JPS6247936A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To clamp an electron gun with almost no variations or make a slip in the clamping position in a single direction, by pressing and clamping the electron gun with force in the single direction. CONSTITUTION:An electron gun 1 is clamped with one side of a member 5 pressed to an inner wall of a neck tube 3 by a spring. An outer diameter r1 at one side of the member 5 is set down to such a value as causing the electron gun 1 to be positioned at the center of the neck tube 3. And, two points P1 and P2, distant at 90 deg. from each other, of the member 5 may be constituted so as to be pressed to the inner wall of the neck tube 3 by dint of the spring 6 installed at the reverse side. Since variations in thickness and a bore of the neck tube 3 is little, the electron gun 1 comes to be clamped to the center of the neck tube 3 with almost no variations in consequence.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a cathode ray tube.

[Summary of the invention]

The present invention fixes the electron gun in a cathode ray tube by suppressing it with a force in a single direction, thereby fixing the electron gun with almost no variation, or making the shift of the fixing position in a single direction.

[Conventional technology]

For example, the electron gun of a picture tube needs to be fixed at the center of the neck tube without any fluctuation in its position.

By the way, as shown in FIGS. 8 and 9, in the conventional electron gun (1), for example, springs (2&) to (2c) are attached to the tip of the electron gun (1) in three directions. 2&) to (2C) were made to come into contact with the inner wall of the neck tube (3), respectively, and were fixed.

[The problem that the invention attempts to solve]

However, with this type of system, if there are variations in the shape of the individual springs or deformation of the fulcrum due to welding, the spring stress of the springs (2 &) to (2c) will vary.
There was also the problem that the position of the electron gun (1) within the neck tube (3) varied.

Figure 10 is a schematic diagram of a reflective flat tube. In the figure, (3) is the neck tube, (1) is the electron gun, and (4) is the fluorescent surface. It is something to observe.

The fluorescent surface (4) of this reflective flat tube cannot be coated with a protective film to prevent ion burning.
is provided apart from the beam axis of the electron gun (1). In this case, since the position of the electron gun (1) varies considerably in the conventional fixing method, the electron gun (1) is provided at a sufficient distance, for example, al, as shown in FIG. 11A.

This large variation in the position of the electron gun (1) results in an increase in the thickness of the flat tube.

Furthermore, if the fluorescent surface (4) is located away from the beam axis, it becomes necessary to increase the size of the means for deflection. In addition, large variations in the position of the electron gun (1) also lead to large variations in the amount of correction for arc distortion and keystone distortion, so it was necessary to widen the adjustment range of the set.

In view of this point, the present invention enables, for example, an electron gun to be fixed with almost no variation.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides means for applying a force in a single direction to the electron gun (1), such as a single spring (6).
) shall be provided. The electron gun (1) is pressed and fixed by a force in a single direction.

[Function] The electron gun (1) is pressed and fixed, for example, against the inner wall of the neck tube by force in a single direction, and there is little variation in the inner thickness and diameter of the neck tube, so the electron gun (1) The position will be fixed with almost no variation.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 and 2. This example is an example applied to the above-mentioned flat tube.

In this example, a donut-shaped support member (5) is fixed to the tip of the electron gun (1) by, for example, spot welding.

The outer diameter r1 of the negative side of this member (5) is such that when this negative side is pressed against the inner wall of the neck tube (3), the electron gun (1) is located at the center of the neck tube (3). be done. On the other hand, the outer diameter r2 of the other side opposite to the negative side of one member (5) is smaller than the outer diameter r1 of the one side, and a spring (6) is attached to this other side.
One end is fixed, for example by spot welding. The other end of the spring (6) is brought into contact with the inner wall of the neck tube (3). Therefore, this spring (6) applies a force from the other side to one side of the member (5), so that the negative side of the member (5) is always pressed against the inner wall of the neck tube (3).

Further, in this example, the axis X from the negative side to the other side of the member (5) is made to coincide with the X axis of the flat tube shown in FIG.

The present example is constructed as described above, and the electron gun (1) is fixed by pressing the negative side of the member (5) against the inner wall of the neck tube (3) by the spring (6). As mentioned above, the negative side outer diameter r1 of the member (5) is such that when this negative side is pressed against the inner wall of the neck tube (3), the electron gun (1)
) is set at the center of the neck tube (3). Further, since there is little variation in the inner thickness and diameter of the neck tube (3), according to this example, the electron gun (1) is fixed at the center of the neck tube (3) with almost no variation.

Therefore, according to this example, since the variation in the position of the electron gun (1) is small, as shown in FIG.
) and the beam axis of the electron gun (1) can be made shorter than conventional ones, for example, a2. Therefore, the thickness of the flat tube can be reduced compared to the conventional one. Also, the means for deflection can be made smaller.

Further, according to this example, since the variation in the position of the sub-gun (1) is small, the variation in the amount of correction of circular distortion and keystone distortion is also small, and the adjustment range of the set can also be narrowed.

According to experiments, the distance between the fluorescent surface (4) and the beam axis of the electron gun (1) can be reduced to about 2/3 of the conventional distance, and
The adjustment range for arc distortion etc. could also be reduced to about 2/3.

Note that the above embodiment is an example applied to a flat tube.
D (bin cushion free deflection) and CFD
It is suitable for application to general picture tubes such as (convergence free deflection) where the position of the electron gun varies greatly.

In addition, by using the portion of the neck tube (3) facing the negative side of the member (5) as the fixed base of the deflection yoke, the neck tube (3)
) can eliminate variations in the aperture diameter, further increasing the effect.

By the way, in order to increase the diameter of the electrostatic focusing lens of the electron gun (1) and reduce aberrations, it is conceivable to form the electrodes of the electron gun (1) on the inner wall of the neck tube (3), for example.

Figure 3 shows an example of this, K and G.

and G2 are a cathode, a first grid electrode, and a second grid electrode. Further, G and G4 are a third grid electrode and a fourth grid electrode constituting a focusing electrode, and are formed by applying a conductor to the inner wall of the neck tube (3), respectively. In this case, the aperture of the focusing lens formed between electrodes G3 and 04 is certainly large, but since the potential difference between electrodes G3 and 04 is large (for example, 1.5 kV% is applied to electrode G3).
8 kV is applied to G4), which has the disadvantage that discharge is likely to occur between them.

Therefore, one of the electrodes G3 and G4, for example, electrode G3.
may be a metal cylindrical electrode (as shown in FIG. 4). In this case, although discharge between the electrodes G3 and 04 is prevented, it is difficult to align the center axes of the electrodes G5 and 04, so astigmatism is likely to occur in the lens.

That is, the part of the electron gun (1) including the pole G3 is
For example, a spring (2a) in three directions as shown in the figure.
In the case of fixing using (2C), the position of electrode G3 varies due to variations in spring stress, so it is difficult to align the center axes of electrodes G3 and G4.

Therefore, it is conceivable to fix the part of the electron gun (1) including the electrode G5 as in the above embodiment.

In this case, although variations in the position of the electrode G3 are certainly reduced, it is difficult to align the center axes of the electrodes G3 and G4 due to variations in the diameter of the neck tube (3).

By the way, when the central axis of the electrode G3 is diagonally shifted from the central axis of the electrode G4, the beam spot shape on the fluorescent surface with respect to a change in focus voltage is as shown in Fig. 5a.
, b, and e. Although the shape of b is circular, it is larger than when the central axes are aligned. Moreover, the shape of & and e is oval, and the long axis and short axis thereof are oriented in an oblique direction. Thus, in this case, for example, a beam indexing tube with a phosphor surface laterally delineated with red, green and blue colored phosphor stripes.

It is impossible to obtain a good image.

However, if the center axis of the electrode G3 is shifted horizontally or vertically from the center axis of the electrode G4, the shape of the beam spot on the fluorescent surface will change depending on the change in focus voltage as shown in Figures 6a and b. , cK changes as shown. In this case, the shape of b is the same as that in Figure 5, but a,
The shape of e is oval, and its major and minor axes are oriented horizontally or vertically. Then, by finely adjusting the focus voltage, the length of the short axis can be shortened to approximately the same extent as the diameter of the beam spot when the central axes are coincident. Therefore, if the center axis of electrode G is shifted horizontally or vertically from the center axis of electrode G4, the long axis of the beam spot can be adjusted to the stripe of the fluorescent surface by adjusting the focus voltage. It is possible to match the directions, and a good image can be obtained with the beam index tube despite astigmatism.

FIG. 7 shows another embodiment of the present invention in consideration of the above points, and is applied to a beam index tube. In FIG. 7, parts corresponding to those in FIG. 4 are designated by the same reference numerals.

In the same figure, the electrode G4 is formed on the inner wall of the neck tube (3) following the internal conductive film (7) formed on the funnel, and is made of carbon, for example, like the internal conductive film (7). Ru. In addition, (4) is a fluorescent surface, for example, red,
It consists of green and blue colored phosphor stripes arranged repeatedly in the horizontal direction.

Further, the electrode G is made of cylindrical metal, and a donut-shaped support member (8) is fixed around the electrode G.

This member (8) is made of metal or ceramic, for example, and its outer diameter is the minimum value of the inner diameter of the neck tube (3). Further, one end of a spring (9) is fixed to one side of the outer periphery of the electrode G3, for example, in a vertical or horizontal position, by spot welding, for example.

The other end of the spring (9) is brought into contact with the inner wall of the threaded tube (3). Therefore, this spring (9) applies force to the electrode G3 in the horizontal or vertical direction, and the other side of the member (8) is connected to the neck tube (3).
is constantly pressed against the inner wall of the

In FIG. 7, C1O is a bead glass for fixing the electrodes G, -G, and αp is a stem pin.

The example in Fig. 7 is constructed as described above, and a force is applied to the electrode G in the horizontal or vertical direction by the spring (9), and the other side of the member (8) is always pressed against the inner wall of the neck tube (3). Since the electrode G3 is placed in a pressed state, even if the center axis of the electrode G3 deviates from the center axis of the electrode G4, the direction is horizontal or vertical.

If the direction of deviation is horizontal or vertical, the long axis of the beam spot can be made to coincide with the stripe direction of the fluorescent surface (4) by adjusting the focus voltage, as described above. Therefore, according to this example,
Good images can be obtained.

In the above embodiment, one spring is used, but a plurality of springs may be used. In short, it is sufficient that the resultant force becomes a force in a single direction.

In addition, in the above embodiment, an example of a picture tube was shown, but
The present invention can be similarly applied to other cathode ray tubes such as image pickup tubes.

〔Effect of the invention〕

According to the present invention described above, the electron gun is suppressed and fixed by a force in a single direction, and the electron gun is fixed with almost no variation. Furthermore, the fixed position can be shifted in a single direction.

[Brief explanation of drawings]

1 and 2 are diagrams showing one embodiment of the present invention, FIGS. 3 to 6 are illustrations for explaining the example in FIG. 7, and FIG. 7 is a configuration showing another embodiment of the present invention. 8 to 11 are diagrams for explaining conventional examples. (1) is an electron gun, (3) is a neck tube, (4) is a fluorescent surface,
(5) and (8) are supporting members, (6) and (9) #i
There is mispring.

Claims (1)

[Claims] A cathode ray tube characterized in that means is provided for applying a force in a unidirectional direction to an electron gun, and the electron gun is pressed and fixed by the force in the unidirectional direction.