JPS5814511Y2 - Indirectly heated cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an indirectly heated cathode ray tube, and in particular to an improvement of the cathode.

Generally, the cathode of an indirectly heated cathode ray tube is made of a cylindrical sleeve 1 made of a thin metal such as nickel, which has a first bulge 2, and a ceramic insulator 3 having an insertion hole, as shown in FIG. After insertion, a second bulge 2' is provided, the insulator 3 is fixed to the sleeve 1, and the first and second bulges 2, 21 are crushed in the axial direction as shown in FIG. , opposing surfaces 2 a of the first and second bulges 2 and 21
, 2'a are brought into close contact with the insulator 3, and the insulator is clamped and fixed. Then, as shown in FIG. 3, a flared part 1a with a large diameter opening is provided at one end of the sleeve 1, and a cap 4 and a cathode tape 5 are welded, respectively. After fixing, cleaning, and drying, a coating material 6 is applied to the upper surface of the cap 4, and the distance between the facing surfaces of the cap 4 and the first grid 7 is kept constant inside the first grid 7. The heater 10 is positioned in the sleeve 1 with a spacer 8 in between and fixed with a retainer 9, and the heater 10 is inserted into the sleeve 1.

However, since the sleeve 1 and the insulator 3 are fixed by caulking at room temperature, the sleeve 1 expands due to the operating temperature of the cathode, and the adhesion with the insulator 3 deteriorates. The distance between the facing surfaces changes.

This distance affects the cutoff characteristics of the cathode ray tube, and in particular, since it is operated at low brightness such as in display equipment, even a slight change in the cutoff voltage can have a large effect on devices whose operating point is set near the cutoff voltage. This has the disadvantage that brightness changes and vibrations cause brightness and noise in the display.

The present invention has been proposed in view of the above-mentioned drawbacks, and it is an object of the present invention to provide an indirectly heated cathode ray tube that eliminates the above-mentioned drawbacks.

Embodiments of the present invention will be described below with reference to the drawings shown in FIGS. 4 to 12.

That is, FIGS. 4 to 6 show the first embodiment, and FIGS. 4 and 5 show a front view and A-A sectional view of the insulator, and FIGS.
The figure shows a side sectional view of the insulator shown in FIG. 4 with a cathode sleeve fixed to it.

In the figure, reference numeral 11 denotes an insulator in which a metal part (metal pin) 13 is embedded in the vicinity of the insertion hole 12 parallel to the insertion hole axial direction, with both ends slightly protruding. The spring IJ-pipe 15 provided above the metal pin 13 is inserted so that the second bulge 14' is above the metal pin 13, and the first and second bulges 14°14' Crush them to bring the sleeve 15 and insulator 11 into close contact,
The first and second bulges 14a and 14'a on both end faces of the metal pin 13 are held between the electrodes of a spot welding machine, pressurized, and energized to separate the first and second bulges and the metal pin 13. Contact part 1
6.16' are welded and fixed to ensure perfect adhesion between the sleeve 15 and the insulator 11.

The following assembly can be done as usual.

In this way, the insulator is closely held by the bulge provided on the sleeve, and the metal pin embedded in the insulator and the bulge are fixed by welding, so the adhesion between the insulator and the sleeve is perfect.

A second embodiment of the present invention is shown in FIGS. 7 to 9.

That is, FIGS. 7 and 8 are a front view of the insulator and B
9 is a side sectional view of the insulator shown in FIG. 7 with a cathode sleeve fixed to it.

In the figure, 17 is an insulator, and insulator 1
A metal pin 19 is installed in the vicinity of the insertion hole 18 of No. 7 in parallel to the axial direction of the insertion hole, and has both ends protruding slightly beyond the thickness of the bulge at a position that almost touches the top of the bulge provided in the sleeve. The first and second bulges 21 are provided on the sleeve 20.
.
0 is pinched and pressurized, and the tops 21a of the first and second bulges,
21'a and the metal pin 19 are welded and fixed, and the sleeve 20
and the insulator 17 have perfect adhesion.

In this way, the insulator is brought into close contact with the bulge provided on the sleeve, and the metal pin embedded in the insulator and the bulge are fixed by welding, so the adhesion between the insulator and the sleeve is perfect, and even when the cathode is operated, the insulator and sleeve can maintain adhesion.

Furthermore, since the bulge and the metal pin can be welded without bringing the welding electrode into contact with the sleeve, welding efficiency is improved.

Further, a third embodiment of the present invention is shown in FIGS. 10 to 12.

That is, FIGS. 10 and 11 show a front view and a sectional view taken along the line CC of the insulator, and FIG. 12 shows a side sectional view of the insulator shown in FIG. 10 with a cathode sleeve fixed thereto.

In the figure, 22 is an insulator having an insertion hole 24 in which a U-shaped notch 23 is provided on the circumferential surface of a cylindrical insulator. A metal pin insertion hole 25 is provided, and the sleeve 26 has first and second bulges 27.
.
A metal pin 28 having approximately the same diameter as this diameter is connected to the notch 2 at both ends.
The sleeve 26 and the wall surface 2 of the notch 23 of the insulator 22 are press-fitted or inserted so as to protrude from the wall surface 23a of the sleeve 26 and the insulator 22.
The metal pin 28 is welded to the side surface 29 of the sleeve by applying a welding electrode to the metal pin 28 protruding from the sleeve 3a.

In this way, the insulator is brought into close contact with the bulge provided on the sleeve, and the metal pin inserted almost perpendicular to the insulator toe axis is welded to the sleeve while locking the insulator, which allows the movement of the insulator and sleeve. At times, the adhesion between the cathode and the sleeve can be maintained.

In addition, the welding electrode is easy to install, so welding workability is good.As described above, according to the present invention, by welding the metal pin inserted through the insulator to the sleeve, it is possible to perfect the adhesion between the insulator and the sleeve. Since the adhesion is maintained even when the cathode is operating, the distance between the opposing surfaces of the cap and the first grid does not change due to vibration etc., and therefore no change in cut-off characteristics occurs, so the operating point is set near the cut-off voltage. When operating at low brightness, it is possible to prevent changes in the detection angle and noise due to vibration, etc.

It should be noted that the present invention is not limited to the above-mentioned embodiments; for example, the first and second bulges may be removed using a jig that can accurately adjust the mounting position of the insulator to the sleeve. can.

Further, the metal pin may have any shape such as not only a rod shape but also a plate shape.

Further, welding may be performed at least in one place on the sleeve side of the metal pin.

Furthermore, the notch part is not limited to the U-shape,
Any shape may be used as long as the first grid and the metal pin (sleeve) are not short-circuited.

[Brief explanation of the drawing]

1 to 3 are drawings explaining a conventional cathode, FIGS. 4 to 6 are drawings explaining a first embodiment of the present invention, FIG. 4 is a plan view of an insulator, and FIG. 5 is a drawing explaining a conventional cathode. is a sectional view taken along the line A-A in FIG. 4, FIG. 6 is a diagram explaining the assembly method, FIGS. 1 to 9 are diagrams explaining the second embodiment of the present invention, and FIG. 7 is a diagram showing the insulator. A plan view, FIG. 8 is a sectional view taken along the line B-B in FIG. 7, FIG. 9 is a drawing explaining the assembly method, and FIGS. 10 to 12 are drawings explaining the third embodiment of the present invention. Figure 10 is a plan view of the insulator;
FIG. 11 is a sectional view taken along the line CC in FIG. 10, and FIG. 12 is a drawing for explaining the assembly method. 1L17,22...Insulaiku, 13,1
9゜28...Metal part, 15, 20, 26...
···sleeve.

Claims (1)

[Scope of utility model registration request] In an indirectly heated cathode ray tube equipped with a cathode formed by fixing a sleeve through an insulator, a metal part that penetrates the insulator and has both ends protruding from the insulator,
buried so that at least one end protrudes near the insertion hole;
An indirectly heated cathode ray tube characterized in that a metal part and a sleeve are fixed by welding.