JPS5810290Y2 - cathode ray tube - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cathode ray tube configured so that the capacitance of a capacitor formed in the funnel portion of a glass envelope can be increased without impairing the mechanical strength of the funnel portion. .

Conventionally, in cathode ray tubes such as picture tubes, conductive films are coated on both the inner and outer surfaces of a funnel portion, and a capacitor is formed therein to improve high voltage stability.

However, from the standpoint of withstand voltage between the anode cap and the external conductive film, between the deflection yoke and the external conductive film, between reinforcing metal fittings, and between the frit seal and the external conductive film, the area where the conductive film is applied and therefore the capacitor had a limited capacity.

The present invention has been devised to eliminate the above-mentioned problems of the conventional art. Next, the cathode ray tube of the present invention will be described in detail along with embodiments shown in the drawings.

In FIG. 1, a face panel 1 forms an envelope together with a funnel 2 sealed thereto, and a reinforcing funnel 3 is provided on the outer surface of the funnel 2.

However, as can be seen from FIG. 2, which is an enlarged view of part A in the figure, an internal conductive film 4 is coated on the inner surface of the funnel 2, and the reinforcing funnel 3 is formed on the outer surface of the funnel 2. It is attached via an external conductive film 5 coated on the surface.

The internal conductive film 4 is connected to the anode and forms a capacitor together with the external conductive film 5 as in the past, but in particular, the reinforcing funnel attachment area of the funnel 2 is compared to the face panel side sealing area of the funnel 2. Form it into a thin layer,
The front edge of the reinforcing funnel 3 is located at the stepped portion between both regions.

In the cathode ray tube configured in this way, the inner conductive film 4 and the outer conductive film 5 are attached to the thin wall portion of the funnel 2, and the reinforcing funnel is attached to the outer conductive film, so that the mechanical strength of the envelope is increased. The distance between both conductive films 4 and 5 can be reduced without damage, the capacitance of the capacitor can be correspondingly increased, and fluctuations in anode potential due to fluctuations in anode load can be suppressed.

Further, the area where the conductive film is coated can be made smaller.

Furthermore, since the stepped portion acts as a positioning stopper when attaching the reinforcing funnel 3, there is an advantage that no positioning jig is required.

Furthermore, the stepped portion prevents the conductive substance or adhesive from protruding toward the sealing portion when the external conductive film 5 is applied or when the reinforcing funnel 3 is attached. This prevents these from adhering to the parts, causing dielectric breakdown and damaging the appearance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a cathode ray tube according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of section A in FIG. 1... Face panel, 2... Funnel, 3... Reinforcement funnel, 4...
Internal conductive film, 5... External conductive film.

Claims (1)

[Scope of utility model registration request] A funnel that is sealed to the face panel and forms an envelope together with the face panel has an internal conductive film on its inner surface and a reinforcing funnel attached to its outer surface via an external conductive film, and the funnel has The cathode ray is characterized in that the attachment region of the reinforcing funnel is formed thinner than the sealing region on the face panel side, and the front edge of the reinforcing funnel is located at a stepped portion between both regions. tube.