JPH0757649A - Color picture tube and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent continuity of an image from being spoiled in an image continuing part between adjacent areas. CONSTITUTION:In a color picture tube, a shadow mask in which divided masks M1 to M5 in which the effective parts 10 having a large number of electron beam passing holes are continued in a plurality in the vertical direction are arranged in a plurality in parallel with each other, is arranged opposite to a phosphor screen formed substantially on an inside surface of a rectangular face plate, and the phosphor screen is scanned dividedly in a plurality of areas through the shadow mask by an electron beam emitted from a plurality of electron guns. The shadow mask is composed of the divided masks formed by using the same mask original plate by photo-etching, and these divided masks are arranged by rotating them by 180 deg. to the adjacent divided masks on a shadow mask plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube and a method for manufacturing the same, and more particularly to a color picture tube and a plurality of divided masks facing a phosphor screen formed on the inner surface of a substantially rectangular face plate. And a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, various studies have been made on high-definition broadcasting or a high-resolution picture tube having a large screen accompanying the broadcasting. Generally, in order to achieve high resolution of the picture tube, the spot diameter of the electron beam on the phosphor screen must be reduced.

On the other hand, conventionally, the electrode structure of the electron gun has been improved, or the electron gun itself has been increased in diameter and length, but sufficient results have not yet been obtained. The main reason for this is that as the tube becomes larger, the distance from the electron gun to the phosphor screen becomes longer and the magnification of the electron lens becomes too large. Therefore, in order to achieve high resolution, it is important to reduce the distance (depth) from the electron gun to the phosphor screen.
Further, in this case, wide-angle deflection causes an increase in the difference in magnification between the center and the periphery of the screen. Therefore, wide-angle deflection is not a good idea for high resolution.

As a picture tube having the above-mentioned large screen and having a short depth and a high resolution, there is disclosed in Japanese Unexamined Patent Publication No. 5-36363.
In the publication, a face plate is flattened, and a phosphor screen having an integral structure formed on the inner surface of the face plate is divided into a plurality of regions and scanned by an electron beam emitted from a plurality of electron guns. A picture tube is shown.

Further, a color picture tube which is divided into a plurality of regions and is scanned by an electron beam emitted from a plurality of electron guns facing a phosphor screen having an integrated structure formed on the inner surface of a flat face plate. As a shadow mask installed facing the phosphor screen, a divided mask in which a plurality of effective portions in which a large number of electron beam passage holes are formed are vertically connected through ineffective portions, and a plurality of divided masks are formed in the horizontal direction. It is proposed to separate and arrange them in parallel.

Due to the design of these picture tubes, the image drawn in each region by the divisional scanning of the electron beams emitted from a plurality of electron guns depends on the signals applied to the electron gun and the deflection device for deflecting the electron beams. It is designed to reproduce overlapping and seamless images on a connected, integrated phosphor screen. However, this color picture tube has the following problems.

That is, in the color picture tube described above, in terms of the division unit of the area, the entire surface of the phosphor screen is scanned by the electron beam emitted from one electron gun through one shadow mask. Since the structure is similar to that of a color picture tube, the problem within each division unit is almost the same as the problem of the conventional color picture tube. However, in this color picture tube, in addition to the problem within each division unit, there is the problem of screen connection between adjacent areas.

The problem of the screen connection between the adjacent areas is
If the components for displaying an image in each area have the same function for all areas, for example, the beam current characteristics and focus characteristics of each electron gun, the deflection characteristics of the deflecting device, and the opening of the electron beam passage hole of the shadow mask. If the pore characteristics are the same, no problem will occur. However, it is not easy to set the same characteristics of the components for displaying an image in each of these areas.

Particularly, the aperture characteristic of the electron beam passage hole of the shadow mask directly affects the image displayed in the area, and the variation or irregularity of the aperture diameter of the electron beam passage hole of the effective portion causes a difference in the screen between adjacent areas. It has a great effect on the connection.

Generally, the shadow mask of a color picture tube is
It is manufactured by a photo-etching method, and is obtained by transferring a pattern drawn on the same mask original plate such that the effective portion, the ineffective portion surrounding the effective portion, the outer shape, etc., and etching. In such a manufacturing method, in general, the diameter of the open hole varies by about 5 to 10 μm within the effective surface. However, since the variation in the aperture diameter is a continuous change, it does not pose a problem even if it is incorporated into a color picture tube to evaluate the image quality. Further, the variation in the aperture diameter of the shadow mask manufactured by the same mask original plate is almost constant and has the same tendency.

On the other hand, when the shadow mask is composed of a plurality of divided masks, as shown in FIG.
If there is a continuous variation in aperture diameter of about 5 to 10 μm in the effective surface of each divided mask M1 to M5, there will be a difference in the aperture diameter between the effective surfaces of the adjacent divided masks, and the image connection between adjacent regions will occur. A brightness difference occurs in a portion, and the continuity of images is impaired. In order to solve this, it is necessary to reduce the variation of the aperture diameter of each divided mask manufactured by the same mask original plate by several μ.
It must be less than m, which makes it extremely difficult to manufacture the required shadow mask.

[0012]

As described above, as a color picture tube capable of realizing a large screen with a short depth and high resolution, it faces a phosphor screen having an integrated structure formed on the inner surface of a flat face plate. A plurality of divided masks are arranged, and a color picture tube which divides and scans the phosphor screen into a plurality of regions through an effective portion of each divided mask by an electron beam emitted from a plurality of electron guns. Is proposed.

In this color picture tube, each division unit is similar to a color picture tube in which a phosphor screen is scanned by a conventional electron beam emitted from a single electron gun through a single shadow mask. Since,
The problem within each division unit is almost the same as the problem of the conventional color picture tube. However, in this color picture tube, in addition to the problem of each division unit, there is a problem of connection of screens between adjacent areas.

The problem of the screen connection between the adjacent areas is as follows.
If the components for displaying the image in each area have the same function in all areas, no problem will occur. However, it is not easy to set the same characteristics of the components for displaying an image in each area, and especially the opening characteristics of the electron beam passage holes of the shadow mask directly affect the image displayed in the area. The variation or unevenness of the aperture diameter of the electron beam passage hole of the effective portion has a great influence on the connection of the screens between the adjacent regions.

That is, in the shadow mask which is usually manufactured by the photo-etching method, the variation of the aperture diameter which continuously changes is about 5 to 10 μm. When the variation of the aperture diameter that continuously changes in a plurality of divided masks occurs, a difference in the aperture diameter occurs between the effective surfaces of the adjacent divided masks, and a difference in brightness or the like occurs in the connecting portion of the images between the adjacent regions. , The continuity of the screen is lost. In order to solve this, it is necessary to make the aperture diameter variation of each divided mask manufactured by the same mask original plate to be several μm or less, which makes it extremely difficult to manufacture a required shadow mask.

The present invention has been made in order to solve the above-mentioned problems, and a plurality of divided masks in which a shadow mask installed to face a phosphor screen having an integral structure is manufactured by the same mask original plate. In the color picture tube which is composed of the following, and the phosphor screen is divided and scanned by the electron beams emitted from a plurality of electron guns, the aperture diameter is changed continuously for each divided mask. It is an object of the present invention to prevent the continuity of the screen at the connecting portion of the images between the adjacent areas from being spoiled even if there is a variation in.

[0017]

An effective portion having a large number of electron beam passage holes is formed in a vertical direction so as to face a phosphor screen having an integral structure formed on an inner surface of a substantially rectangular face plate. A shadow mask is formed by horizontally arranging a plurality of divided masks connected in parallel in a horizontal direction, and the phosphor screen is moved horizontally and vertically through the shadow mask by electron beams emitted from a plurality of electron guns. In a color picture tube and a method of manufacturing the same, each of which is divided into a plurality of areas and scanned, the shadow mask is composed of a division mask formed by using the same mask original plate by photoetching, and the division mask is formed on the surface of the shadow mask. In 180 °, it was rotated by 180 ° with respect to the adjacent divided mask.

[0018]

As described above, the shadow mask is composed of divided masks formed by using the same mask original plate by photoetching, and the divided masks are arranged on the surface of the shadow mask and rotated by 180 ° with respect to the adjacent divided masks. Then, in the divided masks formed by using the same mask original plate, the changes in the aperture diameters over the entire effective surface tend to be almost the same. Therefore, when the divided masks are rotated by 180 ° with respect to the adjacent divided masks, It is possible to eliminate the difference in the aperture diameter between the effective portions of the divided mask, and prevent the continuity of the screen from being impaired, such as the difference in brightness at the connecting portion of the images between the adjacent regions.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 1 shows the overall construction of a color picture tube which is one of the embodiments, and FIG. 2 shows an exploded perspective view thereof. This color picture tube has a substantially rectangular flat glass face plate 1 and a glass side wall 2 which is joined to the peripheral edge of the face plate 1 and extends substantially perpendicularly to the face plate 1. A substantially rectangular flat glass rear plate 3 that is joined to the face plate 1 via the side wall 2 in parallel and is joined in parallel; and a plurality of funnels 4 joined to the rear plate 3. It has a vacuum envelope 5. The plurality of funnels 4 are respectively joined around the plurality of openings 6 formed in the rear plate 3, and in the illustrated example, five in the horizontal direction (X direction),
A total of 20 funnels 4 are joined in the vertical direction (Y direction).

On the inner surface of the face plate 1, blue,
A vertically long striped three-color phosphor layer that emits green and red light is regularly arranged in parallel in the horizontal direction, and a black stripe is provided so as to fill the three-color phosphor layers. A phosphor screen 8 is formed. A shadow mask 9 is arranged inside the phosphor screen 8 so as to face the phosphor screen 8. The shadow mask 9 is composed of a plurality of divided masks, five divided masks M1 to M5 in the illustrated example, and these divided masks M1 to M5 are arranged in parallel in the horizontal direction at a predetermined interval in a relationship described later. . The divided masks M1 to M5 are
A plurality of effective portions 10 having a large number of electron beam passage holes are connected in the vertical direction through ineffective portions having no electron beam passage holes, four in the illustrated example, and each is fixed to the inner surface of the rear plate 3. The mask erection means 11 having a U-shaped cross section is supported in a state in which tension is applied.

Also, each neck 1 of the plurality of funnels 4
Electron guns 13 are provided in each of the two. Further, between the face plate 1 and the rear plate 3, a plurality of plate supporting means 14 for supporting an atmospheric pressure load applied to the face plate 1 and the rear plate 3 of the vacuum envelope 5 are provided.

In this color picture tube, the electron beam emitted from each electron gun 13 is deflected in the horizontal and vertical directions by a magnetic field generated by a deflecting device (not shown) mounted outside each funnel 4. Each divided mask M1
Through the effective portion 10 of M5 to M5, the phosphor screens 8 are divided into a plurality of regions, five in the horizontal direction and four in the vertical direction in the illustrated example.
A total of 20 areas R1 to R20 are divided and scanned. The images drawn on the phosphor screen 8 by this divisional scanning are connected by the signals applied to the electron gun 13 and the deflecting device, and one large image is reproduced on the entire surface of the phosphor screen 8 without duplication or discontinuity. Has become.

This color picture tube is manufactured as follows.

First, with respect to the shadow mask 9, by using the same mask original plate by the photo-etching method, as shown in FIG. 3, a plurality of effective portions 10 are formed in the vertical direction through ineffective portions in which electron beam passage holes are not formed. Number (4 in the illustrated example
Individual pieces) The connected divided masks M1 to M5 (only M1 is shown) are manufactured. Since these divided masks M1 to M5 are used in a flat state, curved surface molding by press molding is not performed unlike the conventional shadow mask.

In assembling the color picture tube, first, the phosphor screen 8 having an integrated structure is formed on the inner surface of the face plate 1 by a photo printing method, for example, using a master mask. On the other hand, at a predetermined position on the inner surface of the rear plate 3, a mask erection means 11 for supporting the divided masks M1 to M5 and a plurality of members for supporting an atmospheric pressure load applied to the face plate 1 and the rear plate 3 of the vacuum envelope 5 are provided. The plate supporting means 14 is fixed by applying and burning frit glass. Neck 12 of a plurality of funnels 4
The electron gun 13 is sealed inside.

Then, the divided masks M1 to M5 manufactured by using the same mask original plate are attached to the mask erection means 11 fixed to the rear plate 3. The division masks M1 to M5 are mounted on the shadow mask surface by 180 ° with respect to the adjacent division masks, as shown in FIG.
Weld to the mask erection means 11 while applying tension while rotating. That is, as shown in FIG. 3 for the division mask M1, if the right side of the vertical axis YM1 of the division mask M1 is R and the left side is L, the division mask M2 adjacent to the division mask M1 has the right side L and the left side. Are welded to become R, and for the next divided mask M3, the right side is R,
The left side is L, the right side is L and the left side is R for the division mask M4, and the right side is R and the left side is L for the division mask M5.
Are welded in the state of being rotated by 180 ° every other.

Next, the face plate 1 having the phosphor screen 8 formed thereon, a plurality of side wall pieces constituting the side wall 2, plate supporting means and the divided mask M as described above.
1 to M5 mounted rear plate 3 and electron gun 1
The plurality of sealed funnels 3 of 3 are positioned in a predetermined relationship, and they are integrally joined by firing the coated frit glass. Then, it is manufactured by exhausting the envelope 5 assembled as one body.

By the way, as described above, the shadow mask 9
Is composed of a plurality of divided masks M1 to M5, and an electron beam emitted from a plurality of electron guns 13 causes the phosphor screen 8 to pass through the effective portions of the divided masks M1 to M5.
In a color picture tube which scans by dividing into a plurality of regions R1 to R20, when the division masks M1 to M5 are installed in a state of being rotated by 180 ° with respect to the adjacent division masks, the image is connected to the adjacent regions. It is possible to prevent a difference in brightness and the like from impairing the continuity of the screen, and it is possible to reproduce a good-quality image on the entire surface of the phosphor screen 8.

That is, a shadow mask, which is generally manufactured by photoetching, is manufactured by the same original plate,
As indicated by the line 15 in FIG. 4, there is a continuous variation in the aperture diameter, but when manufactured with the same mask original plate, the variation in the aperture diameter shows the same tendency. Therefore, the divided masks M1 to M5 produced by the same mask original plate as described above.
Is arranged in a state of being rotated by 180 ° with respect to the adjacent divided mask, it can be ensured that there is almost no difference in the aperture diameter between the effective portions of the adjacent divided masks, as indicated by the line 16 in FIG. 5A. .

As a result, as indicated by the line 17 in FIG. 9B, the difference in beam spot diameter formed between the adjacent regions on the phosphor screen can be eliminated, and the image connecting portion between the adjacent regions can be eliminated. It is possible to form a continuous screen that does not cause a difference in brightness, and an image of good quality can be reproduced on the entire surface of the phosphor screen 8.

In the above embodiment, five divided masks having four effective portions in the vertical direction are arranged in parallel in the horizontal direction. However, the number of effective portions in the vertical direction of the divided masks and the parallel arrangement in the horizontal direction are set. The number is not limited to that in the above embodiment, and for example, as shown in FIG. 6, six divided masks having four effective portions in the vertical direction are arranged in parallel in the horizontal direction, and the divided masks M1 to When every other M6 is rotated by 180 ° and the right side of the vertical axis YM1 of the division mask M1 is R and the left side is L, when the division masks M2 are sequentially adjacent to each other, the right side is L, the left side is R, and the division mask M3 is about,
R for the right side, L for the left side, L for the division mask M4, R for the left side, R for the division mask M5, L for the division mask M5, R for the division mask M6, L for the division mask M6,
By setting R on the left side, the same effect as that of the color picture tube of the above embodiment can be obtained.

Further, in the above-mentioned embodiment, the plurality of division masks are made independent, but the shadow mask shown in FIG. 7 has a pattern corresponding to two adjacent division masks in the above-mentioned embodiment. Using the mask original plate, a divided mask in which two adjacent divided masks M1 and M2 are integrated is manufactured, and the integrated divided masks Mp1 to
Three sets of Mp3 are installed in parallel in the horizontal direction. In this case, since only the connecting portion of the divided masks Mp1 to Mp3 of each set becomes a problem, when the right side of the vertical axis YM1 of the divided mask Mp1 is R and the left side is L, the adjacent divided masks Mp2 are L on the right side, R on the left side, split mask Mp3
As for R, by setting R on the right side and L on the left side, the same effect as that of the color picture tube of the above-described embodiment can be obtained.

In the shadow mask shown in FIG. 8, three masks M1 to M3 which are successively adjacent to each other are formed by using a mask original plate having a pattern corresponding to the three masks which are successively adjacent to each other in the above embodiment. The divided masks that are integrated with each other are manufactured, and the integrated divided masks Mp1 to Mp2 are
The sets are installed in parallel in the horizontal direction. Also in this case, only the connecting portion of the divided masks Mp1 to Mp2 of each set is problematic. Therefore, when the right side of the vertical axis YM1 of the divided mask Mp1 is R and the left side is L, the right side of the adjacent divided masks Mp2 is By setting L and R on the left side, the same effect as that of the color picture tube of the above embodiment can be obtained.

[0035]

According to the present invention, there is provided a divided mask in which a plurality of effective portions having a large number of electron beam passage holes are vertically connected to each other so as to face a phosphor screen formed on the inner surface of a substantially rectangular face plate. A plurality of shadow masks are arranged in parallel in the horizontal direction, and the phosphor screen is divided into a plurality of regions in the horizontal and vertical directions by the electron beams emitted from the electron guns through the shadow masks. In a color picture tube and a method of manufacturing the same in which scanning is performed, the shadow mask is composed of a divided mask formed by using the same mask original plate by photoetching,
When this division mask is arranged on the surface of the shadow mask by 180 ° rotation with respect to the adjacent division mask, in the division mask formed using the same mask original plate, the change of the aperture diameter over the entire effective surface tends to be almost the same. Therefore, by arranging them so that they are rotated by 180 ° with respect to the adjacent divided masks, it is possible to eliminate the difference in the aperture diameter between the effective portions of the adjacent divided masks, and it is possible to reduce the luminance difference in the connecting portion of the images between the adjacent regions. It is possible to prevent the deterioration of the continuity of the screen without causing any trouble, and it is possible to provide a color picture tube which reproduces a good quality image on the entire surface of the phosphor screen.

[Brief description of drawings]

FIG. 1 (a) is a perspective view showing the configuration of a color picture tube according to an embodiment of the present invention, and FIG. 1 (b) is a BB sectional view thereof.

FIG. 2 is an exploded perspective view showing a configuration of the color picture tube.

FIG. 3 is a perspective view for explaining an arrangement of divided masks of the color picture tube.

FIG. 4 is a diagram for explaining variations in aperture diameter of an effective portion of the divided mask.

5A is a diagram for explaining a difference in aperture diameter between effective portions of adjacent divided masks, and FIG. 5B is a diagram for explaining a difference in beam spot diameter between adjacent regions on the phosphor screen. FIG.

FIG. 6 is a diagram showing different arrangements of the division mask of the present invention.

FIG. 7 is a diagram showing still another arrangement of the division mask of the present invention.

FIG. 8 is a diagram showing still another arrangement of the division mask of the present invention.

FIG. 9 is a view for explaining a difference in aperture diameter between effective portions of adjacent divided masks in a known color picture tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Face plate 2 ... Side wall 3 ... Rear plate 4 ... Funnel 5 ... Vacuum envelope 8 ... Phosphor screen 9 ... Shadow mask 10 ... Effective part 11 ... Mask installation means 13 ... Electron gun 14 ... Plate support means M1 to M5 ... Division masks Mp1 to Mp3 ... Division masks R1 to R20 ... Areas

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Takahashi 1-9-2, Harara-cho, Fukaya-shi, Saitama Inside Fukaya Electronics Factory, Toshiba Corporation (72) Inujita Haraguchi 1-9, Harara-cho, Fukaya-shi, Saitama No. 2 inside Toshiba Fukaya Electronics Factory

Claims (2)

[Claims] 1. A plurality of effective portions having a large number of electron beam passage holes vertically connected to each other so as to face a phosphor screen having an integral structure formed on the inner surface of a substantially rectangular face plate. A plurality of divided masks are horizontally arranged in parallel, and a shadow mask is installed. A plurality of phosphor screens are horizontally and vertically arranged through the shadow masks by electron beams emitted from a plurality of electron guns. In a color picture tube which is divided into individual areas and scanned, the shadow mask is composed of a plurality of division masks formed by using the same mask original plate by photoetching, and the division masks are adjacent to each other on the surface of the shadow mask. A color picture tube, which is arranged to be rotated by 180 ° with respect to the divided mask. 2. A divided mask in which a plurality of effective portions having a large number of electron beam passage holes are vertically connected to each other facing a phosphor screen formed on the inner surface of a substantially rectangular face plate. A plurality of shadow masks arranged in parallel in the horizontal direction are installed, and the phosphor screen is horizontally and vertically divided into a plurality of regions through the shadow masks by electron beams emitted from a plurality of electron guns. In the method of manufacturing a color picture tube that divides and scans, a step of forming the plurality of divided masks by using the same mask original plate by photoetching, and a plurality of divided masks formed by using the same mask original plate 180 with respect to the adjacent division mask on the surface of the shadow mask
A method of manufacturing a color picture tube, which comprises a step of rotating and installing.