JPH10302664A - Frame for color selecting mechanism of cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frame for a color selecting mechanism wherein mislanding of an electron beam caused by thermal expansion, earth magnetism, and the like can be suppressed and also dispersion in left/right endmost slits can be prevented, and moreover product costs and equipment costs can be lowered, even in the even that thinning of mask film and reducing of frame weight are conducted at the same time. SOLUTION: This frame 30 is structured so as to support a mask 32 of a color selecting mechanism and to give tension to this mask 32. In this event, this frame 30 comprises a pair of parallel A frames 31 to which the mask 32 is attached, and a pair of parallel B frames 33 which connect both ends of each of these A frames 31 to their counterparts while give tension to the mask 32 attached to the pair of A frames 31 by moving the pair of A frames 31 in the separating direction from each other by elastic restoring force arising after compression force is released, and these B frames 33 are formed so as to be easy in elastic deformation in the direction substantially parallel to the mask 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a frame for supporting a mask of a color selection mechanism in a cathode ray tube and applying tension to the mask.

[0002]

2. Description of the Related Art In a trinitron type cathode ray tube, an aperture grill which is a color selection mechanism in which three electron beams are arranged on the same horizontal plane and slits are formed in a vertical direction like a blind. FIG. 9 is a perspective view showing a color selection mechanism in the cathode ray tube. The color selection mechanism 1 includes a mask 3, a frame-shaped frame 5, a spring holder 7, and the like.

A plurality of vertical slits 9 for transmitting an electron beam are formed in a mask 3 made of a thin metal plate. The frame 5 includes a pair of parallel A frames 11 to which the mask 3 is welded, and a pair of parallel B frames 13 bent in a U-shape in the Z direction connecting both ends of the A frame 11. The spring holder 7 attached to the frame 5 serves as a spring seat plate for supporting the color selection mechanism 1 on the panel of the cathode ray tube.

FIG. 10 is an explanatory view of a procedure for assembling a color selection mechanism. The mask 3 is stretched over a frame 5 welded in a frame shape. To stretch the mask 3 on the frame 5, the B frame 13 is pressurized in the Y-axis direction and elastically deformed so that the A frames 11 approach each other. In this state, the mask 3 is subjected to seam welding or laser welding. Attach to 11. Thereafter, the pressurization of the frame 5 is released, and the B frame 13 is elastically returned in the Y-axis direction. As a result, the mask 3 is stretched over the frame 5 with a high tension in the Y-axis direction. The color selection mechanism stretches the mask 3 in this manner to prevent color shift due to thermal expansion of the mask 3 during operation of the cathode ray tube.

[0005]

By the way, weight reduction and cost reduction of the cathode ray tube are strong demands from the market.
Usually, these market requirements are met by simultaneously reducing the thickness of the mask and reducing the weight of the frame. However, when the conventional B frame 13 shown in FIG. 11 is reduced in weight, a large amount of frame deformation dZ is required at the time of assembly in order to apply the same tension to the mask as the rigid frame before the weight reduction. This has caused an increase in mislanding of the electron beam due to thermal expansion of the mask during operation of the cathode ray tube. That is, the B frame 13 provided with a large frame deformation dZ in the Z direction shown in FIG. 11 has a panel when the compression is released due to the thermal expansion of the mask during the operation of the cathode ray tube as shown in FIG. From the distance Z _{a in the} Z-axis direction. When the mask moves away from the panel with this, the electron beam passing through the slit 9 and hitting the phosphor screen shifts as shown in FIG.
Mislanding occurred. Further, if the thickness of the mask is reduced and the weight of the frame is reduced, the magnetic shielding characteristics of the entire color selection mechanism are reduced as compared with the related art. In addition, as shown in FIG.
Since it is bent in a U-shape in the axial direction, the shield member 1
7 could not be brought close to the mask, a high magnetic shield effect could not be obtained, and it was difficult to sufficiently suppress the mislanding of the electron beam due to terrestrial magnetism. Furthermore, the conventional shape B
Since the frame 13 is linear in the X coordinate as shown in FIG. 15, it is structurally easy to overlap at the same position as the leftmost and rightmost slits 9a formed on the mask, so that the manufacturing accuracy of the frame or the assembly of the color selection mechanism When the positions of the B frame 13 and the slit 9a are relatively displaced due to variations in accuracy, the direction of the moment M affecting the slit 9a changes in different directions to the left and right, and the variation in the width of the slit 9a increases, and the cathode ray tube becomes larger. There was a problem that the quality of the product deteriorated. As shown in FIG. 16, the color selection mechanism connects the spring holder 7 attached to the B frame 13 and the metal stud 21 provided on the panel 19 to the spring 23.
Is attached to the panel 19 by engaging through
Since the B frame 13 and the metal stud 21 have a rigid structure with little deformation in the X-axis direction, a step 25 corresponding to the amount of elastic deformation of the spring 23 at the time of engagement must be pressed into the spring holder 7. This increases the cost of parts and lowers the assembly accuracy. Also, a B frame 13 bent in a U-shape in the Z-axis direction
When the color selection mechanism is used, the height of the color selection mechanism in the Z-axis direction is increased as shown in FIG. 16, so that the color selection mechanism does not fit in the volume of the panel 19 when being combined with the panel 19. As a result, an inexpensive belt conveyor cannot be used in the transportation on the production line, and an expensive roller-type conveyor must be used, which is a factor that increases equipment costs. The present invention has been made in view of the above circumstances. Even when the mask is thinned and the frame is lightened at the same time, thermal expansion, mislanding of the electron beam due to terrestrial magnetism, etc. can be suppressed. It is an object of the present invention to provide a frame for a color selection mechanism that can prevent variations in slits and can reduce product costs and equipment costs.

[0006]

According to the present invention, there is provided a frame for a color selection mechanism for supporting a mask of a color selection mechanism and applying tension to the mask. A pair of parallel A frames to which the mask is attached, and connecting the two ends of the A frames together and moving the pair of A frames in a separating direction by an elastic return force after the compression force is released. A pair of parallel B frames for applying tension to the mask attached to the pair of A frames;
The frame is formed so as to be easily elastically deformed in a direction substantially parallel to the mask. Further, the color selection mechanism frame is characterized in that a bent portion bent in a direction substantially parallel to the mask is formed in the B frame so that the B frame is easily elastically deformed in a direction parallel to the mask. May be used.

In this color selection mechanism frame, the B frame is easily elastically deformed in a direction substantially parallel to the mask, and when the compression of the B frame is released immediately after the operation of the cathode ray tube,
The direction in which the compression of the B frame is released is a direction parallel to the mask, so that the amount of movement of the mask is kept small, and mislanding is kept small. The height of the frame in the direction perpendicular to the mask is reduced, the internal magnetic shield member is close to the mask, the magnetic shield effect is increased, and mislanding of the electron beam due to terrestrial magnetism is suppressed. At the same time, the color selection mechanism can be stored in the panel. The bending dimension in a direction substantially parallel to the mask can be freely designed, so that it is not necessary to press a step portion on the spring holder according to the amount of elastic deformation of the spring, and a spring holder without a step can be formed. Also,
By forming a bent portion bent in a direction substantially parallel to the mask on the B frame, a frame that is easily elastically deformable in a direction parallel to the mask can be easily formed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a frame for a color selection mechanism according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a partial perspective view showing the shape of a frame for a color selection mechanism according to the present invention. The frame (frame) 30 for the color selection mechanism includes a pair of parallel A to which the mask 32 is welded.
It comprises a frame 31 and a pair of parallel B frames 33 connecting both ends of the A frame 31. A frame 3
1 is formed in the same shape as the conventional one. On the other hand, the B frame 33 is conventionally formed by bending in the U-shape in the Z-axis direction, but in the present embodiment, the B-frame 33 is not bent in the Z-axis direction.

The color selection mechanism presses and compresses in the Y-axis direction when assembling. At that time, the B frame 33 is deformed, and the direction of the deformation largely depends on the shape (structure) of the B frame 33. That is, by specifying the shape of the B frame 33, the balance control of the deformation amount dZ in the Z axis direction and the deformation amount dX in the X axis direction of the B frame 33 becomes possible. A conventional B frame has a Z
By bending in a U-shape in the axial direction, the deformation dZ in the Z-axis direction of the B frame was larger than the deformation dX in the X-axis direction. On the other hand, the B frame 33 according to the present embodiment
As shown in FIG. 1, the elastic deformation in the X-axis direction is more easily formed than in the Z-axis direction, so that when pressed and compressed in the Y-axis direction, it is parallel to the X-axis direction, that is, parallel to the mask. The amount of deformation dX in any direction is increased.

To facilitate the elastic deformation of the B frame 33 in the X-axis direction, for example, as shown in FIG.
It can be realized by forming it. In the illustrated example, the bent portion 35 is formed at two places by bending twice, but the bent shape is not limited to this, and the bent portion is configured to facilitate elastic deformation in the X-axis direction. If it is a shape, the whole frame shape may be bent in a U-shape or V-shape in the X-axis direction, or a plurality of bent portions in the X-axis direction may be formed in a step shape.

To facilitate the elastic deformation of the B frame 33 in the X-axis direction, in addition to forming the B frame 33 in a bent shape as described above, as shown in FIG. The moment can also be realized by setting the aspect ratio in the cross-sectional shape of the B frame 33 to be larger in the Z-axis direction than in the X-axis direction. That is, vertical and horizontal dimensions B _X in the X-axis direction and the Z-axis direction, equal diagram B _Z 2 (a)
As compared with the conventional B-frame shown in and larger dimension B _Z dimension B _X than Z-axis direction of the X-axis direction 2
The B frame shown in (b) can make elastic deformation in the X-axis direction easier. In FIG. 2, a square bar is shown as an example, but the material of the B frame 33 is a round bar,
The same effect can be obtained by using a pipe material or an angle material obtained by bending a flat steel.

Next, the operation of the frame 30 configured as described above will be described. FIG. 3 is a view for explaining the deformation of the frame for the color selection mechanism according to the present invention due to the thermal expansion of the mask. Mislanding (temperature drift) of the electron beam due to thermal expansion, especially immediately after the operation of the cathode ray tube, is accompanied by thermal expansion of the mask as shown in FIG.
This occurs because the compression of the frame is released and the Z coordinate of the mask moves away from the panel. Therefore, in order to suppress this, when the compression of the B frame is released, the Z
A structure of a color selection mechanism in which coordinates do not move is required. In the frame 30 of the present embodiment, the direction in which the compression is released becomes the X-axis direction by facilitating the elastic deformation in the X-axis direction, and the movement amount Z _b of the mask in the Z-axis direction as shown in FIG. Is reduced, and as a result, mislanding is suppressed to a small value.

FIG. 4 is a view for explaining the magnetic resistance of the frame for the color selection mechanism according to the present invention. The mislanding (geomagnetic drift) of the electron beam due to terrestrial magnetism is greatly affected by the position of the internal magnetic shield of the cathode ray tube. When the frame 30 of the present embodiment is used, the height of the frame in the Z direction is reduced. In the case of the shape 29, the internal magnetic shield member 36 is about 20 mm thick compared to the structure using the conventional frame shown in FIG. It becomes closer to the mask 32. This makes it easier to form a denser magnetic circuit around the mask, increases the magnetic shielding effect, and suppresses mislanding of the electron beam due to terrestrial magnetism.

Next, with respect to the above-mentioned heat resistance characteristics (temperature drift), geomagnetic resistance characteristics (geomagnetic drift), and shock resistance characteristics (packing drop drift), the mislanding amount between the conventional frame and the frame of the present embodiment is compared. The results obtained will be described with reference to FIGS. FIG. 5 is an explanatory diagram showing the measurement points of the mislanding amount, and FIG. 6 is a comparative explanatory diagram showing the difference of each characteristic due to the difference of the frame. The mislanding amount was measured at nine measurement points 1 to 9 shown in FIG. 5, and the values were shown at corresponding positions in the rectangular frame in FIG. 6 which resembled the panel shape. In addition, the size of the color selection mechanism, the mask plate thickness, and the frame mass for which the measurement was performed were as follows. Conventional color selection mechanism Color selection mechanism of the embodiment Size 29 type 29 type Mask thickness 0.15 mm 0.10 mm Frame mass 4.0 kg 2.8 kg

As can be seen from FIG. 6, the weight is reduced and X
In the color selection mechanism of the embodiment in which the elastic deformation in the axial direction is facilitated and the height of the frame in the Z direction is reduced, the mislanding amount in the temperature drift and the geomagnetic drift is more average than that of the conventional color selection mechanism. In addition to being smaller, the amount of mislanding in the package drop drift was also smaller than that of the conventional color selection mechanism. From this, it was found that even when the weight was reduced, improvement of all the characteristics of the temperature drift, the geomagnetic drift, and the package falling drift was facilitated by facilitating the elastic deformation in the X-axis direction.

FIG. 7 is a view for explaining the stress distribution on the outermost slit when the frame according to the present invention is used. The width of the leftmost and rightmost slits of the mask is most affected by the stress distribution (particularly, the component in the Y-axis direction) at the corners of the frame after assembling the color selection mechanism. In a color selection mechanism using a conventional frame, as shown in FIG. 15, since the B frame is in a straight line direction in the X coordinate, it easily overlaps the leftmost and rightmost slits, and the manufacturing accuracy of the frame (in the case of the 29 type, the X Coordinate accuracy: ± 1.0 mm) or assembling accuracy of the color selection mechanism (accuracy of the positional relationship between the position of the mask and the B frame in the X-axis direction: ± 1.0 mm in the case of type 29) on the B frame. The peak position of the stress in the Y-axis direction varies. At this time, in the conventional B frame shown in FIG. 15, since the endmost slit is located on the B frame, the gradient of the stress distribution in the Y-axis direction of the endmost slit portion becomes positive or negative. Not stable. This gradient of the stress affects the moment M generated in the outermost slit, and the width of the outermost slit varies. On the other hand, in the frame 30 of the present embodiment, as shown in FIG. 7, since the endmost slit 37a is away from the junction of the A frame 31 and the B frame 33, the same stress gradient is always given on the endmost slit 37a, The direction of M becomes the same and the endmost slit 3
Variation in the width of 7a is suppressed.

FIG. 8 is a diagram for explaining the positional relationship between the panel and the color selection mechanism when the frame according to the present invention is used. In a conventional frame, the X coordinate of the B frame is determined by the size of the mask. On the other hand, in the frame 30 of the present embodiment, the X coordinate of the B frame 33 can be arbitrarily set by freely designing the bending dimension in the X-axis direction. Therefore, unlike the conventional frame, it is not necessary to press the spring holder 39 with a stepped portion corresponding to the amount of elastic deformation of the spring at the time of engagement, and it is possible to form the stepless spring holder 39 as shown in FIG. Becomes As a result, the cost of parts can be reduced, and the welding reliability between the spring holder 39 and the frame 30 is improved. Furthermore, a color selection mechanism in which the spring 41 is directly welded to the frame 30 without using the spring holder 39 can be realized.

Further, in the frame 30 of the present embodiment, since the bending in the Z-axis direction is not performed, the height in the Z-axis direction is reduced, and as shown in FIG. Storage becomes possible. This enables transport in a state where the color selection mechanism is stored in the panel 43. As a result, conventionally, since the color selection mechanism does not fit in the panel (see FIG. 16), an expensive roller-type conveyor was required. However, if the frame 30 of the present embodiment is used, the color selection mechanism is used. The mechanism can be stored in the panel 43, and can be conveyed by an inexpensive belt conveyor.

[0019]

As described above in detail, according to the frame for a color selection mechanism according to the present invention, the B frame is easily elastically deformed in a direction substantially parallel to the mask, so that the thickness of the mask can be reduced and the frame can be reduced. Even at the same time, the mislanding of the electron beam due to thermal expansion, terrestrial magnetism and drop impact can be suppressed, and the variation of the right and leftmost slits can be prevented, improving the quality characteristics of the cathode ray tube. In addition, product costs and equipment costs can be reduced. Further, if a bent portion bent in a direction substantially parallel to the mask is formed on the B frame, the B frame can be easily elastically deformed in a direction parallel to the mask.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a shape of a frame for a color selection mechanism according to the present invention.

FIG. 2 is a diagram illustrating a cross-sectional shape of a B frame.

FIG. 3 is a view for explaining a deformation of a frame for a color selection mechanism according to the present invention due to thermal expansion of a mask.

FIG. 4 is a diagram illustrating the magnetic resistance of the frame for a color selection mechanism according to the present invention.

FIG. 5 is an explanatory diagram showing measurement points of a mislanding amount.

FIG. 6 is a comparative explanatory diagram showing a difference in each characteristic due to a difference in a frame.

FIG. 7 is a diagram for explaining a stress distribution on the outermost slit when the frame according to the present invention is used.

FIG. 8 is a diagram illustrating a positional relationship between a panel and a color selection mechanism when a frame according to the present invention is used.

FIG. 9 is a perspective view showing a color selection mechanism in the cathode ray tube.

FIG. 10 is an explanatory diagram of a procedure for assembling a color selection mechanism.

FIG. 11 is a partial perspective view showing the shape of a conventional color selection mechanism frame.

FIG. 12 is a view for explaining deformation of a conventional color selection mechanism frame due to thermal expansion of a mask.

FIG. 13 is a diagram illustrating a mislanding amount of a frame for a color selection mechanism.

FIG. 14 is a diagram illustrating the magnetoresistance of a conventional frame for a color selection mechanism.

FIG. 15 is a view for explaining a stress distribution on the outermost slit when a conventional frame for a color selection mechanism is used.

FIG. 16 is a diagram illustrating a positional relationship between a panel and a color selection mechanism when a conventional frame for a color selection mechanism is used.

[Explanation of symbols]

30 Frame for Color Sorting Mechanism 31 A Frame
32 Mask 33 B frame 35 Bend

Claims (2)

[Claims] 1. A frame for a color selection mechanism of a cathode ray tube for supporting a mask of a color selection mechanism and applying tension to the mask, comprising: a pair of parallel A frames for mounting the mask; A pair of parallel B-frames that connect and move the pair of A-frames in the separating direction by an elastic return force after the release of the compressive force to apply tension to the mask attached to the pair of A-frames; A frame for a color selection mechanism of a cathode ray tube, wherein the B frame is formed so as to be easily elastically deformed in a direction substantially parallel to the mask. 2. The apparatus according to claim 1, wherein a bent portion bent in a direction substantially parallel to the mask is formed in the B frame, so that the B frame is easily elastically deformed in a direction parallel to the mask. 2. A frame for a color selection mechanism of a cathode ray tube according to 1.