JPH0757645A - Color cathode-ray tube - Google Patents

Abstract

PURPOSE:To correct positional dislocation between an electron beam passing hole and the phosphor mosaic caused by thermal expansion of a shadow mask. CONSTITUTION:Mask dimension correcting members 11a and 11b of a construction material having a thermal expansion coefficient different from that of a construction material of support arms are fixed between mask welding bars 9a and 9b and the support arms 10a and 10b of a shadow mask body structure 7. When a shadow mask is thermally expanded in operation, the shadow mask is moved by a constant quantity in the fluorescent screen direction according to it by using a curve of the support arms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask type color cathode ray tube, and in particular, the electron beam passing hole is moved by the thermal expansion of the shadow mask caused by the electron beam bombardment, whereby the electron beam and the phosphor are separated from each other. The present invention relates to a color cathode ray tube that eliminates positional displacement.

[0002]

2. Description of the Related Art A color cathode ray tube which is widely used at present is a so-called shadow mask type color cathode ray tube. The shadow mask provided in this type of color cathode ray tube divides the three electron beams emitted from the electron gun into the inner surface of the panel and divides them into three phosphor phosphor mosaics of red, green and blue. The purpose is to selectively control the path of each electron beam so as to collide with each other.

The shadow mask generally has a thin plate of iron or an iron-nickel alloy having a small coefficient of thermal expansion and has round, rectangular, or interdigital beam passage holes, and the electron beam of the shadow mask is formed on the inner surface of the panel. The phosphor mosaic is formed in a shape corresponding to the shape of the through hole as described above.

The shadow mask having a round electron beam passage hole is a dot type shadow mask, the shadow mask having a rectangular electron beam passage hole is a slot type shadow mask, and the shadow mask having a blind electron beam passage hole is grilled. Type shadow mask.

Generally, the dot type shadow mask and the slot type shadow mask are often formed in a spherical shape,
The grill type shadow mask is held in a cylindrical shape by applying tension to the grill.

The slot type shadow mask can be considered as a structure in which grills arranged in parallel are provided with bridges connecting the grills. It has also been proposed to apply a tension to the slot type shadow mask in the longitudinal direction of the grill in the same manner as the grill type shadow mask to maintain the shape of the cylindrical surface.

The prior art relating to this type of color cathode ray tube is disclosed, for example, in JP-A-62-1336.
45, Japanese Patent Laid-Open No. 59-167936, and Japanese Utility Model Laid-Open No. 48-
No. 76857 can be cited.

[0008]

The shadow mask rises in temperature and thermally expands due to the collision of the electron beam during the operation of the cathode ray tube, and the positional relationship between the electron beam passage hole and the phosphor mosaic is deviated. There is a problem that color development is not possible.

In recent years, the demand for high-definition display has been strengthened in the cathode ray tube, and as the precision of image display has increased, the electron beam on the fluorescent surface due to the displacement of the electron beam passage hole due to the thermal expansion of the shadow mask The need to highly control the deviation of the landing position of the vehicle has become stronger and stronger.

FIG. 5 is a schematic sectional view for explaining the structure of a color cathode ray tube to which the present invention is applied. 1 is a panel, 2 is a funnel, 3 is a neck, 4 is an electron gun, 5 is a deflection coil, and 6 is a deflection coil. Fluorescent screen, 7 is a shadow mask structure, 8 is a slot type shadow mask, 9a and 9b are mask welding bars,
Reference numerals 10a and 10b are support arms, 13a and 13b are spring suspension devices, and r, g and b are red, green and blue electron beams.

FIG. 6 is an enlarged sectional view of a main part of the color cathode ray tube to which the present invention shown in FIG. 5 is applied. The same parts as those in FIG. 5 are designated by the same reference numerals, 6b is a phosphor mosaic, and 8a is It is an electron beam passage hole of the shadow mask. The three electron beams r, g, and b are indicated by B as a whole.

In FIGS. 5 and 6, during operation of the color cathode ray tube, the electron beam B is incident on the entire inner surface of the shadow mask 7, that is, the lower surface in FIG. A part of it passes through the electron beam passage hole 8a of the shadow mask and strikes a predetermined phosphor mosaic 6b to cause this phosphor to emit light.

At this time, the temperature of the shadow mask 8 rises due to the collision of the electron beam B, causing thermal expansion. The shadow mask 7, which has increased in size due to thermal expansion, is radially displaced about the tube axis, and is displaced rightward in FIG. This displacement is larger near the shadow mask.

In this case, the electron beam B passing through the electron beam passage hole 8a of the shadow mask no longer hits the phosphor mosaic 6b.

To correct this, the shadow mask 8 may be moved in the direction of the fluorescent screen 6, that is, in the upward direction in FIG.

This correction amount may be obtained by moving the shadow mask 8 in the tube axis direction so that the electron beam passage hole 8a of the shadow mask 8 moves in the traveling direction of the electron beam B as shown by the broken line in FIG.

The positional deviation between the electron beam passage hole and the phosphor mosaic due to thermal expansion of the shadow mask occurs radially about the tube axis of the color cathode ray tube in a direction perpendicular to the tube axis. On the other hand, the electron beam is also emitted from an electron gun installed near the tube axis and is radially deflected from the tube axis by the deflection coil.

Therefore, by moving the position of the shadow mask by a certain amount in the direction along the tube axis, it is possible to correct the shift in the positional relationship between the electron beam passage hole and the phosphor mosaic due to the thermal expansion of the shadow mask. It is possible.

It is an object of the present invention to provide a color cathode ray tube provided with a mechanism for correcting the positional deviation between the electron beam passage hole and the phosphor mosaic due to thermal expansion of the shadow mask.

[0020]

In order to achieve the above object, the present invention comprises a panel having a phosphor mosaic formed on the inner surface thereof, a neck for accommodating an electron gun, and a funnel for connecting the panel and the neck. In a color cathode-ray tube having at least a shadow mask structure suspended in the panel, wherein the shadow mask structure is composed of a frame and a shadow mask stretched around the frame, The frame is composed of a pair of mask welding bars for welding the shadow mask, and a pair of support arms bridging the pair of mask welding bars for supporting at a constant interval. It is characterized in that a mask dimension correcting member having both ends fixed is provided.

The shadow mask comprises a slot type shadow mask, a grill type shadow mask or a dot type shadow mask in which a pair of parallel ends are stretched over a frame, and the frame is the slot type shadow mask or the grill type shadow mask. A mask or a pair of mask welding bars for welding a pair of parallel end portions of a dot type shadow mask, and a supporting arm that is fixed to the mask welding bar by bridging and supports at a constant interval,
A mask dimension correcting member for moving the thermally expanded shadow mask in the direction of the phosphor screen to maintain the positional relationship between the electron beam and the phosphor mosaic is provided with the both ends fixed to the mask welding bar and the support arm.

[0022]

With the above structure, when the shadow mask thermally expands during operation, the mask dimension correcting member extends,
A certain amount of the shadow mask is moved so that the mask welding bar with the shadow mask stretched along the tube axis and closer to the fluorescent screen.

As a result, the shift in the positional relationship between the electron beam passage hole and the phosphor mosaic due to thermal expansion of the shadow mask is corrected.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a perspective view of a shadow mask structure for explaining one embodiment of a color cathode ray tube according to the present invention as seen from the electron gun side. 7 is a shadow mask structure, 8 is a grill type shadow mask, 9a and 9b are mask welding bars, 10a and 10b are support arms, 11a, 11b and 1
1c and 11d are mask dimension correcting members, 13a, 13b,
13c and 13d are spring suspension devices.

In the figure, the shadow mask structure 7 has a pair of mask welding bars 9a and 9b fixed to a pair of substantially U-shaped support arms 10a and 10b, and a shadow mask 8 attached thereto.
Both ends of the grill extending direction are welded and fixed, and the pair of support arms 10a and 10b connect the pair of mask welding bars 9 to each other.
A and 9b are held at a predetermined interval, and a predetermined tension is applied to the shadow mask 8.

The panel 1 of this color cathode ray tube is flat in one direction (vertical direction) and has a slight convex curve in the other direction (horizontal direction) orthogonal thereto, and the mask welding bars 9a, 9b are It is curved in a shape substantially following the curve in the horizontal direction. Therefore, the shadow mask 8 is fixed so as to have a horizontal curvature similar to that of the mask welding bars 9a and 9b.

It is preferable that the pair of support arms 10a and 10b have their U-shaped quantity ends fixed to the respective vessel points of the mask welding bars 9a and 9b by welding or the like, and the tension applied to the shadow mask. Hold evenly.

Spring suspension devices 13a, 13b, 13 for supporting the shadow mask structure 7 on the inner wall of the panel are provided near the U-shaped corners of the pair of support arms 10a, 10b.
c and 13d are welded to each other, and these spring suspension devices 13a, 13b, 13c and 13d form an electron beam passing through an electron beam passage hole (here, a slot) of the shadow mask constituting the shadow mask structure 7 and the inner surface of the panel. It is suspended so as to match each phosphor mosaic formed.

Then, mask dimension correcting members 11a, 11b, 11c, 11 are provided near both ends of the mask welding bars 9a, 9b and the U-shaped corners of the pair of support arms 10a, 10b.
d is fixed by welding or the like.

The mask dimension correcting members 11a, 11b,
Reference numerals 11c and 11d are made of a metal-based plate that expands and contracts by heat, and has mask welding bars 9a and 9b and support arms 10a and 1d.
It is provided at a position that forms a substantially triangular shape with 0b.

When the shadow mask 8 is bombarded with an electron beam and the temperature rises during the operation of the color cathode ray tube, the mask dimension correcting members 11a, 11b, 11c and 11d are expanded by thermal expansion and the mask welding bar 9a, 9b is moved so as to be pushed out toward the fluorescent screen.

This movement acts so as to eliminate the positional deviation between the electron beam passage hole and the phosphor mosaic caused by the shadow mask 8 expanding in the radial direction orthogonal to the tube axis, and does not cause color deviation. .

Although the above embodiments have been described by applying the present invention to the slot type shadow mask, the same effect can be obtained by applying the present invention to a grill type shadow mask or a dot type shadow mask as well. Is.

A specific method of constructing the shadow mask structure 7 shown in FIG. 1 will be described below.

This shadow mask structure 7 has a vertical size (vertical direction) of 300 mm in its planar shape,
The left and right (horizontal direction) size is 400 mm, and the shadow mask 8 is a 0.025 mm thick iron plate with a width of 0.075 mm.
mm, 0.9 mm long rectangular holes (slots) with vertical pitch 1.0 mm, horizontal pitch 0.3 m
In the vertical direction, 280 mm and 380 mm are provided in the horizontal direction.

In other words, the width is 0.225 mm and the length is 2.
80mm grill is 0.025mm thick and 0.1m wide
The grills are connected by bridges having a pitch of 1.0 mm and a pitch of 1.0 mm, and the grills are adjacent to each other by a half pitch, and the bridges are arranged at the same position in the horizontal direction.

An electron beam passage hole without bridges is provided for every four grills, and the electron beam passage holes without bridges have a vertical length (vertical direction) of 280 mm and a horizontal direction (horizontal direction). Direction) width 0.075mm
It is continuous from top to bottom. Mask welding bar 9a, 9
b is formed of 13 chrome steel and has a cross-sectional thickness of 3.
It is composed of an L-shaped member having a length of 5 mm and a side length of 8 mm, and the mask welding bars 9a and 9b are supported in parallel by 8 mm square U-shaped support arms 10a and 10b of the same material to form a frame. The thermal expansion coefficient of 13 chrome steel is 0.000011.

End of mask welding bar 9a and support arm 1
0a, 10b, and between the end of the mask welding bar 9b and the supporting arm 10a, 10b, the mask dimension correcting member 11a, 11b, 11c has a length of 24 mm, a width of 12 m, and a thickness of 2 mm. , 11d are welded.

The mask dimension correcting members 11a, 11b,
The materials of 11c and 11d are invar on one side and have a coefficient of thermal expansion of 0.000001, and stainless steel on one side and the coefficient of thermal expansion is 0.000014.

FIG. 2 is a side view of the shadow mask structure according to the present invention as seen from the mask welding bar side for explaining the operation of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals.

As shown in the figure, the mask welding bar 9b
(9a) free end and support arms 10a, 10b (10c,
10d) mask dimension correcting member 1 having both ends fixed between
1b and 11c are stretched by heat, so that the distance L between the spring suspensions 13b and 13c and the shadow mask plane is increased to L '.

Since the spring suspension devices 13b and 13c are fixed to the studs embedded in the inner wall of the panel,
The shadow mask 8 moves more in the peripheral portion as shown by the broken line in the fluorescent screen direction.

That is, since the shadow mask 8 is moved, the ends of the supporting arms 10a, 10b (10c, 10d) are fixed to the mask welding bar 9b (9a), so that the electron beam is largely displaced in the peripheral portion. Grows in.

3A and 3B are (a) a plan view and (b) a side view for explaining an example of the shape and structure of the mask dimension correcting member.
11 is a mask dimension correcting member, 11 'is a curved portion, 11 "and 11"' are end portions (fixed portions), 11s is a stainless plate body,
11i is an Invar plate.

As shown in the figure, the mask dimension correcting member 11 is composed of a bonding member of a stainless plate 11s and an Invar plate 11i, and has a curved portion 11 'at the center and end portions which are fixed portions at both ends. It has 11 "and 11"'.

One of the ends 11 "and 11"'is welded to the mask welding bar and the other to the support arm. Since the invar plate body 11i has a relatively large thermal expansion with respect to the stainless plate body 11s, when the mask dimension correction member 11 is heated, the invar plate body 11i side extends and the bending of the bending portion 11 ′ becomes small. The mask dimension correcting member 11 as a whole extends toward the plane.

As a result, the distance between the end of the mask welding bar and the support arm is increased, and the distance between the spring suspension device and the shadow mask is increased from L to L '.
The shadow mask 8 moves to the phosphor screen side. This allows
There is no positional deviation between the electron beam passage hole and the phosphor mosaic, and no color deviation occurs.

FIG. 4 is a plan view (a) and a side view (b) illustrating another example of the shape and structure of the mask dimension correcting member.
Reference numeral 12 is a mask dimension correcting member, and 12 'and 12 "are ends for welding.

The mask dimension correcting member 12 is provided with the end portions 12 'and 12 "at the same positions as the mask dimension correcting member 11 described above.
Are welded together to form a triangle with the mask welding bar and the support arm.

The mask dimension correcting member 12 has a flat plate shape having no curved portion in the shape shown in FIG. 3, and its material is high expansion stainless steel having a thermal expansion coefficient of 0.000014.

When the mask dimension correcting member 12 is used, the gap between the end of the mask welding bar and the supporting arm is widened due to the difference in coefficient of thermal expansion between the mask dimension correcting member and the frame. As a result, the distance between the spring suspension device and the shadow mask becomes large, the shadow mask moves to the phosphor screen side, the positional deviation between the electron beam passage hole and the phosphor mosaic is eliminated, and the occurrence of color misregistration is prevented.

[0053]

As described above, according to the present invention,
When the shadow mask thermally expands during operation, the mask dimension correction member expands and moves the shadow mask a certain amount so that the mask welding bar with the shadow mask stretched is in the direction along the tube axis and closer to the fluorescent screen. Let

As a result, the shift in the positional relationship between the electron beam passage hole and the phosphor mosaic due to the thermal expansion of the shadow mask is corrected.

As described above, according to the present invention, a color cathode ray tube capable of high-definition display can be provided by correcting the shift in the positional relationship between the electron beam passage hole and the phosphor mosaic due to the thermal expansion of the shadow mask. I can.

The shape and structure of the mask dimension correcting member and its installation position, and the shape and structure of the spring suspension device and its installation position are not limited to the configurations shown in the above embodiments, and the effects of the present invention can be obtained. It goes without saying that various modifications can be made within the scope of the present invention as long as the above can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view of a shadow mask structure for explaining an embodiment of a color cathode ray tube according to the present invention as viewed from the electron gun side.

FIG. 2 is a side view of the shadow mask structure according to the present invention as seen from the mask welding bar side for explaining the operation of the present invention.

3A and 3B are a plan view and a side view illustrating an example of the shape and structure of a mask dimension correcting member.

4A and 4B are a plan view and a side view for explaining another example of the shape and structure of the mask dimension correcting member.

FIG. 5 is a schematic sectional view illustrating the structure of a color cathode ray tube to which the present invention is applied.

6 is an enlarged cross-sectional view of a main part of a color cathode ray tube according to the present invention shown in FIG.

[Explanation of symbols]

1 panel 2 funnel 3 neck 4 electron gun 5 deflection coil 6 phosphor screen 6a phosphor mosaic 7 shadow mask structure 8 shadow mask 8a electron beam passage hole 9a, 9b mask welding bar 10a, 10b support arm 11a, 11b, 11c, 11d, 12 Mask Dimension Correction Member 13a, 13b, 13c, 13d Spring Suspension Device.

Claims (1)

[Claims] 1. A shadow mask suspended in the panel, comprising a vacuum envelope composed of a panel having a phosphor mosaic formed on the inner surface thereof, a neck accommodating an electron gun, and a funnel connecting the panel and the neck. In a color cathode ray tube having at least a structure, the shadow mask structure includes a frame and a shadow mask stretched around the frame, and the frame includes a pair of mask welding bars for welding the shadow mask, and the pair of mask welding bars. A pair of support arms bridging the mask welding bar and supporting the mask welding bar at regular intervals, and a mask dimension correcting member having both ends fixed to the mask welding bar and the supporting arm is provided. Cathode ray tube.