JPS5816296B2 - Satsuzoukan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image pickup tube in which a mesh electrode and a focusing electrode are separated, and particularly to a structure for fixing a mesh electrode and a focusing electrode.

Conventionally, in an image pickup tube, for example, a vidicon, as shown in FIG. 1, a face plate 3 on which a photoconductive target 2 is formed is sealed to one side of a cylindrical envelope 1 with a sealing ring 4, and the other side is sealed with a plurality of electrodes. The stem 6 having terminals 501, 502, . . . is integrally provided so as to be sealed.

This stem 6 has an electron gun (
(not shown) is attached.

Further, a mesh electrode 7 is provided near the target 2, and this mesh electrode 7 has i, oo.

It is composed of a mesh 8 of ~1,500 pieces/1 nch and a ring 9 that holds this mesh 8.

One end of a mesh support electrode 10 is fixed to this ring 9, and this mesh support electrode 10 is coaxially fixed to a focusing electrode 12 via an insulator 11.

A plurality of bleeds (not shown) are provided between the focusing electrode 12 and the electron gun.

Then, an electron beam from an electron gun is used to travel over the target 2, and an image formed on the target 2 is discharged to obtain an output.

Then, by separating the mesh electrode 7 from the focusing electrode 12 and applying an appropriate voltage, an electrostatic lens is simply formed by the ring 9 that holds the mesh electrode 7 and the focusing electrode 12,
Image characteristics can be improved by changing the landing of electrons on the target 2 using this electrostatic lens.

Therefore, the positional relationship between the ring 9 and the focusing electrode 12 must be precisely fixed to specified dimensions.

Conventionally, the electrodes are first fixed by first fixing the focusing electrode 12 and the insulator 1.
1 is fixed.

The method is to attach a metallic fixing ring 13 to the end of the focusing electrode 12.
are welded and fixed, an insulator 11 made of a ceramic material is fitted, and fixing rings 13 and 14 are further welded to the tips and fixed.

Next, the method of fixing the mesh support electrode 10 and the insulator 11 is to make a slit in the mesh support electrode or punch two to four slots, and then press one end of the insulator 11 against the tip of the mesh support electrode. The fixation was performed by caulking and hooking it onto the other end of the insulator 11.

Further, if dust or the like adheres to the mesh 8 of the mesh electrode 7, a false signal will be generated.

Therefore, in order to minimize the adhesion of dust etc. to the mesh 8, it is necessary to assemble it near the final process of assembling the image pickup tube.
It is inserted in 2.

Therefore, by inserting the mesh electrode 7, the mesh electrode 7
Since the positional relationship between the ring 9 that holds the mesh 8 and the focusing electrode 12 is determined, the dimensional accuracy and fixing accuracy of the insulator 11 directly affect the image characteristics.

Therefore, as described above, ceramic materials are often used as insulators.

Ceramic materials have advantages such as low outgassing and high heat resistance, but processing that requires high precision is difficult, and in order to achieve dimensional accuracy of the insulator 11 after molding and firing, it is necessary to The diameter is polished.

For this reason, there was a drawback that the unit cost of parts was high.

Furthermore, the mesh support electrode 10 and the focusing electrode 12 are fixed by welding the fixing rings 13 and 14 and caulking with the insulator 11, which has the disadvantage that it is difficult to attach the parts accurately.

An object of the present invention is to eliminate the above-mentioned drawbacks and fix a mesh support electrode and a focusing electrode with high precision and at low cost.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIG.

Note that for parts that are the same as in FIG. 1, the same part numbers as in FIG. 1 are used.

As a method of fixing the mesh support electrode 22 to the tip of the focusing electrode 21, first, a fixing metal fitting 23 is welded and fixed near the tip of the focusing electrode 21, as shown in FIGS.

Next, insert the mesh support electrode 22, which has been drilled in advance, onto the focusing electrode 21, and adjust the mesh support electrode 22 so that it has the specified dimensions.
Temporarily hold it with a fixing jig (not shown) provided by a person.

Figure 2 shows this state. At this time, the fixing metal fitting 23 and the mesh support electrode 22 are spaced sufficiently apart from each other so that they do not come into contact with each other.

Further, the glass insulator 24, which has been heated and softened in advance, is forcibly inserted into the hole of the mesh support electrode 22 and crimped.

The crimped glass insulator 24 is brought into close contact with the holes of the focusing electrode 21, the fixture 23, and the mesh support electrode 22, as shown in the partial cross-sectional view of FIG. The portion between the mesh support electrode 21 and the mesh support electrode 22 and the portion extending outward from the outer peripheral surface of the mesh support electrode 22 have a diameter larger than the hole diameter of the mesh support electrode, and the glass insulator 24 is fixed.

As a matter of course, the glass insulator is completely fixed by fixing the glass insulator at two to four locations around the outer periphery of the focusing electrode.

In addition, as specific examples of the shape of the mesh support electrode 22, the shape of the hole formed in the mesh support electrode 22 may be round, square (FIG. 3a), or ridged (FIG. 3B). There is.

Further, as a substitute for the fixing metal fitting 23, a specific example may be considered in which a focusing electrode is molded and attached to the outer periphery to give a shape.

Although the present invention uses a glass insulator as an example, it is needless to say that heat-curing organic and inorganic insulating materials, as well as room-temperature curing organic insulating materials, can be used.

As described above, according to the present invention, it is easy to fix the mesh support electrode and the focusing electrode or the accelerating electrode, and the manufacturing cost is reduced in mass production, which is very effective.

Further, the precision of the electrostatic lens formed by the mesh support electrode and the focusing electrode can be improved, and thus the image quality can be improved.

[Brief explanation of the drawing]

1. Fig. 1 is a partial cross-sectional view of a conventional vidicon, Fig. 2 is a partial cross-sectional view of a bidicon incorporating the present invention, and Fig. 2a and Fig. 2 are assembly steps of the present invention. FIGS. 3a and 3b are sketches showing partial cuttings showing an example of the hole machining shape of the mesh support electrode. 1... Envelope, 2... Photoconductive target, 3... Face plate, 4...
Sealing ring, 501゜502... Electrode terminal, 6
...Stem, 7...Mesh electrode, 8
...Metshu, 9...Ring, 101
......Mesh support electrode, 11...Insulator, 12...Focusing electrode, 13...Fixing ring A, 14...Fixing ring B, 21...
...Focusing electrode, 22...Mesh support electrode,
23...Fixing metal fittings, 24...Insulator.

Claims (1)

[Claims] 1. An electron gun that emits an electron beam, a target that is scanned by the electron beam, a cylindrical electrode provided at the position where the electron beam travels, and an insulator connected to the end of the electrode on the target side. In an electrode assembly for an image pickup tube comprising a mesh support electrode, a part of which is coaxially inserted and fixed, and a mesh electrode attached to this electrode, fixing of the mesh support electrode and the cylindrical electrode includes: A meltable inorganic insulator in which a hole or notch provided in the mesh support electrode and a hole provided at a position corresponding to the hole or notch at the end of the cylindrical electrode are embedded in the hole or notch. Alternatively, an imaging tube characterized in that it is fixed with an organic insulator of room temperature or heat curing type.