JP2002304953A - Color cathode-ray tube and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color cathode-ray tube equipped with a shadow mask having sufficient strength, and a method for manufacturing it. SOLUTION: A shadow mask 7 is structured by superimposing an auxiliary mask 20 on a mask body 14. The mask body faces the almost whole face of a phosphor screen and has a mask 40 having an almost rectangular effective area where many electron beam passing holes are formed, and a skirt part 17 extending from the peripheral rim of the main face of the mask. The auxiliary mask is fixed by superimposing it on the vicinity area of the short axis Y of the effective area of the mask body, and is formed in a band shape formed with this short axis as a longitudinal direction. It also has many electron beam passing holes corresponding to the many electron beam passing holes of the mask body. The auxiliary mask has a grip part exposed without being superimposed on the mask body and graspable from the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color cathode ray tube having a shadow mask and a method of manufacturing the same.

[0002]

2. Description of the Related Art Generally, a color cathode ray tube comprises an envelope having a panel having a phosphor screen formed on an inner surface thereof, and a substantially rectangular shadow provided in the envelope so as to face the phosphor screen. And a mask. On the effective surface of the shadow mask facing the phosphor screen, a large number of openings are formed in a predetermined arrangement as electron beam passage holes. The shadow mask has a function of selecting three electron beams emitted from the electron gun through the respective apertures and causing the three electron beams to be incident on the three-color phosphor layer constituting the phosphor screen.

In recent years, flat tubes having a substantially flat radius of curvature of 10,000 mm or more on the outer surface of the panel of a color cathode ray tube have become mainstream in order to improve visibility by reducing external light reflection and reducing image distortion. is there. Usually, the effective surface of the shadow mask facing the phosphor screen is formed in a shape corresponding to the inner shape of the panel. for that reason,
The flat tube shadow mask has a smaller curvature than the conventional color cathode ray tube and is almost flattened.

[0004]

However, when a shadow mask having such a small curvature is used, the following problems occur. Normally, the shadow mask has a thickness of 0.2 m
m. When the curvature of the effective surface is small, the shadow mask for a large screen formed of such a thin plate is deformed by its own weight or an external force, and it is difficult to maintain the mask curved surface. That is, when the curvature of the effective surface is reduced, the holding force of the mask curved surface (hereinafter, mask curved surface strength) decreases. In particular, the decrease in the mask curved surface strength is most remarkable at the center of the effective surface, that is, near the center of the screen.

If the strength of the curved surface of the mask is low, the effective surface of the shadow mask is deformed by a small external force during manufacturing or transportation. In this case, the distance relationship between the electron beam passage hole of the shadow mask and the inner surface of the panel fluctuates, and the electron beam emitted from the electron gun does not land on a predetermined phosphor layer, causing a color shift.

[0006] In addition, the mask curved surface strength is reduced because the effective surface of the mask is easily resonated by vibrations such as sound when incorporated into a television set, even if the shadow mask does not reach the deformation, and is not required on the screen. The light and dark.

The simplest method for preventing such a decrease in the mask curved surface strength is to increase the thickness of the shadow mask. However, when the thickness of the shadow mask increases, it becomes difficult to control the etching at the time of manufacturing the shadow mask, and the variation in the diameter of the electron beam passage hole increases. As a result, the production yield of the shadow mask and the production of the color cathode ray tube are reduced, and the screen quality is deteriorated.

An object of the present invention is to provide a color cathode-ray tube provided with a shadow mask having a sufficient mask curved surface strength and a method of manufacturing the same.

[0009]

In order to achieve the above object, a color cathode ray tube according to the present invention comprises a panel having a phosphor screen provided on an inner surface thereof, and an electron beam for emitting an electron beam toward the phosphor screen. A gun, a shadow mask which is arranged inside the panel so as to face the phosphor screen and has a large number of electron beam passage holes formed therein,
A mask frame in which the periphery of the shadow mask is fixed, wherein the shadow mask faces substantially the entire surface of the phosphor screen and has a substantially rectangular effective portion in which a large number of electron beam passage holes are formed. A mask main surface having a mask main surface, and a skirt portion extending from the periphery of the mask main surface; and an electron beam of the mask main body, which is fixed by being superimposed on a region near a short axis of an effective portion of the mask main body. A band-shaped auxiliary mask having a plurality of electron beam passage holes corresponding to the passage holes and having the short axis as a longitudinal direction, wherein the auxiliary mask is exposed without overlapping with the mask body and is externally exposed. It is characterized by having a gripper that can be gripped from above.

According to the color cathode ray tube having the above structure, the curved surface strength of the shadow mask can be improved by overlapping and fixing the auxiliary mask on the mask main body.
The amount of deformation near the center of the mask, which has the largest amount of deformation, can be suppressed. Further, since the auxiliary mask is provided with the gripping portion, the position can be adjusted by gripping the gripping portion at the time of manufacturing the shadow mask, and high-precision assembly becomes possible.

[0011] A method of manufacturing a color cathode ray tube according to the present invention includes a panel having a phosphor screen provided on an inner surface thereof, an electron gun for emitting an electron beam toward the phosphor screen, and a fluorescent lamp provided inside the panel. A shadow mask disposed opposite the body screen and having a large number of electron beam passage holes formed therein, and a mask frame in which the periphery of the shadow mask is fixed, wherein the shadow mask is substantially the same as the phosphor screen. A mask main surface having a substantially rectangular effective portion opposed to the entire surface and having a large number of electron beam passage holes formed thereon, and a mask body having a skirt portion extending from the periphery of the mask main surface, A large number of electron beam passage holes corresponding to the electron beam passage holes of the mask body are fixed by being overlapped on the short axis vicinity region of the effective portion of the mask body. And a band-shaped auxiliary mask having the short axis as the longitudinal direction, and the auxiliary mask has a grip portion that is exposed without overlapping with the mask body and can be gripped from the outside. In the method for manufacturing a tube, a first mask base for a flat mask body having an effective portion in which a large number of electron beam passage holes are formed, and a large number of electron beam passage holes are formed and the grip portion is formed. And a second mask base material for a flat auxiliary mask having the first mask base material, and the second mask base material is arranged so as to overlap with a region near the short axis of the first mask base material. The first and second mask bases are supported so as to be relatively displaceable by holding the base and the gripping portions of the second mask base, respectively, and either one of the first and second mask bases is held. To make a small displacement Ri said first
After positioning the first and second mask base materials with each other and fixing the positioned first and second mask base materials together, the first and second mask base materials are press-formed into a predetermined shape to form the mask body. And forming a shadow mask having an auxiliary mask.

According to the manufacturing method having the above structure, when the auxiliary mask is fixed to the mask main body in a state of the flat mask base material before press molding, one of the mask main body and the auxiliary mask is finely moved to perform the positioning. Can be performed, and positioning can be performed easily and reliably. In this case, the gripping portion of the second mask base material for the auxiliary mask is gripped and finely moved to perform alignment, thereby improving accuracy.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color cathode ray tube according to an embodiment of the present invention will be described below in detail with reference to the drawings. As shown in FIGS. 1 and 2, the color cathode ray tube includes an envelope formed of glass, the envelope includes a rectangular panel 1 having a long axis X in the horizontal direction, and a skirt of the panel 1. It has a funnel 3 joined to the portion 2 and a neck 4 extending from a small diameter portion of the funnel 3. A phosphor screen 5 is formed on the inner surface of the panel 1. The envelope has a tube axis Z passing through the center of the panel 1 and the center of the neck 4, a major axis X extending perpendicular to the tube axis, and a minor axis extending perpendicular to the tube axis and the major axis ( (Vertical axis) Y.

When a 32-inch wide type color cathode ray tube having a screen aspect ratio of 16: 9 and a screen effective diameter of 76 cm is taken as an example, the outer surface of the panel 1 has a radius of curvature of 10,000 mm and is substantially It is flat. The inner surface of the panel 1 has a radius of curvature along the X axis on the X axis of about 7,000 mm, a radius of curvature on the Y axis along the Y axis of about 1,500 mm, and is formed in a substantially cylindrical shape. I have.

In the envelope, a shadow mask structure 6 serving as a color selection electrode is disposed so as to face the phosphor screen 5. The shadow mask structure 6 includes a shadow mask 7 in which a large number of apertures serving as electron beam passage holes are formed, and a mask frame 8 having a rectangular frame shape having an L-shaped cross section to which the periphery of the shadow mask 7 is fixed. are doing. The shadow mask structure 6 is configured such that an elastic support (not shown) provided on the side wall of the mask frame 8 is engaged with a stud pin (not shown) embedded in the skirt portion 2 of the panel.
It is supported inside the panel 1. The opening shape of the electron beam passage hole formed in the shadow mask 7 is formed in a rectangular shape or a circular shape depending on the use.

An electron gun 10 for emitting three electron beams 9R, 9G and 9B arranged in-line on the major axis X is arranged in the neck 4. In the above color cathode ray tube, the electron beams 9R, 9E emitted from the electron gun 10 are used.
G and 9B are deflected by a deflection yoke 11 attached to the outside of the funnel 3, and an image is displayed by scanning the phosphor screen 5 horizontally and vertically via the shadow mask structure 6.

Next, the configuration of the shadow mask 7 will be described in detail. As shown in FIGS. 3 to 5, the shadow mask 7 includes a mask main body 14 and an auxiliary mask 20 that is attached to a part of the mask main body so as to be partially overlapped. ing.

The mask main body 14 is arranged to face the inner surface of the panel 1 and has a substantially rectangular mask main surface 40 formed in a predetermined curved surface shape, and extends along the tube axis Z direction from the periphery of the mask main surface. Skirt portion 17 extending to the electron gun side
And are integrally provided. The mask main surface 40 has a rectangular effective portion 13 in which a large number of openings 12 functioning as electron beam passage holes are formed, and a substantially rectangular frame shape which is located so as to surround the effective portion and has no openings. A non-porous portion 16 of
have.

Each opening 12 of the mask body 14 is
3 is formed in a substantially rectangular shape with the width direction being the major axis X direction. The plurality of apertures 12 form the short axis Y of the effective portion 13.
A large number of aperture rows arranged linearly in the direction via the bridge 18 are provided at a predetermined arrangement pitch PH in the major axis X direction.

As shown in FIG. 6, the cross-sectional shape of each aperture 12 has a substantially rectangular large hole 19a opened on the surface of the effective portion 13 on the side of the phosphor screen 5, and the effective portion 13 on the electron gun 10 side. It is constituted by a communication hole which communicates with a substantially rectangular small hole 19b opened on the surface. Further, the opening 12 is formed such that the center position C1 of the large hole 19a is offset by Δ toward the periphery of the effective portion relative to the center position C2 of the small hole 19b as going toward the periphery of the effective portion 13. A so-called Offsen mask. This is for suppressing the electron beam from passing through the small hole 19b and colliding and reflecting on the side surface within the thickness of the mask body 14 to generate unnecessary light emission on the screen. Direction and the major axis X direction are offset.

As the mask body 14, a metal material such as an invar material (Fe-36% Ni alloy) known as an iron material or a low expansion material, having a thickness of about 0.1 to 0.25 mm can be used.

On the other hand, as shown in FIGS. 3 to 6, the auxiliary mask 20 is formed in an elongated band shape, and on the surface of the mask body 14 on the side of the electron gun 10, not in the entire area of the effective portion 13 but in the vicinity of the short axis Y. Fixed over the area. The major axis direction of the auxiliary mask 20 is provided so as to coincide with the minor axis Y of the mask body 14.

The width LH1 of the auxiliary mask 20 along the major axis X direction is the length LH of the effective portion 13 of the mask body 14 in the major axis direction.
2, and the length along the short axis Y direction is longer than the length of the mask body 14 in the same direction as described later.

The auxiliary mask 20 has an effective portion 21 provided with a large number of openings 42 functioning as electron beam passage holes,
A non-porous portion 23 located outside the effective portion 21 at both ends in the longitudinal direction of the auxiliary mask, and a pair of skirt portions 24 extending from each non-porous portion 23 in both ends are integrally provided.

The auxiliary mask 20 has its effective portion 2
1, the non-porous portion 23 and the skirt portion 24 are fixed to the mask main body in a state of overlapping with the effective portion 13, the non-porous portion 16 and the skirt portion 17 of the mask main body 14, respectively. Thus, the region on the short axis Y of the mask body 14 has a double structure.

Since the length of the auxiliary mask 20 in the short axis Y direction is longer than the length of the mask body along the short axis Y direction, each skirt portion 24 of the auxiliary mask 20 is It extends beyond the lower end of the skirt 17 of the body 14 and is exposed without overlapping the mask body. The two extended ends of the auxiliary mask 20 function as gripping portions 44 during the positioning operation, as described later.

Note that, as shown in FIG.
, The length LV1b of the effective portion 21 in the short axis Y direction is formed larger than the length LV2 of the effective portion 13 of the mask body 14 in the short axis Y direction.

The auxiliary mask 20 is made of an invar material similarly to the mask main body 14, and has a thickness of about 0.25 mm. Further, a width LH1 in the major axis X direction of the auxiliary mask 20 and a length LH3 in the major axis X direction of the mask body 14 are provided.
Is formed to about 1: 5. Therefore, the auxiliary mask 20 is fixed to a region of about 1/5 of the length of the mask body 14 in the major axis X direction, and has a double structure.

The shape and the arrangement interval of the openings 42 formed in the effective portion 21 of the auxiliary mask 20 can be appropriately set within a range that functions as a shadow mask. You.

As described above, the strength of the shadow mask 7, especially the strength in the vicinity of the short axis Y is improved by overlapping and fixing the auxiliary mask 20 to the mask body 14 to form a double structure. The mask curved surface strength of the mask can be increased.

In the shadow mask having the above structure, if the purpose is to improve the mechanical strength, it is more advantageous if the area of the auxiliary mask 20 is increased to cover the entire effective portion of the mask body 14, but it is more advantageous. This poses a problem in terms of alignment accuracy.

That is, the auxiliary mask 20 is connected to the mask body 1
4 when overlapping with the effective portion 13 of the mask body 14
If they do not match, the shadow mask 7 will not function. As the area of the auxiliary mask 20 increases, the number of apertures 12 to be aligned within the range increases, and fine adjustment of the mask aperture row and assurance of accuracy with respect to the short axis direction hole positional deviation are required. It becomes difficult.

In view of this, Japanese Patent Application No. 2000-392991 further examined the width of the auxiliary mask 20 and the mask strength. FIG. 8 is a graph showing the relationship between the width of the auxiliary mask 20 and the amount of mask deformation when a 32-inch color picture tube is used. Here, the horizontal axis is the mask body 14
Mask width LH1 with respect to major axis X direction length LH3
On the vertical axis, the mask maximum displacement amount when the width LH1 of the auxiliary mask 20 is expanded to the length LH3 in the major axis direction of the mask body 14 is 0, and the mask maximum displacement amount when there is no auxiliary mask is 1. The figure shows the ratio of the maximum displacement of the mask when this is done.

As is apparent from FIG. 8, the auxiliary mask 20
Is increased, the maximum displacement of the mask is reduced. However, when the width LH1 of the auxiliary mask 20 is about 1/3 of the length LH3 in the major axis direction of the mask body 14, the change in the maximum displacement becomes gentle, and thereafter there is no significant change.

On the other hand, increasing the width LH1 of the auxiliary mask 20 increases the area of the auxiliary mask 20 and makes accurate alignment difficult. However, the width LH1 of the auxiliary mask 14 is limited in the longitudinal direction of the mask body 14. It was confirmed that the alignment accuracy could be secured sufficiently high if it was within 1/3 of the length LH3. From the above examination results, it is preferable that the auxiliary mask 20 is fixed to the central 1/3 region with respect to the major axis length LH3 of the mask body 14.

Further, as shown in FIG.
0 of the effective portion 21 is the mask body 1
It is desirable to set the length of the effective portion 13 of the fourth portion to be equal to or slightly larger than the length LV2 in the short axis direction. In this case, even if a positional shift in the short axis Y direction occurs between the mask main body 14 and the auxiliary mask 20, it is possible to absorb an alignment error.

The material forming the auxiliary mask 20 preferably has a coefficient of thermal expansion close to that of the material forming the mask body 14.
Ideally, the materials should have the same coefficient of thermal expansion. Since heat of about 400 ° C. is received in the process of manufacturing a color cathode ray tube, if the mask body 14 and the auxiliary mask 20 have significantly different coefficients of thermal expansion, the portion where the auxiliary mask 20 is bonded becomes bimetallic, and the heat-treated shadow This is because even if the mask 7 is deformed or not completely deformed, the mask shape varies.

Further, as in the flat tube according to the present embodiment, in the shadow mask 7 having a small curvature of the curved surface, the color shift due to thermal expansion is remarkable. As described above, the shadow mask having a shape in which color misregistration easily occurs is formed of a material having a small coefficient of thermal expansion such as an Fe-Ni-based alloy, an Fe-Ni-Co-based alloy, or an Fe-Ni-Cr-based alloy. It is desirable to use a shadow mask. For the above reasons, in the present embodiment, both the shadow mask main body 14 and the auxiliary mask 20 use an Invar material.

Further, as shown in FIG.
When the small holes 25b of the auxiliary mask 20 and the small holes 19b of the mask body 14 are bonded to each other so that the small holes 25b and the small holes 19b of the mask body 14 are in close contact with each other,
Since the area in which they contact each other, that is, the area to be fixed, is larger than in the case where the large holes 25a of 0 are in contact with each other, strong and reliable fixing is possible. In the vicinity of the auxiliary mask 20, the center of the small hole 25b on the phosphor screen side is shifted toward the mask peripheral side from the center of the large hole 25a on the electron gun side.
It is preferable to perform offsen.

Further, in the peripheral area of the auxiliary mask 20, when the pitch of the row of apertures is considered with the position of the center of the center of the large hole and the center of the small hole as the opening position, the shadow mask body 1
Comparing the corresponding row of apertures with the mask 4 and the auxiliary mask 20,
It is desirable that the aperture row pitch PH2 of the auxiliary mask 20 be smaller than the aperture row pitch PH1 of the shadow mask body 14.

This is because the electron beam passes through the two masks in the superimposed portion, and when the incident angle of the electron beam approaches the short side of the screen and increases, the change in the position of the electron beam in the longitudinal direction within the plate thickness changes. Becomes larger. If the aperture row pitch PH2 of the auxiliary mask 20 is smaller than the aperture row pitch PH1 of the shadow mask main body 14, the inclination of the aperture can be made to coincide with the electron beam trajectory, thereby suppressing the occurrence of vignetting and the like. be able to.

Next, a method of manufacturing the shadow mask 7 configured as described above will be described. First, as shown in FIG. 9, a thin plate of Invar material is etched to form a flat mask body having a predetermined outer dimension having an effective portion 13 in which a large number of openings are formed with a predetermined diameter and pitch. Of the mask base material (first mask base material) 50 is prepared. Similarly, by etching a thin plate of Invar material, a mask base material for a flat auxiliary mask having a predetermined outer dimension having a plurality of effective portions 21 formed with a predetermined diameter and a predetermined pitch is formed. 2 mask base material) 55 is prepared. In addition, these mask base materials 50 and 55 are subjected to an annealing process in order to improve press formability.

Each of the mask bases 50, 55 has an effective portion 13, 21, in which a large number of openings, which are electron beam passage holes, are formed.
It consists of a peripheral ineffective part, and the ineffective part has a cut 53,
58 and positioning holes 54 and 59 are formed. The positioning holes 54 and 59 are formed in the mask base materials 50 and 55 in order to enable accurate positioning and fixing of both mask base materials.

Subsequently, as shown in FIGS. 10 and 11, the mask base materials 50 and 55 are loaded into the positioning device.
The positioning device includes a mounting table 62 having a support surface 60 having substantially the same size as the mask substrate 50. The support surface 60 is provided with a plurality of magnet chucks 64 for fixing the mask base material 50 by suction. At the center of the support surface 60, a shallow strip-shaped mounting groove 65 for mounting the mask base material 55 is formed.

The positioning device has a pair of adjusting portions 63 for holding and positioning the mask base material 55. Each adjustment unit 63 includes a chuck 66 for gripping an end of the mask base material 55, that is, the gripping unit 44. The chuck is mounted on an XY table 67.

The mask substrates 50, 5
5 is loaded, first, the mask base material 55 is attached to the mounting groove 65.
In this case, both ends of the mask base material 55, that is, the grip portions 44 are respectively protruded to both sides of the support surface 60. Then, each gripping portion 44 of the mask base material 55 is
3 is gripped by the chuck 66.

Next, the mask substrate 50 is placed on the support surface 60 and fixedly supported on the support surface by the magnet chuck 64. As a result, the mask substrate 50 is superimposed and held on the mask substrate 55.

In this state, as shown in FIG. 11, the XY table 67 of each adjustment unit 63 is driven to
Position adjustment is performed in the long-axis direction, the short-axis direction, and the rotation direction of both ends of 5, and the opening formed in the mask base 55 and the opening formed in the mask base 50 are aligned. At this time, the cuts 43, 48 of the mask base materials 50, 55 can be used as references for temporary alignment. Then, the positioning holes 4 formed in the mask base materials 50 and 55 are formed.
The position of the mask base 55 is adjusted while monitoring these positioning holes with a camera (not shown) so that the positions 4 and 49 exactly match each other. The position may be adjusted while observing the openings provided in the mask base materials 50 and 55 together.

Here, when a positional shift occurs between the openings of the mask base materials 50 and 55, the opening area of the overlapping portion becomes smaller than the opening area of the non-overlapping portion. Therefore, the number of electron beams that pass through the aperture and irradiate the phosphor screen is reduced, and the luminance of the phosphor screen corresponding to the overlapping portion is significantly reduced, and the image quality is reduced. Therefore, both mask substrates 50, 55
It is necessary to exactly match the apertures of the holes with positional accuracy on the order of microns.

At this time, in order to make all the openings of the mask base materials 50 and 55 exactly coincide with each other, it is necessary to make the short axes of both mask base materials exactly coincide with each other. Since the mask bases are arranged in rows in the short axis direction, the alignment of the two mask bases in the rotation direction is most important.

As in the present embodiment, the mask bases 50 and 55 in a flat state are held so as to be relatively movable with each other, and one of them is slightly moved, so that both mask bases are accurately aligned. Becomes possible. In particular, by performing positioning while holding the holding portion 44 of the mask base material 55 for the auxiliary mask with the chuck 66, the short axis of the mask base material 55 can be directly controlled, and the rotation direction can be adjusted. In addition, the axes of the mask base materials 50 and 55 can be aligned with high positional accuracy.

Further, the mask base material 55 for the auxiliary mask, which is smaller than the mask base material 50 for the mask body, is finely moved and aligned, so that the position is smaller than when the mask base material 50 is moved. The accuracy is further improved.

After the positioning between the mask bases 50 and 55 is completed by the above-described steps, the two masks 50 and 55 are tightly fixed while holding the mask bases. It is desirable that the two mask base materials 50 and 55 be fixed in a state of being substantially in close contact with each other over the entire surface of the overlapped portion. For the fixing, a method such as diffusion bonding called pressure bonding or welding using laser or resistance can be used. Here, laser welding is the most practical and desirable. As shown by the crosses in FIG. 12, in the case of welding, at least several fixed points are arranged in the effective portion 21 of the mask base material 55.

It is desirable to provide fixing points also in the non-porous portion and the skirt portion of the mask base material 55. In this case,
The wider portion is in a pseudo-thick state, which is more preferable from the viewpoint of improving the mask curved surface strength. In addition,
After welding and fixing the mask bases 50 and 55, the mask base 5
5 may be cut off.

After welding and fixing, these mask base materials 50,
55 is removed from the positioning device, and both mask base materials are simultaneously pressed. FIG. 13 shows a pressing die 70 used when the mask base 55 is fixed to the surface of the mask base 50 on the electron gun side. The basic configuration is the same as that of a conventional press die, and a blank 7 that suppresses an ineffective portion of the mask base 50, a die 72, and a punch 7 having a curved surface for performing a curved overhang of a shadow mask.
3, and a knockout 74.

In the mold 70 for press-molding the shadow mask according to the present embodiment, the shape of the punch 73 is slightly different. That is, a concave portion 75 having a width and a depth capable of accommodating the mask base material 55 is formed on the surface of the punch 73. By forming such a concave portion 75, it is possible to prevent a step from being formed at the boundary between the overlapped portion and the non-overlapped portion in the shadow mask 7 after press molding.

In this embodiment, both mask substrates 5 are used.
Press molding is performed after fixing 0 and 55 in a flat state, in order to secure the positional accuracy of the opening.
As described above, the opening positions of both mask base materials 50 and 55 need to be exactly the same. Each mask base material 50, 55
When the positioning is performed after forming a curved surface, if the displacement of the molding position at the time of pressing occurs, the displacement of the opening position is also caused, so that it is difficult to make the openings of both mask base materials 50 and 55 exactly coincide with each other. Becomes After the molding, the mask base materials 50 and 55 have a curved shape.
It is extremely difficult to match the positions.

For this reason, in the present embodiment, both mask bases 50 and 55 are positioned and fixed in a flat state before the mask is formed, and then press-formed. The press-molded shadow mask may be combined with a mask frame after undergoing a mask blackening process for forming an oxide film on the surface, as in the case of manufacturing a normal color picture tube.

According to the color cathode ray tube and the method of manufacturing the same constructed as described above, by providing the auxiliary mask, it is possible to suppress the deformation of the shadow mask in the vicinity of the center of the screen where deformation is most likely to occur. In addition, the strength of the mask curved surface can be improved. As a result, it is possible to prevent the deformation of the shadow mask and the deterioration of the image due to the vibration, and to obtain a color cathode ray tube with improved image quality.

In the production of a shadow mask,
The mask base material for the mask body and the mask base material for the auxiliary mask can be held in a relatively movable state, and one of them can be finely moved to perform alignment. Can be aligned. Thereby, the assembly accuracy of the shadow mask is improved.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. In the above-described embodiment, the gripping portion for gripping the auxiliary mask at the time of positioning is constituted by the protruding portion projecting from the skirt portion of the mask body, but this gripping portion can be gripped by a chuck or the like of the positioning device. What is necessary is just to be formed, ie, it should just be provided so that it may be exposed, without overlapping with a mask main body.

For example, as shown in FIGS. 14 and 15, the length of the auxiliary mask 20 in the longitudinal direction and the
And the notches 80 may be formed at both short-axis end portions of the mask body. In this case, the ends of the auxiliary mask 20 facing the notches 80 are exposed without overlapping with the mask main body 14, and can function as the gripping portions 44 that can be gripped by a chuck or the like of the positioning device.

In the above-described embodiment, the structure in which the auxiliary mask 20 is arranged on the electron gun side of the mask body 14 has been described. However, the auxiliary mask 20 is arranged on the phosphor screen side of the mask body 14. Is also good.

[0064]

As described above in detail, according to the present invention, a color cathode ray tube provided with a shadow mask having a sufficient mask curved surface strength and a manufacturing method capable of manufacturing the color cathode ray tube with high accuracy are provided. be able to.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view including a major axis of a color cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view including a short axis of the color cathode ray tube.

FIG. 3 is a perspective view showing a shadow mask and a plan view showing an electron beam passage hole in the color cathode ray tube.

FIG. 4 is a cross-sectional view along the major axis direction of the shadow mask shown in FIG.

FIG. 5 is a sectional view of the shadow mask shown in FIG. 3 along the minor axis direction.

FIG. 6 is an enlarged sectional view showing a mask main body and an auxiliary mask of the shadow mask.

FIG. 7 is a plan view showing the relationship between the effective portion length between the mask main body and the auxiliary mask.

FIG. 8 is a characteristic diagram showing a relationship between a width of the auxiliary mask and a shadow mask deformation amount.

FIG. 9 is a plan view showing the mask body and a mask base material for an auxiliary mask.

FIG. 10 is a perspective view showing a positioning device for positioning the mask substrates.

FIG. 11 is a diagram schematically showing a positioning operation of a mask base material using the positioning device.

FIG. 12 is a plan view showing the mask base material positioned and fixed.

FIG. 13 is a cross-sectional view showing a state where the fixed mask base material is placed on a press molding apparatus.

FIG. 14 is a perspective view schematically showing a shadow mask of a color cathode ray tube according to another embodiment of the present invention.

FIG. 15 is a plan view showing a mask base material used for forming a shadow mask according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Panel 5 ... Phosphor screen 6 ... Shadow mask structure 7 ... Shadow mask 8 ... Mask frame 9B, 9G, 9R ... Electron beam 10 ... Electron gun 14 ... Mask main body 20 ... Auxiliary mask 12, 42 ... Opening 13, 21 ... Effective part 17, 24 ... Skirt part 40 ... Mask surface 44 ... Grip part 50, 55 ... Mask base material 54, 59 ... Positioning hole 63 ... Adjustment part 66 ... Chuck

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Masayo Inoue 1-9-2, Hara-cho, Fukaya-shi, Saitama F-term in Toshiba Fukaya Plant (reference) 5C027 HH16 5C031 EE02 EE04 EF05 EH04 EH06 EH08

Claims (6)

[Claims] A panel provided with a phosphor screen on an inner surface thereof; an electron gun for emitting an electron beam toward the phosphor screen; a plurality of electron guns arranged inside the panel so as to face the phosphor screen; A shadow mask in which the electron beam passage holes are formed, and a mask frame in which the periphery of the shadow mask is fixed. The shadow mask faces almost the entire surface of the phosphor screen and has a large number of electrons. A mask main surface having a substantially rectangular effective portion having a beam passage hole formed therein, a mask body having a skirt portion extending from the periphery of the mask main surface, and a short axis near the effective portion of the mask body It is fixed to overlap with the region, has a number of electron beam passage holes corresponding to the electron beam passage holes of the mask body, and has the short axis in the longitudinal direction. And a strip of the auxiliary mask, provided with, the auxiliary mask, the color cathode ray tube, characterized in that it has a grip portion can be gripped externally exposed without overlapping with the mask body. 2. The auxiliary mask has an effective portion in which the electron beam passage hole is formed, and a pair of skirt portions extending on both sides of the effective portion along the short axis direction. 2. The color cathode ray tube according to claim 1, wherein an end of the color cathode ray tube extends from a skirt portion of the mask body to constitute the grip portion. 3. The skirt portion of the mask main body has a notch formed at an edge thereof. The auxiliary mask is formed along an effective portion having the electron beam passage hole formed therein and along the short axis direction. It has a pair of skirts extending on both sides of the effective portion and overlapping with the skirt of the mask body, and each skirt of the auxiliary mask has a part in the skirt of the mask body. 2. The color cathode ray tube according to claim 1, wherein the grip portion is exposed to the outside in opposition to the cutout provided. 4. A panel having a phosphor screen provided on an inner surface thereof, an electron gun for emitting an electron beam toward the phosphor screen, and a plurality of electron guns arranged inside the panel so as to face the phosphor screen. And a mask frame in which the periphery of the shadow mask is fixed. The shadow mask faces almost the entire surface of the phosphor screen and has a large number of electrons. A mask main surface having a substantially rectangular effective portion in which a beam passage hole is formed, a mask body having a skirt portion extending from the periphery of the mask main surface, and a short axis near the effective portion of the mask body The mask has a large number of electron beam passage holes corresponding to the electron beam passage holes of the mask main body, and the short axis is set to the longitudinal direction. A band-shaped auxiliary mask, wherein the auxiliary mask is exposed without overlapping with the mask body and has a gripping portion that can be gripped from the outside. A first mask base for a flat mask body having an effective portion formed with a plurality of electron beam passage holes, and a second mask base for a flat auxiliary mask having the above-described gripping portion and having a gripping portion. And a material is prepared, and the second mask base material is disposed so as to overlap with the region near the short axis of the first mask base material. The superposed first mask base material and the second mask base material Each of the first and second mask bases is relatively displaceably supported by holding the gripping portions, and the first and second mask bases are minutely displaced by the first and second mask bases. Second mask group After the first and second mask base materials positioned above are fixed to each other, the first and second mask base materials are press-formed into a predetermined shape to have the mask body and the auxiliary mask. A method for manufacturing a color cathode ray tube, comprising forming a shadow mask. 5. The first and second mask substrates are fixedly supported by the first mask substrate, gripped by gripping portions of the second mask substrate, and slightly displaced by the gripping portions. The method according to claim 4, wherein the color cathode ray tubes are positioned with respect to each other. 6. A color cathode ray tube according to claim 5, wherein said gripping portion of said second mask base material is finely moved in said long axis direction, short axis direction and rotation direction to be positioned. Production method.