JPH11297244A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibration and deformation of a shadow mask and improve positioning accuracy of the shadow mask with respect to a phosphor screen. SOLUTION: Multiple plate supporting members 16 are installed between a vacuum envelope face plate 1 and a rear plate 3, the base end of each of the plate supporting members 16 is fixed to the rear plate 3, and each of their tips 16c abuts on a phosphor screen 8. Mask supporting members 30 abut on a positioning surface 34 formed on the plate supporting member 16 to be positioned and is supported by the plate supporting member 16. Divided masks 12 abut on the mask supporting member 30 to be positioned and are pressed against mask supporting member 30 by mask pressing members 32.

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,
In particular, the present invention relates to a color cathode ray tube that divides one phosphor screen into a plurality of regions, scans the plurality of regions, combines images drawn in the respective regions, and describes one large image.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a high-resolution cathode-ray tube for high-definition broadcasting or a large screen associated therewith, and its screen display performance is required to be even more severe. To meet these demands, it is necessary to flatten the screen surface, increase the resolution, and reduce the deflection aberration. At the same time, it is necessary to reduce the weight and thickness of the cathode ray tube.

As a color cathode ray tube satisfying such demands, an integrated phosphor screen formed on the inner surface of a flat face plate is divided into a plurality of regions by electron beams emitted from a plurality of electron guns. A cathode ray tube adapted to perform scanning is shown.

According to this cathode ray tube, a flat face plate on which a phosphor screen having an integrated structure is formed;
A vacuum envelope is composed of a flat face plate arranged opposite to the face plate via the side wall, a plurality of funnels joined to the rear plate, and a neck joined to each funnel. A plurality of divided shadow masks are provided in the vacuum envelope, and each shadow mask is supported by a mask support member provided on the rear plate side.

[0005] The shadow mask is provided for selecting an electron beam and causing it to strike a predetermined phosphor. To obtain a good image, the shadow mask is accurately positioned at a predetermined position with respect to the phosphor screen. Need to be placed.

Usually, the shape of the shadow mask is formed to be substantially the same as the shape of the phosphor screen. In a color cathode ray tube of the type described above, the phosphor screen is formed on the inner surface of the face plate and is flat, so that the shadow mask is required to be as flat as possible.

[0007]

However, a flat shadow mask having a simpler shape is more vulnerable to vibration and deformation than a shadow mask pressed into a substantially spherical shape. When the shadow mask is vibrated or deformed, the quality of the displayed image is degraded. In particular, when the size of the color cathode ray tube is increased, a significant problem occurs.

In the color cathode ray tube of the type described above, since the shadow mask is supported by the mask supporting member provided on the rear plate side, the position accuracy of the shadow mask with respect to the phosphor screen formed on the face plate is improved. Depends on the relationship between the height of the atmospheric pressure support member or the side wall supporting the face plate and the height of the mask support member, and cannot be controlled only by the dimensional accuracy of the mask support member. Therefore, in order to increase the positional accuracy of the shadow mask, high processing accuracy and assembling accuracy are required for the entire color cathode ray tube, which leads to an increase in manufacturing cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a color cathode ray tube in which the vibration and deformation of a shadow mask can be reduced and the positional accuracy of the shadow mask with respect to a phosphor screen is improved. It is in.

[0010]

In order to achieve the above object, a color cathode ray tube according to the present invention has a substantially rectangular flat face plate having a phosphor screen formed on an inner surface thereof and a side wall interposed therebetween. A vacuum envelope having a flat rear plate disposed substantially parallel to the face plate and a plurality of electron sources for generating an electron beam for scanning the phosphor screen by dividing the phosphor screen into a plurality of small areas; ,
A shadow mask provided between the phosphor screen and the electron source in the vacuum envelope, and provided between the face plate and the rear plate to support the face plate and the rear plate with respect to the atmospheric pressure. And a plurality of plate supporting members, which are positioned at a predetermined position with respect to the phosphor screen by positioning means, abut against the shadow mask, and separate the shadow mask by a predetermined distance from the phosphor screen. And a plurality of mask support members held at the specified positions.

A color cathode ray tube according to the present invention comprises:
It is characterized in that it comprises a pressing means which is provided opposite to the mask supporting member with the shadow mask interposed therebetween and which elastically presses the shadow mask against the mask supporting member.

Further, the color cathode ray tube according to the present invention is
A vacuum envelope having a substantially rectangular flat face plate having a phosphor screen formed on an inner surface thereof, and a flat rear plate disposed to face the face plate via a side wall; and the phosphor screen. A plurality of electron sources for generating an electron beam for scanning by dividing the electron beam into a plurality of small areas; a shadow mask provided between the phosphor screen and the electron source in the vacuum envelope; A mask frame attached to the plate and supporting the shadow mask, a front end in contact with the face plate, and a base end in contact with the rear plate; A plurality of plate supporting members supported with respect to the phosphor screen; A plurality of mask support members that are arranged and abut against the shadow mask and hold the shadow mask at a predetermined distance from the phosphor screen, and the mask with the shadow mask interposed therebetween. And a pressing means provided to face the support member and elastically pressing the shadow mask against the mask support member.

According to the color cathode ray tube having the above structure, the mask supporting member is positioned at a predetermined position with respect to the phosphor screen by the positioning means, and the shadow mask is held by the mask supporting member. This makes it possible to easily arrange the shadow mask with respect to the phosphor screen with high positional accuracy.

Further, by holding the shadow mask against the mask supporting member by the pressing means, the shadow mask can be held substantially by following the mask supporting member, and the positional accuracy of the shadow mask can be reliably maintained. It is possible to reduce vibration and deformation of the shadow mask.

[0015]

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 3, the color cathode ray tube includes a vacuum envelope 5, which has a substantially rectangular flat face plate 1 and a peripheral portion of the face plate 1. A frame-shaped side wall 2 which is joined and extends substantially perpendicular to the face plate 1; and a substantially rectangular flat rear plate 3 which is joined to the side wall 2 and arranged in parallel with and facing the face plate 1 And rear plate 3
And a plurality of funnels 4 joined to each other.
The vacuum envelope 5 has an X-axis and a Y-axis orthogonal to each other.
Axes as well as a Z axis that is orthogonal to these axes.

A plurality of, for example, 2
Zero rectangular openings 6 are formed and arranged in a matrix, for example, arranged in four rows and five columns. The plurality of funnels 4 have respective openings 6.
, Five in the horizontal direction (X-axis direction), four in the vertical direction (Y-axis direction),
A total of 20 are provided.

On the inner surface of the face plate 1, blue, green,
An integrated phosphor screen 8 having a stripe-shaped three-color phosphor layer extending in the vertical direction Y that emits red light and a black stripe (light shielding layer) provided between the three-color phosphor layers is provided. Is formed.

A fluorescent screen 8 is provided in the vacuum envelope 5.
, A flat shadow mask 7 is arranged. As will be described later, the phosphor screen 8 is scanned by being divided into a plurality of regions R1 to R20 by an electron beam, and the shadow mask 7 has five horizontal regions corresponding to the number of region divisions of the phosphor screen 8 in the horizontal direction. It is divided into two division masks 12. Each of the divided masks 12 is formed in an elongated rectangular shape, is supported on the rear plate 3 via an elongated, substantially rectangular frame-shaped mask frame 14, and extends along the Y-axis direction.

Between the face plate 1 and the rear plate 3, there are arranged a plurality of plate supporting members 16 for supporting the atmospheric load applied to the face plate 1 and the rear plate 3.

An electron gun 20 for emitting an electron beam toward the phosphor screen 8 is provided in each of the necks 18 provided in the plurality of funnels 4. Further, a deflection device 22 is mounted outside each neck 18.

An electron beam emitted from an electron gun 20 functioning as an electron source is deflected in a horizontal direction and a vertical direction by a magnetic field generated by a deflecting device 22, and a plurality of fluorescent screens 8 are moved through a shadow mask 7. Scanning is performed by dividing the region into five regions R1 to R20 in the illustrated example, five in the horizontal direction and four in the vertical direction. Then, the images drawn on the phosphor screen 8 by the divided scanning are connected by signals applied to the electron gun 20 and the deflecting device 22 to form one large continuous image on the entire surface of the phosphor screen 8.

As shown in FIGS. 3 and 4, each division mask 12 has a number of slits through which an electron beam passes, and these slits extend over substantially the entire length of the division mask in the longitudinal direction. The mask frame 14 has a pair of end walls 24 facing each other parallel to each other and a pair of connecting rods 25 extending parallel to each other and connecting the end walls 24 to each other. I have. The divided mask 12 has both ends in the longitudinal direction fixed to the upper end surface of the end wall 24, and is supported by the mask frame in a state where tension is applied along the longitudinal direction. Also,
Each end wall 24 of the mask frame 14 is fixed to the rear plate 3 via a holder 26. Thus, the five divided masks 12 are arranged in the vacuum envelope 5 so as to extend in the Y-axis direction.

As shown in FIG. 2, FIG. 3, FIG. 5, and FIG.
Is provided to support the atmospheric pressure load applied to the face plate 1 and the rear plate 3 of the first embodiment, and is made of a material having a thermal expansion coefficient similar to that of the face plate 1 and the rear plate 3 made of glass, such as a nickel alloy. Is formed. The base end 16a of each plate support member 16 is formed to have an elliptical cross section.
b is formed in a tapered wedge shape toward the phosphor screen 8. Then, the base end portion 1 of each plate support member 16
6 a is fixed to the rear plate 3 by a bonding material such as frit glass, for example, and the front edge 16 c is in contact with the phosphor screen 8.

The plurality of plate supporting members 16 are provided in the respective regions R1 to R20 of the phosphor screen 8 which are divided and scanned.
And the rear plate 3
Extending perpendicular to the Each of the plate support members 16 is arranged such that the leading edge 16c contacts the black stripe of the phosphor screen 8, and the longitudinal direction of the leading edge coincides with the longitudinal direction of the black stripe. Each of the divided masks 12 described above is arranged between two plate support members 16 adjacent in the X-axis direction.

Further, the color cathode ray tube is provided with a plurality of mask supporting members 30 which abut against each of the divided masks 12 of the shadow mask 7 to define the positions of the divided masks with respect to the phosphor screen 8, and a mask supporting member which sandwiches the divided masks. And a mask pressing member 32 that is provided to face the mask and elastically presses the divided mask against the mask supporting member.

Each mask support member 30 is formed in an elongated rectangular plate shape, and is positioned at a predetermined position with respect to the phosphor screen 8 by the plate support member 16 functioning as a positioning means. Then, the divided mask 12 is pressed against the mask supporting member 30 by the mask pressing member 32, thereby holding the divided mask at a position separated from the phosphor screen 8 by a predetermined distance.

More specifically, as can be clearly understood from FIGS. 5 and 6, the leading end of each plate support member 16 has a positioning surface 3 facing the phosphor screen 8 in parallel.
4 are formed. Positioning surface 34 and plate supporting member leading edge 16 along the axial direction of plate supporting member 16
The distance d with respect to c is formed to a predetermined value with high accuracy.

A pair of engaging grooves 36 extending in the axial direction of the plate supporting member 16 are formed on both sides of the leading edge 16c in the wedge-shaped distal end portion 16b of the plate supporting member 16. Each engagement groove 36 extends from the positioning surface 34 to the vicinity of the leading edge 16c.

The mask supporting member 30 is an elongated rectangular metal plate, is formed slightly longer than the width of the divided mask 12, and is provided between two adjacent plate supporting members 16 in the X-axis direction. And the phosphor screen 8. Both end portions of each mask support member 30 are fitted into engagement grooves 36 formed in the two mask support members 30, respectively. Thereby, each mask support member 30 is arranged in a state where its longitudinal direction matches the X-axis direction and stands upright with respect to the phosphor screen 8.

The side surface of each mask supporting member 30 on the side of the divided mask 12 functions as a mask setting surface 30a. At both ends of the mask supporting member 30 fitted into the engaging grooves 36 of the plate supporting member 16, Setting surface 30a
Are in contact with the positioning surfaces 34 of the plate support members 16 respectively.

Thus, each mask setting surface 30a has the same height as the positioning surface 34, that is, the plate supporting member 1
6 is positioned with high precision at a distance d from the leading edge 16c. Here, since the leading edge 16c of the plate supporting member 16 is in contact with the phosphor screen 8, the distance d between the positioning surface 34 and the leading edge 16c is equal to the distance between the positioning surface 34 and the phosphor screen 8. I do. Therefore, the distance between the mask setting surface 30a of the mask support member 30 positioned by the positioning surface 34 and the phosphor screen 8 is set to the distance d with high accuracy.

Such mask supporting members 30 are provided for each divided mask 12 by five, and are arranged at predetermined intervals in the Y-axis direction. These mask support members 30 face the boundaries extending in the X-axis direction of the respective divided regions R1 to R20 in the phosphor screen 8.

On the other hand, as shown in FIGS. 4 to 6, the mask pressing member 32 is formed in an elongated rod shape having a rectangular cross section, and two frame supporting members 1 adjacent in the X-axis direction.
6, it is disposed between the division mask 12 and the connecting rod 25 of the mask frame 14. Each mask pressing member 3
2 are attached to the connecting rod 25 via leaf springs 38, respectively. Then, the mask pressing member 32 is urged toward the divided mask 12 by the leaf spring 38, and the pressing surface 32 a of the mask pressing member 32 is pressed against the divided mask 12.

Five mask pressing members 32 are attached to each mask frame 14, and are arranged at positions facing the mask supporting members 30 with the divided mask 12 interposed therebetween. Thereby, each mask pressing member 32 presses the divided mask 12 against the mask setting surface 30a of the mask support member 30 by the urging force of the leaf spring 38, and elastically sandwiches the divided mask between the mask support member and the mask support member 30. I have.

As described above, each of the divided masks 12 is held in close contact with the mask setting surface 30a of the mask support member 30, and as a result, the divided mask 12 is separated from the phosphor screen 8 by the distance d with high precision. Are located.

The assembling of the color cathode ray tube having the above structure is performed by the following steps. First, after the divided mask 12 is attached to the mask frame 14, the mask pressing member 32 is inserted between the divided mask 12 and the connecting rod 25 with the mask pressing surface 32 a facing the rear plate side surface of the divided mask 12. Then, the mask pressing member is attached to the connecting rod via the leaf spring 38. At this time, using a temporary fixing jig (not shown), each mask pressing member 32 is pressed and contracted to the rear plate 3 side, and temporarily fixed so as not to contact the divided mask.

Subsequently, after the plate supporting member 16 is mounted at a predetermined position on the rear plate 3, the mask frame 14 on which the divided mask 12 and the mask pressing member 32 are mounted is placed on two plate supporting members arranged in the X-axis direction. 16
It is fixed to the rear plate 3 via the holder 26 so that the distance d between the divided mask 12 and the phosphor screen 8 substantially matches the specified value after assembly.

Next, both ends of the mask support member 30 are fitted from above into the engagement grooves 36 of the two plate support members 16 arranged in the X-axis direction, and the mask setting surface 30a of the mask support member is set. The mask support member is fixed to these plate support members while being brought into contact with the positioning surface 34 of the plate support member. Thereby, the mask setting surface 3
2a is positioned at a position separated from the front edge 16c of the plate supporting member 16 by a predetermined distance d from the phosphor screen 8.

In this state, when the temporary fixing jig attached to the mask pressing member 32 is removed, the mask pressing member 32 is urged toward the divided mask 12 by the leaf spring 38, and comes into contact with the divided mask 12 and is pushed up. Thereby, the divided mask 12 is pressed against the mask setting surface 30 a of the mask support member 30, and at the same time, is elastically held between the mask support member 30 and the mask pressing member 32.

Thereafter, the side wall 2, the face plate 1 on which the phosphor screen 8 is formed, and the funnel 4 are joined to the rear plate 3, and the electron gun 20 and the deflecting device 22 are joined.
By assembling, a color cathode ray tube is assembled.

According to the color cathode ray tube configured as described above, the positioning surface 34 is provided on the plate supporting member 30 having the front edge 16c abutting on the phosphor screen, and the mask supporting member is positioned and fixed by the positioning surface. By doing so, it is possible to position the mask support member at a predetermined position with high accuracy with reference to the leading edge of the plate support member abutting on the phosphor screen, that is, with reference to the phosphor screen. By defining the position of the shadow mask by the mask support member, the positional accuracy of the shadow mask with respect to the phosphor screen can be easily improved.

The shadow mask is a mask pressing member 3
2 against the mask support member 30, and
Since the shadow mask is elastically held between the mask pressing member 32 and the mask support member 30, the shadow mask can be always kept in close contact with the mask setting surface 30a of the mask support member, and the shadow mask can be kept at a predetermined position. It can be held with precision. At the same time, the mask pressing member 32 functions as a damper for attenuating the vibration of the shadow mask, and the vibration and deformation of the shadow mask can be reduced. From the above, it is possible to provide a color cathode ray tube capable of displaying a good image.

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 positioning surface 34 functioning as a positioning portion of the mask support member is
Although the surface is opposed to the phosphor screen 8, the surface opposed to the rear plate 3 constitutes a positioning surface, and the end surface of the mask support member on the phosphor screen side is brought into contact with the above-mentioned positioning surface for positioning. It may be configured.

Further, as shown in FIG.
The plate support member 16 may have a slit 40 formed at the distal end portion 16b. In this case, the slit 40 extends along the axial direction of the plate support member 16 and opens at the leading edge 16c. The positioning surface 34 is formed by the bottom surface of the slit 40. The mask support member 30 is fixed to the plate support member 16 in a state fitted to the slit 40, and is brought into contact with the positioning surface 34 so that the phosphor screen 8
Is positioned with respect to

The mask support member 30 is provided for each of the divided masks 12.
It is not limited to an independent one every time, and as shown in FIG. 7, it may be formed long enough to extend over two or more divided masks 12.

In the color cathode ray tube according to the present invention,
The division mask 12 and the mask support member 30 may be provided not only in the X-axis direction of the phosphor screen but also in the Y-axis direction. In this case, each plate support member 16
Are arranged such that the longitudinal direction of the tip edge 16c coincides with the Y-axis direction. Further, the side wall of the vacuum envelope is not limited to the case where the independent side wall is joined to the face plate, but may be formed integrally with the face plate by a single plate glass. Further, the shadow mask may be provided with an electron beam passage hole instead of the slit.

[0047]

As described above in detail, according to the present invention, a mask support member positioned at a predetermined position with respect to a phosphor screen is provided, and a shadow mask is positioned by contacting the mask support member. From that,
A color cathode ray tube capable of easily improving the positional accuracy of a shadow mask with respect to a phosphor screen can be provided.

According to the present invention, by providing the mask pressing member for pressing the shadow mask against the mask supporting member, the shadow mask can be held at a predetermined position with high accuracy, and the vibration and deformation of the shadow mask can be reduced. A cathode ray tube can be provided.

[Brief description of the drawings]

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

FIG. 2 is an exploded perspective view of the color cathode ray tube.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a perspective view showing a shadow mask and a mask frame in the color cathode ray tube.

FIG. 5 is a perspective view showing the internal structure of the color cathode ray tube.

FIG. 6 is a sectional view taken along line BB in FIG. 1;

FIG. 7 is a perspective view corresponding to FIG. 5, according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Face plate 2 ... Side wall 3 ... Rear plate 4 ... Funnel 5 ... Vacuum envelope 7 ... Shadow mask 8 ... Phosphor screen 12 ... Division mask 14 ... Mask frame 16 ... Plate support member 18 ... Neck 20 ... Electron gun 22 Deflecting device 30 Mask support member 30a Mask setting surface 32 Mask pressing member 32a Press surface 34 Positioning surface 36 Engagement groove 38 Plate spring 40 Slit

Claims (11)

[Claims] 1. A vacuum outside having a substantially rectangular flat face plate having a phosphor screen formed on an inner surface thereof, and a flat rear plate disposed to face and substantially parallel to the face plate via side walls. An envelope, a plurality of electron sources for generating an electron beam for scanning the phosphor screen by dividing the phosphor screen into a plurality of small regions, and provided between the phosphor screen and the electron source in the vacuum envelope. A plurality of plate supporting members provided between the face plate and the rear plate for supporting the face plate and the rear plate with respect to the atmospheric pressure; And is in contact with the shadow mask, and the shadow mask is moved a predetermined distance from the phosphor screen. And a plurality of mask support members held at positions spaced apart from each other. 2. The apparatus according to claim 1, wherein said plate support member has a base end fixed to said rear plate and a front end in contact with a face plate, and said positioning means is provided at a position separated from said front end by a predetermined distance. The color cathode ray tube according to claim 1, further comprising a positioning portion formed on the support member, wherein the mask support member is provided in contact with the positioning portion. 3. The positioning section has a positioning surface formed on the plate support member and facing one of the phosphor screen and the rear plate. The mask support member includes a shadow mask, a phosphor screen, 3. The color cathode ray tube according to claim 2, wherein the color cathode ray tube has a mask setting surface which is disposed between the mask and the positioning surface and the shadow mask. 4. A collar according to claim 3, wherein said mask support member is formed in an elongated plate shape extending in parallel with the phosphor screen, and has a side surface constituting said mask setting surface. Cathode ray tube. 5. The shadow mask has a plurality of elongated divided masks arranged in parallel with each other, and the plurality of plate support members are arranged side by side on each of the divided masks. The support members extend in a direction perpendicular to the longitudinal direction of the divided mask and are disposed apart from each other along the longitudinal direction of the divided mask, and each mask support member is supported by the plate support member. The color cathode ray tube according to any one of claims 1 to 4, wherein: 6. The collar according to claim 5, wherein each of said mask support members has a pair of ends supported by two plate support members located on both sides of said divided mask. Cathode ray tube. 7. The color cathode ray tube according to claim 5, wherein each of said mask supporting members extends over a plurality of divided masks. 8. The apparatus according to claim 5, further comprising a mask frame attached to said rear plate and supporting both longitudinal ends of said divided mask. Color cathode ray tube. 9. The image forming apparatus according to claim 1, further comprising a pressing means provided to face said mask support member with said shadow mask interposed therebetween, and to press said shadow mask elastically against said mask support member. 9. The color cathode ray tube according to any one of 1 to 8. 10. A mask pressing member provided opposite to the mask supporting member with the shadow mask interposed therebetween, and a biasing device for urging the mask pressing member toward the mask supporting member. 10. A color cathode ray tube according to claim 9, comprising a member. 11. A vacuum envelope having a substantially rectangular flat face plate having a phosphor screen formed on an inner surface thereof, and a flat rear plate disposed opposite to the face plate via a side wall. A plurality of electron sources for generating an electron beam for scanning the phosphor screen by dividing the phosphor screen into a plurality of small regions; and a shadow provided between the phosphor screen and the electron source in the vacuum envelope. A mask, a mask frame attached to the rear plate and supporting the shadow mask, and a front end in contact with the face plate and a base end in contact with the rear plate. A plurality of plate supporting members supporting the rear plate with respect to the atmospheric pressure; and A plurality of mask support members that are positioned at predetermined positions, abut against the shadow mask, and hold the shadow mask at a predetermined distance from the phosphor screen, and A color cathode ray tube, comprising: a pressing means provided opposite to the mask supporting member with the pressing means elastically pressing the shadow mask against the mask supporting member.