JPH06187928A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To reduce the dislocation of landing to a three-color phosphor vessel due to the inappropriate space between a phosphor screen and a shadow mask part by fitting a shadow mask to a mask fixation part fixed to a rear plate to practically position the shadow mask on the rear plate. CONSTITUTION:A vacuum case 6 consists of a rectangular flat face plate 1, a rectangular flat rear plate 3, funnels 5 bonded to twenty opening holes 4 of the rear plate 3, which is positioned separately from the face plate 1 by side walls 2, necks 8 and electron guns 9. A flat mask fixation part 22 is fixed on the inner surface of the rear plate 3, and a shadow mask 10 is fitted to this fixation part 22, and practically positioned on the rear plate 3. As a result, a space between the shadow mask 10 and the rear plate 3 and a space between the shadow mask 10 and a phosphor screen 7 formed on the inner surface of the face plate 1 are decided accurately by the fixation part 22, the side walls 2 and supports 24. Dislocation of landing to a three-color phosphor due to the inappropriate space between the screen 7 and the shadow mask 10 is thereby reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a shadow mask arranged inside a flat face plate, which faces a phosphor screen formed on the inner surface of the face plate, to divide the phosphor screen into a plurality of regions. And a scanning cathode ray tube.

[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 a larger diameter.
Although efforts have been made to expand it, it has not yet achieved sufficient results. 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.

Therefore, a method of arranging a plurality of independent small-sized picture tubes to obtain a high-resolution large screen has hitherto been disclosed in JP-A-48-90428, JP-A-49-21019 and JP-A-53. -117130 gazette etc. are disclosed. This kind of method is effective for displaying a huge screen with a large number of divisions arranged outdoors, but the screen size is 40
When displaying a medium-sized large screen of about inch, the connection part of the screen between each area is conspicuous and an unpleasant image is reproduced.
Therefore, when it is used as a home television receiver or as a terminal for graphic display in computer-aided design (CAD), the connection part of the screen becomes a fatal defect.

In contrast, US Pat. No. 3,071,7
No. 06, Japanese Utility Model Publication No. 39-25641, Japanese Patent Publication No. 42-4929, Japanese Patent Publication No. 50-17167 disclose a structure in which a plurality of independent picture tube cleans are integrated. Has been done. The picture tube having the phosphor screen of this integrated structure is composed of a face plate on which the phosphor screen is formed, a rear plate opposed to the face plate, a plurality of funnels adjacent to the rear plate and each funnel. A vacuum envelope is formed by the plurality of necks provided. The face plate is made of glass and the rear plate is made of glass or metal.

However, in such a structure, when the screen surface becomes large, the face plate and the rear plate must be thickened so that they can withstand the load of atmospheric pressure (external pressure), and the tube shaft must be thick. It is also necessary to have a large curvature in the direction. As a result, the weight of the envelope becomes very heavy, and if it has a large curvature in the tube axis direction,
The screen becomes difficult to see. Furthermore, the distance between the phosphor screen and the electron gun enclosed in the neck becomes large, and the electron lens becomes unfavorable in terms of magnification.

As a cathode ray tube which solves such a problem, the present inventors have developed a cathode ray tube (color picture tube) shown in FIGS. 2 and 3. This cathode ray tube has a substantially rectangular flat face plate 1 and a substantially rectangular flat face plate 1 facing in parallel with the face plate 1 via a substantially vertically extending side wall 2 joined to a peripheral portion of the face plate 1. Rear plate 3, a plurality of holes 4 formed in this rear plate 3
A phosphor screen having a three-color phosphor layer formed on the inner surface of the face plate 1 which has a vacuum envelope 6 composed of a plurality of funnels 5 which are separately joined around the periphery of the face plate 1.
7 is an electron gun installed in the neck 8 of each funnel 5.
By the electron beam emitted from 9, through a flat shadow mask 10 in which a large number of electron beam passage holes are formed,
Scanning is performed by dividing into a plurality of regions, for example, as shown in FIG. 2, a total of 20 divided into 5 in the horizontal direction and 4 in the vertical direction.
The individual regions R1 to R20 are horizontally and vertically scanned to form a structure for displaying a color image.

In this cathode ray tube, a supporting column 11 is arranged between the face plate 1 and the rear plate 3 in order to support the load of the atmospheric pressure applied to the flat face plate 1 and the rear plate 3. Further, the shadow mask 10 has a plurality of fixing parts 12 fixed to the inner surface of the rear plate 3 by frit glass, and is attached to the mask erection means 13 fixed to the fixing parts 12 so that the phosphor screen 6
And are opposed to each other at a predetermined interval. The fixed portion 12 is formed of a metal material having a thermal expansion coefficient substantially the same as that of the rear plate 3,
It is fixed to the rear plate 3 by frit glass, and the mask erection means 13 is attached to this fixing portion 12 by welding.

In such a cathode ray tube, in order to dispose the flat shadow mask 10 so as to face the flat face plate 1 at a predetermined interval (q value), it is fixed to the inner surface of the rear plate 3. It is necessary to control the heights of the plurality of fixing parts 12 and the mask erection means 13 with high accuracy. However, as described above, the shadow mask 10 is provided on the rear plate 3 via the fixing portion 12 and the mask erection means 13.
In the structure for mounting, the fixing part 12 and the mask erection means 13
Not only increases the error in the height dimension of the frit glass, but also the thickness of the frit glass that fixes the fixing part 12 varies, so it is possible to manage the distance from the inner surface of the rear plate 3 to the shadow mask 10 with high accuracy. Have difficulty. The height of the shadow mask 10 is set based on the inner surface of the rear plate 3 as described above, while the phosphor screen 6 is attached to the rear plate 3 via the side wall 2. Since it is formed on the inner surface of the face plate 1 thus formed, it is difficult to make the distance between the phosphor screen 6 and the shadow mask 10 highly accurate in this respect as well.

As a result, there is a problem that the landing of the electron beam on the three-color phosphor layer is deviated and the color purity is deteriorated.

[0010]

As described above, in a cathode ray tube in which a phosphor screen is divided into a plurality of regions and scanned by an electron beam emitted from a plurality of electron guns, the resolution is short and the depth is short. However, there are various problems when trying to obtain a cathode ray tube having a simple structure with an easy-to-see screen.

The present inventors have previously proposed, as a cathode ray tube capable of solving these problems, a substantially rectangular flat face plate and a substantially vertically extending side wall joined to its peripheral portion. , A substantially rectangular flat rear plate facing parallel to the face plate through the side wall, and a vacuum envelope composed of a plurality of funnels joined to the rear plate, and formed on the inner surface of the face plate The phosphor screen composed of the three-color phosphor layer is divided into a plurality of regions through a flat shadow mask by an electron beam emitted from an electron gun arranged in the neck of each funnel, and horizontally. We have developed a cathode ray tube that displays one color image on a phosphor screen by vertical scanning.

In this cathode ray tube, the shadow mask has a plurality of fixing portions fixed to the inner surface of the rear plate by frit glass, and is attached to the mask erection means welded to the fixing portions so that the shadow mask and the phosphor screen have a predetermined distance. It has a structure facing each other.

In such a cathode ray tube, in order to arrange the flat face mask so as to face the flat face plate at a predetermined interval, a plurality of fixing portions fixed to the inner surface of the rear plate and the mask. It is necessary to control the height of the erection means with high accuracy, but as described above, the fixing part is fixed to the inner surface of the rear plate by the frit glass, and the rear plate is inserted through the mask erection means welded to this fixing part. In the structure in which the shadow mask is mounted on the top, not only the height error of the fixing part and the mask erection means is added and it becomes large, but also the thickness of the frit glass that fixes the fixing part varies, so the shadow from the inner surface of the rear plate It is difficult to control the distance to the mask with high accuracy. In addition, the height dimension of the shadow mask is set with reference to the inner surface of the rear plate, whereas the phosphor screen is formed on the inner surface of the face plate attached to the rear plate through the side wall. Also in this respect, it is difficult to make the distance between the phosphor screen and the shadow mask highly accurate. As a result, 3
The landing of the electron beam on the color phosphor layer is displaced,
There is a problem that the color purity deteriorates.

The present invention has been made in order to solve the above-mentioned problems, and is a cathode ray tube in which the distance between the phosphor screen provided on the inner surface of the flat face plate and the flat shadow mask can be set with high accuracy. The purpose is to configure.

[0015]

[Means for Solving the Problems] First flat surface having a substantially rectangular shape
A vacuum envelope having a plate, a side wall extending substantially perpendicularly from a peripheral portion of the first plate, and a second flat plate having a substantially rectangular shape facing the first plate in parallel with the side wall through the side wall; A support means for supporting the first and second plates is arranged between the first plate and the second plate, and the phosphor screen formed on the inner surface of the first plate is arranged on the second plate side. In the cathode ray tube which scans by dividing into a plurality of regions through the shadow mask by the electron beam emitted from the beam emitting means,
By fixing the flat plate-shaped mask fixing portion to the inner surface of the second plate,
A shadow mask was attached to this mask fixture and positioned substantially above the second plate.

[0016]

As described above, when the flat plate-shaped mask fixing portion is fixed to the inner surface of the second plate and the shadow mask is attached to the mask fixing portion and positioned substantially on the second plate, the second plate The shadow mask part can be attached to the inner surface with high accuracy. As a result, the distance between the phosphor screen formed on the inner surface of the first plate and the shadow mask is determined by the height of the side wall between the first plate and the second plate. However, the height of this side wall is easier to manage compared to the conventional mounting of the shadow mask part by the fixing part and microphone installation means, and the interval between the phosphor screen and the shadow mask part is set with high accuracy. Therefore, it is possible to reduce the landing deviation of the electron beam with respect to the three-color phosphor layer due to the improper spacing between the phosphor screen and the shadow mask portion.

[0017]

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

FIG. 1 shows a cathode ray tube which is an embodiment of the present invention. This cathode ray tube comprises a flat glass face plate 1 (first plate) having a substantially rectangular shape, a glass side wall 2 which is joined to a peripheral edge thereof and extends substantially vertically, and a face plate 2 via this side wall 2. A substantially rectangular flat glass rear plate 3 (second plate) facing in parallel with 1 and a plurality of apertures 4 formed in this rear plate 3
It has a vacuum envelope 6 composed of a plurality of glass funnels 5 which are separately bonded around the periphery of the vacuum envelope. On the inner surface of the face plate 1, a striped light absorption layer which is elongated in the vertical direction is formed over almost the entire surface, and stripe-shaped phosphor layers which emit blue, green and red are provided in the gaps of the light absorption layer. A formed phosphor screen 7 is provided, and a shadow mask 10 is arranged inside the phosphor screen 7 so as to face the phosphor screen 7 and be separated by a predetermined distance. On the other hand, an electron gun 9 (beam emitting means) is arranged in each neck 8 of the plurality of funnels 5.

Then, the electron beam emitted from each electron gun 9 is deflected by horizontal and vertical deflection magnetic fields generated by a deflection yoke (not shown) mounted outside each funnel 5, and passes through a shadow mask 10. The phosphor screen 7 is divided into a plurality of regions in the horizontal and vertical directions, for example, 5 in the horizontal direction and 4 in the vertical direction.
Scanning is performed by dividing into individual regions (see FIG. 3). The image drawn on the phosphor screen 7 by this divisional scanning is closely connected by the signals applied to the electron guns 9 and the deflection yokes, and one large color image with no breaks or overlaps on the entire surface of the phosphor screen 7. It is structured to draw.

In such a cathode ray tube, the shadow mask 10 has a plurality of electron beam passage holes through which electron beams emitted from the electron guns 9 arranged in the necks 8 of the funnels 5 pass. An ineffective portion that has an effective portion 20 and has no electron beam passage hole formed between it and the adjacent effective portion 20.
It is formed into a structure with 21. Meanwhile, the rear plate 3
A plurality of plate-shaped mask fixing portions 22 made of a nickel alloy having substantially the same thermal expansion coefficient as the rear plate 3 are fixed to the inner surface of the shadow mask 10, and the shadow mask 10 is attached to the mask fixing portions 22 by welding or the like. . Since the mask fixing portion 22 has a small plate thickness, the shadow mask 7 attached to the mask fixing portion 22 approaches the inner surface of the rear plate 3 and is substantially located on the rear plate 3.

The attachment of such a shadow mask 7 is
The mask fixing part 22 is bonded to the rear plate 3 in advance by frit glass or is directly welded to the rear plate 3 and the mask fixing part 22 is assembled at the time of assembling the cathode ray tube.
It can be attached by welding the shadow mask 7 to.

Further, in this cathode ray tube, a flat face plate 1 and a rear plate are provided on the mask fixing portion 22.
A support pillar 24 (supporting means) for supporting the atmospheric pressure load applied to and is attached. The support column 24 is composed of a metal round bar or the like having a flat edge portion formed at the tip thereof, penetrates the ineffective portion 21 of the shadow mask 10, and the edge portion of the tip is subjected to the division scanning. It is in contact with the stripe-shaped light absorption layer located on the boundary of the regions. The longitudinal direction of the edge portion of the support column 24 that is in contact with the striped light absorbing layer coincides with the longitudinal direction of the striped light absorbing layer.

By the way, as described above, the thin mask fixing portion 22 is fixed to the inner surface of the rear plate 3, and the inner surface of the rear plate 3 is brought close to the mask fixing portion 22 so that the mask fixing portion 22 is substantially on the rear plate 3. When the shadow mask 10 is attached so as to be positioned, the space between the phosphor screen 7 provided on the inner surface of the face plate 1 and the shadow mask 10 is a sidewall that extends substantially vertically from the peripheral portion of the face plate 1.
Determined by a height of 2. Moreover, the height of the side wall 2 can be controlled more than when the fixing portion is fixed to the rear plate, the mask erection means is fixed to the fixing portion, and the shadow mask is attached to the mask erection means. It's easy. Meanwhile phosphor screen 7 and shadow mask
Since the interval with 10 is uniquely determined by the height of the side wall 2, it can be set with high accuracy. As a result, the phosphor screen
The landing of the electron beam on the three-color phosphor layer due to the improper spacing between the shadow mask 7 and the shadow mask 10 can be greatly reduced, and a cathode ray tube with no color shift and being highly practical can be obtained.

[0024]

The first flat plate having a substantially rectangular shape, the side wall extending substantially vertically from the peripheral portion of the first plate, and the substantially rectangular shape parallel to the first plate through the side wall. A vacuum envelope having a flat second plate is provided, and a support means for supporting the first and second plates is arranged between the first plate and the second plate, and is formed on the inner surface of the first plate. Second phosphor screen
In a cathode ray tube that scans by dividing into a plurality of regions through a shadow mask by an electron beam emitted from a beam emitting means arranged on the plate side, a flat plate mask fixing portion is fixed to the inner surface of the second plate, and the shadow is fixed. The shadow mask can be attached to the inner surface of the second plate with high accuracy by attaching the mask to the mask fixing portion and substantially locating the mask on the second plate. As a result, the distance between the phosphor screen formed on the inner surface of the first plate and the shadow mask is determined by the height of the side wall between the first plate and the second plate. Moreover, the height of this side wall is easier to control than the conventional mounting of the shadow mask portion by the fixing portion and the microphone erection means, and the interval between the phosphor screen and the shadow mask portion is uniquely set. Since it can be determined, it can be set with high accuracy, and the landing deviation with respect to the three-color phosphor layer caused by the improper spacing between the phosphor screen and the shadow mask portion can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a cathode ray tube which is an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a conventional cathode ray tube.

FIG. 3 is a sectional view showing a configuration of a conventional cathode ray tube.

[Explanation of symbols]

 1 ... Face plate (first plate) 2 ... Side wall 3 ... Rear plate 5 ... Funnel 6 ... Envelope 7 ... Phosphor screen 9 ... Electron gun (beam emitting means) 10 ... Shadow mask 22 ... Mask fixing part 24 ... Support Pillar

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiji Kambara 1-2-9 Harara-cho, Fukaya-shi, Saitama Stock company Toshiba Fukaya electronics factory

Claims (1)

[Claims] 1. A substantially rectangular flat first plate, a side wall extending substantially vertically from a peripheral portion of the first plate, and a substantially rectangular shape parallel to and facing the first plate through the side wall. A vacuum envelope having a flat second plate, a phosphor screen formed on the inner surface of the first plate, and arranged on the second plate side, and dividing the phosphor screen into a plurality of regions. Beam emitting means for emitting a scanning electron beam, a flat plate-shaped mask fixing portion fixed to the inner surface of the second plate, and a mask fixing portion attached to the mask fixing portion and positioned substantially on the second plate. A shadow mask facing the phosphor screen at a predetermined interval, and a support means disposed between the first plate and the second plate for supporting the first and second plates. Cathode-ray tube, characterized in that.