JPS587009B2 - ink yokusenkan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube in which the direction of emission and scattering of metal vapor is restricted to a specific direction.

In cathode ray tubes that use a so-called evaporative getter device that evaporates metal materials such as barium or magnesium within the tube, if the getter metal emitted from the getter device adheres to the fluorescent surface of the cathode ray tube, electrons can pass through the tube. It is well known that the brightness of the image is reduced by inhibiting the brightness of the image.

For this reason, the getter metal vapor is directed approximately in the radial direction so that the getter metal is preferentially distributed in the funnel portion of the cathode ray tube body and a reduced amount of getter metal adheres to the fluorescent surface of the cathode ray tube. A getter device has been proposed.

A cathode ray tube using such a conventional getter device will be described below with reference to the drawings.

FIG. 1 is a partially cutaway sectional view of a cathode ray tube equipped with a conventional getter device, and FIG. 2 is a perspective view showing an example of a conventional getter device.

In the figure, reference numeral 1 denotes a tube body, which consists of a neck portion la, a funnel portion 1b, and a panel portion 1C.

2 is an electron gun installed in the neck portion 1a; 3 is a fluorescent surface formed by coating on the inner wall of the panel portion 1C; and 4 is an inner wall of the funnel portion 1b, one end of which is fixed to the tip of the electron gun 2. An antenna spring 5 extending along the antenna spring 4 is held at the other end of the antenna spring 4 and is arranged substantially parallel to the inner wall of the funnel 1b.

This is a getter device arranged using a so-called antenna mount method.

This getter device 5 is constructed as shown in FIG.

6 is an annular container having an opening; 7 is a getter metal material in which the container 6 is filled with, for example, powdered barium by a compression method; and 8 is a getter metal material whose surface is inclined at an angle α with respect to the axis A of the getter device 5; A conical facing member is fixed in coaxial relation to the inner circumferential edge 6a of the container 6 and extends in the radial direction so as to be coextensive with the outer circumferential edge 6b of the container 6.

Further, the outer circumferential edge 8a of the deflection member 8 is spaced apart from the outer circumferential edge 6b of the container 6 at a certain distance, that is, at a distance that allows the getter metal vapor to scatter in a substantially radial direction from the axis A of the getter device 5. It is located.

In such a cathode ray tube, when the getter metal material 7 is evaporated by, for example, induction heating in order to remove residual gas in the tube body 1 after evacuation and increase the degree of vacuum, the getter metal vapor released from the container 6 is collides with the deflection member 8, and the first
As shown by the broken line 9 in the figure, the particles change direction approximately in the radial direction and scatter along the inner wall of the funnel portion 1b of the tube body 1.

Furthermore, by appropriately selecting the inclination angle α of the deflection member 8,
The getter metal vapor scatters over the inner wall of the funnel portion 1b of the tube body 1 with a sufficient spread.

Therefore, the getter metal preferentially and widely adheres to the inner wall of the funnel portion 1b of the tube body 1 to satisfy the predetermined getter function, and a reduced amount of getter metal adheres to the fluorescent surface 3. can do.

However, according to such a method, some amount of getter metal will adhere to the fluorescent surface 3, and furthermore, the method of adhesion is different from that of the fluorescent surface on the side where the getter device 5 is disposed. The flow 9 of the getter metal vapor is locally concentrated on the fluorescent surface 3, resulting in an inconvenience that the thickness of the adhered getter metal becomes larger than that on other parts of the fluorescent surface 3.

Incidentally, if the deviation in the film thickness of the target metal on the fluorescent surface 3 is simply to be reduced, the inclination angle α of the deflection member 8 may be increased. It has been found that there is a disadvantage that the getter metal concentrates locally, forming a thick film of getter metal, and the getter function is impaired.

Furthermore, the getter metal vapor flow 9 that diffuses from the narrow diameter part of the funnel part 1b to the neck part 1a goes around the vicinity of the electron gun 2 and is absorbed into the electron gun 2 or the neck part 1.
It has been found that there are drawbacks such as adhesion to the inner wall of a, significantly reducing the withstand voltage characteristics.

This invention has been made in view of the above points, and it is possible to restrict the emission and scattering direction of the getter metal vapor to a specific direction to prevent the getter metal vapor from scattering toward the electron gun and the fluorescent surface, for example. By doing so, the object is to obtain a cathode ray tube that satisfies the getter function without impairing the original function of the cathode ray tube.

FIG. 3 is a perspective view showing an example of a getter device which is a feature of the present invention, and FIG. 4 is a sectional view taken along the line ■--■ in FIG.

In the figure, 6 is an annular container having an opening, 7 is a getter metal material filled in the container 6, and 10 is arranged facing the opening of the container 6, and is welded to the inner circumferential partition wall 6a of the container 6 at a point 11. It is a disc-shaped shielding member fixed in a coaxial relationship.

This shielding member 10 has an extension portion that extends to the outer peripheral edge 6b of the container 6 in the direction in which the antenna spring 4 extends, and a shielding portion 10a that covers a part of this outer peripheral edge 6b.
and a deflecting portion 10b formed by folding the surface thereof at an angle β with respect to the axis A of the getter device 5 on the other portion of the outer peripheral edge 6b.

The deflecting portion 10b extends in the radial direction so as to have the same extent as the outer peripheral edge 6b of the container 6, and the outer peripheral edge 10c
is folded up at a specific distance from the outer periphery 6b of the container 6, that is, at a distance that allows the getter metal vapor to scatter approximately radially from the axis A of the getter device 5.

Further, it is connected to the shielding part 10a, and this shielding part 10a
A flange portion 10d is formed by bending an extended portion of the container 6, and this flange portion 10d faces the side surface of the container 6 in close proximity and completely covers the outer peripheral edge 6b of the container 6.

As described above, the getter device 5 configured in this way is connected to the first
A cathode ray tube is mounted using the antenna mounting method shown in the figure, and is arranged so that the scattering opening of the getter metal formed by the deflection part 10b and the outer peripheral edge 6b of the container 6 faces the inner peripheral direction of the funnel part 1b. When the target metal material 7 is evaporated, the target metal vapor is released from the scattering port formed between the outer peripheral edge 6b of the container 6 and the deflection part 10b of the shielding member 10, but it collides with the deflection part 10b. , change direction approximately in the radial direction, scatter along the inner wall of the funnel portion 1b of the tube body 1, and adhere only to the inner circumferential direction of the funnel portion 1b.

On the other hand, the side of the outer periphery 6b of the container 6 that faces the electron gun 2 and the fluorescent surface 3 is completely covered with the shielding part 10a and the flange part 10d, so that the getter metal vapor is absorbed by the electron gun 2 and the fluorescent surface. It does not scatter toward surface 3.

Therefore, by appropriately selecting the bending angle β and the length of the bent portion of the deflecting portion 10b, the getter metal vapor is widely distributed only on the inner wall in the inner circumferential direction of the funnel portion 1b of the tube body 1, and satisfies the predetermined getter function. However, it is not distributed in the electron gun 2 and the fluorescent surface 3.

Why is it that in the getter device 5 of the present invention, the flange portion 10b
The purpose of the present invention is to prevent the getter metal from scattering in the direction of the fluorescent surface 3 and the electron gun 2, as described above, but if there is no flange portion 1b, Then, when the getter metal material 7 melts and scatters, the vapor pressure of the molten getgeter metal material 7 increases instantaneously, and as a result, distortion occurs at the outer circumferential edge of the shielding part 10a of the shielding member 10. There is a risk that the metal vapor will spout out from places other than the above-mentioned scattering ports, such as gaps, and the metal will scatter and adhere in the direction of the fluorescent surface 3 and the electron gun 2, which are undesirable directions. In the invention, since the flange portion 10d is provided, even if distortion occurs,
By this flange portion 10d, the flow of the ejected getter metal vapor changes direction and reaches the inner wall of the funnel portion 1b of the tube body 1 where the getter device 5 is installed, forming a desired getter film. This makes it even more effective.

In the embodiment, a structure in which two deflecting portions 10b are provided is shown, but the number, position, and shape of the deflecting portions 10b are not limited thereto depending on the usage state of the getter device 5.

As described above, according to the present invention, the container is held within the cathode ray tube body and has an opening;
a metal material that releases metal vapor when heated; a shielding part disposed opposite to the opening of the container and having an extension part extending to a part of the outer periphery of the container; a flange portion formed by bending an extension portion and facing closely to the side surface of the container; and a deflection portion that regulates and releases the scattering direction of the getter metal vapor from the container in the inner circumferential direction of the funnel portion. Since the shielding member is provided to prevent the above-described metal vapor from scattering toward the electron gun and the fluorescent surface, it is possible to obtain a cathode ray tube that satisfies the target function without impairing the original function of the cathode ray tube. can.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view of a cathode ray tube equipped with a conventional getter device, FIG. 2 is a perspective view showing an example of a conventional getter device, and FIG. 3 is an example of a getter device featuring the present invention. The perspective view shown in FIG. 4 is a sectional view taken along the line ■-■ in FIG. 3. In the figure, 1 is a tube body, 2 is an electron gun, 3 is a fluorescent surface, 6 is a container, 7 is a getter metal material, and 10 is a shielding member. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A neck part in which an electron gun is housed, a funnel part,
a tube body consisting of a panel part having a fluorescent surface; a container supported by an antenna spring extending from the electron gun and having an opening disposed on the inner wall of the funnel part; a getter metal material that emits; a shielding part disposed opposite to the opening of the container and having an extension part extending to a part of the outer periphery of the container; and a shielding part connected to the shielding part and having the extension part bent. a flange portion formed in a manner close to and facing a side surface of the container;
A cathode ray tube characterized in that the cathode ray tube is equipped with a shielding member having a deflection section that regulates and releases the getter metal vapor from the container in an inner circumferential direction of the funnel section.