JPS58201225A - Cathode structure - Google Patents

Abstract

PURPOSE:To check a wasteful thermal loss from outside of a sleeve, while moreover missing no former function regarding a quick action thus realizing a fixed cathode structure by selectively blackening only the inside of a sleeve to form a blackened layer. CONSTITUTION:The present cathode structure consists of an emitter part 1, a sleeve 2 for supporting the emitter and of a heater (not illustrated) heating cathode. The heater is inside of the cylindrical sleeve 2 and when the heater is red-heated by the applied electric power, the sleeve indirectly-heated thereby heats a heated emitter part to emit electrons therefrom, whereby a blackened layer 2 is formed exclusively inside of the sleeve 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a sleeve having an emitter support function of an indirectly heated cathode assembly for an electron tube, and more particularly to a sleeve with a blackened inner surface suitable for saving power in cathode heating.

As shown in FIG. 1, an indirectly heated cathode structure for an electron tube includes an emitter section 1, a sleeve 2 for supporting the emitter, and a heater (not shown) for heating the cathode.

The heater is located inside a cylindrical sleeve, and when power is applied to the heater and it becomes red hot, the sleeve receives indirect heat and heats up the emitter section, which emits electrons. Note that 2a is a blackened layer formed on the inner and outer surfaces of the sleeve 2.

An interlocking type cathode is used to efficiently receive this heat, and is currently widely used as a cathode that emits electrons quickly after power is applied to the heater. The methods used to efficiently receive heat from the heater include blackening the aluminum layer covering the heater and blackening the cathode sleeve. The blackening of the arunna layer of the heater increases the heat radiation of the heater, and the blackening of the sleeve increases the
Increases the ability to absorb radiant heat from the heater located in the sleeve. Therefore, the heat of the heater can be efficiently transmitted to the sleeve and the construction vine, and electron emission after application of heater power is fast.

However, the blackened sleeves currently in use are blackened on both the inner and outer surfaces of the cylindrical shape, which increases the ability to absorb heat from the heater and at the same time increases heat radiation from inside the sleeve, resulting in wasted waste. This wastes heat and may also cause unnecessary heating of other electron tube components, leading to undesirable results.

The present invention has improved the above-mentioned drawbacks, and is characterized in that only the inner surface of the sleeve is selectively blackened. That is, as shown in FIG. 2, by selectively blackening only the inner surface of one sleeve 2 to form a blackened layer 2a, wasteful heat loss from the outer surface of the sleeve can be prevented, and the interlocking performance can be improved. , a predetermined cathode structure can be realized without compromising conventional functionality.

Example 1 Before cutting a nichrome sleeve into a predetermined length, the entire sleeve was subjected to hydrogen treatment (55%) while passing wet hydrogen through the sleeve.
00C~100011:') To do this, select and worsen the inner surface of the four sleeves of the nichrome sleeve, and then make it to the specified length! /l cut and used as a cathode sleeve.

Example 2 Aluminum foil is rolled and welded to the inner surface of the cylindrical sleeve before it is processed into a cylindrical sleeve! do. Thereafter, heating and annealing is repeated to form a predetermined cylindrical sleeve. As a result of this heating annealing, a blackened film of the aluminum and nichrome alloy layer is formed. The sleeve thus produced is cut into a predetermined length and used as a cathode sleeve.

As described above, the cathode structure of the present invention has the effect of eliminating unnecessary heat loss and providing interlocking performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a conventional interlocking type cathode assembly, and FIG. 2 is a sectional view of a main part of an embodiment of the cathode assembly of the present invention. 1-...11 ivy section, 2@11 fist sleeve, 2a...
...Blackened layer.

Claims (1)

[Claims] 1. An indirectly heated cathode assembly comprising an emitter part and a cylindrical nichrome sleeve supporting the emitter part, characterized in that only the inner surface of the nichrome sleeve is selectively blackened.