JPS5981829A - Cathode structure for electron tube - Google Patents

Abstract

PURPOSE:To produce cathode structure of super quick response, easy to manufacture and having long service life by heating base metal through thermal transmission via contacting section with heat transmission metallic member and thermal radiation via space. CONSTITUTION:A cathode structure for electron tube is arranged around the electron gun axis Z along envelop top face of cathode sleeves 26, 26 while comprising base metal 28 where end section is fixed to each of said sleeves 26, 26 through welded points 27, 27, oxide layer 29 for emitting thermion applied on said base metal 28 and heater 36 where space section 24 is provided between said sleeves 26, 26 and base metal 28. The base metal 28 is positioned in the center of heater and heated quickly through thermal transmission through the sleeve 26 and thermal radiation to exhibit quick response. The heater 36 and base metal 28 are contactless (because of said space 34) thereby emission of thermion from the oxide layer 29 applied on the base metal 28 will not deteriorate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cathode structure for single-lens and U-type cathode structures, and particularly to a cathode structure for super-J and DI-4119 suitable for use in a filter gun of a color picture tube. Cathode for tubules (concerning 14 bodies).

[Technical background of the invention and its problems]

An example of a conventional ultra-fast double-type tube tube cathode 41 body is shown in Fig. 1 and WJ2.
21 (with 21 inside and an electron emissive oxide layer (3
) is attached to the top surface, and the heater (2) (2> is a filament (4) made of a coiled tungsten wire with a wire diameter of 20μφ to 30μφ and a sintering device that hardens this filament (4) from both the inside and outside. It consists of an insulating layer (5) of alumina, the outer peripheral surface of which is in close contact with a part of the cathode cylinder (1), and is almost completely surrounded by this part.Such a cathode cylinder The field (1) is initially shown in Figure 2 with the symbol (11
As shown in 1, it is formed into a cylindrical shape with a rectangular cross section, and its internal space is designed to be large enough to leave a considerable nitrogen gap even after the heater 12) [2) is inserted. . Then, in the compression process, the shaping table 16) +6) is
Heater (2) by moving it in the direction of the arrow in the figure.
(The above-mentioned relationship is established between 21 and 21.

In such a cathode structure for a flying tube, a part of the cathode cylinder forms an overlapping part due to the compression process applied to the cathode cylinder, and Since the entire cathode cylinder is deformed around this heater, the degree of mechanical and thermal coupling between the heater and the cathode cylinder is extremely high. It is said that it not only eliminates various harmful effects, but also improves heating efficiency by 1!+, and exhibits excellent effects especially when used as a compact Brown<H thermionic emission source.
On the other hand, as shown below, C has fatal drawbacks as a cathode groove body for round tubes.

(1) Since the filament is supported only by its ends, considering the thermal deformation characteristics of the filament, the gap between the electron-emitting oxide layer and the grid electrode facing it (G
,-ni between I! 1%) is not constant, and therefore the cut-off area of the grid electrode varies, resulting in poor white balance in color picture tubes.

(2) IJIJ of the filament When the filament is 1tJi, the filament may break 1tJi or the coating material may break due to the difference in thermal expansion of the filament, especially the cathode f, which is mainly made of nickel, and the coating material of alumina. Touch damage between the filament and the cylindrical body due to peeling is likely to occur.

(3) Step of inserting the heater into the cathode cylinder with a rectangular cross section, and then bringing the cathode cylinder into close contact with the outer peripheral surface of the insulating layer of the heater through a compression process, and forming an overlapping part in a part of the cathode cylinder. The process of inserting a heater and then compressing the material is extremely difficult considering the fragility of the filament and alumina.
There is t'.

(4) An important mermaid is the connection between the coiled tungsten filament that forms the heater and the alumina (W+A403→Wm0n-1-Al (however, m,
The so-called gas doping phenomenon occurs in which the oxygen in WfflOfl diffuses through the grain boundaries of the cathode structure of 40μ or less, which is mainly composed of nickel, and changes the composition of the upper oxide layer. occurs, extremely shortening its life as a cathode.

[Purpose of the invention]

The present invention is an ultra-fast acting type that overcomes the above-mentioned conventional drawbacks, does not change the G-K interval, is easy to manufacture, and has a long life and high reliability. It is intended to provide a cathode structure for the basal tube.

[Summary of the invention]

In the present invention, a base metal is provided with an electron emitting surface on one surface, and a reflecting surface facing the electron emitting surface is formed to form a space of f; 15 minutes, which is far from the center of the electron emitting surface. A heat transfer metal body that contacts and holds the base metal at a portion thereof, and a heater that is provided on the heat transfer metal body and heats the base metal mainly through the heat transfer metal body, and the heater The base metal is heated by heat radiation through the contact portion of the heat transfer metal body with the base metal by heat radiation through the space between the heat transfer metal body and the base metal. 1iSl for electric P tube which is busy and 1 yen melted! +ii It is a structural tree.

Example Next, the first example of the cathode structure for electron 8 of the present invention will be described in the 31st example.
This will be explained with reference to FIGS. The figure shows a state in which three sets of 4!-7-tube cathode bath bodies are arranged in parallel on one insulating base (jl) for use in color picture tubes.
・: Figures 34 and 51 show the three sets of electron tube cathodes 1
FIG. 2 is a plan view and a front view, respectively, showing essential parts of one Y-shaped cathode assembly for an electron tube. In this embodiment, a cathode sleeve (2(9t?e) is used as the heat transfer metal body.

In other words, the cathode structure for an electron tube consists of a filament conductor (
22+ (2a and a support supporting the cathode structure (2IQ
The support piece 04] (241) is arranged perpendicularly and parallel to the electron gun axis fZ+ through the support piece 04] (241) and the contact point (251 (2!19) For example, 15μ thick with blackened inner and outer surfaces.
Two cathode sleeves (C) made of nickel-chromium nitungsten alloy with a diameter of 1.3" and a diameter of 1% (3 mm) are placed along the envelope IR plane of these cathode sleeves QωQω with the electron gun axis as the center. For example, the cathode sleeve cao C2+Q has a thickness of 0.05 mm, and the vicinity of the end is fixed to each of the cathode sleeves C2+Q through welding points.
A base metal (2) mainly made of nickel with a diameter of 1.5 mm, an oxide layer that emits thermoelectrons formed on the base gold tic2s, and a cathode sleeve ('!+9 (,'Q
41. are wound into a coil that can be inserted through the openings in the same direction. Alumina 0υ is sintered on the inside and outside of the filament (toward) to form a U-shape, and the vicinity of both "J" parts are
Each conductor is formed from a heater 01 which is connected to a -C conductor through a welding point. There is now a section between votes (→).

Next, the main parts of the method for manufacturing a cathode assembly for an electron tube will be explained with reference to FIGS. 6 to 12.

First, as shown in FIG.
．． :3n, nickel-chromium-tungsten cathode sleeves (1) (a) in the order of 3 are fixed so that they are parallel to each other at the welding points. Next, as shown in FIG. 7, between the two top surfaces of the two cathode sleeves (a) at approximately the center in the longitudinal direction, that is, along the envelope top surface, 1.
llb (Thickness Q: Q51111 centered on Zl
1. Weld point c! near the peripheral edge of a disc-shaped base metal 78) mainly made of nickel with a diameter of 1.5 gates. ? ) Fixed at @. Next, as shown in Fig. 8, two cathode sleeves (2
fZ) so that the thickness is 0.05 degrees,
A pair of supporting pieces C24J sieve made of amber alloy with a width of 0.5 mm are fixed at welding points (241) (241).

Next, such a semi-finished product is subjected to blackening treatment on the inner and outer surfaces of the cathode sleeves (c) and (a) in a wet hydrogen furnace.
As shown in the figure, the support piece 041 (24) is formed into an L-shape, and carbonates of Ba, Sr, and Ca, which will become an oxide layer in the aging process, are applied on the base gold 1=IGHI. Next, as shown in FIG.
Attach the support piece (241041) to 1C23 at the button welding point (23□) (231) so that the inside of the cathode sleeve and the base gold FA@ are at an angle of 1α to the electron gun axis fZ. Next, in a separate process, the filament wound into a coil is bent into a U-shape, coated with alumina, and sintered as shown in Fig. Insert each cathode sleeve (shoulder (A)) in the direction of the arrow, and connect the exposed portion of the filament (toward) near both ends to the insulating substrate (211).
A conductor is installed through the conductor (fixed by welding point C (1) on two opposite sides to complete the electron tube @ pole structure.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the figure, the same parts as in the embodiment 1 are given the same reference numerals and will not be explained to the samurai.

In this embodiment, a pair of cathode sleeves (21CR) are connected without welding directly.
, and the welding points (3FOC) are connected to the top and bottom surfaces with each cathode sleeve/2I9 (to) separated by the desired distance, so the base metal!7'4 A fixing piece (28I) is protruded from both sides as shown in FIG. This makes it possible to reduce deformation by reducing the amount of molybdenum in the center of the base metal (c).
It is now possible to reduce the amount of impurities such as tungsten, oxygen, and copper.Next, the third embodiment of the present invention is shown in FIG. 14! 7 i+a
I will clarify. The same reference numerals as in the embodiment column 1 in the figure indicate the same parts, and no particular explanation will be given.

That is, in this embodiment, the support piece C! 41 (24 is provided on the cathode sleeve so as to form an acute angle with respect to !I'd i21'9, which allows better rotation during cathode/filJ operation.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

In this embodiment, one cathode sleeve (20) is used as the heat transfer metal body, and a base metal scrap (stain) is provided in the center of the sleeve to form a space through the tongue O1.

In this case, the structure is simple and power consumption can be further reduced.

Next, a filament adapted to another embodiment of the present invention is first added.
This will be explained with reference to Figure 6. In other words, a coiled filament corresponding to the base metal placed along the top surface of the envelope of the cathode sleeve pattern 9 so as to be approximately centered on the electron gun axis.
The pitch of the cathode sleeve is made closer than other parts, that is, barrier pitch, so that the temperature of the cathode sleeve in this part is raised more rapidly than in other parts, and the interlocking performance is improved.

The above-mentioned embodiment is a typical example of the present invention. In addition, the cross-sectional shape of the cathode sleeve may be changed, only the outer surface may be blackened,
C may be used without blackening, the shape of the base metal may be non-circular such as an oval or square instead of a small circle, and the substrate CD may be made of, for example, four gold plates instead of an insulator. Connect the upper conductor (2'IJ (c) to the eyelet through the insulator)
There is no need to explain that it is also possible to provide a C-shaped heater, insert a linear heater instead of the U-shaped heater, or even make the shape so that it can be inserted into the support tube of a conventional indirectly heated cathode. .

[Effects of the Invention, 1] Next, the characteristics of the cathode structure for an electron tube completed in this way will be described.

('') The base metal is a fast-acting type because it is rapidly heated by external heat conduction and heat radiation from the cathode sleeve, which is a heat transfer metal body. -IJ In this embodiment, the electron gun is located approximately at the center of the length of the cathode sleeve.

Since the structure is such that the base metal is placed with the axis as the center, the base metal 6 is located approximately at the center of the heater.

In this case, the heater temperature rises after applying U pressure to the heater.
If you look at ts A, ql and q, you will see that the temperature is outside the center of the length of the heater.As a result of the experiment, it was possible to obtain an image output characteristic of 1.5 seconds. Ta.

(The reason why the temperature at the center of the sleeve is the highest is that firstly, the heat dissipated from the heater is transferred to the cathode sleeve, and then the heat is transferred from the cathode sleeve to the support piece. Since both ends of the cathode sleeve are open, the 1;^ from the heater escapes from both ends of the cathode sleeve, lowering the temperature of this part.

(2) A structure in which the heater and the base metal scrap are non-contact (space 04
), and the particles scattered from the heater adhere to the cathode sleeve but not to the base metal.

Therefore, impurities do not diffuse into the base metal, and there is no deterioration in the emission of thermoelectrons from the oxide layer deposited on the base metal.

(3) The cathode sleeve is made of metal containing chromium, tungsten, etc., and if oxygen, etc. generated by the reaction between chromium, tungsten, or tungsten and alumina diffuses into the base metal scrap, it will cause deterioration of the metal. However, in the case of this embodiment, it is fixed to the cathode sleeve at two points near the periphery, and there is a void in the center, which is a non-contact structure, so that chromium, tungsten, oxygen, etc. can be diffused. However, in the case of an electron gun for an electron tube, the hole diameter t of the pair of grid magnetic poles is smaller than the diameter of the cathode (child radiation part), so the I section F radiation is performed only from the central part. ?q Since it is now, in the case of one example, K
Diffusion of ld impurities is extremely small, which is advantageous in terms of emissions, and also has a long life.

(4) The fixation between the base metal (4) and the cathode sleeve is done near the periphery of the 75 body metal, so no matter how many pieces of welding, welding, or steel, for example, steel are used, it is fixed near the periphery. .

(5) Since there is no need to insert a heater and then go through a compression process as in the conventional method, your method is extremely simple and requires no royal authority to compress the heater.
There are very few chances of filament breakage in the heater or contact between the filament and the cathode sleeve, and the reliability of the cathode structure is high.

(6) Since the support structure 1 is axially symmetrical with respect to the child gun axis, it has a structure in which thermal deformation of each component can be avoided by rotation, and there is little dimensional change (for example, gap change in G-) during the life.

[Brief explanation of drawings]

1 and 2 are diagrams showing an example of a conventional cathode structure for magneton tubes. FIG. 1 is a perspective view, FIG. 2 is an explanatory diagram showing an intermediate process, and FIGS. 3 to 5 are diagrams of the present invention. FIG. 3 is a perspective view, FIG. 4 is an enlarged side view of main parts, and FIG.
FIG. 5 is an enlarged side view of the main parts, FIGS. 6 to 12 are explanatory diagrams sequentially showing the main parts of the manufacturing process of the first embodiment, and FIG. 13 is a plan view showing the second embodiment of the present invention. 414 is a plan view showing the third embodiment of the present invention, FIG. 15 is a diagram showing another embodiment of the present invention, and FIG. 16 is a simplified diagram of a filament adapted to another embodiment of the present invention. It is an explanatory diagram.

Claims (4)

[Claims] (1) One surface [base metal provided with a quadrupole radiation surface,
Iy>' (a heat transfer metal body that contacts and holds the base metal) is formed so as to form a space between the electron emission surface and a portion of the opposite surface facing the electron emission surface, and is located at a portion far from the center of the electron emission surface. , a heater provided on the heat transfer metal body to heat the base metal mainly through the heat transfer metal body, and a contact portion of the heat transfer metal body with the base metal that causes the heater to generate heat. The base metal is heated by heat conduction through the metal body and by heat radiation through the space between the heat transfer metal body and the base metal.
Cathode feeder for Ryoko tube. (2) The base metal is welded and held at a position that is a relatively high temperature part of the temperature distribution of the heat transfer metal body generated by the heat generated by the heater.
Cathode for magneton tube of item 1 fii< f! body. (3) The heat transfer metal body has a structure in which two cathode sleeves are arranged in parallel and fixed to each other directly or via a connecting piece.
A heater is provided inside each of the cathode sleeves L and L, and a base metal is welded and held in the longitudinally buried central part iL, and a space is defined in a region surrounded by the base metal and the two cathode sleeves. An electronic/birth cathode structure according to claim 1, characterized in that the cathode structure is formed. (4) Make sure that the inner and outer surfaces of the cathode sleeve are blackened.
I'f characteristic as stated in claim 3? For boson tubes [% polar structure. (57) The heater has a combination of close winding and coarse winding, and a coiled filament with a barrier pull pitch, and the vicinity of the part corresponding to the base metal is tightly wound. The cathode structure for an electron tube according to item 3.