KR19980043256A - Shadow Mask Frame Assembly for Color Cathode Ray Tube - Google Patents

Abstract

The present invention relates to a shadow mask frame assembly for a color cathode ray tube. The present invention relates to a shadow mask frame assembly for a color cathode ray tube including a shadow mask having a plurality of battery beam through holes formed therein, and installed on an inner surface of the panel to support the shadow mask and include a support portion and a flange portion. According to the present invention, the Invar (INVAR) material having a small thermal expansion rate is attached to the inner surface of the supporting part of the frame, thereby preventing deformation of the frame due to thermal expansion and deformation of the electron beam through hole of the shadow mask. By preventing the movement of the through-holes, it is possible to prevent deterioration of the image due to the drift phenomenon of the electron beam.

Description

Shadow Mask Frame Assembly for Color Cathode Ray Tube

The present invention relates to a shadow mask frame assembly installed inside the panel in a color cathode ray tube having a color discrimination function, and more particularly, to a shadow cathode ray frame frame assembly for improving a mislanding phenomenon by reducing an amount of thermal expansion. It is about.

Typically, as shown in FIG. 1, the cathode ray tube includes a panel 10 having a fluorescent film 11 formed on an inner surface thereof, and a shadow mask 21 spaced apart from the fluorescent film 11 by a predetermined distance inside the panel 10. ) And a shadow mask frame assembly 20 to which the frame 22 supporting the same and the inner shield 23 fixed to the frame are coupled and the panel 10 is sealed to the neck portion 31. 40 is enclosed and the cone part 33 is provided with the funnel 30 provided with the deflection yoke 50. As shown in FIG.

The cathode ray tube configured as described above has an electron beam emitted from the electron gun 40 mounted on the neck portion 31 to be deflected selectively by the deflection yoke 50 so that the shadow mask 21 has a color discrimination function. An image is formed by passing through an electron beam passing hole formed in the film and landing at each fluorescent point of the fluorescent film 11. As described above, the electron beam emitted from the electron gun 40, that is, the hot electrons, does not pass all the electron beams emitted from the electron gun 40 while passing through the electron beam passing holes of the shadow mask 21, and only 15 to 18% passes. The remainder is landed in the shadow mask and lost as heat.

However, the shadow mask 21 and the frame 22 supporting the same are heated by an electron beam that does not pass through the electron beam passing hole, thereby causing thermal expansion, and thus, the doming phenomenon of the shadow mask 21 supported by the frame 22. This is caused. Therefore, the phenomenon that the electron beam through hole (not shown) formed on the hole of the shadow mask moves relatively to each pixel of the fluorescent film formed on the inner surface of the panel. This phenomenon prevents the electron beam emitted from the electron gun 40 from landing at the fluorescent point of the fluorescent film 11 accurately.

In order to solve this problem, the shadow mask frame assembly 20 is conventionally coupled to a stud pin (not shown) formed on the inner surface of the panel 10 by a hook spring using a bimetal principle as a support. The shadow mask frame assembly is moved to the fluorescent film side to compensate for the doming phenomenon.

However, as described above, the compensation of the shadowing of the shadow mask due to thermal expansion of the shadow mask frame assembly is performed because the frame 22 and the hook spring 25 supporting the shadow mask 21 are heated first, and thus the The problem is that it takes a long time to compensate for the phenomenon.

That is, as shown in Figures 3 and 4, initially the thermal expansion amount of the shadow mask and the spring is relatively large and the thermal expansion amount of the frame is relatively small, so that the initial domming amount, which is their sum, becomes relatively large. Therefore, the initial stabilization time of the cathode ray tube becomes relatively long.

On the other hand, in order to prevent the above dominant phenomenon, the shadow mask is conventionally made of an invar (INVAR) material having a very low thermal expansion rate, thereby reducing the amount of electron beam drift due to thermal expansion of the shadow mask.

However, even if the shadow mask is made of Invar as described above, the support frame is made of a material having a relatively high coefficient of thermal expansion, and thus there is a problem in that the amount of dominance due to the shadow mask is overcorrected.

The technical problem to be solved by the present invention is to solve the above problems to reduce the amount of thermal deformation of the frame without a hook spring to prevent over-correction of the dominant amount by the shadow mask, furthermore to ensure that the electron beam is landing on the fluorescent film accurately It is to provide a shadow mask frame assembly for a color cathode ray tube that can improve the resolution.

1 is a cross-sectional view of a general color cathode ray tube.

FIG. 2 is a graph showing thermal expansion amounts of a conventional shadow mask, a frame, and a hook spring with time.

3 is a graph showing a dominant amount of a conventional shadow mask.

Figure 4 is an exploded perspective view showing a shadow mask frame assembly according to the present invention.

Explanation of symbols for main parts of the drawings

10 ... Panel 11 ... Phosphor

30 ... Funnel 40 ... Gun

50 ... deflection yoke 70 ... shadow mask

70H ... E-beam through hole 71 ... Pole hole

72 ... skirt 80 ... frame

81 ... support 82 ... flange

100 ... Inbajae

In order to achieve the above object, in the present invention, a shadow mask having a shadow portion having a plurality of electron beam through hole formed therein, and a frame provided on the inner surface of the panel to support the shadow mask and comprising a frame made of a support portion and a flange portion; In the frame assembly, there is provided a shadow mask frame assembly for a color cathode ray tube, characterized in that the invar (INVAR) material is attached to the inner surface of the support portion of the frame.

In the present invention, instead of installing the hook spring, the invar having a low thermal expansion rate is attached to the inside of the frame as a reinforcing material, thereby preventing the doming phenomenon.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a conventional color cathode ray tube is sealed with a funnel 30 in which an electron gun 40 and a deflection yoke 50 are installed in the neck portion and the cone portion, and a fluorescent film 11 is formed on an inner surface thereof. (10) is fixedly installed inside.

In addition, as shown in Figure 4, in the shadow mask frame assembly according to the present invention, a hole portion 71 in which a plurality of electron beam through holes 70H is formed and a skirt portion 72 bent vertically from the edge of the hole portion. ) Is formed with a shadow mask 70 and a frame 80 for supporting the shadow mask (0), the frame 80 includes a support portion 81 and a flange portion 82 and the four sides Invar material 100 of a predetermined length is attached to the inner central portion of the support. The length of the invar material 100 is made into the appropriate length which can offset the dominant amount of a shadow mask.

Referring to the operation of the shadow mask frame assembly for a color cathode ray tube according to the present invention configured as described above are as follows.

In the shadow mask frame assembly according to the present invention mounted on the color cathode ray tube, hot electrons, which are electron beams emitted from the electron gun, do not pass through all of the electron beam through holes 70H of the shadow mask 70, as shown in FIG. It hits the perforations of the shadow mask 70 to heat the shadow mask.

As the shadow mask 70 is heated, heat is sequentially applied to the frame 80, and the thermal expansion amount thereof is dommed by a relative sum.

However, in the present invention, as shown in Figure 4, the Invar material having a small amount of thermal expansion attached to the inner surface of the support portion of the frame can reduce the thermal expansion of the frame. As a result, the drift of the electron beam emitted from the electron gun can be prevented and landed at each fluorescent point.

As described above, in the shadow mask frame assembly for a color cathode ray tube of the present invention, the deformation of the shadow mask may be prevented by attaching an invar material to the inner surface of the frame support to prevent deformation due to thermal expansion. Further, the electron beam through hole is prevented from moving. Accordingly, the shadow mask frame assembly for a color cathode ray tube according to the present invention has an advantage of preventing deterioration of an image due to drift of an electron beam.

Claims (1)

In the shadow mask frame assembly for a color cathode ray tube comprising a shadow mask having a plurality of electron beam through-holes formed therein, and a frame provided on the inner surface of the panel to support the shadow mask and comprising a support portion and a flange portion, Shadow mask frame assembly for a color cathode ray tube, characterized in that the invar (INVAR) material is attached to the inner surface of the support portion of the frame.