JPH01159938A - Color image-receiving tube - Google Patents

Abstract

PURPOSE:To correct purity drift for a long period of time properly by forming the body of a shadow mask from a material with low coefficient of thermal expansion, constituting the mask frame from a material with high coefficient of thermal expansion, and supporting this shadow mask by a frame holder equipped with No.1 and No.2 elastically deforming parts which are inclined in acute angle to the two edges of a detent part for detention to a stud pin. CONSTITUTION:The body 22 of a shadow mask 24 is formed from a material with low coefficient of thermal expansion such as invar material, while the mask frame 23 to support its peripheries constituted from a carbon steel material with relatively high coefficient of thermal expansion, and the shadow mask 24 is borne by a stud pin 29 at the inside of a panel 1. When an electron beam collides with this shadow mask 24, the mask body presents little thermal expansion due to its low coefficient of thermal expansion, and the mask frame 23 displaces in the radial direction as shown by the arrow 36, and No.1 and No.2 elastic deforming parts 32 of the frame holder 28 deform elastically. As these elastically deforming parts 32a, 32b are folded in approx. equal angle with respect to a detent part 31, there is little displacement of the mask frame 23 in the direction toward the fluorescent screen.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a color picture tube, and particularly has a mask support means for suppressing long-term purity drift due to thermal expansion of a shadow mask. Regarding color picture tubes.

(Prior Art) A shadow mask type color picture tube has an envelope consisting of a panel and a funnel, and a phosphor screen consisting of three color phosphor layers that emit red, blue, and green light formed on the inner surface of the panel. A shadow mask is disposed inside the two panels opposite to and spaced apart from by a predetermined distance. Usually, this shadow mask consists of a mask body with a large number of electron beam passage holes formed therein, and a mask frame that supports the surrounding area.A frame holder made of an elastic body attached to the mask frame is attached to the inner wall of the skirt part of the panel. It is supported by being locked to a stud pin fixed to the.

In such a color picture tube, as shown in FIG. 8, in Japanese Patent Publication No. 46-4/04, the panel (1) is formed in a substantially rectangular shape with a skirt (2) around the periphery, and the inside thereof For a color picture tube in which a substantially rectangular shadow mask (3) is disposed, wedge-shaped frame holders (6) are attached to the four corners of the mask frame (5) that supports the mask body (4), and its free movement is A structure is shown in which the locking part (7a) on the end side is engaged with a stud pin (8) fixed to the inner wall of the skirt part (2) of the panel (1).

The features of this shadow mask support method are: First, the shadow mask (7) is supported at the four corners of the mask frame (2), which has high mechanical strength, so it is supported at the center of each side of the mask frame. It is possible to reduce the deformation of the mask frame (5) compared to the usual support method, and to suppress the landing error of the electron beam to the three-color phosphor layer constituting the phosphor screen (9).

Second, for the same reason, landing errors due to vibration can be reduced.

Thirdly, the so-called long-term purity drift that occurs after 30 minutes or more has elapsed from the start of operation can be corrected without using the bimetallic element used in the conventional support system. That is, the wedge-shaped frame holder (6
), as shown in Fig. 8, when the shadow mask (3) is heated by the collision of the electron beam and thermally expands in the radial direction shown by the arrow (10), at this time, the frame holder (5) is almost parallel to the shadow mask (3). Locking part (7a) and fixing part (7b)
The elastic deformation part (7
By deforming c), the shadow mask (3) is changed to -dotted chain line (
] As shown in 1), it is displaced in the direction closer to the phosphor screen (9). As a result, for example, the electron beam passage hole indicated by (], 2a) will be at the position (12b) only by the thermal expansion in the radial direction, but the electron beam passage hole shown by (], 2a) will be at the position (12b), but
Due to the action of bringing it closer to 9), it becomes the position (12c),
Landing mistakes can be prevented. In addition, (1
3) passes through the electron beam passage hole and passes through the phosphor screen (9).
) is the trajectory of the electron beam that hits the target.

However, in order to eliminate the initial purity drift immediately after the start of operation, the mask body (4) is made of a low thermal expansion material such as invar material, while the mask frame (5) is made of a material with low thermal expansion, such as in the case of a normal shadow mask. When a wedge-shaped frame holder (6) is used for a shadow mask (3) made of carbon steel with a relatively high coefficient of thermal expansion, the landing of the electron beam on the three-color phosphor layer is prevented. A long-term purity drift occurs in the opposite direction to that of a normal shadow mask.

As shown in FIG. 9, the mask body (4) made of a low-expansion material does not undergo much thermal expansion even when heated by the collision of electron beams, but the mask frame (5) made of a material with a high coefficient of thermal expansion does not. Thermal expansion occurs in the radial direction, and the deformation of the frame holder (6) at this time causes a shadow mask (
3) in the direction of approaching the phosphor screen (9) as shown by the - dotted chain line (11), and as a result, (12a
This is because the electron beam passing hole shown in ) is at the position (12b), and the landing position of the electron beam moves as shown in (13) and (13a).

In order to eliminate this long-term thermal drift, both the mask frame (6) and the mask body (4) may be made of a low thermal expansion material, but such a high thermal expansion material has a thickness of 1-high. Not practical.

(Problems to be Solved by the Invention) As described in item 2, wedge-shaped frame holders are attached to the four corners of the mask frame of a conventional substantially rectangular shadow mask to support the shadow mask inside the panel. Therefore, there is a color picture tube that prevents the long-term pipulity 1-rif I-, but the support method for this shadow mask is a shadow mask consisting of a combination of a mask body made of a low thermal expansion material and a mask frame made of a high thermal expansion material. When applied to a mask, there is a problem that compensation for long-term utility drift is exceeded and the beam landing position changes in the opposite direction to that of a normal shadow mask.

This invention was made in order to solve the problem described in item 2, and is directed to a color picture tube using a shadow mask consisting of a mask body made of a low thermal expansion material and a mask frame made of a high thermal expansion material. The purpose is to prevent the long-term purity drift 1 to occur even if the

[Structure of the invention]

(Means for solving the problem) A mask frame is attached to the periphery of a mask body in which a large number of electron beam passage holes are formed inside a substantially rectangular panel, and the mask body is made of a material with a low coefficient of thermal expansion. The mask frame has a substantially rectangular shadow mask made of a material with a relatively high coefficient of thermal expansion relative to the mask body, and this shadow mask is fixed to a frame holder and a panel that are attached to the mask frame. In a color picture tube supported by a mask support means consisting of a stud pin that locks the frame holder, the frame holder is configured to have a locking portion that locks the frame holder to the stud pin, and a frame holder that is inclined at an acute angle from one end edge of the locking portion. a first elastically deformable part that faces the locking part and has a distal end fixed to the mask frame; , and a second elastically deformable portion whose tip portion is fixed to the mask frame.

(Function) As described above, the shadow mask, which is composed of a mask body made of a material with a low coefficient of thermal expansion and a mask frame made of a material with a relatively high coefficient of thermal expansion, has both ends of the locking part that locks on the stud pin. If the mask frame is supported by a frame holder having a first and second elastic deformation part inclined at an acute angle from the edge and facing the locking part, even if the mask frame is displaced in the radial direction due to thermal expansion, it will not come close to the phosphor screen. It is possible to appropriately correct long-term utility drift by suppressing the effect in the direction of

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

FIG. 1 shows a color picture tube which is an embodiment of the present invention. This color picture tube has an envelope (21) consisting of a substantially rectangular panel (1) with a skirt (2) formed around its periphery and a funnel (20).

A phosphor screen (9) consisting of a three-color phosphor layer that emits red, blue, and green light is formed on the inner surface of the panel (1), and is placed opposite to the phosphor screen (9) and spaced apart by a predetermined distance. Mask body with many electron beam passage holes (
A substantially rectangular shadow mask (24) consisting of a mask frame (22) and a mask frame (23) with a cross-sectional shape supporting the peripheral portion thereof.
) are provided. Also, an electron gun (26) that emits three electron beams into the neck (25) of the funnel (20).
) are provided. Then, the three electron beams emitted from the electron gun (26) are projected onto the phosphor screen (9) through the electron beam passing hole of the shadow mask (24). Color images are now displayed.

By the way, in the shadow mask (24) of this example, the mask body (22) is made of a material with a low coefficient of thermal expansion such as invar material, and the mask frame (23) supports the peripheral part of the mask body (22). The mask body (2
2) is a part of the scar 1 (27) provided around it.
is attached to the inside of the mask frame (23) by welding. This shadow mask (24) has a frame holder (28) attached to the outer surface of the four corners of the mask frame (23), which will be described later, attached to the panel (1).
It is supported inside the panel (1) by being engaged with stand pins (29) fixed to the inner walls of the four corners of the panel (1).

The frame holder (28) has a thickness of, for example, 0.2
- A lock made of stainless steel (SO5631) of about 0.3 mm and provided with a through hole (30) that engages with a stud pin (29), as shown in Figures 2 and 3. (31) and the end edge (one edge) of this locking portion (31) on the phosphor screen (9) side is bent from both sides and is inclined at an acute angle θ□ to form a locking portion ( a pair of first elastically deformable portions (32a) facing the locking portion (31);
1) A locking portion (31) is bent from the center of the other end edge (electron gun side edge) and is also inclined at an acute angle 02.
and one second elastically deformable part (32b) facing the mask frame (23), and a fixing part (32b) for welding to the mask frame (23) is provided at the tip of each elastically deformable part (32a) and (32b).
33) is provided. The x mark is the welding point.

Therefore, this frame holder (28) is connected to the pin axis of the stud pin (29) and the tube axis (34) of the picture tube (
The projections of the first and second elastic deformation parts (32a) and (32b) onto a plane including
, the second elastically deformable portions (32a) and (32b) are bent approximately equiangularly with respect to the locking portion (31), so that 01=02 (1).

=11- Now, attach the frame holder (28) of the above shape to the four corners of the mask frame (23) and attach the shadow mask (2
4), the shadow mask (24) is heated by the collision of the electron beam, and even if the mask frame (23), which has a particularly high coefficient of thermal expansion, thermally expands, the shadow mask (24)
3 by suppressing the displacement toward the phosphor screen (9).
It is possible to eliminate landing errors of the electron beam on the color phosphor layer.

That is, as shown in FIG.
) even if an electron beam collides with it, the coefficient of thermal expansion is approximately 2.
The mask body (22) made of an amber material with a coefficient of thermal expansion of 0 x 10-7 causes only slight thermal expansion due to its low coefficient of thermal expansion, but the mask frame (23) made of carbon steel with a coefficient of thermal expansion of 120 x 10-7. is an arrow (36)
The frame holder (2) is displaced in the radial direction as shown in
8) first and second elastic deformation parts (32a) and (32b
) is elastically deformed. However, this frame holder
(28) The first and second elastic deformation parts (32a), (3
2b) is bent approximately equiangularly with respect to the locking part (31) and satisfies formula (1), so it deforms approximately equally and moves toward the phosphor screen (9) of the mass frame (23). Displacement is eliminated, and even if there is, the amount of displacement is small. Moreover, even if the mask frame (23) is displaced in the radial direction, the displacement of the mask frame (23) is absorbed by the skirt portion (27) of the mask body (22), so that the displacement of the mask frame (23) is reduced by the displacement of the mask body (22). Since the effect on the effective area can be reduced, the landing of the electron beam (13) on the three-color phosphor layer can be made almost unchanged.

As a specific example, a 32-inch color picture tube is shown in which the frame holder (28) has a thickness of 0.6 mm.
SUS 631 is used, and the width of the locking part (31) is 20mm.
．． The first and second elastic deformation parts (32a) and (32b) respectively at the locking portion (3).
It was formed at an angle of 45° with respect to 1). Then, this frame holder (28) is attached to the shadow mask (2).
After operating the color picture tube supporting 4) for 90 minutes at an anode voltage of 29 kV and anode current of 1700 μA, we measured the landing state of the electron beam. In some cases, the landing position of the electron beam moved by about 70 μm, but this could be reduced to 10 μm or less.

Next, other embodiments will be described.

In the frame holder of the above embodiment, the first and second elastically deformable parts are inclined at approximately equal angles with respect to the locking part so that the lengths of the elastically deformable parts are equal, but the frame holder shown in FIG. In (28), the length of the second elastic deformation part (32b) is longer than the length of the first elastic deformation part (32a), where 01≧02 (2).

When the mask frame (23) thermally expands, the frame holder (28) having such a shape will cause the mask body (2
2) is displaced away from the phosphor screen (9), so the shadow mask (24) can be used in situations where the panel (1) is thermally expanded due to heat generated by the deflection yoke or receiver circuit, and this thermal expansion cannot be ignored. This works effectively when it is necessary to correct the distance from the phosphor screen (9), and prevents the long-term purity drift.

Further, in the above embodiment, the first and second elastic deformation parts were provided on both ends of the locking part, but as shown in FIG.
The second elastic deformation portions (32a) and (32b) have locking portions (
31) may be provided at the edge portions on both sides of the stud pin (29) so that their projections on a plane that includes the pin axis of the stud pin (29) and is perpendicular to the tube axis of the picture tube intersect. Especially for such a frame holder (28), 01 unit θ2245°
...(3) It is best to form it as follows.

Furthermore, in the above embodiment, the locking portion and the first and second elastic deformation portions of the frame holder were integrally formed by folding lobes, but this frame holder, as shown in FIG.
The locking part (31), the first and second elastic deformation parts (32a), (
32b) may be formed separately and integrated by welding.

Furthermore, in order to give appropriate elastic constants to the first and second elastic deformation parts, slits may be provided in the first and second elastic deformation parts, or they may be divided into two or more parts. may be done arbitrarily.

[Effects of the Invention] For a substantially rectangular shadow mask in which a mask frame made of a material with a relatively high coefficient of thermal expansion is attached to the periphery of a mask body made of a material with a low coefficient of thermal expansion, A locking part that locks the frame holder to be attached to a stud pin fixed to a corner of a substantially rectangular panel, and a locking part that slopes at an acute angle from one edge of the locking part and faces the locking part. a first elastically deformable part whose tip end is fixed to the mask frame; and a first elastic deformable part which is inclined at an acute angle from the other end edge of the locking part and faces the locking part, and whose tip part is fixed to the mask frame. When the mask body has a low coefficient of thermal expansion and the mask frame has a high coefficient of thermal expansion, the long-term purity drift that conventionally occurs, that is, the mask frame thermally expands. ,
By suppressing displacement of the shadow mask as it approaches the phosphor screen, it is possible to appropriately correct long-term utility drift.

[Brief explanation of the drawing]

1 to 7 are detailed explanatory diagrams of the present invention, in which FIG. 1 is a sectional view showing the structure of a color picture tube as an embodiment thereof, and FIG. 2 is a perspective view showing the structure of the frame holder. ,
3(A) and 3(B) are respectively a front view and a side view of the frame holder, FIG. 4 is a diagram for explaining the function of the frame holder, and FIG. 5 is a frame holder of another embodiment. 6 is a diagram for explaining the shape of the frame holder of another different embodiment and its operation, and FIG. 7 is a diagram for explaining the shape of the frame holder of another different embodiment. Figure 8 is a diagram to explain the shape and its function. Figure 9 is a diagram to explain the shape and function of a conventional frame holder. Figure 9 is a diagram to explain the shape and function of a conventional frame holder. FIG. 3 is a diagram for explaining the effect of a conventional mask frame on a shadow mask to which a mask frame made of a material with a high coefficient of thermal expansion is attached.

Claims (6)

[Claims] (1) A mask consisting of an envelope having a substantially rectangular panel with continuous funnels, and a mask disposed facing a phosphor screen formed on the inner surface of the panel, with numerous electron beam passage holes formed therein. a substantially rectangular shadow mask in which a mask frame is attached to a peripheral portion of the main body, the mask main body is made of a material with a low coefficient of thermal expansion, and the mask frame is made of a material with a relatively high coefficient of thermal expansion with respect to the mask main body; A frame holder made of an elastic body attached to the mask frame, and a mask support means made of a stud pin fixed to the panel to lock the frame holder, the frame holder being locked to the stud pin. a first elastic deformable part that is inclined at an acute angle from one end edge of the locking part and faces the locking part, and has a tip fixed to the mask frame; A color image receiver, characterized in that it is formed in a shape comprising a second elastic deformation part that is inclined at an acute angle from the other end edge, faces the locking part, and has a tip fixed to the mask frame. tube. (2) A patent claim characterized in that the frame holder is attached to the mask frame so that one edge of the locking portion faces the phosphor screen and the other edge faces the opposite side. The color picture tube according to item 1. (3) A patent claim characterized in that the first and second elastically deformable parts of the frame holder are provided so that their projections onto a plane containing the pin axis of the stud pin and the tube axis of the color picture tube intersect. A color picture tube according to item 2. (4) A patent characterized in that the first and second elastically deformable parts of the frame holder are provided so that their projections on a plane including the pin axis of the stud pin and perpendicular to the tube axis of the color picture tube intersect. A color picture tube according to claim 1. (5) The color picture tube according to claim 1, wherein the first and second elastic deformation parts of the frame holder are formed separately from the locking part and welded to the locking part. . (6) The frame holder has an inclination angle of θ_1 of the first elastic deformation part with respect to the locking part and an inclination angle of the second elastic deformation part of θ_2.
The color picture tube according to claim 1, wherein the color picture tube is provided in a relationship that satisfies θ_1≧θ_2.