JP2586758B2 - Picture tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art FIG. 3 is a view showing a schematic structure of a conventional color CRT including a partly broken portion. The structure shown in FIG. 3 is generally used as a shadow mask type color CRT. It has a square screen with a size-to-length ratio of 4: 3.

In FIG. 1, a CRT 1 includes a panel portion 2 having a panel screen portion 2A and a panel side portion 2B,
It is configured as a glass vacuum container comprising a funnel-shaped funnel 4 connected to the panel 2 and a neck 5 containing an electron gun (not shown). Reference numeral 6 denotes a shadow mask formed of a thin metal plate having a large number of round holes or square holes, and is held by a frame 7. further,
A fluorescent screen 3 is formed by printing on the inner surface of the panel screen portion 2A so as to face the shadow mask 6.

FIG. 4 is a view of the panel screen portion 2A shown in FIG. 3 viewed from the back side (the neck portion 5 side). As is clear from FIG. 4, the shadow mask 6 held by the frame 7 is The panel portion 2 is suspended from four pins (on-axis pins) 8 provided at or near the major axis X and minor axis Y via a metal leaf spring 9 attached to the frame 7.

However, the on-axis pin 8 as described above
According to the mounting method described in the above, the frame 7 may be deformed and adversely affect the shadow mask 6. If the rigidity of the frame 7 is increased by, for example, increasing the thickness of the frame 7 in order to prevent the deformation of the frame 7, there is a disadvantage that the weight of the frame 7 itself increases. This is particularly remarkable in the case of a horizontally long screen (width: height ratio: 16: 9) in which the width of the conventional screen having a width-to-length ratio of 4: 3 is lengthened horizontally.

In order to solve the above-mentioned inconvenience, in order to be applicable to the case of a horizontally long screen, a recent shadow mask design technique is not a mounting method using an axial pin as shown in FIG. As shown in the figure, a so-called corner pin mounting method is used in which a shadow mask is suspended and supported by pins 8 planted on a diagonal axis (P axis) of a panel screen.

According to the mounting method using the corner pins,
Due to the structure of the rectangular frame 7, there is an advantage that the deformation of the frame 7 is smaller and the weight of the frame 7 itself can be reduced as compared with the case of the mounting method using the axial pin shown in FIG.

As described above, the mounting method using the corner pins has an advantage that the deformation of the frame is small and the weight of the frame itself can be reduced.
In particular, in the case of a picture tube having a horizontally long screen, it is often used as a desirable shadow mask suspension means.

Here, the means for suspending the shadow mask in the above-described landscape screen will be described with reference to FIGS. FIG. 5 is a view showing only a quarter surface of a panel screen having a width-to-length ratio of 16 to 9 as viewed from the back side as in FIG.
FIG. 6 is an enlarged view of the pin portion shown in FIG. Specifically, as shown in FIG. 6, the pin 8 shown in FIG. 5 has its base end planted on the inner surface of the corner of the panel 2 and its tip formed in a frusto-conical shape. The reference surface (diameter) 12 is set at the tip.

FIG. 7 shows a relationship between a pin 8, a leaf spring 9 attached to a frame and having a hole fitted into a reference surface, and a nail 10 of a jig for attaching / detaching a shadow mask for attaching a shadow mask. Is shown.

As shown in FIG.
In order to remove a shadow mask (not shown) from the panel part 2, the nail 10 of the jig for attaching and detaching the shadow mask is a leaf spring. 7 and the pin 8 is inserted between the bases, and the claw 10 is moved in the direction of the arrow in FIG.
The shadow mask can be detached from the panel unit 2 by bending the shadow mask to make the entire shadow mask smaller than the top of the pin 8. When the shadow mask is mounted on the panel section 2, the above operation procedure may be reversed.

[0012]

However, as described above, when the above-mentioned claw 10 is operated when the shadow mask is attached or detached, as shown in FIG. 7, the tip 10A of the claw 10 and the long side A of the panel portion are removed. There is an inconvenience that the possibility of contact with the inner surface of the second member increases the possibility of damaging the inner surface.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages. When the shadow mask is attached or detached, the claws of the jig for attaching / detaching the shadow mask do not come into contact with the inner surface of the panel portion. It is an object of the present invention to provide a picture tube having a mounting structure of a shadow mask that does not damage the picture tube.

[0014]

In order to achieve the above object, according to the first aspect of the present invention, a frame holding a shadow mask is planted in a hole of a leaf spring attached to the frame on an inner surface of a corner portion of a panel portion. In a picture tube having a configuration in which a shadow mask is attached to a panel portion by being fitted into a reference surface of a pin provided, a recess is provided in an inner surface of the panel portion located on an extension of the reference surface of the pin, and a jig for mounting and dismounting a shadow mask is provided. The claw does not contact the inner surface of the panel portion when the claw is operated. Further, the invention of claim 2 is characterized in that, especially in the case of a horizontally long screen type, a recess is provided only on the inner surface on the long side of the panel portion.

[0015]

According to the first aspect of the present invention, since the shadow mask is attached to and detached from the panel portion, the recess is provided on the inner surface of the panel portion even when the claw of the jig for attaching and detaching the shadow mask is operated. The claws do not contact the inner surface of the panel, and the inner surface of the panel is not damaged.
Therefore, even if there is some variation in the pin placement position, unevenness of the unevenness of the inner surface of the panel portion, variation in the insertion position of the nail of the jig, etc., these variations can be efficiently absorbed by the dent, and as a result, Thus, there is no possibility of damaging the inner surface of the panel portion, and the tolerance for these variations is increased. Since there is a tolerance for such variations, the productivity is improved and the reliability of the product is also improved.

Further, when the screen is of a horizontally long type as in the second aspect of the present invention, the claw of the jig for attaching / detaching the shadow mask does not come into contact with the inner surface of the panel by providing a recess only on the long side of the panel. In this manner, the shadow mask can be attached and detached, and there is no need to provide a recess on the short side of the panel portion, so that a simpler structure can be achieved.

[0017]

FIG. 1 is an enlarged view showing a main part of a panel portion according to an embodiment of the present invention, and FIG. 2 is a perspective view of the same, and portions which are the same as or correspond to those of FIGS. The same reference numerals are given and the description is omitted.

FIG. 1 shows an improved example of a CRT having a horizontally long screen having a diagonal length of 66 cm and an aspect ratio of 16: 9.
The recess formed in the side inner surface, the reference surface 12 of the pin 8
It is provided at a position on the extension of.

The depth of the recess 11 is, for example,
It is about 3 mm. If the depth of the recess 11 is concerned only with the attachment / detachment of the nail of the jig for attaching / detaching the shadow mask,
About 5 mm is most preferable, but the panel part 2
Is excessively cut into the thickness of the glass, which may cause deterioration of the strength of the panel portion 2.

In FIG. 1, for example, in the conventional case where the recess 11 is not provided, the distance between the pin 8 and the long side A is about 7.3 mm, and the distance between the pin 8 and the short side B is about 12.5m
In this embodiment, in which the recess 11 is provided, as shown in the figure, the gap is provided on the long side A side with respect to the distance between the pin 8 and the long side A side. When the depth of the recess 11 is 3 mm, the distance between the pin 8 and the long side A is about 10 mm, and the two can be balanced. Thus, if the depth of the recess 11 is about 3 mm, the distance between the pin 8 and the long side A is about 10 m.
m, which is desirable.

Further, as shown in FIG. 2, the width of the recess 11 is determined by the distance between the seal surface 13 with the funnel glass and the pin 8.
And a width (with respect to the screen 3 direction) from the lower end position 14 of the pin to about +8 mm.

As described above, for example, since the recess 11 is provided in a part of the long side A of the panel part 2, the glass thickness of the part is reduced.
When the RT is completed, the high stress portions generated in the glass are in the X-axis direction and the Y-axis direction. Therefore, even if the recess 11 is provided on the inner surface of the panel portion as described above, the strength of the panel portion 2 is not improved. No inconvenience.

[0023]

As described above, according to the present invention, the shadow mask mounting can be performed with a simple configuration in which the nail of the shadow mask attaching / detaching jig is provided with a recess on the inner surface of the panel portion which is easily damaged. Even if there is some variation in the installation position of the pin for the panel, unevenness of the unevenness of the inner surface of the panel part, or unevenness in the insertion position of the nail of the above jig, the shadow mask is attached to the panel part without damaging the inner part of the panel part. Since the CRT can be attached and detached, it is easy to manufacture the CRT, and therefore, there is an effect that the reliability of the CRT can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an enlarged view showing a main part of a panel unit according to an embodiment of the present invention.

FIG. 2 is a perspective view of a pin portion of FIG.

FIG. 3 is a schematic view including a partially broken portion of a conventional color CRT.

FIG. 4 is a view of the panel screen shown in FIG. 3 as viewed from the back side (neck side).

FIG. 5 is a view of only a 1/4 face of a panel screen having a width-to-length dimension ratio of 16 to 9 as viewed from the back side.

FIG. 6 is an enlarged view of a pin portion shown in FIG. 5;

FIG. 7 is a diagram for explaining a state in which a leaf spring is attached to and detached from a pin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Picture tube 2 Panel part 8 Pin 9 Leaf spring 10 Claw 11 Depression 12 Reference surface (diameter)

Claims (2)

(57) [Claims] 1. A frame holding a shadow mask,
By fitting the hole of the leaf spring attached to this frame to the reference surface of the pin implanted in the inner surface of the corner portion of the panel portion, the picture tube with the shadow mask attached to the panel portion has an extension line extending from the reference surface of the pin. A picture tube, wherein a concave portion is provided on the inner surface of the panel portion located at the position. 2. The picture tube according to claim 1, wherein a recess is provided only on the inner surface on the long side of the panel portion.