JPH0785821A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To raise pressure resistance in the vicinity of the upper part of the end surface of the neck part between stem pins. CONSTITUTION:In a cathode-ray tube, in which a plurality of stem pins to be connected to an electron gun in a tubular body, are planted on the end surface 4 of a neck part, recessed parts 4b are provided on the end surface 4 of the neck part between a stem pin 5G4 to which high pressure is to be applied, and stem pins 5G1 and G2 which are placed in the vicinity of the stem pin 5G4, and to which low pressure is to be applied. Protruded parts 4a are provided on the end surfaces of the neck parts around the stem pin 5G4 to which high pressure is to be applied, to extend the creeping distance between the stem pins 5G4 and 5G1, G2 of the end surface 4 of the neck part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube in which a plurality of stem pins connected to an electron gun in a tube are erected on an end surface of a neck portion.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional unipotential electron gun of a cathode ray tube. K indicates a cathode and G1 to G5 indicate grids. An example of the voltage applied to these electrodes will be described.
30kV for grids G3 and G5, 1 for grid G4
A voltage of 3 kV, a voltage of 200 V is applied to the grid G2, and a voltage of 0 V is applied to G1. The main lens is composed of the grids G3, G4, and G5, but in order to improve the resolution, the grid G
4 tends to increase the voltage applied.

[0003]

High voltage is applied to the grids G3 and G5 from the anode cap provided in the cone portion of the cathode ray tube, but the other electrodes are applied from the stem pin erected on the end face of the neck portion. To be done. Therefore, the grid G4 to which high voltage is applied and the grid G to which low voltage is applied
Discharge between 1 and G2 becomes a problem.

The tube body of the cathode ray tube is usually made of glass, and this tube body has a uniform thickness in order to secure a strength sufficient to withstand the external atmospheric pressure and to take into consideration the distortion during processing. , Its surface is flat, and the end face of the neck is no exception.

The withstand voltage between the stem pins planted on the end face of the neck portion is about 1 kV per 1 mm when the end face is flat.
It is said that if this is exceeded, discharge will occur between the stem pins. In order to increase the pressure resistance between the stem pins, a silicon resin layer (silicon rubber) is adhered to the end surface of the neck portion, and a stem base is further adhered on the silicon resin layer. If there are air bubbles in it, it is difficult to expect a sufficient increase in the pressure resistance between the stem pins on the end face of the neck portion.

In view of the above point, the present invention intends to propose a cathode ray tube capable of increasing the withstand voltage near the end face of the neck portion between the stem pins.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a plurality of stem pins 5 connected to an electron gun in a tube are attached to an end surface 4 of a neck portion.
In the cathode ray tube in which the high pressure is applied, on the end face 4 of the neck portion between the high pressure applied stem pin 5 (G4) and the low pressure applied stem pins 5 (G1), (G2). The convex portion 4b is provided, and the convex portion 4 is provided on the end face of the neck portion around the stem pin 5 (G4) to which a high voltage is applied.
a is provided, and both stem pins 5 (G
The creepage distance between 4) and 5 (G1) and (G2) is increased.

[0008]

According to the present invention, the creeping distance between the stem pin (G4) to which a high pressure is applied on the end face 4 of the neck portion and the stem pins 5 (G1) and (G2) adjacent to which the low pressure is applied is reduced. , It becomes longer than the case where the end surface 4 of the neck portion is flat, and both stem pins 5 (G4) and 5 (G1),
The breakdown voltage during (G2) increases.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, the neck portion 1 of the cathode ray tube (1) to which the present invention is applied will be described with reference to the rear and side views of the neck portion of the cathode ray tube (1) shown in FIGS. 2 and 3, respectively. The electron gun G shown in FIG. 7 is housed in the neck portion 1.

A large number of stem pins 5 are erected on the end face 4 of the neck portion, and the grid G3 of the electron gun 1 in the neck portion 1 is
Each electrode except G5, that is, the grids G1, G2, G5,
It is connected to the cathode K, a heater and the like. 5 (G4) is a stem pin connected to the grid G4, 5 (G1), 5
(G2) are stem pins connected to the grids G1 and G2, respectively. The distance between the stem pin 5 (G4) and the stem pins 5 (G1) and 5 (G2) is 7 m here.
m. As is clear from the above, the stem pin 5 (G
A voltage of 13 kV is applied to 4) and the stem pin 5 (G
Voltages of 0 V and 200 V are applied to 1) and 5 (G2), respectively. The tip tube 6 projects to the center of the end face 4 of the neck portion so as to communicate with the neck portion 1, and finally the end portion is sealed.

A silicon resin layer (silicon rubber) 2 is adhered on the end face 4 of the neck portion, and a disc-shaped stem base 3 made of polycarbonate is adhered thereon.
The stem pin 5 is fitted in a socket (not shown).

Next, referring to FIG. 1, the end surface 4 of the neck portion
The shape of will be described. Reference numerals 2, 3, and 4 in FIG. 1 denote the end faces of the silicone resin (silicon rubber) layer, the stem base, and the neck portion described above with reference to FIGS. A convex portion 4b is provided on the end face 4 of the neck portion between the stem pin 5 (G4) to which a high voltage is applied and the stem pins 5 (G1) and (G2) adjacent to which a high voltage is applied, and the high voltage is applied. Stem pin 5 (G4) and stem pin 5 (G
1) Protruding portions 4a are provided on the end surfaces of the neck portion around 5 (G2), and both stem pins 5 of the end surface 4 of the neck portion are provided.
The creepage distance between (G4) and 5 (G1), (G2) is made long. The convex portion (4b) is, as shown in FIG.
Stem pin 5 (G4) and stem pin 5 (G1), 5
It has an elongated shape (3 mm × 2 mm) long in a direction substantially orthogonal to a straight line connecting (G2). The convex portion 4a is shown in FIG.
It has an annular shape as shown in. The height of each of the protrusions 4a and 4b is 0.7 mm.

Next, another cathode ray tube (2) to which the present invention can be applied will be described with reference to FIGS. 4 and 5, but in FIGS. 4 and 5, a portion corresponding to FIGS. Are denoted by the same reference numerals and redundant description will be omitted. In this cathode ray tube, the stem pin 5 (G4) and 5 (G
1) In the case of providing the partition wall 7 that isolates it from 5 (G2). 7f is a sleeve portion that contacts the periphery of the tip tube 6,
Reference numerals a, 7b, 7c and 7d denote partition walls extending in the radial direction, and reference numeral 7e denotes an arc-shaped partition wall which projects above the stem pace 3. The stem pin 5 (G4) is a part of the sleeve portion 7f,
It is surrounded by partitions 7b, 7c, 7e. The stem pin 5 (G1) is a part of the sleeve portion 7f and the partition walls 7a and 7b.
Surrounded by. The stem pin 5 (G2) is surrounded by a part of the sleeve portion 7f and the partition walls 7c and 7d. Therefore, the stem pin 5 (G4) and the stem pin 5
The breakdown voltage of the portion above the upper surface of the stem base 3 between (G1) and 5 (G2) is sufficiently high.

In the case of the cathode ray tube (2) shown in FIGS. 3 and 4, the shape of the end face 4 of the neck portion is the same as that described with reference to FIG.

As shown in FIG. 6, between the stem pins 5 (G4) and 5 (G1) described in FIG. 1 (although not shown,
The same applies to the stem pins 5 (G4) and 5 (G2)}, and the protrusions 4b arranged side by side between the pins may have a plurality of wavy cross-sections, here three protrusions. . By doing so, the creepage distance between the pins is further increased.

Incidentally, the shapes of the convex portions 4a and 4b are not limited to those in the above-mentioned embodiment, but may be arbitrary.

[0017]

According to the present invention described above, it is possible to obtain a cathode ray tube capable of increasing the withstand voltage near the end face of the neck portion between the stem pins.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a rear view of the neck portion of the cathode ray tube (1) to which the present invention is applied.

FIG. 3 is a side view of a neck portion of a cathode ray tube (1) to which the present invention is applied.

FIG. 4 is a rear view of the neck portion of the cathode ray tube (2) to which the present invention is applied.

FIG. 5 is a side view of a neck portion of a cathode ray tube (2) to which the present invention is applied.

FIG. 6 is a sectional view showing another embodiment of the present invention.

FIG. 7 is a layout drawing showing an example of an electron gun of a cathode ray tube.

[Explanation of symbols]

 1 Neck Part 2 Silicone Resin Layer 3 Stem Base 4 End Surface of Neck Part 4a Convex Part 4b Convex Part 5 Stem Pin 6 Chip Tube 7 Partition

Claims (2)

[Claims] 1. A cathode ray tube comprising a plurality of stem pins connected to an electron gun in a tube, which are erected on an end face of a neck portion, wherein a stem pin to which a high voltage is applied and a stem pin to which a low voltage is applied are adjacent to the stem pin. Between the two stem pins on the end surface of the neck portion, a convex portion is provided on the end surface of the neck portion between, and a convex portion is provided on the end surface of the neck portion around the stem pin to which the high pressure is applied. A cathode ray tube characterized in that the creepage distance of is increased. 2. The convex portion on the end face of the neck portion between the stem pin to which the high voltage is applied and the stem pin to which a low pressure is applied in the vicinity of the stem pin is formed into a plurality of convex portions juxtaposed between the both stem pins. It is configured as follows.
The described cathode ray tube.