KR200148989Y1 - Cathode-tay tube - Google Patents

Abstract

An invader shadow mask-frame assembly of a cathode ray tube is disclosed that minimizes temperature differences across the entire surface of the shadow mask to eliminate local doming.

In a shadow mask-frame assembly of a cathode ray tube welded and assembled to a vertical portion supporting an invader shadow mask on a panel, the vertical portion is adapted to minimize the temperature difference across the entire surface of the shadow mask heated by the electron beam from the electron gun. An invadible shadow mask-frame assembly of a cathode ray tube is characterized by having a structure for heat transfer from a shadow mask to a frame. The invadible shadow mask may be welded and assembled such that the vertical portion is heat-transmitted only at the central portion of the frame and at both corners of the frame.

Accordingly, by suppressing heat transfer to the frame and reaching the thermal equilibrium state by most of the radiation, it is possible to prevent the temperature rise of the local shadow mask surface and to remove the local doming phenomenon.

Description

Invader Shadow-Frame Assembly of Cathode Ray Tubes

1 is a schematic front view in partial cross section of a color cathode ray tube;

Figure 2 is a plan view illustrating the heat transfer system and local doming phenomenon of a conventional shadow mask-frame assembly.

3 is a perspective view of a frame according to an embodiment of the present invention.

Figure 4 is a plan view illustrating a heat transfer system of the shadow mask-frame assembly according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

10 cathode ray tube 11 electron gun

12: panel 13: funnel

14 neck 15 anode button

16,26: shadow mask 17: deflection yoke

18: panel face plate 19a, 19b: electron beam

20: fluorescent screen (screen) 21, 30: frame

31 to 34: corner vertical portion 35 to 38: edge portion vertical portion

A: Local domining part W: Welding point

The present invention relates to an invadible shadow mask-frame assembly of a cathode ray tube, and more particularly to a shadow mask having an improved heat transfer system to eliminate local dominant phenomenon.

In general, the cathode ray tube, as shown in FIG. 1, has a vacuum bulb divided into a panel 12, a funnel 13 and a neck 14, and the neck 14 thereof. An electron gun 11 mounted therein and a shadow mask 16 mounted on the side wall of the panel 17 are provided.

A fluorescent surface 20 is formed on the inner surface of the face plate 17 of the panel 12, and the electron beams 19a and 19b emitted from the electron gun 11 are focused and accelerated by various lens systems, and the anode button 15 It is greatly accelerated by the high voltage applied through the deflection yoke (17) and deflected by the deflection yoke (17) and passed through the apertures or slits (16a) of the shadow mask (16) to the fluorescent surface (20).

The fluorescent surface 20 is formed on the back surface of the face plate 18, and in the case of a color, a plurality of stripe or dot shaped shapes (R, G, B) of a constant array structure and the respective phosphors It is formed of light-absorbing materials such as black coating. In addition, an aluminum thin film layer is formed as a conductive film layer on the back surface to increase the luminance of the fluorescent surface, to prevent ion damage of the fluorescent surface, and to prevent the potential drop of the mold surface. Although not shown, a resin such as a lacquer is applied between the fluorescent surface and the conductive film layer in order to increase the plan view and reflectance of the aluminum thin film layer.

As the material of the shadow mask 16 described above, Al-kiltal decarburized steel having a high purity of iron as a main component, for example, 0.1 mm to 0.3 mm in thickness, is mainly used.

However, as TVs become larger and higher in quality, color purity deterioration due to thermal expansion of shadow masks has become a big problem.

Therefore, in order to prevent color purity deterioration due to thermal expansion of the shadow mask, an Invar material (Invar material: an alloy of Fe and Ni with low thermal expansion coefficient and no corrosiveness) is used.

Invar material has a thermal expansion rate of about one tenth of that of Al-killed carbon steel used in shadow masks, which not only solves problems such as color stains due to thermal expansion of shadow masks, but also meets the requirements of high-definition TVs. It becomes suitable.

However, in the case of the shadow mask made of the above-described Invar material, its thermal expansion rate is extremely low. However, in the conventional shadow mask-frame assemblies 16 and 21, as shown in FIG. Since heat transfer occurs due to conduction over, the difference between the temperature at the outer periphery of the shadow mask and the temperature at the central part of the shadow mask increases, resulting in a difference in thermal expansion rate. There is a problem that occurs.

The object of the present invention is to provide an invadible shadow mask-frame assembly of a cathode ray tube that minimizes the temperature difference across the entire surface of the shadow mask, thereby eliminating local doming.

In order to achieve this object, the present invention provides a shadow mask-frame assembly of a cathode ray tube welded and assembled on a vertical portion that supports an invader shadow mask on a panel, the entire surface of the shadow mask heated by an electron beam from an electron gun. The vertical portion has a structure for heat transfer from the shadowmask to the frame to minimize the temperature difference across the cathode ray tube. The invader shadow mask may be welded and assembled such that the vertical portion is configured to transmit heat only at a corner portion between the central portion of the frame and both ends of the frame.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention.

Figure 3 shows a perspective view of the frame 30 left in accordance with an embodiment of the present invention. The frame 30 has four corner portions and corner vertical portions 31 to 34 and long portions vertical portions 35 to 38 extending in the center portion of each side.

The shadow mask 16 is welded and assembled at the corner vertical portions 31 to 34 and the edge vertical portions 35 to 38 of the frame 30.

The heat transfer system by conduction of the shadowmask-frame assembly thus welded and assembled is shown schematically in FIG. 4 (where the weld point is denoted by W).

In FIG. 4, the heat of the shadow mask heated by the electron beam is transmitted to the frame having a large heat capacity through the corner vertical portion and the side vertical portion, which are welding and assembly portions, as passages.

Therefore, the heat transfer path is narrower and the heat transfer speed is slower than the conventional shadow mask-frame assembly, thereby increasing the peripheral surface temperature of the shadow mask. In other words, the temperature difference decreases over the entire shadow mask surface.

Accordingly, it is possible to minimize the difference in thermal expansion rate over the entire surface of the shadow mask, thereby removing high thermal expansion due to local high temperature.

Unlike heat transfer by heat conduction as described above, heat transfer by electron radiation from the shadow mask surface does not have a great influence on the local high thermal expansion because it occurs over the entire shadow mask surface.

Therefore, by removing the high thermal expansion due to the local high temperature, a relatively uniform thermal expansion occurs over the entire shadow mask surface, especially in the case of the shadow mask made of Invar, the local doming phenomenon as shown in FIG. Removed.

In addition, it is welded and assembled only partially by the frame 30, so that the expansion force due to thermal expansion of the shadow mask 16 is elastically at the corner vertical portions 31 to 34 and the edge vertical portions 35 to 38. Since it is absorbed to some extent, the surface stress due to the difference in thermal expansion coefficient with the frame acting on the surface of the shadow mask 16 can be removed to some extent.

As described above, in the case of the invader shadow mask having a low expansion coefficient by the configuration and operation according to the present invention, the temperature rise of the local shadow mask surface is suppressed by suppressing heat transfer to the frame and reaching the thermal equilibrium state by radiation. It can prevent local doming phenomenon.

Although the present invention has been described by the specific embodiments, the present invention is not limited thereto, and it will be understood by those skilled in the art that various modifications and applications are possible without departing from the spirit and scope of the appended claims.

Claims (2)

In a shadow mask-frame assembly of a cathode ray tube welded and assembled to a vertical portion supporting an invader shadow mask on a panel, the vertical portion is adapted to minimize the temperature difference across the entire surface of the shadow mask heated by the electron beam from the electron gun. An invader shadow mask-frame assembly of a cathode ray tube, characterized in that it has a structure for heat transfer from the shadow mask to the frame. The invad shadow mask frame of claim 1, wherein the invad shadow mask is welded and assembled such that the vertical portion is heat-transmitted at the center of the frame and at both corners of the frame. Assembly.