JP2001250485A - Cathode body structure for cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cathode body structure, in which a cup can be easily press fitted to a sleeve without enlarging the sizes of a cup and a sleeve that are components. SOLUTION: The cathode body structure for a cathode ray tube has a structure, in which an opening of a straight tubular sleeve 120A, which is a component, to press fit a cup 110 is formed a bell mouth 121A shape, and the cup 110 where a cathode substrate R has been fixed can be easily press fitted. Further, by widening the opening of the other end, insertion of a heater 140 to heat the cathode substrate R becomes easier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode structure constituting an electron gun of a cathode ray tube used for a color television receiver or the like, and more particularly to a porous structure impregnated with an electron emitting material constituting the cathode structure. The present invention relates to a structure for accommodating a cathode base and a sleeve for holding the cup.

[0002]

2. Description of the Related Art First, the structure and structure of a cathode structure of a generally used cathode ray tube electron gun will be described with reference to the drawings.

FIG. 6 is a partial cross-sectional side view of a first conventional cathode assembly, FIG. 7 is a conceptual drawing of the assembly of the cathode assembly shown in FIG. 6, and FIG. 8 is incorporated in the cathode assembly shown in FIG. FIG. 9A shows a cross-sectional side view of each part, FIG. 9B shows a cross-sectional side view of the assembled state of each part, and FIG. 10 is a partial sectional side view of a prior art electron gun incorporating the cathode structure shown in FIG. 10, FIG. 10 is a partial sectional side view of a second prior art cathode structure, and FIG. FIG. 2 is a partial cross-sectional side view of the cathode assembly of FIG.

First, the configuration and structure of a cathode structure according to a first embodiment of the prior art will be described with reference to FIGS.

The conventional indirectly heated cathode structure 10A is of a power saving type. Generally, as shown in FIGS. 6, 7 and 8, a cathode base R, a cup 110 and both ends are opened. A relatively small-diameter sleeve 120, a relatively large-diameter sleeve 130 capable of accommodating the sleeve 120,
0, multiple straps 150, sleeve holder 160
It is composed of such parts. The cathode substrate R is, for example, a porous tungsten member coated or impregnated with an electron emitting material.

The cup 110 is a container having a depth capable of accommodating the cathode base R therein. The bottom outer peripheral portion 111 of the cup 110 is formed in a tapered shape so as to be easily inserted into the opening 121 at one end of the sleeve 120. I have. The cathode base R is fixed to the center of the flat bottom surface. Also, the cup 110
A flange 112 having a predetermined width is formed at the periphery of the opening.

[0007] The sleeve 120 is a straight pipe type cylinder having both ends open. The cup 110 is fitted and mounted in one opening 121, and the heater 140 is inserted and mounted through the opening 122 at the other end. This heater 140 is used for this sleeve 1
20 and the cup 110 are heated, and the cathode substrate R contained in the cup 110 is heated.

[0008] The other large-diameter sleeve 130 is also a cylinder having both ends open, and has a cup 110 containing a cathode base R therein and a heater 140 incorporated therein.
20 are incorporated.

The sleeve holder 160 is a cylinder for mounting the sleeve 130 in which various components are incorporated as described above to the electron gun, and the upper end thereof is formed on the flange 131.

As shown in FIGS. 7 and 8, the cathode structure 10 A has a cup 110 in which a cathode base R is accommodated in a flat bottom portion and the cathode base R is fixed from the bottom of the cup by laser welding. After being press-fitted or fitted into the opening 121 and fixed by laser welding from the outer surface of the sleeve 120, the sleeve 120 is
And the upper part of the cup 110 is slightly protruded from the opening of the sleeve 130 by the plurality of straps 150.
0 is attached to the other end (lower end) of the sleeve 120 and the other end of the strap 150 is attached to the upper end of the sleeve 130 by laser welding. And then the sleeve 120
Heater 1 for heating cathode substrate R from opening 122 at the other end of
40 is inserted, fixed and assembled.

The cathode structure 10A thus configured is
For example, using an insulating substrate I made of ceramics, it is attached to the electron gun 20 as shown in FIG. FIG. 9 shows an electron gun for a color cathode ray tube. In this case, three cathode assemblies 10A for emitting electron beams for controlling red, green and blue colors are incorporated. Reference numeral G1 indicates the first grid electrode, which has a shallow circular cup-shaped integral structure, and is inserted and fixed while adjusting the distance between the first grid electrode G1 and the cathode substrate R. Behind the first grid electrode G1, a cover 210 that covers the periphery and a part of the three mounted cathode structures 10A and supports the insulating substrate I is combined with the first grid electrode G1. Then, the heater 140 for heating the cathode base R is inserted from the opening 122 at the other end of the sleeve 120 and fixed, and the cathode assembly in the electron gun 20 is completed. Note that reference sign G2 in FIGS. 6 and 7 indicates the second grid electrode.

The cathode structure shown in FIG. 10 is a cathode structure 10B according to a second embodiment of the prior art, which is not a power-saving type.
0 is excluded, a sleeve 130A having a structure in which the diameter of the sleeve 130 is narrowed is used, the lower end of the sleeve 120 is inserted into the upper end opening of the sleeve 130A, and both are directly welded and attached. The other components are the same as those of the cathode structure 10A, and thus are denoted by the same reference numerals.

FIG. 11 shows a third embodiment of a cathode assembly 10C according to the prior art. The above-mentioned both cathode structures 10A, 10B
Has a two-body structure of the sleeve 120 and the sleeve 130 or the sleeve 130A.
At 0C, both are formed in an integrated structure. The integrated sleeve is shown as a sleeve 180.

[0014]

The cathode bases R in the cathode structures 10A, 10B, and 10C having the above-described structures are all of an impregnated type of a tungsten disk impregnated with an electron emitting material, Is fixed to the inner surface at the bottom center by welding. As shown in FIG. 8, the cup 110 to which the cathode base R is fixed is press-fitted into an opening 121 at one end of the sleeve 120 and fixed by welding. In this press-fitting, the outer peripheral portion 111 of the bottom surface of the cup 110 is formed in a tapered shape so that the press-fitting into the sleeve 120 can be easily performed. If the size of the tapered shape is insufficient, when the cup is press-fitted in the automatic assembling machine, the cup 110 cannot be press-fitted unless the positioning of the cup 110 and the sleeve 120 is strictly performed, or the sleeve 120 is deformed. Would.

Therefore, in order to further facilitate the press-fitting operation, if the shape of the tapered portion 111 is increased,
The bottom of the cathode base R rides inside the tapered portion 111, and the cathode base R is inclined in the cup 110. Usually, the outer diameter of the cylindrical portion of the cup 110 is designed to be larger than that of the cathode base R so that the diameter of the flat bottom surface of the cup 110 is larger than the outer diameter of the bottom of the cathode base R.

If the outer diameter of the cylindrical portion of the cup 110 is designed to be sufficiently large, giving priority to the workability of press-fitting the cup 110, the gap between the cathode base R and the inner peripheral surface of the cylindrical portion of the cup 110 is increased. As a result, the overall shape of the cathode assembly 10 becomes large, and the attachment to the electron gun is restricted. Further, the heat loss of the cathode assembly 10 increases, and the power consumption of the cathode heater 140 increases. I do. For example, if the outer diameter of the cathode assembly 10 is increased, as shown in FIG. 9, when the cathode assembly 10A is supported and fixed to the electron gun 20, a sufficient interval between the cathode assemblies 10A cannot be ensured, and Structure 1
There is a high possibility that a problem such as an increase in leakage current between 0 A will occur.

Therefore, since there is a restriction in increasing the tapered portion 111 of the cup 110, there is a problem in workability when the cup 110 is press-fitted into the sleeve 120.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a cathode assembly which does not increase the size of a cup or a sleeve and which can easily press a cup into a sleeve. is there.

[0019]

Therefore, according to the first aspect of the present invention, a cathode substrate accommodating an electron-emitting substance, a cup capable of accommodating and fixing the cathode substrate and a cathode are provided in an opening at one end. In a cathode ray tube cathode assembly comprising a sleeve into which a cup can be fitted and fixed, the above-mentioned problem is solved by forming a shape around an opening at one end of the sleeve into a trumpet shape.

According to the second aspect of the present invention, the cathode substrate accommodating the electron-emitting substance, a cup capable of accommodating and fixing the cathode substrate and the cup can be fitted and fixed to an opening at one end, In a cathode ray tube cathode assembly comprising a sleeve in which a heater can be mounted inside through an opening at the other end, and a sleeve holder capable of accommodating and holding the sleeve inside, a shape around the opening at one end of the sleeve is a trumpet shape. The above-mentioned problem is solved by forming a shape around the opening at the other end with a diameter having a size that remains within the inner diameter of the sleeve holder.

Further, in the invention according to claim 3, the outer peripheral end of the opening of the cup in the cathode assembly for a cathode ray tube according to claim 1 or 2 is formed in a flange shape, and The problem is solved by forming the outer diameter of the wrapper formed at the one end opening so as not to exceed the outer diameter of the flange.

Further, in the invention according to a fourth aspect, in the cathode assembly for a cathode ray tube according to the second aspect, the shape around the opening at the one end of the sleeve is formed in a trumpet shape, and around the opening at the other end. In order to solve the above-mentioned problem, the diameter of the hole is larger than the outer diameter of the wrapper and is substantially equal to the inner diameter of the sleeve holder.

Therefore, according to the cathode ray tube cathode structure of the first aspect of the present invention, the cup can be mounted on the sleeve very easily.

According to the cathode structure for a cathode ray tube of the second aspect of the present invention, not only can the cup be mounted on the sleeve very easily, but also the heater for heating the cathode structure can be inserted into the sleeve. Can be easily inserted.

Further, according to the cathode assembly for a cathode ray tube according to the third aspect of the present invention, in addition to the operation of the cathode assembly for a cathode ray tube according to the first or second aspect of the invention, a current automatic assembling machine is used. Thus, the mounting of the cup on the sleeve can be performed extremely easily while holding and positioning the cup as before.

Further, in the cathode ray tube cathode assembly according to the present invention, the cup and the cathode assembly can be extremely easily mounted on the sleeve, and the sleeve is attached to the sleeve holder. Can be installed directly.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cathode structure for a cathode ray tube according to the present invention will be described below with reference to FIGS.

FIG. 1 is a partial cross-sectional side view of a cathode structure according to an embodiment of the present invention, and FIG. 2 shows a structure of a sleeve according to a first embodiment suitable for use in the cathode structure of the present invention shown in FIG. 3A is a cross-sectional side view of the cup and the sleeve before the cup is mounted on the sleeve, FIG. 3B is a cross-sectional side view of the cup and the sleeve with the cup mounted on the sleeve, FIG.
Shows the sleeve of one embodiment showing the size of the sleeve shown in FIG. 2, FIG. A is a side view, FIG. B is a partially enlarged cross-sectional side view of a wrapper portion of the sleeve of FIG. FIG.
Shows the structure of the sleeve of the second embodiment suitable for use in the cathode assembly of the present invention. FIG. A is a sectional side view of the cup and the sleeve before the cup is mounted on the sleeve, and FIG.
Is a cross-sectional side view of the cup and the sleeve with the cup mounted on the sleeve, and FIG. 5 shows the structure of the sleeve of the third embodiment suitable for use in the cathode assembly of the present invention;
FIG. A is a cross-sectional side view of the cup and the sleeve before the cup is mounted on the sleeve, and FIG. B is a cross-sectional side view of the cup and the sleeve with the cup mounted on the sleeve.

In the following description, when the components of the cathode structure of the present invention are constituted by the same components as those of the conventional cathode structure 10A, the same reference numerals are given.
A description thereof will be omitted.

First, the first embodiment of the present invention will be described with reference to FIGS.
The configuration and structure of the cathode assembly of the embodiment will be described.

In FIG. 1, reference numeral 50A denotes a first embodiment of the present invention.
Refers to the cathode assembly of the embodiment. This cathode structure 50A is shown in FIG.
Is the same as the configuration of the cathode structure 10A according to the first embodiment of the prior art shown in FIG. 1, except for the structure of the opening 121 at one (upper end) of the sleeve 120 in the cathode structure 10A. FIG. 2 is an enlarged view of the sleeve 120A. This sleeve 120A has an opening 121A at the upper end in a trumpet-shaped structure. The cup 110 in which the cathode base R is accommodated and fixed in the opening 121 is press-fitted and fixed by, for example, laser welding.

The work of press-fitting the cup 110 is performed by the sleeve 1
By forming the opening 121A at the upper end of the 20A in a trumpet shape in this way, if the tapered portion 111 of the cup 110 and the tapered portion 121A of the sleeve 120A are positioned in a range where the tapered portion 111 and the sleeve 120A are in contact with each other, the cup 110 can be opened. It can be press-fitted into 121A very easily.

Next, an example of the size of the sleeve 120A will be described with reference to FIG. In this case, the inner diameter φa of the cylinder of the sleeve 120A is 1.31 mm, and the outer diameter φ is
b is 1.39 mm or less, plate thickness T is 22 μm, length La to the base of the wrapper is 4.8 mm, and maximum outer diameter φc of the wrapper
The length Lb to the part (tip of the horn) is 4.875m
m, the maximum outer diameter φc of the wrapper formed in the opening 121A is within 1.59 mm, the width of the wrapper protruding from the outer peripheral surface of the cylinder (the width to the outermost peripheral edge of the wrapper) W is 0.1 mm, and the maximum height of the wrapper H is 0.075 mm.

The dimension of the wrapper portion 121A protruding from the outer peripheral surface of the cylinder of the sleeve 120A is, for example, in order to keep the direction of the sleeve 120A constant when the sleeve 120A is supplied by a parts feeder by an automatic assembling machine. It is the smallest dimension that allows the K sleeve 120A to be sent along the rail. In this case 0.1
mm.

The outer diameter dimension φc of the wrapper portion 121A
For example, when press-fitting the cup 110 with an automatic assembler, the holding and positioning of the cup 110 are performed at the outer diameter portion of the flange 112 of the cup 110. There is a need to. With such dimensions, the cup 110 can be pressed into the sleeve 120A using an existing automatic assembling machine.

Next, the structure of the sleeve 120B of the second embodiment suitable for use in the cathode structure of the present invention will be described with reference to FIG. In this sleeve 120B, an opening 121A at one end (upper end) is formed in a trumpet structure, and an opening 122A at a lower end is also formed in a trumpet structure.

The workability of the work of inserting the heater 140 is improved by forming the opening 122A at the lower end portion with the trumpet structure.

Next, the structure of the sleeve 120C of the third embodiment suitable for use in the cathode structure of the present invention will be described with reference to FIG. This sleeve 120C is a sleeve 120B
And a sleeve 1 used in the prior art cathode structure 10C shown in FIG.
Opening 1 at one end (upper end) for mounting 80 cups 110
81 is formed in a trumpet structure, and the diameter of the opening 182 at the other end (lower end) into which the heater 140 is inserted is adjusted to the opening 181 at the upper end.
It is made larger and has a shape having a diameter substantially matching the inner diameter of the sleeve holder 160 that supports the sleeve 180.

By using the sleeve 180 having such a structure, the sleeve 130 and the strap 150 can be omitted, and there is an advantage that the number of assembly steps can be reduced along with the reduction in the number of parts.

[0040]

As described above, according to the cathode structure of the present invention, by improving the structure of the sleeve for mounting the cathode structure 10 and the heater 140, the cup having the cathode base fixed can be used as the sleeve of the present invention. The press-fitting became easier, and the workability of the press-fitting work was greatly improved. With this sleeve structure, it was possible to reduce defects such as sleeve deformation, insufficient press-fitting, and cup tilting when the cup was mounted (press-fitted) by an automatic assembly machine, and the yield of the cathode assembly could be improved. .

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view of a cathode assembly according to an embodiment of the present invention.

FIG. 2 shows a structure of a sleeve according to a first embodiment suitable for use in the cathode structure of the present invention shown in FIG. 1;
Is a cross-sectional side view of the cup and the sleeve before the cup is mounted on the sleeve, and FIG. B is a cross-sectional side view of the cup and the sleeve with the cup mounted on the sleeve.

3 shows a sleeve of one embodiment showing the size of the sleeve shown in FIG. 2; FIG. 3A is a side view thereof, and FIG. 3B is a partially enlarged cross section of a wrapper portion of the sleeve of FIG. It is a side view.

FIG. 4 shows the structure of a sleeve according to a second embodiment suitable for use in the cathode assembly of the present invention. FIG. 4A is a sectional side view of the cup and the sleeve before the cup is mounted on the sleeve. B is a cross-sectional side view of the cup and the sleeve with the cup attached to the sleeve.

FIG. 5 shows the structure of a sleeve according to a third embodiment suitable for use in the cathode assembly of the present invention. FIG. 5A is a sectional side view of the cup and the sleeve before the cup is mounted on the sleeve. B is a cross-sectional side view of the cup and the sleeve with the cup attached to the sleeve.

FIG. 6 is a partial cross-sectional side view of a cathode structure according to a first embodiment of the related art.

FIG. 7 is a conceptual diagram of assembling the cathode assembly shown in FIG. 6;

8 shows a cathode base, a cup and a sleeve, which are main components incorporated in the cathode structure shown in FIG. 6, wherein FIG. 8A is a sectional side view of each component, and FIG. It is sectional side view of the state which assembled | assembled.

FIG. 9 is a partial cross-sectional side view of a conventional electron gun incorporating the cathode structure shown in FIG. 6;

FIG. 10 is a partial sectional side view of a cathode structure according to a second embodiment of the related art.

FIG. 11 is a partial cross-sectional side view of a cathode structure according to a third embodiment of the related art.

[Explanation of symbols]

50A, 50B, 50C: the cathode structure of the embodiment of the present invention, 110: cup, 111: tapered portion 112: flange, 120A, 120B: the sleeve of the first embodiment suitable for use in the cathode structure of the invention, 121A, 122A: opening (wrapper), 130: sleeve, 140: heater,
150: strap, 160: sleeve holder, 180
... Sleeve of the second embodiment, 181 ... Opening part (wrapper), 182 ... Opening part, R ... (Porous) impregnated with an electron emitting substance

Claims (4)

[Claims] 1. A cathode ray tube comprising: a cathode substrate accommodating an electron-emitting substance; a cup capable of accommodating and fixing the cathode substrate; and a sleeve capable of fitting and fixing the cup in an opening at one end. The cathode structure for a cathode ray tube, wherein a shape around an opening of the one end of the sleeve is formed in a trumpet shape. 2. A cathode base accommodating an electron-emitting substance, a cup capable of accommodating and fixing the cathode base and surrounding the cathode base, a cup fitted and fixed in an opening at one end, and a heater inside the opening at the other end. In a cathode ray tube cathode assembly comprising a sleeve that can be mounted and a sleeve holder that can house and hold the sleeve inside, a shape around an opening at one end of the sleeve is formed in a trumpet shape, and the other end is formed. The cathode structure for a cathode ray tube, characterized in that the shape of the periphery of the opening is formed so as to have a diameter that is smaller than the inner diameter of the sleeve holder. 3. An outer peripheral end of the cup is formed in a flange shape, and an outer diameter of a wrapper formed at the one end opening of the sleeve does not exceed an outer diameter of the flange. The cathode assembly for a cathode ray tube according to claim 1, wherein the cathode assembly is sized. 4. A shape of the sleeve around the opening at one end is formed in a trumpet shape, and a diameter around the opening at the other end is larger than an outer diameter of the wrapper and substantially matches an inner diameter of the sleeve holder. The cathode assembly for a cathode ray tube according to claim 2, wherein the cathode assembly is formed to have a diameter.