JPS6222354A - Shadow mask type color picture tube - Google Patents

Abstract

PURPOSE:To extremely reduce mislanding generated in the rotary direction with respect to a tube axis due to thermal expansion of a mask structure and a spring, by using a material having a low thermal spring expansion coefficient below 5X10<-6> and supporting a mask structure while making the fixing positions to a frame to be near the center of its side. CONSTITUTION:Stud pins 2a-2d are burried in the positions swerved in the anti-clockwise direction, while being positioned in the thickness center of respective sides near the corner parts of the inside of the sidewalls of a face panel 1. A shadow mask 3 is welded to a frame 4, while the springs 5a-5d are fixed directly or through bimetals for temperature compensation about in the centers of the frame sides. An amber material (36% Ni-Fe alloy) is used as a material having a low thermal expansion coefficient. When temperature rise of the springs is 40 deg.C, the amber springs extend only for 1.6mum so that mislanding due to thermal expansion of the springs generates no wrong in the property of the springs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color picture tube number, and particularly to the material 8 and mounting position of a spring for supporting a shadow mask structure.

[Conventional technology]

Conventionally, the spring for supporting the shadow mask structure of a color picture tube has generally been treated as a spring material.

So-called 18-8 stainless steel (CRIB heavy fi%,
f [iL%, alloy of 74 wt% Fe) has been mainly used.

[Problem that the invention seeks to solve]

When the color picture tube is in operation, approximately 80% of the electron beam emitted from the electron gun impinges on the shadow mask, and the kinetic energy of the electron beam is converted into heat, raising the temperature of the shadow mask. As a result, it is well known that two types of mislanding, called doming, occur due to thermal expansion of the shadow mask and mislanding due to thermal expansion of the frame part. Many countermeasures have been proposed to counter these problems. ing.

However, this time, we have developed a color image receiving system that utilizes a face panel in which the positions of the l stuff and pins, which are mainly used in color picture tubes that emphasize vibration resistance such as those used in aircraft, are installed near each corner of the face panel as shown in Figure 2. It has been found that during operation of the tube, mislanding occurs due to causes other than the thermal expansion of the mask, which causes the tube to move in the rotational direction with respect to the tube axis.

This is mainly due to mislanding caused by the rotation of the mask structure relative to the face panel due to thermal expansion of the spring connecting the frame and the stud bottle.

[Means for solving problems]

In the color picture tube of the present invention, a material with a low coefficient of thermal expansion of 5X10-'/'C or less is used for the spring for supporting the shadow mask structure, and the mounting position of the spring to the shadow mask structure is substantially fixed to the frame. It is characterized by being located near the center of the side.

〔Example〕

Next, one embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of a portion of a panel assembly according to an embodiment of the present invention. Stud bins 2 a t 2 b # 2 c e 2 d are installed near the inner corner of the side wall of the face panel 1.
are lined up in the center of each side and offset in a counterclockwise direction. The shadow mask 3 has eight springs 5a welded to the frame 4.

5b, 5c, and 5a are fixed to approximately the center of the sides of the frame by welding directly or via a bimetal (not shown) for temperature compensation. By fitting these springs into the stud bins of the face panel, the face panel and the mask patient are accurately positioned. When the valve size is an 8-base tube, the distance between the opposing stud pin and the center outer side of the frame is approximately 40 tll. Amber material (36%Ni-Fe
alloy). The coefficient of thermal expansion of amber material is approximately I at room temperature.
X 10-'fc, and the temperature rise of the spring during operation is about 40°C, so the spring extension Δl is Δ! Amber=4Q(mm)X lXl0-'(1/'C
)X40('C)=1.6X10 M=1.6μ wind. Conventional 18-8 stainless steel has a coefficient of thermal expansion of 1.6
Since X10-'/'C, the spring extension Δ! Stainless steel is Δ! Stainless steel = 40 (a) X 1.6 X 1
0-'(17℃) X40('C)=25.6X 10
g=25. (5 μm.Dot pitch is 0.3
In the case of (2), the diameter of the phosphor dot and the wind beam diameter are usually set to about 173 .mu.m, so the guard width is (173-120)/2=26.5 .mu.m. In the case of stainless steel springs, when the temperature rise of the spring is 40℃, the spring will expand by 25.6 μm, so the shadow mask structure will rotate around the tube axis by this amount of expansion, and the periphery of the face panel will Most of the guard width is lost, and the tolerance for manufacturing variations becomes extremely small, easily resulting in defects in characteristics such as other colors appearing. However, in the case of an amber spring, the elongation is only 1.6 μm, and mislanding due to thermal expansion of the spring does not cause any problems in terms of characteristics.

In addition, even if the mounting position of the spring to the frame is actually small, the frame will expand by the amount due to thermal expansion of the frame (mainly made of iron, with a coefficient of thermal expansion of approximately 1.1 x 10 - Celsius) relative to the length away from the center of the side. This is because it will rotate.

2. In the above embodiment, a case was described in which amber was used as the spring material, but the material is not limited to this, and any material having a coefficient of thermal expansion of 5×10-'/° C. or less can be used.

〔Effect of the invention〕

As explained above, the present invention has a panel stud bin of about 4
A spring supporting the mask structure of a color picture tube using a face panel embedded near the corners of a rectangular face panel uses a material with a low coefficient of thermal expansion of 5 x 10 ''/°C or less.

By setting the substantial attachment position to the frame near the center of the side, mislanding occurring in the rotational direction with respect to the tube axis due to thermal expansion of the mask structure and the spring can be greatly reduced.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a portion of a panel assembly according to an embodiment of the present invention, and FIG. 2 is a plan view of a face panel in which stud bins are embedded near corners. 1...Face panel, 2a*2be2Ce2
d...Stud bottle, 3...Shadow mask, 4...Frame, 5at5be5C*
5d...Spring. Agent Patent Attorney Susumu Uchihara ′-“8z Diagram

Claims (1)

[Claims] In a color picture tube using a face panel in which stud pins for locking the shadow mask structure are installed near the corners of the approximately square-shaped face panel inside the side walls,
The spring used to lock the shadow mask structure to the stud pin is made of a material with a low coefficient of thermal expansion of 5 x 10^-^6/℃ or less, and the mounting position of the spring to the frame is set to the panel stud pin. A shadow mask type color picture tube characterized by having a shadow mask type color picture tube set approximately at the center of the sides of opposing frames.