JPH04101344U - Cathode structure for cathode ray tube - Google Patents

Abstract

(57) [Summary] [Structure] The surface area of the cathode sleeves 4 located on both outer sides is reduced by 10 to 30% compared to the cathode sleeve 4 located at the center. [Effect] It is possible to obtain an in-line cathode structure with high display quality that does not cause color change such as white balance collapse that occurs when the heater 5 is ignited.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to cathode assemblies for cathode ray tubes, especially when the white balance is adjusted when the heater is ignited. The present invention relates to a stable cathode assembly for a cathode ray tube.

0002

[Conventional technology]

Conventionally, cathode ray tubes use insulators such as ceramics for this type of cathode support. As shown in FIG. 3, the cathode assembly (hereinafter referred to as cathode assembly) for The cathode sleeve 4 is heated by a heater 5 inserted through the open end of the cathode sleeve 4, which is welded and fixed to the The reducing agent and cathode contained in the cap-shaped cathode base 2 which is welded and fixed to the cathode sleeve 4 The reaction with the alkaline earth oxide 3 applied to the top of the substrate 2 is promoted, and the Electron emission occurs at an operating temperature of 800°C. At this time, on the color picture tube screen The cathode current Ik taken out is determined by the hole diameter of the hole made in the first grid electrode, the cathode, It is determined by the positions of the first grid electrode and the second grid electrode and the applied voltage.

0003

[Problem that the idea aims to solve]

In the conventional cathode structure described above, all three cathodes have the same cathode sleeve support and cathode structure. Since a pole sleeve is used, the temperature of the central cathode base when the heater is ignited is lower than that of the outside Due to heat radiation and conduction of the cathode, the temperature is higher than the temperature of both outer cathode substrates. On the other hand, when taking out the cathode current Ik in the operating state, the cathode, first grid, and second grid Set the voltage for each electrode after sufficient time has elapsed after igniting the heater. Maintains thermal equilibrium.

0004 However, when the heater is ignited, the distance between the cathode and each electrode changes due to the temperature difference between the cathodes. move. Therefore, due to the temperature difference between the three cathodes, the Ik characteristic of the conventional central cathode shown in FIG. As shown in C, when the heater is ignited, only the central cathode has the maximum peak value of the cathode current Ik. The color tone is dull or takes a long time to stabilize, which is called white balance imbalance. There were disadvantages such as changes in

[0005] The purpose of this invention is to reduce the color tone change called white balance collapse that occurs when the heater is ignited. An object of the present invention is to provide a cathode structure that allows a cathode ray tube with high display quality to be obtained without causing distortion. .

[0006]

[Means to solve the problem]

This idea is (1) A cathode sleeve support and a cathode sleeve held by the cathode sleeve support , a cap-shaped cathode base fixed to the cathode sleeve, and a cap-shaped cathode base coated on the top of the cathode base. and a heater inserted into the cathode sleeve. A cathode line in which cathodes are arranged in a straight line in an insulator containing ceramics. In the tube cathode structure, the cathode sleeve is located at the center, and the cathode sleeve is located at both outer sides. The surface area of the cathode sleeve is reduced by 10 to 30%. (2) A cathode sleeve support and a cathode sleeve held by the cathode sleeve support. , a cap-shaped cathode base fixed to the cathode sleeve, and a cap-shaped cathode base coated on the top of the cathode base. and a heater inserted into the cathode sleeve. A cathode line in which cathodes are arranged in a straight line in an insulator containing ceramics. In the tube cathode assembly, the cathode located at the center with respect to the cathode located on both outer sides. The welding fixation area between the cathode sleeve supporter and the cathode sleeve of the cathode is 1.5 to 1.5. It is characterized by being twice as large.

[0007]

【Example】

Next, embodiments of the present invention will be described with reference to the drawings.

[0008] FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

[0009] In the first embodiment, as shown in FIG. 1, the cathodes 1 are arranged in parallel on a straight line, and the cathode A support fixture is attached to a glass rod (not shown) via the leaf support 6 and the cathode support 8. has been established. Each cathode 1 was fixed to the cathode sleeve 4 by welding. It consists of a cathode substrate 2 and an alkaline earth oxide 3 coated on the top of the cathode substrate 2, A heater 5 is inserted into each cathode sleeve 4, and the heater 5 is attached to a heater support (not shown). (without welding).

0010 Here, among the three cathodes 1, both outer cathodes 1 are connected to the cathode sleeve 4 and the cathode sleeve. A part of the surface of the cathode sleeve 4 is cut, leaving the welded part 9 of the support 6, and the surface is removed. The area should be 10 to 30% smaller than that of the central cathode 1.

[0011] FIG. 2 is a longitudinal sectional view of a second embodiment of the present invention.

0012 In the second embodiment, as shown in FIG. 2, the cathode sleeve 4 of the central cathode 1 and the cathode sleeve The welding fixation area of the tube support 6 is made 1.5 to 2 times larger than that of the cathodes 1 on both outer sides. . For example, while the outer cathodes 1 are 2-point welded, the central cathode is 3-point welded. Then, the welding fixation area is increased by 1.5 times.

[0013]

[Effect of the idea]

As explained above, the present invention provides an in-line cathode structure with both sides facing the center. Cut the outer cathode sleeve and also cut the center cathode sleeve and the cathode sleeve on both sides. The temperature of the cathode base of the three cathodes can be increased by increasing the welding area with the electrode sleeve support. By making them the same, the amount of variation in the distance between the cathode base and the electrode when igniting the heater can be kept approximately the same. This can prevent changes in color tone such as white balance disruption that occurs when the heater is ignited. This has the effect of providing an in-line cathode structure with high display quality that does not cause .

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a second embodiment of the present invention.

FIG. 3 is a longitudinal cross-sectional view of an example of a conventional cathode assembly.

FIG. 4 is a characteristic diagram showing changes in cathode current Ik with respect to time from heater ignition.

[Explanation of symbols]

1 cathode 2 Cathode substrate 3 Alkaline earth oxides 4 Cathode sleeve 5 Heater 6 Cathode sleeve support 7 Cathode sleeve auxiliary support 8 Cathode support 9 Welded fixed part

Claims (2)

[Scope of utility model registration request] 1. A cathode sleeve support, a cathode sleeve held by the cathode sleeve support, a cap-shaped cathode base fixed to the cathode sleeve, and an alkaline earth metal coated on the top of the cathode base. In a cathode assembly for a cathode ray tube in which three cathodes each having an oxide and a heater inserted in the cathode sleeve are arranged in line in a straight line using an insulator including ceramics, with respect to the cathode sleeve located at the center. The surface area of the cathode sleeves located on both outer sides is 1
A cathode assembly for a cathode ray tube, characterized in that it is 0 to 30% smaller. 2. A cathode sleeve support, a cathode sleeve held by the cathode sleeve support, a cap-shaped cathode base fixed to the cathode sleeve, and an alkaline earth coated on the top of the cathode base. In a cathode assembly for a cathode ray tube in which three cathodes each having an oxide and a heater inserted in the cathode sleeve are arranged in a straight line in a straight line using an insulator including ceramics, with respect to the cathodes located on both outer sides. A cathode assembly for a cathode ray tube, characterized in that a welding area between the cathode sleeve support of the cathode located at the center and the cathode sleeve is increased by 1.5 to 2 times.