JPS60205942A - Exhausting of electron tube - Google Patents

Abstract

PURPOSE:To obtain simultaneous gas discharge from a metallic part and a glass casing wall by providing inside of a high-frequency coil an insulating cylinder whose inner surface is coated with a heat-reflecting film having a slit extending partly in the circumferential direction. CONSTITUTION:An insulating cylinder 3 is provided inside of a high-frequency coil 2. The inner surface of the insulating cylinder 3 is coated with a heat-reflecting film 4 such as of Cr and Al so as to shut off and reflect the radiant heat. There is provided a slit 5 to prevent generation of current to the film itself due to high frequency and heating of the film itself. Flow of current to the high- frequency coil 2 causes high-frequency heating of a metallic part 7 such as a desired electrode in a camera tube 6, resulting in gas discharge from the metallic part 7, and at this time, as the radiant heat from the metallic part 7 is reflected by the heat-reflecting film 4 of the insulating cylinder 3 to effectively heat a glass casing 8 of the camera tube 6, symultaneous gas discharge from the wall of the glass casing 8 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electron tube exhaust method suitable for use, for example, in exhausting an image pickup tube.

[Technical background of the invention and its problems] Conventionally, when releasing gas from metal parts such as electrodes during the exhaust process during the manufacture of electron tubes, such as image pickup tubes, high-frequency It was heated by passing an electric current through it. Further, gas release from the wall of the glass envelope has been carried out by placing an electron tube in a baking furnace such as an electric furnace or a gas furnace and heating it.

However, as mentioned above, in the conventional exhaust method, the gas release from the metal parts and the gas release from the glass envelope wall must be performed separately or at the same time using large-scale equipment, making the process complicated. However, the manufacturing efficiency is low, and a bulky baking oven is required.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for evacuating an electron tube that can simultaneously release gas from metal parts and from the wall of a glass envelope, and which does not require a baking oven.

[1@Summary of the Invention] This invention provides an insulating cylinder on the inner surface of which is coated with a heat reflective film having a cut in a part in the circumferential direction, and an insulating cylinder that is coated inside the high-frequency coil. Place the exhaust electron tube,
The above-mentioned coil is heated by passing a high-frequency current through it, and the radiant heat from the metal parts of the upper self-electron tube and the reflected heat from the heat-reflecting film are used to simultaneously release gas from the glass envelope wall. This is an exhaust method.

[Embodiments of the invention]

The electron tube evacuation method according to the present invention utilizes the residual heat from the heating process of metal parts and simultaneously carries out the heating process of the glass envelope wall, as shown in FIGS. 1 and 2. It is configured.

That is, an insulating cylinder 3 made of, for example, glass is provided inside a high-frequency coil 2 whose both ends are connected to a high-frequency electric current p, 7. The inner surface of the insulating cylinder 3 is coated with a heat reflecting material 4 such as Cr or At, as shown in FIG. 2, in order to shield and reflect radiant heat. In this case, a cut 5 of a small size is formed in a part in the circumferential direction.

This cut 5 prevents the generation of current in the membrane itself due to the frequency and prevents the membrane itself from generating heat.

To exhaust an electron tube, for example, an image pickup tube, the image pickup tube is housed in the insulating cylinder 3, and a high-frequency current is passed through the high-frequency coil 2 to remove a desired metal part 7 such as an electrode inside the image pickup tube μ.
Perform high frequency heating. Then, gas is released from the metal part 7. At this time, the radiant heat emitted from the metal part 7 is reflected by the heat reflection film 4 of the insulator cylinder 3, and the image pickup tube μ housed inside the insulator cylinder 3 is thereby reflected. The glass envelope 8 is also effectively heated, and gas release from the walls of the glass envelope 8 takes place at the same time.

〔Effect of the invention〕

According to this invention, the wall of the glass envelope 8 can be heated at the same time by using the radiant heat emitted from the metal part 7 by high-frequency heating, so the exhaust process is simplified and the efficiency is excellent. No baking oven required. Needless to say, the configuration is simple. By appropriately positioning the heat-reflecting film, it is possible to suppress heating of, for example, the photoelectric converter portion of the image pickup tube, and to heat only the predetermined electrode and envelope portions and cause gas to be released therefrom.

In the above embodiment, the '#l image-776 was used as an example of the electron tube, but the present invention is also applicable to the case of exhausting electron tubes other than image pickup tubes.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a method for evacuation of an electron tube according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the lower part of FIG. 1. 2... High frequency coil, 3... Insulator circular surface, 4... Heat reflective film, 5... Cut, μ imaging # (electron tube), 7...
...Metal parts, 8...Glass envelope.

Claims (1)

[Claims] (υ An insulating cylinder whose inner surface is coated with a heat reflective film having a cut in a part in the circumferential direction is disposed inside a high-frequency coil, Place the electron tube in
A method for exhausting an electron tube, characterized in that a high frequency current is passed through the coil to heat it, and gases from metal parts and a glass envelope wall of the electron tube are simultaneously discharged. (2) The electron/U dispersion method according to claim 1, wherein the insulating cylinder is made of glass, and the heat reflecting film is made of Cr or At.