JPH06196103A - Cathode structure for color picture tube - Google Patents

Abstract

PURPOSE:To provide a color picture tube of high quality without generation of color tone change called white balance breakage by forming projecting fins on a cathode sleeve of a center one out of three basic metals, and making temperatures equal at the basic metals of three cathodes. CONSTITUTION:Three cathodes of blue, green and red are fixed via a common hermetic supporter 5. A temperature of a center basic metal 2b is equal to those of basic metals 2a, 2c located on both sides of the center basic metal 2b. Annular projecting fins 10b are formed in the lower portion of a center one 1b out of cathode sleeves 1a, 1b, 1c. Consequently, heat radiation in the center cathode sleeve 1b is enhanced in comparison with the right and left cathodes sleeves 1a, 1c so that an increase in temperature of the center basic metal 2b can be restrained and a temperature at the center basic metal 2b becomes equal to those of the basic metals on both sides of the center basic metal 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode assembly of a color picture tube, and more particularly to a cathode assembly of an in-line type color picture tube.

[0002]

2. Description of the Related Art Conventionally, the cathode assembly of a color picture tube is shown in FIG.
As shown in FIG. 3, three cathodes of blue, green and red, which are cathode sleeves 1a, 1b and 1c in which heaters 3a, 3b and 3c are inserted and base metals 2a, 2b and 2c are fixedly contacted, are formed. It is supported by each cathode support 4a, 4b, 4c, and is arranged and fixed in a straight line by a common Herme support 5, and the cathode located at the center can conduct heat conduction and heat radiation from the cathodes located on both sides. receive.

By the way, in the above-mentioned conventional cathode assembly, the three cathode sleeves 1a, 1b and 1c for blue, green and red and the cathode supports 4a, 4b and 4c have the same shape. Therefore, in the center cathode among the three cathodes, the temperature of the base metal 2b of the center cathode is 2 ° C. due to the heat conduction and heat radiation of the cathodes on both sides. 10 ° C higher than the above, the diffusion rate of the reducing agents such as Mg and Si contained in the base metal 2b in the center increases, and the consumption becomes severe, so the electron emission characteristics of the center cathode are earlier than those of the cathodes on both sides. However, there was a problem that the color tone started to deteriorate and a change in color tone called white balance collapse occurred during long-term use.

[0003]

In the cathode assembly of the color picture tube according to the present invention, a protruding fin made of, for example, an annular body is fitted to the cathode sleeve or the cathode support located at the center in order to enhance the efficiency of heat release. It is constructed by using a conventional type without fins for the cathode sleeve or the cathode support of the cathode located on both sides.

[0004]

With the above structure, the heat dissipation of the base metal of the cathode located at the center among the above three cathodes is made higher than that of the base metal of the cathodes located on both sides. Lower the temperature of the base metal by about 10 ℃ from the base metal on both sides,
The temperature of the three base metals is made uniform.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a cathode assembly of a color picture tube showing an embodiment of the present invention. 1a, 1b and 1c are cathode sleeves, 2a, 2b and 2c are cathode sleeves 1a, 1b and 1c. Base metal fixed on top, 3
a, 3b and 3c are heaters inserted in the cathode sleeves 1a, 1b and 1c, 4a, 4b and 4c are cathode supports for supporting the sword sleeves 1a, 1b and 1c, and 5 is three cathode supports A common hermetic support 10b for supporting 4a, 4b, 4c is a protruding fin made of an annular body fitted to the centrally located cathode sleeve 1b, which is a feature of the present invention.

Next, the operation of the above cathode assembly will be described.

The three cathodes for blue, green, and red are fixed by a common Herme support 5, and the base metal 2b located at the center of the bases 2a, 2b, and 2c of the three cathodes and both sides are fixed. In order to equalize the temperature with the base metal 2a, 2c located at, the cathode sleeve 1b located at the center of the cathode sleeve 1a, 1b, 1c is provided with an annular projection fin 10b at the lower part. As a result, the heat emission from the central cathode sleeve 1b is increased as compared with the cathode sleeves 1a and 1c on both sides, the temperature rise of the central base metal 2b is suppressed, and the base metal 2a and 2c on both sides are suppressed.
And the temperature of the central base metal 2b becomes equal.

As a result, a uniform and stable electron emission characteristic is obtained for a long time together with the three cathodes for blue, green, and red, and a high-quality color picture tube that does not cause a change in color tone called white balance breakdown is obtained. To be

[0010]

[Embodiment 2] FIG. 2 is a vertical sectional view of a cathode assembly of a color picture tube according to a second embodiment of the present invention.

In the drawings, the same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The characteristic part of this embodiment is that a protruding fin 40b made of an annular body is fitted to the lower part of the cathode support 4b of the cathode located at the center, so that heat generated by heat conduction and heat radiation from the cathodes on both sides is absorbed. Since it is configured to release, it has the same effect as that of the first embodiment.

According to this embodiment, the radiation fins 40b fitted to the cathode support 4b of the center cathode can be brought into contact with the lower surface of the Herme support 5, so that the Herme support is better than the cathodes on both sides. It is also possible to release the heat that is conducted through the inside, and the heat release effect is great.

The radiation fins 10b and 40b may be provided at two locations in the configuration including the first and second embodiments.

Further, in each of the above-mentioned embodiments, the cathode sleeve 1a, 1b, 1c is described as having a structure in which the cathode sleeves 4a, 4b, 4c are arranged on the Herme support 5 so that the present invention is not limited thereto. Without being limited to
The cathode sleeves 1a, 1b, 1c themselves can be applied to the structure in which the cathode sleeves 1a, 1b, 1c themselves are directly arranged on the Herme support 5 by a supporting portion formed by working or by firmly contacting other members.

[0016]

As described above, according to the present invention,
In the cathode assembly of the color picture tube, in which the three cathodes for green and red are supported by their respective cathode supports and arranged and fixed in a straight line, the cathode sleeve of the cathode located at the center of the three cathodes or Providing protruding fins on the cathode support,
By equalizing the temperatures of the base metals of the three cathodes,
With the three cathodes for blue, green, and red, uniform and stable electron emission characteristics can be obtained over a long period of time, and it is possible to obtain a reliable and high-quality color picture tube that does not cause a change in color tone called white balance breakdown. it can.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a cathode assembly of a color picture tube which is an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a cathode assembly of a color picture tube which is a different embodiment of the present invention.

FIG. 3 is a vertical sectional view of a cathode assembly of a conventional color picture tube.

[Explanation of symbols]

 1a, 1b, 1c cathode sleeve 2a, 2b, 2c base metal 3a, 3b, 3c heater 4a, 4b, 4c cathode support 5 herme support 10b protruding fin (annular body) 40b protruding fin (annular body)

Claims (4)

[Claims] 1. A blue base metal having a cap which is shaped like a cap and containing a reducing agent is fixedly contacted on the upper part of the cathode sleeve, an alkaline earth metal oxide is coated on the base metal, and a heater is inserted inside the cathode sleeve. In the cathode assembly of the color picture tube in which the three cathodes for green and red are respectively supported and fixed in a straight line by the Herme support through the cathode support,
A cathode assembly for a color picture tube, characterized in that, of the individual cathode sleeves, a protrusion fin is provided on the cathode sleeve located at the center. 2. A base metal which contains a reducing agent and is shaped like a cap is fixedly in contact with the upper part of the cathode support, an alkaline earth metal oxide is coated on the base metal, and a heater is inserted inside the cathode support. In the cathode structure of the color picture tube in which the three cathodes for blue, green, and red are respectively supported and fixed linearly by the Herme support via the cathode support, the center of the three cathode supports A cathode assembly for a color picture tube, characterized in that a projection fin is provided on a cathode support located at. 3. A base metal, which contains a reducing agent and is shaped like a cap, is fixedly contacted to the upper part of the cathode sleeve, and an alkaline earth metal oxide is coated on the base metal. In the cathode structure of the color picture tube in which the three cathodes for green and red are respectively supported by the Herme support and arranged and fixed in a straight line, of the three cathode sleeves, the protruding fin is provided on the cathode sleeve located in the center. The cathode structure of a color picture tube characterized by being provided. 4. The cathode assembly of a color picture tube according to claim 1, wherein the projection fin is an annular body fitted to a cathode sleeve or a cathode support.