JPH0528931A - Picture tube - Google Patents

Abstract

PURPOSE:To prevent dispersion in the relation of a fluorescent screen to a shadow mask. CONSTITUTION:A CRT main body 1, which comprises a panel 2 having a mosaic fluorescent screen 3 applied thereto, a funnel 4 and a neck portion 5 enclosing an electron gun, has a pin 11 provided to the panel 2. A frame 7 for holding a shadow mask 6 and an internal magnetic shield 10 are independently attached to the pin 11 so the shadow mask 6 is not deformed when the internal magnetic shield 10 is installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picture tube (hereinafter referred to as CRT) used in a television receiver or a computer terminal.

[0002]

2. Description of the Related Art FIG. 5 is a longitudinal sectional view showing a conventionally used shadow mask type color CRT.

The CRT body 1 is a glass vacuum container consisting of a panel 2 having a mosaic fluorescent screen 3 coated on its inner surface, a funnel-shaped funnel 4, and a neck 5 containing an electron gun (not shown). . The electrons emitted from the electron gun are focused and accelerated, pass through the holes of the shadow mask 6 serving as a color selection electrode, collide with the fluorescent screen 3, and cause the fluorescent screen 3 to emit light.

On the other hand, the shadow mask 6 is formed with small round holes, square holes, slits, etc.
Since it is made of a thin cold-rolled steel plate of about 25 mm, it is easily deformed. Therefore, 1.2-2.3m
It is welded and held on a metal frame (hereinafter referred to as a frame) 7 having a plate thickness of m to prevent its deformation. Finally, such a shadow mask 6 is suspended by a pin 9 provided on the inner surface of the panel 2 via a leaf spring 8.

Further, since the electron beam emitted from the electron gun has a distance until it collides with the fluorescent screen 3, the focusing performance varies due to the influence of the earth's magnetism before reaching the fluorescent screen 3. In order to reduce this effect, an internal magnetic shield 10 formed of a metal plate having the same material and thickness as the shadow mask 6 is provided between the shadow mask 6 and the electron gun, and is usually welded to the frame 7 by welding or welding. It is fixed with a clip.

The CRT having the above structure is obtained by the following manufacturing process. That is, the fluorescent screen 3
After the shadow mask 6 is attached to and detached from the panel 2 several times to complete, the internal magnetic shield 10 is fixed to the frame 7 holding the shadow mask 6.

[0007]

Since the conventional picture tube is constructed as described above, after the fluorescent screen 3 is formed on the inner surface of the panel 2, the internal magnetic shield 10 is attached to the frame 7 holding the shadow mask 6. Since it is fixed, the shadow mask 6 is deformed at the time of fixing, and the relationship of the relative positions of the phosphor dots of the phosphor screen 3 and the holes of the shadow mask 6 cannot be maintained correctly.

The present invention has been made to solve the above problems, and an object thereof is to prevent variations in the relative relationship between the fluorescent screen and the shadow mask.

[0009]

In the picture tube according to the present invention, a pin provided on a panel which is a constituent element of a CRT main body is provided with a frame for holding a shadow mask and an internal magnetic shield separately and independently. It is installed.

A picture tube according to a second aspect of the invention is a CR tube.
The panel which is a component of the T main body is provided with a truncated cone-shaped pin, and one of the frame holding the shadow mask and the internal magnetic shield is attached to the top surface of the pin and the other is attached to the conical surface of the pin.

[0011]

In the picture tube according to the first aspect of the present invention, the frame for holding the shadow mask and the internal magnetic shield are separately attached to the pins provided on the panel, so that the deformation of the shadow mask is prevented when the internal magnetic shield is attached. it can.

In the picture tube according to the second aspect of the invention, the mounting is easy by mounting the frame on one of the top and the conical surface of the truncated cone pin provided on the panel and the inner magnetic shield on the other. Easy to use

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a truncated cone-shaped pin 11 is formed on a panel, and an opening 11a is formed on the top surface of this pin 11. In this embodiment, the opening 8a of the leaf spring 8 is fitted to the pin 11, and the shadow mask 6 can be attached to and detached from the panel 2. By this attachment / detachment, after forming the fluorescent screen 3 on the inner surface of the panel, the frame 7 is attached to the leaf spring 8, and then the inner magnetic shield 10 is applied so as to abut on the top surface of the pin 11, and the tip of the plurality of tips is provided from outside. So-called "multiple fingers" shaped like a collection of leaf springs
A hole 10a provided with 12 in the inner magnetic shield 10 and an opening 1
Insert into 1a to fix both.

At this time, since the leaf spring 8 is in contact with the conical surface of the pin 11 and the inner magnetic shield 10 is in contact with the top surface of the pin 11, they are independently fixed without contacting each other.

Moreover, in the example of FIG. 1, the shadow mask 6 and the internal magnetic shield 10 are fixed to the same pin 11 in close proximity. If the separation distance is within 10 mm, the magnetic resistance between the shadow mask 6 and the internal magnetic shield 10 can be effectively reduced, and the demagnetization of the shadow mask 6 and the internal magnetic shield 10 from the outside of the CRT 1 is more effective. The power for degaussing can be reduced. Of course, if the power is not taken into consideration at this time, there is no particular problem even if it exceeds 10 mm.

FIG. 2 is a rear view of a panel 2 showing another embodiment of the present invention. Corner pin groups 12a are provided at the four corners of the inner peripheral surface of the panel and axial pin groups 12b are provided at the center of each side. It is a composition.

In this embodiment, as shown in FIGS. 3 and 4, for example, the shadow mask 6 is held by the corner pin group 12a,
The arrangement of the pin groups 12a and 12b may be selectively used depending on the function so that the axial magnetic pin group 12b holds the inner magnetic shield 10. Further, the same fixing method as that of the embodiment of FIG. 1 may be applied to either or both of the two pin groups 12a and 12b.

[0018]

As described above, according to the first aspect of the present invention, since the internal magnetic shield is held by the pins provided on the panel separately from the shadow mask, they may interfere with each other. In addition, the shadow mask 6 is not deformed when the internal magnetic shield is attached. According to the second aspect of the present invention, the frame for holding the shadow mask is attached to one of the conical surface or the top surface of the truncated cone pin provided on the panel, and the inner magnetic shield is attached to the other. There is an effect that it can be easily mounted with a simple structure.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing an attachment portion of a shadow mask and an internal magnetic shield in a picture tube according to an embodiment of the present invention.

FIG. 2 is a rear view of a panel according to another embodiment of the present invention.

FIG. 3 is a rear view of the panel of FIG. 2 with a shadow mask attached.

FIG. 4 is a rear view of the panel of FIG. 2 with a frame attached.

FIG. 5 is a diagram showing a structure of a conventional shadow mask type color CRT.

[Explanation of symbols]

1 CRT body 2 panels 3 fluorescent screen 4 funnel 5 neck 6 shadow mask 7 frames 8 leaf springs 9 pin 10 Internal magnetic shield 11 Frustum-shaped pin 12a, 12b pin group

Claims (2)

[Claims] 1. A panel having a mosaic fluorescent screen, a shadow mask, a frame for holding the shadow mask, pins provided on the panel for attaching the frame to the panel, and a funnel shape. A picture tube comprising a funnel, a neck portion including an electron gun, and an internal magnetic shield attached to the pin independently of the frame, wherein the internal magnetic shield is attached to the pin. A picture tube which does not interfere with the frame at the time. 2. The picture tube according to claim 1, wherein the pin has a truncated cone shape, one of the frame and the inner magnetic shield is a conical surface of the pin, and the other is a top surface thereof. A picture tube characterized by being attached to each.