JPH0982232A - Color cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the movement of a shadow mask toward the electron gun side by making the coefficient of thermal expansion of a base plate large on the mask welding bar side and small on the supporting arm side. SOLUTION: A mask welding bar 22 and a supporting arm 23, which are the body structure 13 of a shadow mask 21, are arranged on the opposite side each other to a pin plane surface P containing a fixed part to the tube wall of each of spring suspending mechanisms 24, 25. A base plate 24A fixed to the mask bar 22 side is made of a material having relatively large coefficient of heat expansion, and a base plate 25A fixed to the supporting arm 23 side is made of a material having small coefficient of thermal expansion. The movement of the shadow mask 21 toward the electron gun side is eliminated by suppressing the thermal expansion of the base plate 25A as much as possible, the movement toward the fluorescent material side is conducted with the base plate 24A, and the positional dislocation of the shadow mask 21 caused by the thermal expansion to the fluorescent material of an electron passing through hole can be prevented.

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, it relates to the improvement of the shadow mask structure.

[0002]

2. Description of the Related Art A color cathode ray tube is provided with a so-called shadow mask.

Before each electron beam from the electron gun assembly consisting of three electron guns is projected on the phosphors for red (R), green (G) and blue (B) arranged adjacent to each other. In the step, the same electron passing hole formed in the shadow mask is passed.

That is, with this shadow mask,
The path of each electron beam is selectively controlled so that each electron beam is divided into the corresponding red, green, and blue phosphors and impinges on them.

This shadow mask is used for each electron gun of the electron gun assembly when each phosphor is formed on the inner wall of the panel portion forming a part of the vacuum envelope of the color cathode ray tube by the so-called photolithography technique. It is used as a photomask for a light source arranged so as to correspond to the arrangement position of, and remains fixed to the panel section at that stage. From this, the geometrical arrangement of each phosphor with respect to the electron passage hole of the shadow mask is in a highly accurate state.

However, it has been clarified that the position of the electron passage hole of the shadow mask with respect to each phosphor is slightly deviated when the color cathode ray tube having such a structure is used. This is because the temperature of the shadow mask rises due to the collision of the electron beam during the operation of the color cathode-ray tube, and the thermal expansion of the shadow mask itself causes the position of the electron passage hole of the shadow mask with respect to each phosphor to be displaced.

For this reason, conventionally, a structure has been tried in which the shadow mask can be displaced toward the phosphor surface side as the temperature rises. This is because the shadow mask thermally expands radially from its center, while the electron beam from the electron gun is positioned and irradiated on the central axis of the shadow mask.

[0008]

However, as a shadow mask, a mask welding bar is fixed along each side parallel to the one direction, and the mask welding is performed along each side parallel to the other direction. In a structure which is fixed to a bar and which has a support arm for applying a biasing force in a direction in which these mask welding bars are separated from each other,
It has been pointed out that the above-mentioned attempts are extremely difficult.

For example, a spring suspension mechanism via a base plate is provided on each of the mask welding bar and each of the support arms, and furthermore, a fixing portion of the spring suspension mechanism with respect to a pipe wall is arranged in a so-called pin plane. This is because if the shadow mask is to be displaced toward the phosphor surface side due to the thermal expansion of the base plate, the support arm will move to the opposite side of the phosphor. That is, the base plate extending from the mask welding bar extends to the electron gun side, whereas the base plate extending from the support arm extends to the phosphor side.

The present invention has been made under such circumstances, and an object of the present invention is to provide a color cathode ray tube in which the electron passage holes of the respective phosphors are not displaced even by the thermal expansion of the shadow mask. To provide.

[0011]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, a shadow mask is built in the pipe, and this shadow mask has a mask welding bar fixed along each side parallel to one direction and at each side parallel to the other direction. A supporting arm fixed to each of the mask welding bars to apply a biasing force to the mask welding bars in a direction in which the mask welding bars are separated from each other, and each of the mask welding bars and each of the supporting arms are springs via a base plate. It is fixed to the pipe wall by a suspension mechanism, and the mask welding bar and the support arm are arranged on opposite sides to the pin plane including the fixing portion for the pipe wall of each spring suspension mechanism. In addition, the thermal expansion coefficient of the base plate attached to the support arm is the same as that of the base plate attached to the mask welding bar. Is characterized in that less than the thermal expansion coefficient of the bets.

[0013]

The color cathode ray tube thus constructed has a structure in which the thermal expansion of the base plate attached to the support arm is suppressed as much as possible, thereby eliminating the movement of the shadow mask to the electron gun side. is there.

The movement of the shadow mask to the phosphor side is intended to be performed by the base plate attached to the mask welding bar side.

Therefore, since the movement of the shadow mask to the electron gun side is suppressed as much as possible in this way, the electron passage hole does not cause a positional deviation with respect to each phosphor even by the thermal expansion of the shadow mask. You will be able to.

[0016]

2 is a sectional view showing an embodiment of a color cathode ray tube according to the present invention.

In FIG. 1, first, there is an electron gun assembly 11 that emits electrons as a beam. The electron gun assembly 11 has an integrated structure of R (red), G (green), and B (blue) electron guns, and each electron gun 12 emits an electron beam 12. .

Further, the fluorescent screen 4 faces the electron gun assembly 11.
Are arranged, and the phosphor screen 4 is provided with regions of respective pixels arranged in a matrix.

A region corresponding to one pixel of the fluorescent screen 4 is irradiated with the electron beams 12 to generate R.
Phosphors that emit (red), G (green), and B (blue) are arranged adjacent to each other. One pixel configured as described above has a shadow mask structure 1 which will be described in detail later by each electron beam 12 from each electron gun of the electron gun structure 11.
A predetermined color is exhibited by being controlled by 3 and being irradiated to the corresponding phosphor.

The electron gun structure 11 and the fluorescent screen 4 are enclosed by a vacuum envelope 20 made of glass, and the fluorescent screen 4 is contained in the panel portion 1 of the envelope 20.
It is arranged so as to be attached to the inner wall surface of the part called. Here, the panel portion 1 serves as a display portion of a color cathode ray tube, and an observer can recognize the color development of each pixel of the phosphor screen 4 through the panel portion 1.

The portion of the envelope 20 that encloses the electron gun assembly 11 is called a neck portion 3, and the portion between the neck portion 3 and the panel portion 1 is called a funnel portion 2.

A deflection yoke 7 is arranged on the outer periphery of the funnel portion 2 of the envelope 20. The deflection yoke 7 causes each electron beam 12 from the electron gun assembly 11 to be directed to each pixel on the phosphor screen 4. The horizontal scanning (x direction in the figure) and the vertical scanning for sequentially irradiating the same are performed.

Then, the envelope 2 in the funnel portion 2
Inside 0, an inner shield (internal magnetic shield) 6 is arranged so as to surround the scanned area of the electron beam 12.

Further, in the envelope 20 of the panel portion 1,
The shadow mask structure 13 is arranged to face the phosphor screen 4. As will be described later in detail, the shadow mask structure 13 is composed of a shadow mask in which electron passing holes are formed at positions on the phosphor screen 4 that substantially face each phosphor, and a frame body of this shadow mask. There is.

Here, in the shadow mask structure 13, the spring suspension mechanism 14 formed in the frame thereof has a panel portion 1
It is fixed in the vacuum envelope 20 by being fitted into the pin 15 formed on the inner wall of the.

FIG. 1 is a perspective view of the structure of only the shadow mask structure 13 as viewed from the electron gun structure 11 side.

First, the shadow mask 2 having a substantially rectangular shape.
There is one. The shadow mask 21 is, for example, a so-called slot type shadow mask,
As shown in FIG. 3, each electron passage hole 21A has its y
The holes are elongated in the same direction, arranged in parallel in the same direction, and have a staggered relationship with adjacent electron passage holes.

Further, a mask welding bar 22 extending along each side of the shadow mask 21 in the x direction (horizontal direction) in the drawing is fixed. Each of these mask welding bars 22 is formed to be slightly curved,
This prevents the distance from the electron gun structure 11 to each part of the shadow mask 21 from being greatly different.

Further, a support frame 23 extending along the y-direction side (vertical direction side) of the shadow mask 21 in the figure is fixed to the mask welding bar 22. That is, each support frame 23
Has a U-shape bent at both ends thereof along the extending direction of the mask welding bar 22, and each end is fixedly attached to the mask welding bar 22.
The bending portion of the support frame 23 along the extending direction of each mask welding bar 22 has an urging force with respect to the other bending portion in a direction in which they are separated from each other in the y direction in the drawing, As a result, the shadow mask 21 is applied with a uniform tension in the y direction in the figure.

Each of the mask welding bars 22 described above is provided with a spring suspension mechanism 24 for fixing the shadow mask structure 13 to the inner wall of the panel portion 1. That is, a base plate 24A extending in the z direction in the drawing is fixed to the mask welding bar 22 extending in the x direction in the drawing at the substantially central portion thereof, and further extends in the x direction in the drawing at the base plate 24A. The spring plate 24B is fixed. A hole 24C is formed in the spring plate 24B so that the pin 15 formed on the inner wall of the panel portion 1 can be fitted therein.

Further, the support arm 2 extending in the y direction in the figure
Each of 3 is also provided with a spring suspension mechanism 25 for fixing the shadow mask structure 13 to the inner wall of the panel portion 1. That is, a base plate 25A extending in the −z direction in the figure (a direction away from the electron gun assembly 11) is fixed to the support arm 23 at a substantially central portion thereof, and further, the base plate 25A has a y direction in the figure. A spring plate 25B extending in the direction is fixed. A hole 25C is formed in the spring plate 25B so that the pin 15 formed on the inner wall of the panel portion 1 can be fitted therein.

The holes 24C and 25C of the spring plates 24B and 25B thus mounted, that is, the fixing portions to the pipe wall, are positioned within the so-called pin plane P.

In this embodiment, in particular, the base plate 24A fixed to the mask welding bar 22 side is made of a material having a relatively large thermal expansion coefficient, and the base plate 25A fixed to the support arm 23 side is thermal expansion coefficient. Is composed of a small material.

FIG. 4 is an explanatory view showing the action of the spring suspension mechanism 24 when the heat generated in the shadow mask 21 is transferred to the mask welding bar 22. In the figure,
The heat transferred to the mask welding bar 22 is further transferred to the base plate 24A, which expands because it is made of a material having a relatively large thermal expansion coefficient.

Since the portion of the hole 24C of the spring plate 24B (the portion included in the pin plane P) is fixed, the expansion of the base plate 24A causes the shadow mask 21 to move in the -z direction in the figure (on the phosphor surface side). ) Will be moved to.

FIG. 5 is an explanatory view showing the action of the spring suspension mechanism 25 when the heat generated in the shadow mask 21 is transferred to the support arm 23. In the figure, the heat transferred to the support arm 23 is further transferred to the base plate 25.
Although transmitted to A, the base plate 25A is hardly expanded because it is made of a material having a small thermal expansion coefficient.

Here, when the base plate 25A is made of a material having a relatively large thermal expansion,
Since the portion of the hole 25C of the spring plate 25B (the portion included in the pin plane P) is fixed, the shadow mask 21 moves in the z direction (electron gun assembly side) in the figure due to the expansion of the base plate 25A. However, this movement disappears as described above.

As described above, according to the color cathode ray tube according to the above-described embodiment, the shadow mask 21 can be moved toward the electron gun side by making the thermal expansion of the base plate 25A attached to the support arm 23 as small as possible. I tried to lose it.

Therefore, as described above, the shadow mask 2
Since it is configured to suppress the movement of the No. 1 toward the electron gun side as much as possible, it is possible to provide a configuration in which the electron passing hole of the shadow mask 21 is not displaced with respect to each phosphor even by the thermal expansion of the shadow mask 21. .

Hereinafter, a more specific configuration of the above configuration will be described. The shadow mask structure 13 has a y-direction size of 300 mm and an x-direction size of 400 mm.
It is. The shadow mask 21 has a plate thickness of 0.0.
A rectangular electron passage hole 21A having a width of 0.075 mm and a length of 0.9 mm is formed on a 25 mm iron plate with a y-direction pitch of 1.0.
mm, pitch in the x direction is 0.3 mm, and 280 mm in the y direction,
It is provided over 380 mm in the x direction.
In other words, a so-called grill having a width of 0.225 mm and a length of 280 mm is connected by a so-called bridge having a thickness of 0.025 mm, a width of 0.1 mm and a pitch of 1.0 mm, and the adjacent grills are half-sized. It has a structure in which bridges are arranged at the same position in the x direction every other pitch offset.

The mask welding bar 22 is made of 13 chrome steel and is composed of an L-shaped member having a cross-sectional thickness of 3.5 mm and a side length of 8 mm.
Is supported in parallel by a support arm 23 of the same material and having a square shape of 8 mm square to form a frame. The thermal expansion coefficient of 13 chrome steel is 0.000011.

In the spring suspension mechanism 24, SUS304 having a plate thickness of 2.0 mm is used for its base plate 24A, and ferritic stainless steel (coefficient of thermal expansion 0.000011) is used for the spring plate 24B.

In the spring suspension mechanism 25, an amber material having a plate thickness of 2.0 is used for its base plate 25A, and ferritic stainless steel is used for the spring plate 25B like the mask welding bar 22.

Although ferritic stainless steel is used for the spring plates 24B and 25B, the same effect can be obtained by using a bimetal material having a correction function.

In the embodiment described above, the shadow mask 21
As a so-called slot type, it is not limited to this, and it goes without saying that it may be a so-called grill type or dot type. In short, as the shadow mask structure 13, the mask welding bar 22 is fixed along each side parallel to one direction of the shadow mask, and the mask welding bar 22 is connected to each mask welding bar 22 along each side parallel to the other direction. The present invention can be applied as long as it is provided with a support arm 23 that is fixed and applies an urging force in a direction in which these mask welding bars 22 are separated from each other.

In the present invention, the coefficient of thermal expansion of the base plate 24A on the mask welding bar side is larger than the coefficient of thermal expansion of the mask welding bar and the supporting arm, and the thermal expansion coefficient of the base plate 25A on the supporting arm side is the same as that of the supporting arm and the welding bar. It becomes more effective when it is smaller than the coefficient of thermal expansion.

[0047]

As is apparent from the above description,
According to the color cathode ray tube according to the present invention, it is possible to prevent the electron passage hole from being displaced with respect to each phosphor even by the thermal expansion of the shadow mask.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram showing an embodiment of a color cathode ray tube according to the present invention.

FIG. 2 is an overall configuration diagram showing an embodiment of a color cathode ray tube according to the present invention.

FIG. 3 is an explanatory diagram of a shadow mask used in an embodiment of the color cathode ray tube according to the present invention.

FIG. 4 is an explanatory view showing the operation of the color cathode ray tube according to the present invention on the mask welding bar side.

FIG. 5 is an explanatory view showing the operation of the support arm side of the color cathode ray tube according to the present invention.

[Explanation of symbols]

21 ... Shadow mask, 22 ... Mask welding bar, 2
3 ... Support arm, 24, 25 ... Spring suspension mechanism, 24A, 25A ... Base plate, 24B, 25
B ... Spring plate, 24C, 25C ... Hole.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hideo Tanabe 3300 Hayano Mobara-shi, Chiba Electronic Device Division, Hitachi, Ltd. In company

Claims (1)

[Claims] 1. A pipe having a shadow mask built-in, wherein a mask welding bar is fixed along each side parallel to one direction of the shadow mask and each side parallel to the other direction. A supporting arm fixed to each of the mask welding bars to apply a biasing force to the mask welding bars in a direction in which the mask welding bars are separated from each other, and each of the mask welding bars and each of the supporting arms are springs via a base plate. It is fixed to the pipe wall by the suspension mechanism, and the mask welding bar and the support arm are arranged on opposite sides to the pin plane including the fixing portion of the spring suspension mechanism to the pipe wall. The thermal expansion coefficient of the base plate attached to the support arm is equal to that of the base plate attached to the mask welding bar. Color cathode ray tube, characterized in that less than expansion coefficient.