JP2000268743A - Cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode ray tube with an enhanced image quality by maintaining a shadow mask and an inside surface of a panel at a desired relative positional relationship. SOLUTION: Electron gun structures projecting electron beams to a phosphor screen and scanning on the phosphor screen divided in to two divided areas are arranged on two necks 22 respectively in an vacuum envelope 10. A mask main body 36 of a shadow mask 30 has two effective areas corresponding to the individual divided areas and having large number of electron beam through holes formed, and a border area positioned between the two effective areas and opposing to a border between the divided areas on the phosphor screen. An adjusting member 52 that can adjust (q) values at multiple locations on the border area is fixed to an inside surface of the border area. After (q) values are adjusted, the adjusting member is fixed to a mask frame 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device,
In particular, the present invention relates to a display device in which one phosphor screen is divided into a plurality of regions and scanned, and images drawn in the respective regions are combined to obtain one image.

[0002]

2. Description of the Related Art In recent years, various studies have been made on a high-definition picture tube having a high-definition broadcast or a large screen associated therewith. Generally, in order to achieve high resolution of a picture tube, the spot diameter of an electron beam on the phosphor screen must be reduced. In contrast,
Attempts have been made to improve the electrode structure of the electron gun or to enlarge and extend the diameter 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 into a plurality of areas by using a plurality of electron guns and a plurality of deflection yokes, and a large screen is formed by connecting images of the respective areas. Has been proposed, for example, JP-A-7-45215,
Japanese Patent Application Laid-Open No. 2-51831 discloses a display device that connects two images to obtain a large screen. Further, JP-A-61-256552 and JP-A-61-256551.
Japanese Patent Laid-Open Publication No. HEI 7-214969 proposes a display device that connects a larger number of images to obtain a large screen.

That is, such a cathode ray tube is a vacuum tube comprising a panel, a funnel connected to the panel and having, for example, two funnel-shaped cones, and two necks connected to the funnel. It has an enclosure. A deflection device is mounted outside each funnel cone, and an electron gun is disposed inside each neck.

That is, such a cathode ray tube is a vacuum tube comprising a panel, a funnel connected to the panel and having, for example, two funnel-shaped cones, and two necks connected to the funnel. It has an enclosure. A deflection device is mounted outside each funnel cone, and an electron gun is disposed inside each neck.

In the cathode ray tube having the above structure, the electron beam emitted from each electron gun is deflected by the magnetic field generated by the corresponding deflecting device, and the corresponding two phosphor screens integrally formed on the inner surface of the panel. Is divided and scanned. The images drawn on the phosphor screen by the divided scanning are connected by controlling signals applied to the electron gun and the deflecting device, so that one image without breaks or overlaps on the entire surface of the phosphor screen is reproduced.

[0008]

As described above, in the cathode ray tube which scans the phosphor screen by dividing the phosphor screen into a plurality of regions by the electron beams emitted from the plurality of electron guns, a break is formed at the boundary between the divided regions. In order to obtain an image with no overlap or overlap, the outermost opening position of the adjacent shadow mask with respect to the phosphor screen at the boundary must be a position in consideration of the beam incident angles of each other. That is, it is necessary that the mutual position between the phosphor screen and the outermost opening of the adjacent shadow mask has a predetermined positional relationship, and the predetermined positional relationship also needs to be maintained in the boundary direction.

In the above-described structure of the cathode ray tube, the relative position between the shadow mask and the panel is determined during the manufacturing process, and is greatly affected by assembly accuracy. Even with a general picture tube, a variation in pitch and a variation in width of several tens of μm on a phosphor screen can be visually and significantly determined. For this reason, assembling accuracy between the shadow mask and the panel requires higher accuracy.

The accuracy of assembling a shadow mask and a panel in a general picture tube is about several hundreds of micrometers, and in the case of the above-described split-scan type cathode ray tube, a similar assembling method can obtain continuity of an image at a boundary. Is difficult.

Further, accuracy of a single component such as a shadow mask or a panel is also important. That is, the variation of the molding accuracy with respect to the design value of the shadow mask and the variation of the inner surface precision with respect to the design value of the panel in a general picture tube also occur in the order of several hundred μm. In consideration of such variations, it is very difficult to achieve the desired accuracy at the boundary between the divided images when a split-scan type cathode ray tube is configured by a conventional structure and assembling method.

Also, when the shadow mask thermally expands due to the collision of the electron beam, or when the shadow mask vibrates due to external vibration and howling occurs, the relative position between the shadow mask and the phosphor screen is changed. And the image quality is degraded due to the landing deviation of the electron beam. In particular, in a split-scan type cathode ray tube, a landing deviation of an electron beam easily occurs at a boundary portion of the divided regions, and it is difficult to obtain image continuity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a cathode ray tube capable of maintaining a desired relative positional relationship between a shadow mask and an inner surface of a panel and having improved image quality. It is in.

[0014]

In order to achieve the above object, a cathode ray tube according to the present invention comprises a vacuum envelope having a panel having a phosphor screen formed on an inner surface thereof, and a cathode ray tube provided in the vacuum envelope. A plurality of electron gun assemblies that emit an electron beam toward the phosphor screen, divide the phosphor screen into a plurality of divided regions, and scan the plurality of divided electron beams. A plurality of effective areas in which the beam passage holes are formed, and a boundary area located between the effective areas and facing a boundary between the divided areas of the phosphor screen, and the phosphor screen and the electron gun assembly And a connection member connected to the boundary area of the shadow mask and holding the boundary area at a predetermined position.

According to the cathode ray tube having the above structure, since the boundary region of the shadow mask is held at a predetermined position by the connecting member, even when the shadow mask thermally expands or receives external vibration, The displacement of the shadow mask is regulated by the connecting member, and the shadow mask and the phosphor screen can be held at a predetermined relative position. Therefore, in the boundary area of the shadow mask, the landing deviation of the electron beam caused by the variation of the interval (q value) between the inner surface of the panel and the shadow mask is reduced, and the images displayed in the plurality of divided areas are cut or overlapped. And the image quality can be improved.

Further, a cathode ray tube according to the present invention has a vacuum envelope having a panel having a phosphor screen formed on an inner surface thereof, and a cathode ray tube disposed inside the vacuum envelope and directing an electron beam toward the phosphor screen. A plurality of electron gun assemblies for emitting a beam and dividing the phosphor screen into a plurality of divided areas for scanning, and a plurality of effective areas respectively corresponding to the divided areas and having a large number of electron beam passage holes formed therein And a boundary area located between the effective areas and facing a boundary between the divided areas of the phosphor screen, and a shadow mask disposed between the phosphor screen and the electron gun assembly; And a position adjusting mechanism for adjusting the distance between the inner surface of the panel and the shadow mask at a plurality of positions in the boundary region of the shadow mask.

According to the cathode ray tube configured as described above, by providing the position adjusting mechanism for adjusting the distance (q value) between the inner surface of the panel and the shadow mask at a plurality of points in the boundary area of the shadow mask, The q value can be adjusted in a process before assembling the vacuum envelope.

For this reason, the variation in the shading accuracy of the shadow mask and the variation in the inner surface accuracy of the panel can be adjusted at a plurality of points in the boundary area due to the variation in the q value caused by the variation in assembling the panel and the shadow mask. Gives q
It is possible to correct the variation of the value and set the value to an accurate value over almost the entire area.

Therefore, when exposing the phosphor screen, the screen pitch at the boundary between the divided areas can be continuously formed. At the same time, when the cathode ray tube is operated, each of the plurality of divided areas can be accurately scanned, and a continuous image having no breaks or overlaps at the boundaries of the divided areas can be displayed.

Further, according to the cathode ray tube of the present invention, the shadow mask comprises: a mask body having an electron beam passage hole formed therein; a mask body attached around the mask body;
And the position adjustment mechanism includes an adjustment member fixed to the mask body. The adjusting member is fixed to the mask frame after adjusting the q value.
Therefore, even when the shadow mask thermally expands or receives external vibration, the displacement of the shadow mask is regulated by the adjusting member, and the shadow mask and the phosphor screen can be held at a predetermined relative position. it can. Therefore, it is possible to reduce the landing deviation of the electron beam due to the variation of the q value and improve the image quality.

[0021]

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 to 4, the cathode ray tube has a vacuum envelope 10, which is composed of a panel 12 made of glass, And a glass rear envelope 14 integrally having the above funnel 16. The panel 12 integrally includes a substantially rectangular face plate 18 having a 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 major axis (horizontal axis) X and a minor axis (vertical axis) Y passing through its center 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, fringe, and red light, 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. A neck 22 made of glass is joined to the small-diameter end of each funnel 16 and extends parallel to each other. An electron gun structure 24 for emitting an electron beam toward the phosphor screen 20 is arranged in each neck 22. Also, outside each funnel 18,
A deflection device 28 for deflecting the electron beam emitted from the electron gun assembly 24 is mounted.

A substantially rectangular shadow mask 30 having a large number of electron beam passage holes is provided in the vacuum envelope 10 and is located opposite to the phosphor screen 15. The shadow mask 30 is supported by the panel 12 via a holder 32 fixed to a mask frame described later and 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 areas A and B aligned with the long axis X with the short axis Y as the boundary C. These divided areas A and B have the same rectangular shape. And two necks 2
The electron gun assembly 2 and the electron gun assembly 24 are arranged such that the central axis D thereof coincides with a normal passing substantially through the center of the corresponding divided areas A and B.

According to the color cathode ray tube having the above-described structure, the electron beams emitted from the two electron gun assemblies 24 are deflected by the magnetic fields generated by the corresponding deflecting devices 28, and are deflected by the phosphor screen through the shadow mask 30. 15-2
The two divided areas A and B are scanned horizontally and vertically, respectively.
The images drawn on each of the divided areas A and B of the phosphor screen 15 by this divided scanning are separate, but are connected by controlling the signals applied to the electron gun assembly 24 and the deflecting device 28, and One large image is reproduced without interruption over the entire surface of the image.

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 46 includes the phosphor screen 15.
Rectangular effective areas a and b corresponding to the divided areas A and B, respectively, and a non-porous portion 40 located around each effective area.
And A large number of electron beam passage holes 42 are formed in the effective areas a and b, respectively. Further, a boundary region 41 located between the effective regions a and b in the non-porous portion 40 faces a boundary C of the phosphor screen 15.

The substantially rectangular mask frame 38
Is provided with a bridge portion 44 extending between the pair of long walls along the short axis Y direction. The bridge portion 44 is located so as to face the boundary region 41 of the mask body 36 and has a width slightly larger than the boundary region. A plurality of, for example, five, rectangular openings 46 are formed in the bridge portion 44 side by side in the short axis Y direction.

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

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

The adjusting 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 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 bridge portion 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 region 41 of the mask body 36
The distance (q value) between the boundary region 41 and the inner surface of the panel 12 can be adjusted at a plurality of positions, that is, at five positions.

The position adjusting mechanism 50 includes a bridge 4
4 comprises a fixation rod 58 fixed to and extending across the five openings 46. After the q value is adjusted, the five position adjustment knobs 56 of the adjustment member 52 respectively move the mask frame 3 via the fixed rod 58.
8 is fixed by welding.

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 connecting portion 54 of the adjustment member 52 is fixed by welding to the boundary region 41 of the mask body 36 in advance, and the position adjustment knobs 56 are inserted through the openings 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
The exposure light is applied to the inner surface of the panel through the reference numeral 0. And
The q value is detected at a plurality of points in the boundary area 41, and when the q value deviates from the predetermined value, the position adjustment knob 56 is used to adjust the q value to the predetermined value.

That is, as shown in FIG. 6B, when the q value matches the predetermined value, the electron beam passage hole a1 located closest to the boundary region 41 in the effective region a of the shadow mask 30 is set. A1 passing through the electron beam passage hole b1 and the light B1 passing through the electron beam passage hole b1 located closest to the boundary region 41 in the effective region b are separated by a boundary C on the inner surface of the face plate 12.
Cross on

However, as shown in FIG. 6C, when the q value is larger than the predetermined value, the light A1 passing through the electron beam passage hole a1 and the light B passing through the electron beam passage hole b1 are reflected.
1 intersects before entering the inner surface of the face plate 12, 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 adjusting member 52 is pushed toward the face plate 18 along the tube axis, and together with the connecting portion 54, the boundary region 4 of the mask body 36 is moved.
1 is displaced toward the face panel 18. When the q value matches the predetermined value, that is, when the lights A1 and B1 are incident on the predetermined position on the boundary C of the inner surface of the face plate 12, the position adjustment knob 56 is moved to the bridge of the mask frame 38. Fixed rod 5 fixed to part 44
Temporarily fix to 8.

As shown in FIG. 6D, 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 adjusting member 52 is pulled in the direction away from the face plate 18 along the pipe 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 on the inner surface of the face plate 12, the position adjustment knob 56 is moved to the bridge portion 44 of the mask frame 38. Is temporarily fixed to a fixing rod 58 fixed to the fixing rod 58.

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 connecting rod 58 by welding. It is fixed to the mask frame 38 via a rod.

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 the exposure, unnecessary portions are removed by etching the phosphor.
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 phosphor screen forming process as described above, the q value is previously adjusted to a predetermined value at a plurality of locations in the boundary region 41 of the mask main body 36 as described above. The phosphor layer is continuously formed at a predetermined pitch at the boundary C between the divided areas A and B 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, the electron gun assembly 24 is sealed in each neck 22, and the funnel 16 By mounting the deflection device 28 on the outer periphery, a color cathode ray tube is completed.

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. Thereby, with the q value adjusted accurately,
The phosphor screen 15 can be formed on the inner surface of the panel 12, and the phosphor layers can be continuously formed at a predetermined pitch at the boundary C between the divided areas A and B of the phosphor screen without causing any overlap or break.

After the q value is adjusted by the position adjusting mechanism 50, the adjusting member 52 is fixed to the mask frame 38 so that the boundary area 41 of the mask body 36 is positioned at a predetermined position with respect to the boundary C of the phosphor screen 15. In particular, it can be maintained at a predetermined q value. That is, the adjusting member 52 fixed to the mask main body 36 and fixed to the mask frame 38 functions as a connecting member, restricts thermal expansion of the shadow mask 36, movement in the tube axis direction due to doming, and externally. The movement of the shadow mask in the tube axis direction due to the vibration of can be restricted.

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. A continuous image can be formed, and image quality can be improved.

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 embodiment, the number of divided regions of the phosphor screen is not limited to two, and can be increased as necessary. Further, a plurality of shadow masks and a plurality of mask frames may be used, and a combination of the number of shadow masks and the number of mask frames can be arbitrarily set.

According to another embodiment shown in FIG. 7, the phosphor screen 15 has three rectangular divided regions A, B, and E arranged in the direction of the long axis X, and the boundary C
1, adjacent to each other across C2. Correspondingly, the rear envelope 14 has three funnels 16 and three necks 22, in each of which the electron gun assembly is located. 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 fluorescent material. It has two boundary areas 41 facing the boundaries C1, C2 of the screen 15, respectively.
An adjusting member 52 of a position adjusting mechanism having a configuration similar to that of the above-described embodiment is fixed to the boundary region 41 of the mask body 36. 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 region 41 of the mask main body 36, and after the adjustment, the movement in the tube axis direction is regulated to define each boundary region. It can be held in place. 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.

Further, the number of position adjusting knobs of the adjusting member can be increased or decreased as necessary. The shape of the adjustment member is
The shape is not limited to the comb shape, but can be variously modified as needed. The mask body can be freely selected as long as the position of the mask body in the tube axis direction can be adjusted.

[0056]

As described above in detail, according to the present invention, a position adjustment mechanism capable of adjusting the q value is provided in the boundary region of the shadow mask, and after the adjustment, the adjustment member of the position adjustment mechanism is attached to the mask frame. By fixing and functioning as a connecting member, the shadow mask and the inner surface of the panel can be maintained in a desired relative positional relationship, and the image quality that can reproduce one image without breaks or overlaps on the entire surface of the phosphor screen is improved. A cathode ray tube can be provided.

[Brief description of the drawings]

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

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

FIG. 3 is a cross-sectional view of the cathode ray tube taken along line AA of FIG.

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

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

FIG. 6 is a view schematically showing a process of adjusting a q value by an adjusting mechanism provided in the shadow mask.

FIG. 7 is a sectional view and a front view showing a cathode ray tube according to 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 assembly 30 ... Shadow mask 36 ... Mask body 38 ... Mask frame 41 ... Boundary area 44 ... Bridge Part 46: Opening 50: Position adjustment mechanism 52: Adjusting member 54: Connecting part 56: Position adjustment knob 58: Fixed rod A, B: Dividing area a, b: Effective area C, C1, C2: Boundary

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tokuo Hashimoto 1-9-2 Harara-cho, Fukaya-shi, Saitama Prefecture Inside the Toshiba Fukaya Electronics Factory (72) Inventor Yuji Kuwahara 1-9-1, Harara-cho, Fukaya-shi, Saitama No. 2 F-term in Toshiba Fukaya Electronics Factory (reference) 5C031 EE01 EE08 EE15

Claims (9)

[Claims] A vacuum envelope having a panel having a phosphor screen formed on an inner surface thereof; and a vacuum screen disposed in the vacuum envelope and emitting an electron beam toward the phosphor screen. A plurality of electron gun assemblies for scanning by dividing the plurality of divided regions into a plurality of divided regions, a plurality of effective regions respectively corresponding to the divided regions and having a large number of electron beam passage holes, and a position between the effective regions. A shadow mask disposed between the phosphor screen and the electron gun assembly, and having a boundary area facing the boundary between the divided areas of the phosphor screen; and a shadow mask connected to the boundary area of the shadow mask. And a connecting member holding the boundary region at a predetermined position. 2. The shadow mask includes a substantially rectangular mask body having the effective area and the boundary area, and a substantially rectangular mask frame attached to a peripheral portion of the mask body. The cathode ray tube according to claim 1, wherein the member is connected to the inner surface of the mask body, extends over substantially the entire length of the boundary region, and is connected to the mask frame. 3. A vacuum envelope having a panel having a phosphor screen formed on an inner surface thereof; and a vacuum screen disposed in the vacuum envelope and emitting an electron beam toward the phosphor screen. A plurality of electron gun assemblies for scanning by dividing the plurality of divided regions into a plurality of divided regions, a plurality of effective regions respectively corresponding to the divided regions and having a large number of electron beam passage holes, and a position between the effective regions. A shadow mask disposed between the phosphor screen and the electron gun assembly; and a plurality of positions on the boundary area of the shadow mask. And a position adjusting mechanism for adjusting the distance between the inner surface of the panel and the shadow mask. 4. The position adjusting mechanism includes an adjusting member fixed to the shadow mask, wherein the adjusting member includes a connecting portion extending along the boundary region of the shadow mask.
A plurality of position adjustment knobs extending in a direction opposite to the phosphor screen from a plurality of positions of the connection portion and adjusting the position of the shadow mask in the tube axis direction via the connection portion. The cathode ray tube according to claim 3, wherein 5. A shadow mask comprising: a substantially rectangular mask body having the effective area and the boundary area; and a substantially rectangular mask frame attached to a periphery of the mask body. The connecting portion of the member is connected to the inner surface of the boundary region of the mask body, and the position adjustment knobs are connected to the mask frame after adjusting the distance between the shadow mask and the inner surface of the panel, respectively. The cathode ray tube according to claim 4, wherein 6. A mask frame, comprising: a bridge portion facing a boundary region of the mask body; and a plurality of openings formed in the bridge portion and through which the position adjustment knobs are respectively inserted. The position adjusting knob is connected to the bridge portion.
A cathode ray tube according to claim 1. 7. 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 connection portion of the adjustment member extends in the short axis direction, and the plurality of position adjustment knobs are arranged at predetermined intervals in the short axis direction. The cathode ray tube according to any one of claims 4 to 6. 8. The phosphor screen has two divided areas, and the shadow mask has two effective areas and one boundary area located between these effective areas. The cathode ray tube according to any one of claims 3 to 7, wherein 9. The phosphor screen has three divided areas located in parallel, and the shadow mask is located between three effective areas respectively corresponding to the divided areas and an adjacent effective area. The cathode ray tube according to any one of claims 3 to 7, further comprising two boundary regions, wherein the position adjustment mechanism is provided in each boundary region.