JPH0117805Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an electron gun attached to a cathode ray tube, and its purpose is to increase the support strength of multiple cylindrical electrodes arranged coaxially in a straight line to prevent axis misalignment. .

There are various types of electron guns, such as unipotential and bipotential types, but they generally consist of a cathode that emits hot electrons and multiple electrodes that accelerate and focus the emitted hot electrons. As an example, a unipotential type electron gun is shown in Fig. 1. 1 is a cathode, and 2, 2, . . . are a plurality of various cylindrical electrodes (first to fifth grid electrodes) having an electron beam transmission hole in the center. The cathode 1 is fixed within an electrode 2 at one end via an insulator 3. Each electrode 2, 2... is formed in a straight line by fixing the tips of supporting members 4, 4... integrally protruding from the side wall at 180° intervals to two parallel insulating support rods 5, 5 made of glass or the like. They are integrated coaxially and spaced apart from each other at predetermined intervals.

There are two types of supporting members: pin-shaped and plate-shaped.Generally, in order to stably support the electrode 2, it is necessary to attach a large number of pin-shaped ones, such as four or six, to one electrode 2. There are many structural disadvantages. On the other hand, a plate-shaped one is used, for example, as shown in FIG. 2, which is a rectangular flat metal plate with the center portions of both ends cut out. This plate-shaped support member 4
are the protruding pieces 4a on both sides of the notch groove 6 at one end,
The tip of the electrode 4a is brought into contact with the outer circumferential surface of the electrode 2 parallel to the axial direction, and spot welded. The other end of the plate-shaped support member 4 also has a cutout groove 6' formed in the center, and projecting pieces 4b, 4b on both sides of the notch groove 6'. is pushed in. This pushing of the support rod 5 is carried out by aligning each electrode 2, 2... with a core pin 7, positioning and holding it with a jig 8, and pushing the support rod 5 in two directions from 180° opposite radial directions, as shown in Fig. 3. This is done by simultaneously pressing the supporting rods 5, 5 against the tips of the supporting members 4, 4. One plate-shaped support member 4 of this type has the function of two pin-shaped support members, so it has the advantage of reducing the number of parts by half, but it has the following problem.

The plate-like support member 4 has a flat shape over its entire surface, and has notched grooves 6, 6' at its ends, so that the mechanical strength of the protruding pieces 4a, 4a, 4b, 4b is particularly weak. Therefore, when the support rod 5 is pushed into the tip of the support member 4, the external force is concentrated on the protruding pieces 4a, 4a welded to the electrode 2, and the external force is concentrated on the protruding pieces 4a, 4a, as shown by the chain lines in FIG. deforms in the thickness direction,
When the jig 8 and the core metal pin 7 were removed from the electrode 2 after assembly was completed, the electrode 2 sometimes became axially misaligned due to residual stress caused by the deformation. Such axis misalignment of the electrode 2 becomes a major factor that impairs the operating characteristics of the electron gun.

The present invention has been made in view of the problems of such a plate-shaped support member, and provides an electron gun in which the strength of the plate-shaped support member is improved and the axis shift of the electrodes is eliminated.

The configuration of the present invention will be explained below with reference to the embodiments shown in FIGS. 4 and 5.

The feature of the present invention is that only the shape of the plate-shaped support member is changed, for example, as in support member 9 shown in FIG. 4. This support member 9 has cutout grooves 10, 10 formed at the center of both ends of a rectangular flat metal plate, and protruding pieces 9a, 9a, 9b, 9b provided on both sides. One of 9a, 9a is made wider, and a part thereof is integrally provided with a cut-and-raised part 9c which is bent about 90 degrees in the width direction. The raised portion 9c is formed for the purpose of mechanically reinforcing the supporting member 9, particularly the protruding piece portion 9a, in the thickness direction.

The support member 9 is, for example, a set of two pieces, with pieces 9a and 9 protruding in the axial direction at opposite positions on the outer peripheral surface of the electrode 2.
Point a and spot welding will be carried out. This welding is performed at a total of three locations: the end faces of the two protruding pieces 9a, 9a, and the end face of the cut and raised portion 9c. As shown in Fig. 5, the electrode assembly after welding involves passing the core pin 7 through the electrode 2, holding the electrode 2 in position by clamping it with jigs 8 from both sides, and inserting the 2 pins extending 180° in opposite directions. This is done by pushing the protruding pieces 9b, 9b at the tips of the two support members 9, 9 into the support rods 5, 5, respectively. It is desirable to limit the pushing direction of the support rods 5, 5 as follows.

The strength of the other support member 9 is greater in the side direction where the cut and raised portion 9c is located, so that deformation in this direction is difficult to occur against an external force applied from the tip in the length direction. Therefore, the direction of pushing into the support rod 5 is slightly biased toward the side surface of the support member 9 where the cut-and-raised portion 9c is located, as shown by the arrow in FIG. Then, a biased external force is applied to the support member 9, but the protruding piece 9 is
a is reinforced, and furthermore, since the contact area with the electrode 2 is large, there is no need to worry about the support member 9 being deformed due to external force being dispersed. Because of this bias in the external force, it is desirable that the two support members 9, 9 attached to both sides of the electrode 2 be attached so that their respective cut-and-raised portions 9c, 9c face in opposite directions.

Furthermore, by providing two cut-and-raised portions 9c of the support member 9, and by reversing the directions of these two cut-and-rise portions, the support member 9 will be able to withstand external forces biased toward both side surfaces and bias applied in the length direction. Stable against external forces. However, in order to form two cut-and-raised portions in different directions on the support member 9, at least two pressing steps are required, which is unfavorable in terms of processing, and the support member 9
It is also necessary to widen the width, which is not preferable.

Note that the present invention is not limited to the above-mentioned embodiments; for example, three protruding pieces may be provided at one end of the plate-shaped support member, and each of the protruding pieces may have a cut-and-raised portion bent in the same direction. It is also possible to do 1
The present invention can also be applied to an electron gun, etc., in which three supporting members are attached at 120° intervals in the circumferential direction of one electrode.

As described above, according to the present invention, the mechanical strength of the plate-shaped support member in the thickness direction is increased, so that deformation during electrode assembly can be easily prevented, and therefore, it is possible to prevent the electrode from misaligning. A highly reliable electron gun with stable operating characteristics can be provided.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view showing an example of a conventional electron gun, FIG. 2 is a partial perspective view of FIG. 1, and FIG. 3 is a partially sectional view of the electron gun shown in FIG. FIG. 4 is a partially exploded perspective view showing an embodiment of the present invention, and FIG. 5 is a partially sectional view of the electrode shown in FIG. 4 when assembled. 2... Electrode, 5... Support rod, 9... Support member,
9a...Protruding piece part, 9c...Cut and raised part, 10...
Notch groove.

Claims (1)

[Scope of utility model registration request] A plurality of cylindrical electrodes are coaxially arranged in a straight line at predetermined intervals, and the tip of a support member protruding from the side wall of each electrode is buried in an insulating support rod to integrate the electrodes, wherein the support member is made of metal. It is characterized in that an end of the flat plate is cut out to form a protruding piece that comes into contact with the electrode at the end, and the protruding piece is provided with a cut-and-raised part that is partially bent in the width direction. electron gun.