diameter part side is the funnel part. The opening is opened toward the neck along the inner surface shape, and has the function of mitigating the influence of the external magnetic field of the electron beam.

FIG. 1 is a partially sectional front view of a color cathode ray tube. In the figure, 1 is a panel portion with a fluorescent film formed on its inner surface;
2 is a funnel part in which an electron gun is housed in the neck part; 3 is a shadow mask attached to a bin 4 provided in the panel part 1; 5 is a support frame for the shadow mask 3 fixed to the peripheral part of the shadow mask 30; 6 is a contact spring whose base is fixed to the frame 5, and T is the frame 5.
Inner shield semi-fixed on its large diameter end side, 8
9 is an interior graphite film made of a fish boat etc. applied to the inner surface of the funnel part 2, 9 is a frit glass that joins the panel part 1 and the funnel part 2, and the tip of the contact spring 6 is attached to the interior by its elastic force. The small diameter portion side of the inner shield T is arranged along the inner surface of the funnel portion 2 in electrical contact with the graphite film 8 .

Further, FIG. 2 is a sectional view of the main parts showing the mounting structure of the contact spring 6 and the inner shield T. In the figure, a contact spring 6 is welded and fixed to the frame 5, and the base of the inner shield T is semi-fixed thereon by a locking spring (not shown). and,
The contact spring 6 contacts the inner graphite film 8 formed on the inner surface of the funnel portion 2 with a contact pressure of about 15 p, thereby supplying the shadow mask 3 with a sufficient high voltage.

However, in the above-mentioned configuration, the inner shield has a single mask frame src that is semi-fixed and is not a rigid body, so it is easily vibrated by external shocks. Therefore, it is extremely easy to vibrate due to handling during the manufacturing process or shock during processing. -Ninth, the contact spring 6 is in contact with the inner shield 1 on the mask frame 5 and at the bent portion, and the contact spring 6 vibrates in resonance with the vibration of the inner shield 1 due to the above-mentioned impact. The contact portion of the interior graphite film 8 will be scraped. There was a problem in that the graphite scraped by this adhered to the electron gun and the like, significantly reducing the withstand voltage characteristics.

[Purpose of the invention]

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a cathode ray tube in which resonance of contact springs is prevented and voltage resistance characteristics are improved.

[Summary of the invention]

In order to achieve such an object, the present invention changes the shape of the inner shield so that there is no contact tube between the contact spring and the inner shield.

[Embodiments of the invention]

Next, embodiments of the present invention will be described in detail using the drawings.

FIG. 3 is a perspective view of essential parts showing a contact spring and inner shield mounting structure showing an example of a cathode ray tube according to the present invention. In the figure, the mask frame 5 (
A first four part 1a such as a notch part is formed on the side (see FIG. 2), and a second four part 1b is formed in a part facing the bent part of the contact spring 6,
The structure is such that the inner shield 1' and the contact spring 6 do not come into contact with each other.

According to such a configuration, the vibration of the inner shield l caused by an external impact is not transmitted to the contact spring 6, so there is no resonance of the contact spring 6. Therefore, the inner graphite film 8 ( (See Figure 2)
It is possible to prevent the contact parts from being scratched.

〔Effect of the invention〕

As described above, according to the present invention, there is no resonance of the contact spring, and the internal graphite film can be prevented from being scraped, so that the extremely excellent effect of greatly improving the withstand voltage characteristics can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view of a color cathode ray tube, Fig. 2 is a sectional view of essential parts of a color cathode ray tube showing an example of a conventional contact spring and inch-shield structure, and Fig. 3 is a partial sectional view of a color cathode ray tube according to the present invention. FIG. 2 is a perspective view of a main part of a contact spring and inner shield mounting structure showing an example of a negative iπ9 tube. 1@・-・Spring/1. Part, 2--11-funnel part-3...1111 shadow mask, 4...Φ pin, 5
...*e7 frame, 6φΦ・drop contact spring,
T, 1...Fist inner shield, 7B...First recess, 1b@-...Second recess, 811...Inner cloth guide (force-coating, 9.0...Fritted glass .

Claims (1)

[Claims] A contact spring is arranged along the inner wall surface of the funnel portion and has an elastic portion in contact with an internal graphite film formed on the inner wall surface of the funnel portion, and a base portion thereof is fixed to a support frame constituting a shadow mask; 1. A cathode ray tube comprising at least an inner shield fixed to a support frame, characterized in that a portion of the inner shield that comes into contact with the contact spring is provided with four parts.