JP2001110332A - Color picture tube - Google Patents

Abstract

(57) [Problem] To provide a color cathode ray tube capable of maintaining a desired mutual positional relationship between a shadow mask and a screen surface and having improved image quality. An electron gun that divides a phosphor screen into two divided regions by an electron beam and scans the two regions is provided at two necks of a vacuum envelope. The mask body 36 of the shadow mask 30 corresponds to each of the divided areas and has two effective areas a and b in which a large number of electron beam passage holes 42 are formed. Boundary part 41 facing the boundary between
And The connecting portion 54 of the connecting member 52 is fixed to the inner surface of the boundary portion. A plurality of tongue pieces 56 extending in the tube axis direction from the connection portion are fixed to the intermediate frame of the mask frame 38. And the length in the tube axis direction is formed long.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and more particularly, to a so-called phosphor screen obtained by dividing a single phosphor screen into a plurality of regions and scanning them, and synthesizing images drawn in the respective regions to obtain one image. The present invention relates to a split scanning type color cathode ray tube.

[0002]

2. Description of the Related Art In recent years, various studies have been made on a high-definition cathode ray tube having a high-definition broadcast or a large screen accompanying the broadcast. Generally, in order to achieve high resolution of a cathode ray tube, the spot diameter of an electron beam on the phosphor screen must be reduced. On the other hand, conventionally, attempts have been made to improve the electrode structure of the electron gun or to increase the diameter and length of the electron gun itself, but no satisfactory results have yet been obtained.

The biggest cause of this is that the distance from the electron gun to the phosphor screen becomes longer as the tube becomes larger, and the magnification of the electron lens becomes too large. Therefore, it is important to reduce the distance (depth) from the electron gun to the phosphor screen in order to realize high resolution. Also, in this case, wide-angle deflection causes an increase in the magnification difference between the center and the periphery of the screen, so that it is not advisable to increase the resolution.

Therefore, conventionally, a single phosphor layer is divided and scanned into a plurality of regions using a plurality of electron guns and a plurality of deflection yokes, and a so-called large screen is formed by connecting images of the respective regions. A split scanning type color cathode ray tube has been proposed. For example, JP-A-7-45215, JP-A-2-
Japanese Patent No. 51831 discloses a cathode ray tube that connects two images to obtain a large screen. Also, JP-A-61-25
JP-A-6552 and JP-A-61-256551 propose a cathode ray tube for connecting a larger number of images to obtain a large screen.

[0005]

The above-described split-scan type cathode ray tube generally includes a panel having a phosphor screen formed on an inner surface thereof, and a shadow mask is disposed opposite the phosphor screen. ing. The funnel of the vacuum envelope has a number of cones corresponding to the number of divisions, and each cone is provided with an electron gun.

In such a split scanning type color cathode ray tube, in order to obtain a continuous image at the boundary between the divided scanning regions adjacent to each other on the phosphor screen, the vicinity of the boundary of the phosphor screen is required. The shadow mask must be kept at a predetermined position, that is, at a predetermined interval.

However, the panel facing the shadow mask is deformed into a dome shape due to the collision of the electron beam and the radiant heat of the shadow mask. Then, since the phosphor screen is formed on the inner surface of the panel, when the panel thermally expands, the amount of deformation of the phosphor screen increases as it approaches the center, and the distance between the phosphor screen and the shadow mask increases. Therefore, when the boundary between the divided scanning regions is located near the center of the panel, a discontinuous image is displayed near the boundary.

Further, since the temperature rise of the panel due to the collision of the electron beam increases as the image becomes brighter, the displayed image must be darkened in order to prevent the display of the discontinuous image as described above. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a color cathode ray tube which can maintain a desired mutual positional relationship between a shadow mask and a screen surface and has improved image quality. Is to do.

[0010]

In order to achieve the above object, a color cathode ray tube according to the present invention includes a vacuum envelope having a panel having a phosphor screen formed on an inner surface thereof and a vacuum envelope facing the phosphor screen. A shadow mask provided in the vacuum envelope, and an electron beam is provided in the vacuum envelope, and emits an electron beam to the phosphor screen through the shadow mask, respectively. A plurality of electron guns for scanning while being divided into divided regions, wherein the shadow mask is located at a plurality of effective regions in which a large number of electron beam passage holes are formed, and at a boundary between the effective regions. A mask body having a boundary portion facing the boundary between the divided regions of the phosphor screen, and a substantially rectangular mask frame holding a peripheral portion of the mask body, A connecting member that supports the boundary of the mask body and is displaced in accordance with the thermal expansion of the phosphor screen to hold the boundary of the mask body at a predetermined position with respect to the boundary of the phosphor screen. And, it is characterized by having.

Further, according to the color cathode ray tube of the present invention, the connecting member has a plurality of portions having different thermal expansion amounts, and a portion opposed to a central portion of the phosphor screen has the lowest thermal expansion amount. It is characterized by being formed large.

Further, according to the color cathode ray tube of the present invention, the mask frame has an intermediate frame extending between a pair of opposed side walls and facing a boundary portion of the mask body. A connection portion fixed to the boundary portion of the mask body and extending over substantially the entire length of the boundary portion, and extending in a direction opposite to the phosphor screen along a tube axis direction from a plurality of positions of the connection portion. And a plurality of tongue pieces fixed to the intermediate frame. The plurality of tongue pieces have a higher thermal expansion coefficient as the tongue pieces are closer to the center of the phosphor screen. Further, according to the present invention, the plurality of tongues of the connecting member are formed such that the closer to the center of the phosphor screen, the longer the length along the tube axis direction.

As described above, in the color cathode ray tube according to the present invention, when the temperature of the internal components of the cathode ray tube rises due to the scanning of the electron beam, the connecting member of the shadow mask determines the amount of thermal expansion in the tube axis direction at the center of the screen. , So as to follow the amount of deformation of the phosphor screen surface facing the boundary of the shadow mask. Therefore, even when the phosphor screen is deformed into a dome shape due to thermal expansion,
In the vicinity of the boundary of the shadow mask, the phosphor screen and the shadow mask can be maintained in a desired positional relationship, and bright and good image quality can be obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a color cathode ray tube according to an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 to 4, the color cathode ray tube has a vacuum envelope 10, which is composed of a glass panel 12 and two funnels provided opposite to the panel. And a rear enclosure 14 made of glass integrally having the same 16. The panel 12 integrally includes a substantially rectangular face plate 18 having a substantially rectangular phosphor screen 15 formed on an inner surface thereof, and a skirt portion 20 erected on a peripheral portion of the face plate. The panel 12 has a tube axis passing through the center thereof and substantially perpendicular to the panel, and a long axis (horizontal axis) X and a short axis (vertical axis) Y passing through the tube axis and orthogonal to each other.

The phosphor screen 20 has a plurality of stripe-shaped three-color phosphor layers extending in the short-axis Y direction and emitting blue, green, and red, and a black layer provided between these three-color phosphor layers. And stripes. The phosphor screen 20 is integrated over the entire screen area and is formed continuously without any seams.

The rear envelope 14 is joined to the end face of the skirt portion 20 of the panel 12 by, for example, frit glass. Each funnel 16 comprises a cone 21 and a neck 22 joined to the small diameter end of the cone.
And The two necks 22 extend parallel to each other and are located side by side in the long axis X direction.
An electron gun 24 for emitting an electron beam toward the phosphor screen 20 is arranged in each neck 22. A deflecting device 2 for deflecting the electron beam emitted from the electron gun 24 horizontally and vertically is provided outside each cone 21.
8 is attached.

A substantially rectangular shadow mask 30 in which a large number of electron beam passage holes are formed is provided in the vacuum envelope 10, and is located opposite to the phosphor screen 15. The shadow mask 30 is supported inside the panel 12 by engaging a holder 32 fixed to a mask frame described later with a stud pin 34 protruding from the skirt portion 20 of the panel 12.

As can be seen from FIGS. 2 and 3, in the present embodiment, the phosphor screen 15 is
Has two divided scanning areas A and B arranged in the long axis X direction with the short axis Y as a boundary C. These divided scanning areas A and B have the same rectangular shape. And 2
The two necks 22 and the electron gun 24 are arranged such that the central axis D passes through substantially the center of the corresponding divided scanning areas A and B.

According to the color cathode ray tube having the above-described structure, the electron beams emitted from the two electron guns 24 are deflected by the magnetic fields generated by the corresponding deflecting devices 28, and the phosphor screens 15 are passed through the shadow mask 30. Are scanned horizontally and vertically, respectively.
Although the images drawn on each of the divided scanning areas A and B of the phosphor screen 15 by this divided scanning are separate,
The connection is achieved by controlling signals applied to the electron gun 24 and the deflecting device 28, thereby reproducing one large image without a break on the entire surface of the phosphor screen.

Next, the configuration of the shadow mask 30 will be described in detail. As shown in FIGS. 3 to 5, the shadow mask 30 includes a substantially rectangular mask main body 36 having a skirt at the peripheral edge, a substantially rectangular mask frame 38 attached to the peripheral edge of the mask main body, It has.

The mask body 36 includes the phosphor screen 15.
And the rectangular effective areas a and b respectively corresponding to the divided scanning areas A and B, and the non-porous portion 4 located around each effective area.
0. A large number of electron beam passage holes 42 are formed in the effective areas a and b, respectively.
Further, a boundary portion 41 located between the effective regions a and b of the non-porous portion 40 faces a boundary C between the divided scanning regions A and B on the phosphor screen 15. And the boundary part 41
A connection member of a position adjustment mechanism described later is fixed to the inner surface of the, and extends toward the electron gun 24 along the tube axis direction from the boundary.

The mask frame 38 has a substantially rectangular shape, and each side wall has an L-shaped cross section. The mask frame 38 includes an intermediate frame 44 integrally provided on a side edge on the electron gun 24 side. The intermediate frame 44 extends from a central portion of one of the long side walls of the mask frame 38 to a central portion of the opposite long side wall, and connects the long side walls to each other.

The intermediate frame 44 is arranged so as not to block an electron beam for scanning a range necessary for displaying an image. That is, the intermediate frame 44 is
The boundary portion 41 of the mask body 36 extends along the short axis Y direction.
And is formed to have a width slightly larger than the boundary. Also, the intermediate frame 44
Is formed such that its central portion in the short axis Y direction is the widest and its width gradually decreases toward the long side wall of the mask frame 38, and has a substantially barrel shape as a whole. This allows
The intermediate frame 44 also has a function of blocking an electron beam unnecessarily incident on the other divided region among the electron beams emitted from the electron gun 24 corresponding to one divided region.

The intermediate frame 44 has a plurality of, for example, 5
The rectangular openings 46 are formed side by side in the short axis Y direction. Adjustment knobs of a connecting member, which will be described later, are inserted into these openings 46 so that the connecting portion can be operated from outside the mask frame 38.

Since such an intermediate frame 44 is provided on the bottom side of the mask frame 38, that is, on the side of the electron gun 24, it can be integrally formed when the mask frame 38 is pressed. It can be manufactured at almost the same cost.

The mask frame 38 is provided with a fixing portion 48 for fixing a connecting member described later. According to the present embodiment, the fixing portion 48 is configured such that the fixing member 60 separate from the mask frame 38 is attached to the intermediate frame 44.
It is constituted by welding.

More specifically, as shown in FIG.
Reference numeral 0 denotes an elongated rectangular fixing portion 48 formed by bending a metal plate, and six legs 62 extending perpendicularly to the fixing portion from one side edge of the fixing portion. Have.
The leg portions 62 are arranged at predetermined intervals in the longitudinal direction of the fixing portion 48, and extend in mutually opposite directions.

The fixing member 60 has six legs 62.
Are fixed to the intermediate frame 44 by welding to the intermediate frame 44. In this case, the leg 62 is welded to the intermediate frame 44 avoiding the opening 46. In the fixed state, the fixing portion 48 of the fixing member 60 extends in the short axis Y direction, and stands substantially perpendicular to the intermediate frame 44 and toward the mask body 36.

On the other hand, the distance between the mask body 36 and the inner surface of the panel, ie, q
A position adjusting mechanism 50 for adjusting the value is provided. The position adjusting mechanism 50 includes, for example, a connecting member 52 formed in a comb shape by a metal plate material.

The connecting member 52 has an elongated connecting portion 54, which is fixed to the inner surface of the boundary 41 of the mask body 36 by welding, and the short axis Y extends over substantially the entire length of the boundary 41.
Extending in the direction. The connecting portion 54 is provided at a position facing the boundary C of the phosphor screen 15. Further, the contact surface 54a of the connecting portion 54 with the mask body 36 is
The mask main body 36 is formed in a substantially arc shape having the same curvature as a predetermined curvature set in advance.

The connecting members 52 are connected to the connecting portions 5 respectively.
4 along the direction parallel to the tube axis and the mask body 3
A plurality of, for example, five position adjustment knobs 56 extending in a direction away from 6 are integrally provided. These position adjustment knobs 56 are provided at predetermined intervals along the short axis Y direction.

The five position adjustment knobs 56 are provided with five openings 46 formed in the intermediate frame 44 of the mask frame 38.
Are inserted with a gap therebetween. Then, as will be described later, by moving an arbitrary position adjusting knob 56 in the tube axis direction, the position of the mask body 36 adjacent to the position adjusting knob can be adjusted in the tube axis direction. Thereby, the boundary portion 41 and the panel 12 are formed at a plurality of positions of the boundary portion 41 of the mask body 36, that is, at five positions.
The distance (q value) from the inner surface can be adjusted. Then, after adjusting the position of the mask body 36, each position adjustment knob 56
Are fixed to the fixing portion 48 of the fixing member 60 fixed to the intermediate frame 44 by welding. Thus, the boundary 41 of the mask body 36 is fixed to the mask frame 38 via the connecting member 52.

In this embodiment, the color cathode ray tube has a screen diagonal of 86 cm and an aspect ratio of 16: 9.
And a mask body 36 of the shadow mask 30 is made of an invar material. The connecting portion 5 of the connecting member 52 welded to the mask body 36
Numeral 4 is formed of an invar material, and its length and curvature are substantially the same as the boundary 41 of the mask body 36,
It is 00 mm, R1800 mm and the width is 10 mm.

The five position adjustment knobs 56, each functioning as a tongue piece, are formed using three types of materials, and the position adjustment knob closer to the center of the phosphor screen 15 has a length in the tube axis direction. It is formed long. As shown in FIG. 6, the center position adjustment knob 56a is formed of an aluminum material to have a length of 38 mm, and a pair of position adjustment knobs 56b located on both sides thereof are each formed of a SUS material having a length of 3 mm.
It is formed to 5.8 mm. Further, a pair of position adjustment knobs 56c located at the outermost position are made of amber material and have a length of 29.
mm. These aluminum materials, SUS materials,
The coefficient of thermal expansion of the Invar material was 23 × 10 ⁻⁶ , 1
The design values are 7.2 × 10 ⁻⁶ and 1.3 × 10 ⁻⁶ .

When the temperature of the inner surface of the panel 12 rises by 10 ° C. due to the rise in the temperature of the color cathode ray tube due to the impact of the electron beam, the temperature distribution of each position adjusting knob 56 changes
The portion on the 6 side has a temperature of approximately 40 ° C., the middle portion has a temperature of approximately 30 ° C., and the portion welded to the intermediate frame 44 of the mask frame 38 has a temperature of approximately 25 ° C. At this time, the center of the panel 12 rises about 30 μm outward and is thermally deformed into a dome shape. The position adjustment knob 56 of the connecting member 52 fixed to the intermediate frame 44 is set such that the amount of thermal expansion decreases from the center position adjustment knob 56a toward the position adjustment knobs at both ends. As shown in FIG.
The central portion is deformed into an arch shape which is raised in the direction of the screen by about 30 μm.

Therefore, even when the phosphor screen 15 is deformed into a dome shape together with the panel 12, the distance between the boundary C of the phosphor screen 15 and the boundary 41 of the mask body 30 is kept constant by the deformation of the connecting member 52. be able to. Therefore, even when an image with high luminance is displayed, a discontinuous image does not occur at the boundary between adjacent divided scanning regions, and a good image without deterioration can be obtained.

In this embodiment, three different materials are used for the position adjusting knob 56 of the connecting member 52. However, more position adjusting knobs are provided, and more materials having different coefficients of thermal expansion are used. You may. Further, one position adjustment knob may be made of a plurality of materials having different coefficients of thermal expansion, and the length ratio thereof may be adjusted.

For example, the position adjusting knob is made of two kinds of materials, a part of which is made of the same material as the connecting portion 54, for example, an amber material, and the other part is made of an aluminum material. Then, by adjusting the length of the aluminum part of the position adjustment knob located at the center and the ratio of the length to the amber material part, the amount of thermal expansion is the largest compared to other position adjustment knobs, It is set so that the amount of thermal expansion decreases as the position adjustment knob is moved. Thereby, the thermal deformation of the connecting member 52 can be designed in an arch shape. As described above, there are countless selections and combinations of the length, the number, the thermal expansion coefficient, and the ratio of the thermal expansion coefficient of the position adjusting knobs 56 of the connecting member 52.

The color cathode ray tube constructed as described above is manufactured and assembled by the following steps. That is, first, when the phosphor screen 15 is formed on the inner surface of the face plate of the panel 12, the shadow mask 30 is attached to the panel 1 via the holder 32 and the stud pins 34.
Attach to 2. At this time, the boundary 4 of the mask body 36 is previously determined.
1, the connecting portion 54 of the connecting member 52 is fixed by welding, and each position adjusting knob 56 is inserted through the opening 46 of the mask frame 38 without being fixed.

In this state, the panel 12 is set in an exposure apparatus (not shown), and the light source of the exposure apparatus sets the shadow mask 3
The exposure light is applied to the inner surface of the panel through the reference numeral 0. And
As shown in FIG. 8A, the q value is detected at a plurality of points on the boundary portion 41, and when the q value deviates from the predetermined value, the q value is adjusted to the predetermined value by using the position adjustment knob 56.

That is, as shown in FIG. 8B, when the q value matches the predetermined value, the electron beam passage hole a1 located closest to the boundary portion 41 in the effective area a of the shadow mask 30 is set. And the light B1 that has passed through the electron beam passage hole b1 located closest to the boundary portion 41 in the effective area b are incident on the boundary C on the inner surface of the face plate 18.

However, as shown in FIG. 8 (c), when the q value is larger than a predetermined value, the light A1 passing through the electron beam passing hole a1 and the light B passing through the electron beam passing hole b1.
1 intersects before entering the inner surface of the face plate 18, and as a result, the light passing through the effective area a and the light passing through the effective area b of the shadow mask 30 overlap at the boundary C.

In such a case, the position adjusting knob 56 of the connecting member 52 is pushed toward the face plate 18 along the pipe axis, and the connecting portion 54 and the boundary 41 of the mask body 36 are joined together.
To the face plate 18 side. When the q value matches the predetermined value, that is, when the lights A1 and B1 are incident on the predetermined position of the boundary C on the inner surface of the face plate 18, the position adjustment knob 56 is moved to the middle of the mask frame 38. Fixing member 6 fixed to frame 44
Temporarily fixed to the fixed part 48 of the “0”.

As shown in FIG. 8D, when the q value is smaller than a predetermined value, the light A1 passing through the electron beam passage hole a1 and the light B1 passing through the electron beam passage hole b1 intersect. As a result, between the light passing through the effective area a of the shadow mask 30 and the light passing through the effective area b,
A gap, that is, a cut is formed at the boundary C.

In such a case, the position adjusting knob 56 of the connecting member 52 is pulled in the direction away from the face plate 18 along the tube axis, and together with the connecting portion 54, the mask body 3
6 is displaced in a direction away from the face panel 18. Then, when the q value matches the predetermined value, that is, when the lights A1 and B1 intersect on the boundary C of the inner surface of the face plate 12, the position adjustment knob 56 is moved to the intermediate frame 44 of the mask frame 38. Is temporarily fixed to the fixing portion 48 provided at

The above-described adjustment of the q value is performed at each position of the five position adjustment knobs 56. After the adjustment at all positions is completed, each position adjustment knob is fixed to the fixing portion 48 by welding. 36 is fixed to the mask frame 38 via the connecting member 52 and the fixing member 60. Note that the adjustment of the q value as described above is performed at a level of several hundreds to several μm, which is significantly different from the adjustment width of several hundreds to several thousand μm when performing general adjustment of a general color cathode ray tube. .

Thereafter, the shadow mask 30 is once removed from the panel 12 and a phosphor is applied to the inner surface of the face plate 18, and the shadow mask is mounted on the panel 12 again. Subsequently, the panel 12 is set on the exposure apparatus,
The phosphor layer is exposed through the shadow mask 30. After exposure, the phosphor layer is etched to remove unnecessary portions. The above steps are performed for each of the red, blue, and green phosphors, and thereafter, a black stripe is formed, whereby the phosphor screen 15 is completed.

In the above-described phosphor screen forming process, as described above, the q value is previously adjusted to a predetermined value with high precision at a plurality of locations on the boundary portion 41 of the mask body 36. The phosphor layer of the body screen 15
Over the entire boundary C between the divided areas A and B, they are continuously formed at a predetermined pitch without any overlap or break.

Then, after the rear envelope 14 is joined to the skirt portion 20 of the panel 12 on which the phosphor screen 15 is formed, an electron gun 24 is sealed in each neck 22, and furthermore,
A color cathode ray tube is completed by mounting the deflection device 28 on the outer periphery of each funnel 16.

According to the color cathode ray tube configured as described above, since the shadow mask 30 includes the position adjustment mechanism 50 for adjusting the q value, the vacuum envelope 1
0, the boundary region 41 of the mask body 36
Can be accurately adjusted at a plurality of locations. As a result, the phosphor screen 15 can be formed on the inner surface of the panel 12 with the q value adjusted with high precision, and the incident position of the electron beam can be accurately determined over the entire boundary C between the divided areas A and B of the phosphor screen. Can be set to As a result, it is possible to ensure the continuity of the phosphor pitch at the boundary C without causing any overlap or break.

After the q value is adjusted by the position adjusting mechanism 50, the connecting member 52 is fixed to the intermediate frame 44 of the mask frame 38 via the fixing portion 48,
The boundary portion 41 of the mask main body 36 can be held at a predetermined position with respect to the boundary C of the phosphor screen 15, particularly at a predetermined q value. That is, the connecting member 52 fixed to the mask main body 36 and the mask frame 38 regulates the thermal expansion of the shadow mask 36 and the movement in the tube axis direction due to doming, and the movement of the shadow mask in the tube axis direction due to external vibration. Can be regulated.

Therefore, by scanning the phosphor screen 15 with the electron beam through the shadow mask 30, the images displayed in the divided areas A and B are continuous without any overlap or break at the boundary C, and one continuous Image can be formed, and the image quality can be improved.

When the member forming the connecting member 52 is configured as described above, the temperature of the shadow mask 30 rises due to the collision of the electron beam, and when the temperature of the connecting member rises due to the radiant heat or heat transfer, the position adjusting knob 56 is used. The closer to the center of the connecting member in the longitudinal direction, the larger the amount of expansion is, and the whole of the connecting member 52 is distributed with the amount of thermal expansion in an arch shape. Since the distribution of the thermal expansion is designed to match the doping arch shape of the phosphor screen when the temperature rises, the positional relationship between the boundary 41 of the shadow mask 30 and the boundary C of the phosphor screen 15 is determined. The predetermined relationship can always be maintained. Therefore, even when an image with high luminance is displayed, a good image without deterioration can be obtained.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. For example, in the above-described embodiment, the fixing portion of the mask frame is configured by the separate fixing member 60, but may be formed integrally with the intermediate frame of the mask frame.

As shown in FIG. 9, according to a color cathode ray tube according to another embodiment of the present invention, similarly to the above-described embodiment, the mask frame 38 of the shadow mask 30 is provided.
Is provided integrally with an intermediate frame 44 extending from the center of one long side wall to the center of the other long side wall. A plurality of openings 46 are formed in the intermediate frame 44 at predetermined intervals in the longitudinal direction.

In the case of the present embodiment, the fixing portion 48 for fixing the connecting member 52 of the position adjusting mechanism 50 by welding is formed integrally with the intermediate frame 44. That is, the fixing portion 48 is formed by cutting and raising a portion to be the opening 46 of the intermediate frame 44 and bending the portion substantially vertically.
It is constituted by. After the position of the mask body 36 is adjusted, the connecting member 52
a. Other configurations are the same as those of the above-described embodiment, and the same portions are denoted by the same reference numerals and detailed description thereof will be omitted.

According to the other embodiment, the independent fixing member can be omitted, and the step of welding the fixing member to the mask frame can be omitted, so that the manufacturing cost of the mask frame can be further reduced. Becomes In the case of the mask frame having the above configuration, a reinforcing member may be attached to the intermediate frame as needed. With such a frame structure, the mask position can be held sufficiently stably.

In the present color cathode ray tube, the number of divided areas of the phosphor screen is not limited to two, but can be increased as necessary. According to another embodiment shown in FIG. 10, the phosphor screen 15 has three rectangular divided regions A, B, and E arranged in the long axis X direction, and sandwiches the boundaries C1, C2, respectively. Are adjacent. Correspondingly, the rear envelope 14 has three funnels 16 and 3
It has two necks 22, in each of which an electron gun 24 is arranged. A deflecting device 28 is mounted on the outer periphery of each funnel 16.

The mask body 36 of the shadow mask 30 has three effective areas a, b, and e corresponding to the three divided areas A, B, and E, and is located between these effective areas and has a phosphor. It has two boundaries 41 facing the boundaries C1, C2 of the screen 15, respectively. The connecting member 5 of the position adjusting mechanism having the same configuration as that of the above-described embodiment is provided on the boundary portion 41 of the mask body 36.
2 are fixed respectively.

The mask frame 38 is provided integrally with a pair of intermediate frames 44 extending between a pair of long side walls, respectively, and these intermediate frames 44 are arranged to face the boundary 41 of the mask body 36, respectively. Have been. The configuration of each intermediate frame 44 is the same as that of the above-described embodiment. After the position adjustment of the mask main body 36, the connecting member 52 is fixed to the intermediate frame 44 via the fixing portion 48.
The other configuration is the same as that of the above-described embodiment, and the same portions are denoted by the same reference characters and detailed description thereof will not be repeated.

Also in the color cathode ray tube having such a configuration, the q value can be adjusted at a plurality of points in each boundary portion 41 of the mask body 36, and after the adjustment, the movement in the tube axis direction is restricted to define each boundary region. It can be held in place. Also, by providing the intermediate frame 44 on the mask frame 38, the rigidity of the mask frame can be increased, and the mask main body 38 can be reliably and stably held at the adjusted position. Further, by displaying a high-luminance image, even when the phosphor screen and the shadow mask are thermally expanded, the boundary member 41 of the shadow mask is deformed into a dome shape by the action of the connecting member 52 in accordance with the phosphor screen. Thus, the positional relationship between each boundary portion 41 of the shadow mask and the boundaries C1 and C2 of the phosphor screen can be kept constant. Therefore, the same function and effect as those of the above-described embodiment can be obtained.

In the above-described embodiment, the phosphor screen is divided into a plurality of regions arranged in the longitudinal direction of the panel for scanning. However, the present invention is not limited to this. They may be set side by side in the axial direction.
In this case, the boundary between the divided regions extends along the long axis, and the adjustment member is also provided along this boundary.

The number of position adjusting knobs of the adjusting member can be increased or decreased as necessary, and the shape of the adjusting member is not limited to the comb shape, and the position of the mask body in the tube axis direction can be adjusted. Can be freely selected. Similarly, the shape of the intermediate frame, the number of openings, and the like can be variously changed.

[0064]

As described above, even when the panel and the shadow mask are thermally expanded, the shadow mask and the screen surface can be maintained in a desired mutual positional relationship, and a color cathode ray tube with improved image quality can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the back side of a color cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a front view showing a panel of the color cathode ray tube.

FIG. 3 is a sectional view of the color cathode ray tube taken along line AA of FIG. 1;

FIG. 4 is a sectional view of the color cathode ray tube taken along line BB of FIG. 1;

FIG. 5 is an exploded perspective view showing a shadow mask of the color cathode ray tube.

FIG. 6 is a side view showing a connecting member of an adjustment mechanism provided in the shadow mask.

FIG. 7 is a side view showing a state where the connecting member is thermally expanded.

FIG. 8 is a view schematically showing a process of adjusting a q value of a shadow mask by the adjusting mechanism.

FIG. 9 is an exploded perspective view showing a shadow mask of a color cathode ray tube according to another embodiment of the present invention.

FIG. 10 is a cross-sectional view and a front view showing a color cathode ray tube according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Vacuum envelope 12 ... Panel 14 ... Rear envelope 15 ... Phosphor screen 16 ... Funnel 22 ... Neck 24 ... Electron gun 30 ... Shadow mask 36 ... Mask body 38 ... Mask frame 41 ... Boundary part 44 ... Intermediate frame 46 ... Opening 58 ... Fixing part 48 ... Position adjusting mechanism 48a ... Bending piece 52 ... Connecting member 54 ... Connecting part 56 ... Position adjusting knob 60 ... Fixing member A, B, E ... Division area a, b, e ... Effective area C, C1, C2 ... border

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuyuki Seino, Inventor Kazuyuki 1-9-2, Harara-cho, Fukaya-shi, Saitama Prefecture Toshiba Fukaya Plant (72) Inventor Tokuo Hashimoto 1-9-9, Harara-cho, Fukaya-shi, Saitama No. 2 In the Toshiba Fukaya Plant (72) Inventor Takashi Nishimura 1-9-2 Hara-cho, Fukaya-shi, Saitama F-term in the Toshiba Fukaya Plant (reference) 5C031 EE08

Claims (9)

[Claims] A vacuum envelope having a panel having a phosphor screen formed on an inner surface thereof; a shadow mask provided in the vacuum envelope so as to face the phosphor screen; and the vacuum envelope. And a plurality of electron guns disposed in the plurality of electron guns, each of which emits an electron beam to the phosphor screen through the shadow mask, and divides the phosphor screen into a plurality of divided regions to scan. Has a plurality of effective regions each having a large number of electron beam passage holes formed therein, and a boundary portion located at the boundary between the effective regions and facing the boundary between the divided regions of the phosphor screen. A mask main body, a substantially rectangular mask frame holding a peripheral edge of the mask main body, and the phosphor screen supporting the boundary of the mask main body. Is displaced in accordance with the thermal expansion, color cathode ray tube, characterized in that the boundary portion of the mask body and a, a connecting member for holding in position relative to the boundaries of the phosphor screen. 2. The connecting member according to claim 1, wherein the connecting member has a plurality of portions having different amounts of thermal expansion, and a portion facing the central portion of the phosphor screen has the largest amount of thermal expansion. Item 2. A color cathode ray tube according to item 1. 3. The mask frame has an intermediate frame extending between a pair of opposed side walls and facing a boundary of the mask body, wherein the connecting member is fixed to the boundary of the mask body. A connecting portion extending over substantially the entire length of the boundary portion; and a plurality of fixing portions extending from the plurality of positions of the connecting portion in a direction opposite to the phosphor screen along the tube axis direction and fixed to the intermediate frame. 3. The color cathode ray tube according to claim 2, further comprising: a tongue piece, wherein the plurality of tongue pieces have a higher thermal expansion coefficient as the tongue piece is closer to the center of the phosphor screen. 4. . 4. The mask frame includes an intermediate frame extending between a pair of opposed side walls and facing a boundary of the mask body, wherein the connecting member is fixed to the boundary of the mask body. A connecting portion extending over substantially the entire length of the boundary portion; and a plurality of fixing portions extending from the plurality of positions of the connecting portion in a direction opposite to the phosphor screen along the tube axis direction and fixed to the intermediate frame. 3. A tongue piece comprising: a plurality of tongue pieces, the closer to the center of the phosphor screen, the longer the length along the tube axis direction. The color cathode ray tube as described. 5. The color cathode ray tube according to claim 4, wherein the plurality of tongue pieces have a higher thermal expansion coefficient as the tongue pieces are closer to the center of the phosphor screen. 6. The panel and the shadow mask are formed in a substantially rectangular shape, have a major axis and a minor axis passing through a tube axis and orthogonal to each other, and a boundary between the divided regions is substantially equal to the minor axis. The connecting portion of the connecting member extends in the short axis direction, and the plurality of tongue pieces are arranged at predetermined intervals in the short axis direction. 6. The color cathode ray tube according to any one of items 3 to 5. 7. The color cathode ray tube according to claim 3, wherein the intermediate frame has a plurality of openings through which the tongue pieces are inserted. 8. The method according to claim 1, wherein the phosphor screen has two divided areas, and the mask body has two effective areas and one boundary located between these effective areas. The color cathode ray tube according to any one of claims 1 to 7, wherein 9. The phosphor screen has three divided areas located in parallel, and the mask body is located between three effective areas respectively corresponding to the divided areas and an adjacent effective area. The color cathode ray according to any one of claims 3 to 7, further comprising two boundary portions, wherein the mask frame includes two intermediate frames each facing the boundary portion. tube.