KR20000034945A - Direct heating cathode unit and electron gun using the same - Google Patents

Abstract

PURPOSE: A cathode unit is provided to be capable of being applied to a vacuum electronic apparatus which requires a brightness, an endurance and a reliability, and to reduce a cost and a working process frequency according to a join of a heater wire and an emitter. CONSTITUTION: A cathode unit comprises an emitter(110), two heater wires(120,130) and a pair of heater supports(141,142). The heater wire(120) has a center part(121) welded to one side of the emitter(110) and support parts(122,123) extended from the center part(121). The heater wire(130) has a center part(131) welded to the other side of the emitter(110) and support parts(132,133) extended from the center part(131). Ends of the support part(122,132) are welded to the heater support(141), and ends of the support part(123,133) are welded to the heater support(142). The heater supports(141,142) are supported by current supply holder pins(143,144) which are supported vertically at an insulator(151) of a holder body(150). The insulator(151) is supported by a cylindric sleeve(152). The heater supports(141,142) are welded to the current supply holder pins(143,144).

Description

Direct heating cathode unit and electron gun using the same

The present invention relates to an electron gun of an electronic device, and more particularly, to a direct type negative electrode unit used as an electron emission source of various electronic devices, and an electron gun using the negative electrode unit.

Electron vacuum devices such as color cathode ray tubes, oscillographs, radiolocation, and high-density electron beams are equipped with electron guns and electron beams emitted from the electron guns to form images. .

The electron gun used in the electron vacuum apparatus includes a cathode unit, which is an electron emission source, and a plurality of focusing electrodes forming an electron lens for focusing and accelerating the electron beam emitted from the cathode unit.

In the electron gun, a cathode unit, which is an electron emission source, is one of the most important components that affects the brightness, power consumption, speed, and lifespan of screens of electron vacuum devices.

The cathode unit has a direct heating method and an indirect heating method of the electron emitting material. At this point, a direct oxide cathode including a method of directly heating the electron emitting material is widely used as an emission source of electrons. The electron-emitting ability of this series oxide cathode is limited, and abundant current density of 1 A / cm 2 or more cannot be obtained continuously. The tandem oxide cathode is insufficient for the application of electron vacuum devices that require high brightness in recent years.

Indirect heating type oxide cathode units are delayed in heat transfer from the heater to the emitter. This is because there is no direct thermal contact between the heater and the emitter. The delay in heat transfer from such a heater to the emitter causes additional power loss due to the preheating of the emitter.

An example of a thermal unit of an electronic vacuum apparatus is USA. 4,137,747.

As shown in FIG. 1, the series cathode electrode structure 10 is fixed at one side to the current supply holders 13 and 14 and the holders 13 and 14, and the other end thereof is connected to the emitter 11. It includes two filaments (15, 16: HEATING WIRE) fixed to the side.

In the cathode structure 10 as described above, since the ends of the two filaments 15 and 16 are welded to the side of the emitter 11, the supporting force of the emitter 11 by the filaments 15 and 16 is unstable, In particular, deformation in the direction perpendicular to the linear side of the cathode structure 10 is observed. (OK!) And both holders 13 and 14 have a large structural support force, but the vertical direction of the cathode structure 10. As a result, bearing capacity is insufficient. Therefore, there is a problem that the vibration of the unit and the positional movement of the emitter 11 supported on the filaments 15 and 16 occur even with a small mechanical shock.

Another example of a series negative electrode unit is disclosed in Russian Federation Patent No. 2,052,856.

As shown in FIG. 2, the series negative electrode unit 20 includes two filaments 22 and 23 connected to the main body of the emitter 21 by a central portion, and ends of the two filaments 22 and 23. Paired cross arms 24 and 25; current feeders 26 and 27 to which the cross arms 24 and 25 are fixed and supported on the insulator of the cathode stamp. . Wherein the electrical resistance of the cross arms 24, 25 is less than the electrode resistance of the filaments 26, 27, and is located between the emitter 21 and the cross arms 24, 25. The branches are the same length. And the groove 21a to which a filament is mounted is formed in the lower surface of the said emitter.

The cathode structure 20 constructed as described above is difficult to manufacture and requires a lot of time due to the very small grooves on which the filaments are mounted and the gaps between them are narrow.

One example of another cathode and heater assembly is disclosed in Canadian Patent No. 2,034,919.

As shown in FIG. 3, the cathode unit includes a hot electron emitter 31 having a geometric vertical axis; In a group of end portions having a first periphery, at least two or more parietal heater members 32, 33 having an end portion and the same length as the second periphery and having an emitter 31 fixed to the central portion, The first and second peripheral portions are located at the same acute angle with respect to the geometric vertical axis of the thermoelectron emitter 31, and both ends of the first and second peripheral portions of the mutually orthogonal axes of the symmetry intersections located at the geometric vertical axis of the thermoelectron emitter 31 are formed. A group of filament heater members 32 and 33 positioned at the vertex of the regular polygon; A first current application lead (24) (25) connected to an end of the first peripheral portion of the filament heater member (32) (33) and having a shaft; The axis of which the end portion of the second peripheral portion of the filament heater member is fixed to the axis of symmetry of the regular polygon, and one of the axes of symmetry of the regular polygon is the first current, the second current passing through the leads 34 and 35 and the axes of the retard. Applied lead (36) (37); And a base 38 fixed to the first and second application leads 34, 35, 36, 37.

The cathode and heater assembly constructed as described above cannot absorb the amount of thermal expansion of the filament heater member because the ends of the filament heater members 32, 33 are located at the apex of the geometric vertical axis of the emitter. Therefore, there is a problem in that the position of the emitter is moved in the vertical axial direction due to thermal expansion of the filament heater member, it is structurally complicated. In addition, due to the interface reaction between the emitter and the filament heater member, the dropping or disconnection of the emitter and the filament proceeds with time, and there is a problem of low heat transfer efficiency between the filament heater member and the emitter.

The present invention is to solve the above problems, it can be applied to the vacuum electronic device that requires the brightness, durability, reliability, etc., reducing the labor cost and manufacturing cost due to the manufacturing of the emitter body and the combination of the heater wire and the emitter The present invention provides a direct type cathode unit.

Another object of the present invention is to provide a series of negative electrode unit that can improve the continuous emission characteristics of the electron.

Still another object of the present invention is to provide an electron gun using the series negative electrode unit.

1 is a side view showing a conventional direct type cathode structure;

Figure 2 is a perspective view showing another example of a conventional direct type cathode structure,

Figure 3 is a perspective view showing another example of a conventional direct type negative electrode structure,

4 is a side view of an electron gun employing a series cathode electrode unit according to the present invention;

5 is a perspective view showing an extract of the series negative electrode unit shown in FIG.

6 is a side view of a series negative electrode unit according to the present invention;

7 is a perspective view showing an extract of a heater wire embedded in the emitter,

8A to 8C are diagrams illustrating resistance welding of an emitter and a heater wire.

In order to achieve the above object, the direct type negative electrode unit of the present invention

An emitter made of an electron-emitting metal alloy having at least two parallel sides extending transverse to the geometric longitudinal axis passing through the base portion,

Two heater wires welded centrally to two corresponding sides of the emitter,

Holder body with current supply holder pin,

Both ends of the pair of heater wires connected to the holder pins are fixed, and the heater supports are connected to the current supply holder pins so that the vertical axis of the holder body and the vertical axis of the emitter axis coincide with each other.

In the present invention, the emitter is rectangular and its thickness may vary within a range of 1/2 to 1/5 of the base part specification between the sides parallel to each other, and the emitter is over the connected area. The length of the protruding heater wire line is preferably 2 to 5 times the diameter of the heater wire. The heater support is made of a high resistance iron-nickel alloy.

A series negative electrode unit having another feature of the present invention has at least two sides extending transversely with respect to the geometric longitudinal axis passing through the base portion and having 0.5 to 9.0% by weight of the rapid flux of cerium group, 0.5 to 9.0% by weight of tungsten and / or rhenium. 15 weight percent, 0.5-10 weight percent hafnium and the remainder of the emitter made of an electron-emitting metal alloy consisting of iridium, an emitter made of an electron-emitting metal alloy, and two centrally welded two corresponding sides of the emitter Heater wires, a holder having a current supply support, and both ends of a pair of heater wires connected to the support are respectively fixed, and heater supports connected to a current supply holder pin so that the vertical axis of the holder body and the vertical axis of the emitter axis coincide with each other. Include.

And an electron gun for a cathode ray tube employing the series cathode electrode unit having an emitter made of an electron-emitting metal alloy having at least two parallel sides extending transversely with respect to the geometric longitudinal axis passing through the base portion, and corresponding to the emitter. Two heater wires each having a central portion welded to each of the two side surfaces, a holder body having a current supply holder pin, and both ends of a pair of heater wires connected to the holder pins, respectively, fixed to the vertical axis and the emitter of the holder body. A cathode unit comprising heater supports connected to the current supply support such that the vertical axis of the shaft coincides:

It characterized in that it comprises a control electrode and a screen electrode which is sequentially provided from the cathode unit to form a tripolar portion, and a plurality of focusing electrodes which are provided adjacent to the screen electrode to form a main lens and an auxiliary lens.

In the present invention, the electron-emitting metal alloy is an electron-emitting metal alloy consisting of 0.5 to 9.0% by weight of rare earth metal of cerium group, 0.5 to 15% by weight of tungsten and / or rhenium, 0.5 to 10% by weight of hafnium and the remaining amount of iridium It is preferable to form.

Figure 4 shows an embodiment of an electron gun employing a series of negative electrode unit used in the electronic vacuum apparatus according to the present invention.

As shown in the drawing, the electron gun forms a triode, and includes a series negative electrode unit 100 that emits an electron beam, a control electrode 200 and a screen electrode 300 sequentially installed from the series negative electrode unit 100, and And a plurality of focusing electrodes 400 and a final focusing electrode 500 for focusing and accelerating the electron beam. Each of the electrodes has electron beam through holes for forming an electron lens, and the shapes of the electron beam through holes may be modified in various forms according to the electron lens to be formed.

5 and 6 show an example of a series negative electrode unit mounted on the electron gun for the vacuum electronic device and used as an electron emission source.

As shown, the series negative electrode unit 100 includes a emitter 110 of a predetermined shape, and a central portion 121 welded to the mutually parallel and parallel side surfaces 113 and 115 of the emitter 110, respectively. 131 and two heater wires 120, 130 having support portions 122, 123, 132, and 133 extending from the central portion, and the heater wires 120 and 130, respectively. A pair of heater supports 141 and 142 to which the ends of the support portions 122, 123, and 132, 133 are welded, respectively. The heater supports 141 and 142 are supported by current supply holder pins 143 and 144 that are vertically supported by the insulator 151 of the holder body 150. The insulator 151 is supported by the cylindrical sleeve 152, the shape of the insulator 151 and the cylindrical sleeve 152 is modified and adjusted in various forms when mounted on the cathode unit of the electronic vacuum device, electron gun for cathode ray tube, etc. It is possible.

The heater supports 141 and 142, to which end portions of the heater wires 120 and 130 are fixed, are welded and fixed to the current supply holder pins 143 and 144, and the heater supports 141 and 142 have a current. The supply holder pins 143, 144 form a cross. The material of the heater support (141, 142) is preferably used to flow the heat from the heater wire 120, 130 to the heater support (141, 142) in a minimum state. Such materials are suitable for high-resistance iron-nickel alloys with low electrical conductivity and low thermal conductivity. The selection of the shape and the material of the heater support as described above can improve the heating efficiency despite the use of a short length of heater wire.

FIG. 7 shows in detail the welding and supporting states of both parallel sides of the cathode emitter configured as described above and the central portion of the heater wire.

As shown, the central portions 121 and 131 of the heater wires 120 and 130 are welded to the entire length of the mutually parallel side surfaces 113 and 115 of the emitter 110 and have a predetermined length L on both sides. It has protruding protrusions 124, 125, and 134, 135. In addition, the support parts 122, 123, 132, and 133 of which the ends are supported by the heater supports 141 and 142 are formed from the protrusions 124, 125, 134, and 135. Herein, the lengths of the protrusions 124, 125, and 134, 135 are preferably 2 to 5 times the diameter of the heater wires 120 and 130. The limitation of this length is obtained by considering the depth at which the atoms of the electron-emitting metal alloy easily diffuse into the heater wires 120 and 130 during the high temperature operation of the cathode. The protruding length can be selected according to the preservation requirement of the high standard of the design safety standard. As above, the corresponding parallel side of the emitter and the center of the heater wires 120, 130 are welded and the ends of the heater wires 120, 130 supports are supported on the holder supports 141, 142. The fixed shape forms a truncated square pyramid.

The center portion of the heater wires 120 and 130 and the emitter 110 are coupled by resistance welding. That is, as shown in FIGS. 8A to 8C, the heater wire 120 or 130 is supported between the side of the emitter 110 supported by the die 601 and the welding electrode 600. In this state, the current is supplied to the emitter 110 and the electrode 600 to allow the interposed heater wire 120 or 130 to generate heat, and to heat the heater wire 120 or 130 using the welding electrode 600. Pressurization to the emitter side allows the heater wire to be embedded in the side of the emitter as shown in FIG. 7. At this time, the central portion of the heater wire welded to the side of the emitter 110 should be located in a straight line at the center of the side of the emitter 110.

The emitter 110 supported by the heater wires 120 and 130 has a geometric shape that penetrates the center portion of the bottom 112 of the emitter 110 and the center portion of the holder body 150. It has a rectangular parallelepiped shape having four side surfaces 113, 114, 115, and 116 sides extending laterally with respect to the vertical axis C. At least two mutually opposite surfaces of the four side surfaces 113, 114, 115, and 116, that is, the two side surfaces 113 and 115 to which the central portions 121 and 131 of the heater wires 120 and 130 are welded. ) Are parallel. And the thickness of the emitter is variable within the range of 1/2 to 1/5 of the base specification by the narrow side of the emitter 110 welded to the heater wire made of tungsten and the requirements of manufacturing technical process. desirable.

The emitter 110 is made of an electron-emitting metal alloy consisting of 0.5 to 9.0% by weight of rare earth rapidity of cerium group, 0.5 to 15% by weight of tungsten and / or rhenium, 0.5 to 10% by weight of hafnium and the remainder of iridium. .

If the rare earth metal content of the cerium group is less than 0.5% by weight of the material constituting the electron-emitting metal alloy, the lifetime of the negative electrode is shortened due to the deficiency of the rare earth metal of the cerium group as an active ingredient. There is a problem in that a compound such as Ir2Ce or Ir2La is formed on the cathode surface. Here, the rare earth metal of the cerium group is preferably at least one selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, and samarium. And the content of tungsten and / or rhenium is selected within the limit that the plasticity and electron-emitting ability of the alloy is not lowered, if the content is less than 0.5% by weight, the melting point of the alloy is lowered, the high temperature operation of the cathode is difficult and the content is 15.0 If the weight percentage is exceeded, there is a problem that the electron-emitting ability and plasticity of the negative electrode are lowered. Hafnium content of 0.5 to 10% by weight of the material constituting the electron-emitting alloy, if the content of hafnium is less than 0.5% by weight increase the work function and operating temperature, the effect of improving the lifetime of the negative electrode and the brittleness (brittleness) of the alloy Also, if the content exceeds 10% by weight, the content of iridium is relatively decreased, so that the electron emission characteristic of the alloy is lowered and the melting point of the alloy is also lowered.

One embodiment of the standard that can be practically applied to each series negative electrode unit configured as described above is as follows.

The emitter 110 is manufactured in a size of 0.6 × 0,6 × 2 mm, and heater wires 120 and 130 of tungsten rhenium alloy (tungsten 80 wt% rhenium 20 wt%) have a diameter of 50 μm. The lengths of the heater wires 120 and 130 are completely equal to 4 mm. The holder supports 141 and 142 made of a corrosion resistant metal use a wire having a diameter of 0.23 mm. The holder supports 141 and 142 are equal in length to 3 mm. The current supply holder pins 143 and 144 are made of cobar wire having a diameter of 0.4 mm. The insulator 151 of the holder body 150 is made of glass C48-2. The cylinder sleeve 152 of the holder body 150 is made of a Kover roll having an outer thickness of 0.2 mm and an outer diameter of 4.25 mm. The length of the parallel part, ie, the center part, of the heater wires is equal to 0.9 mm. And the lengths of the protrusions projecting from the emitter 110 are equal to three times the diameter of the heater wire.

As described above, the operation of the series-type negative electrode unit and the operation of the electron gun employing the same will be described below.

First, heater wire voltage and current are applied to the current supply holder pins 143 and 144 of the holder body 150 at 1.2V and 1,2A, respectively. When a voltage is applied as described above, the heater wires 120 and 130 having the ends of the support portion fixed to the heater supports 141 and 142 generate heat to heat the emitter 110 to about 1400 degrees or more. At this temperature, the current emission density from the emitting surface of the cathode emitter is 5 A / cm 2 or more.

As described above, the electron beam having a high current density emitted from the cathode unit is focused and accelerated by a prefocus lens formed between the screen electrode and the focusing electrode and then focused by the main lens formed between the focusing electrode and the final acceleration electrode. And accelerated.

The direct heater type negative electrode unit and the electron gun using the same according to the present invention configured as described above have the following effects.

first; High heat transfer efficiency between heater wire and emitter minimizes power consumption.

second; During operation, disconnection or dropping of the heater wire due to an interface reaction between the heater wire and the emitter does not occur.

third; Compared with other direct thermal metal cathode structures, the thermal stability is excellent under high temperature operating conditions, so the deformation of the cathode structures is small.

fourth; Compared to other direct thermal metal cathode structures, it has high mechanical stability and is resistant to external shocks.

Fifth: The size of the emitter is small and the advantages of the electron gun, such as focus and cut-off, are excellent due to the above advantages.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (24)

An emitter made of an electron-emitting metal alloy having at least two parallel sides extending transverse to the geometric longitudinal axis passing through the base, Two heater wires each having a center welded to two corresponding sides of the emitter, Holder body with current supply holder pin, Both ends of the pair of heater wires connected to the holder pins are fixed to each other, and a direct type negative electrode unit comprising heater supports connected to the current supply holder pins so that the vertical axis of the holder body and the vertical axis of the emitter axis coincide with each other. . The method of claim 1, The emitter is a rectangular series of negative electrode unit, characterized in that the thickness is varied within the range of 1/2 to 1/5 of the base standard. The method of claim 1, And the parallel portion of the heater wire lines extends from the welded portion of the body of the emitter. The method of claim 3, wherein The length of the heater wire protruding from the side of the emitter is a direct heater type negative electrode unit, characterized in that 2 to 5 times the diameter of the heater wire. The method of claim 1, And a center portion of each heater wire is connected to a center portion of an emitter side surface. The method of claim 1, The heater support is a series of negative electrode unit, characterized in that made of a high resistance iron-nickel alloy. The method of claim 1, Each of the heater supports has a center portion thereof connected to a current supply holder pin. The method of claim 1, And the heater supports are coupled to the current supply holder pin to form a cross shape with the current supply holder pin. The method of claim 1, Heater wires supported by the heater support is a direct-heat negative electrode unit, characterized in that made of a shape such as truncated square horns. The method of claim 1, The side of the emitter and the center portion of the heater wire is a direct-heat negative electrode unit, characterized in that the resistance welded. The method of claim 10, The resistance welding heats the heater wire by supplying a current while the heater wire is interposed between the welding electrode and the emitter, and presses the heater wire to the side of the emitter by the welding electrode so that the heater wire is embedded in the side of the emitter. A series negative electrode unit, characterized in that made. 0.5 to 9.0% by weight of the rapid pressure of cerium group, 0.5 to 9.0% by weight of tungsten and / or rhenium, 0.5 to 10% by weight of hafnium, with at least two parallel sides extending transverse to the geometric longitudinal axis passing through the base And an emitter made of an electron-emitting metal alloy consisting of iridium in the remainder, Two heater wires welded to two corresponding sides of the emitter, Holder body with current supply holder pin, Heated heaters, characterized in that the heater pins are connected to the holder pins, and both ends of the pair of heater wires are fixed to each other, and heater supports connected to the current supply holder pins so that the vertical axis of the holder body and the vertical axis of the emitter coincide with each other. Wire cathode unit. The method of claim 12, The emitter is a rectangular series of negative electrode unit, characterized in that the thickness is varied within the range of 1/2 to 1/5 of the base standard. The method of claim 12, And a parallel portion of the heater wire lines extends from the welded portion of the body of the emitter. The method of claim 14, The length of the heater wire protruding from the side of the emitter is a direct type negative electrode unit, characterized in that 2 to 5 times the diameter of the heater wire. The method of claim 12, And a center portion of each heater wire is connected to a center portion of an emitter side surface. The method of claim 12, The heater support is a series of negative electrode unit, characterized in that made of a high resistance iron-nickel alloy. The method of claim 12, Each of the heater supports has a center portion thereof connected to a current supply holder pin. The method of claim 12, The holder supports are coupled to the current supply holder pin to form a cross-shaped negative electrode unit, characterized in that coupled to the current supply holder pin. The method of claim 12, Heater wires supported by the holder support is a direct-type negative electrode unit, characterized in that formed in the shape of a truncated square horn. The method of claim 12, The side of the emitter and the center portion of the heater wire is a direct-heat negative electrode unit, characterized in that the resistance welded. The method of claim 21, The resistance welding heats the heater wire by supplying a current while the heater wire is interposed between the welding electrode and the emitter, and presses the heater wire to the side of the emitter by the welding electrode so that the heater wire is embedded in the side of the emitter. A series negative electrode unit, characterized in that made. An emitter made of an electron-emitting metal alloy having at least two parallel sides extending transverse to the geometric longitudinal axis passing through the base, two heater wires welded to two corresponding sides of the emitter, and a current supply Cathode unit comprising a holder body having a holder pin, and both ends of the pair of heater wires connected to the support and the heater supports connected to the current supplying holder pins so that the vertical axis of the holder body and the vertical axis of the emitter axis coincide with each other. Wow; A control electrode and a screen electrode which are sequentially installed from the cathode unit to form a triode together with the cathode unit; a plurality of focusing electrodes disposed adjacent to the screen electrode to form a main lens and an auxiliary lens; Electron gun characterized in that it has been included. The method of claim 23, wherein The electron-emitting metal alloy is made of an electron-emitting metal alloy consisting of 0.5 to 9.0% by weight of the rapid flow rate of cerium group, 0.5 to 15% by weight of tungsten and / or rhenium, 0.5 to 10% by weight of hafnium and the rest of iridium Gun.