JPH0212732A - Image tube - Google Patents

Abstract

PURPOSE:To improve the reliability of maintaining the vacuum degree by providing a getter membrane for gas absorption purpose at the inner wall of an image tube. CONSTITUTION:A bulb main body 100 and a photoelectric screen plate 3 are set at different positions, and the inside of a vacuum chamber is evacuated. The photoelectric screen 2 is formed in a photoelectric screen forming member 16. In this case, a getter movement manipulator 18 with a flash getter 19 installed at the tip is lowered to evaporate the flash getter 19 at a specific position in the bulb main body 100, to form a getter film 1. After that, the getter movement manipulator 18 is lifted, the photoelectric screen plate 3 is moved, and the bulb main body 100 is sealed up. By forming the getter film 1 in such a way, an image tube requiring no getter wire and no current feeding electrode to the getter wire in the structure can be supplied. Consequently, the reliability in respect to maintaining the vacuum degree by reducing the soldered parts can be improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the structure of an image tube.

[Conventional technology]

FIG. 4 shows the structure of an image tube using the conventional photocathode moving type manufacturing method. In the figure, a photocathode face plate 3 having a photocathode 2 formed thereon is welded to a tube body 101 in a vacuum chamber via a metal such as indium (In) 4. 5 is a photocathode electrode, 6 is an MCP electrode, 7 is an electrode for arc welding, 8
9 is a phosphor screen electrode, 9 is a frit glass, 10 is a ceramic, and 11 is a phosphor screen plate.

12 is a phosphor screen, and 13 is a micro channel plate (MCP).In order to maintain the degree of vacuum in this type of image tube for a long period of time, there is a getter inside the image tube that adsorbs gas released from the tube wall. is placed.

There are two types of getters: a so-called active getter, in which the getter wire 22 is activated by energization and adsorbs gas, and the other is a so-called active getter, in which the getter wire 22 is energized and the wire evaporates, forming a film with getter action. This is the so-called 1-flash getter'.

When any getter is used, it is necessary to supply electricity to the getter, and the getter has at least one electrode.

Normally, the getter wire is energized immediately before the photocathode face plate 3 is sealed.

[Problem to be solved by the invention]

The conventional image tube structure described above has at least one electrode 23 that is not used at all after the image tube is sealed. The electrodes 5 to 8, 23 in the tube body 101 and the insulating ceramic 10 are usually sealed with brazing, but as the number of electrodes increases, the number of brazed parts also increases, and the vacuum required for image tube operation increases. The reliability of maintaining the temperature becomes low.

Another disadvantage is that the increased number of electrodes and ceramics makes it difficult to reduce the cost of the image tube during mass production.

An object of the present invention is to provide an image tube that solves the above problems.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a manufacturing method in which the photocathode face plate and the bulb body are located at different positions in a vacuum chamber, the photocathode is manufactured, and then the photocathode face plate is moved to the bulb part and sealed. The image tube according to the method includes a getter wire for maintaining the degree of vacuum inside the image tube after sealing, and a getter film for gas adsorption formed on the inner wall of the image tube.

〔Example〕 Next, the present invention will be explained with reference to the drawings.

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

The bulb body 100 has a getter film 1 formed by a method described later without having a getter wire and its current-carrying electrode.
have.

If the getter film is deposited across two electrodes via an insulating ceramic, the insulation between the two electrodes will deteriorate, so in FIG. Although an example has been shown in which the getter film 1 is formed on one side, the present invention is not limited to this position.

FIG. 2 is a longitudinal sectional view showing an example of a vacuum chamber for manufacturing the image tube of the present invention.

The tube body 100 and the photocathode face plate 3 are installed at different positions, and the inside of the vacuum chamber is evacuated. The photocathode 2 is formed in the photocathode forming section 16 . Here, the getter moving manipulator 18 with the flash getter 19 attached to its tip is lowered to evaporate the flash getter 19 at a predetermined position on the bulb body 100, thereby forming the getter film 1. after that,
The getter moving manipulator 18 is raised, the photocathode face plate 3 is moved, and the tube body 100 is sealed.

FIG. 3 shows an example of the relationship between the MCP electrode 6 and the getter moving manipulator 18 when the getter film 1 is formed. A cover 21 is provided around the flash getter 19 to limit the position of the getter film 1 formed by evaporation from the flash getter 19.

〔Effect of the invention〕

As explained above, since the getter film is formed in the present invention, it is possible to provide an image tube that structurally does not require a getter wire and its current-carrying electrode.

The reduction in the number of brazed parts has the effect of improving reliability in maintaining the vacuum level, and lowering costs by reducing the number of parts.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the image tube of the present invention, FIG. 2 is a vertical cross-sectional view of a vacuum chamber for manufacturing the image tube of the present invention, and FIG. 3 is a diagram showing the positional relationship between the MCP electrode and the flash getter. , FIG. 4 is a longitudinal sectional view of a conventional image tube. 1... Getter film 2... Photocathode 3...
Photocathode face plate 4... Indium 5... Photocathode electrode 6... MCP electrode 7... Arc welding electrode 8... Fluorescent screen electrode 9... Frit glass 10... Ceramic 11...・Phosphor screen plate
12... Fluorescent screen 13... Micro channel plate (MCP) 14... Vacuum chamber 15... Manipulator for moving the photocathode surface plate 16...
Photocathode forming part 17...Photocathode deposition material 18.
...Getter movement manipulator 19...Flash getter 20.23...Getter energization electrode

Claims (1)

[Claims] (1) In an image tube manufactured by a manufacturing method in which the photocathode face plate and the tube body are placed in different positions in a vacuum chamber, the photocathode is fabricated, and then the photocathode face plate is moved to the tube part and sealed. What is claimed is: 1. An image tube comprising: a getter wire for maintaining the degree of vacuum within the image tube after the image tube is stopped; and a getter film for gas adsorption formed on the inner wall of the image tube.