KR20000004497A - Shadow mask used in flat and bended type crt - Google Patents

Abstract

PURPOSE: A shadow mask used in flat and bended type CRTs is provided to prevent the deformation due to weak impulse and μ-phonic phenomenon because the advantage of a tension type is used and a tension type shadow mask is bent for forming curvature in case that the mask is fixed by the tension in lengthwise direction. CONSTITUTION: The shadow mask used in flat and bended type CRT comprises: plural TSMs formed by prescribed gap between each other in lengthwise direction; and plural FSMBs connecting the TSMs in widthwise direction by 7-8mm gap.

Description

Shadow mask combined using flat type CRT and curve type CRT

The present invention relates to a shadow mask provided inside a cathode ray tube (hereinafter referred to as a CRT) of a television receiver, and more particularly to a shadow mask combining advantages of a mark form type and a tension type.

In general, a CRT is a display device that focuses electrons emitted from a cathode enclosed in a tube and then accelerates them to make an electron beam and control its direction by the action of an electric field or a magnetic field.

Referring to FIG. 1 attached to the structure of the above-described CRT, the heater 410 and the heater 410 to increase the temperature of the cathode 420 by generating heat by receiving the image-amplified R, G and B signals. The cathode 420 which emits electrons when a negative voltage is supplied from the control grid, the control grid 430 which modulates the luminance (change of brightness) by adjusting the amount of electrons emitted from the cathode 420, and the cathode 420. ) To supply a constant voltage (for example, + 110V to 400V) to reach the fluorescent surface 492 on the back of the panel 490, attracting electrons with charges and accelerating in the axial direction. 440, a medium acceleration grid 450 for secondaryly accelerating electrons primarily accelerated by the acceleration grid 440 by supplying a constant voltage (eg, +10 mA or more), and emitted from the cathode 420. Electrons traveling toward the fluorescent surface 492 of the panel 490 diffuse by the repulsive force between the electrons. Focusing axially to create a thinner electron beam, and a constant voltage (e.g., electrons emitted from cathode 420 and accelerated twice through acceleration grid 440, medium acceleration grid 450). : A high acceleration grid 470 for supplying +10 kV or more and accelerating in the third order to collide with the fluorescent surface 492 of the panel 490, and a high voltage of a predetermined voltage (for example, +10 kV) or higher for the glass tube 490. An anode terminal 480 is provided for supplying to the aluminum film of the fluorescent surface 492 and discharging a high voltage when the power is "off".

In this case, a shadow mask, which is a porous metal plate attached to a position about 10 mm away from the fluorescent surface 492, is required in order to accurately match the beam emitted from the electron gun with the set fluorescent position.

Referring to FIGS. 2 to 4 attached to a conventional shadow mask for performing the above function, in the case of the color CRT, the electron gun has three electron guns: red (R), green (G), and blue (B). Depending on the arrangement of electron guns, it is divided into delta type and inline type.

Accordingly, FIG. 2 is an exemplary diagram for explaining a relationship between a shadow mask and a fluorescent surface in a CRT equipped with a delta electron gun, which is commonly used in computer monitors. The reason why it is not well applied to a television is because the dot pitch of the fluorescent screen pixels is small and the screen is relatively bright.

Therefore, as shown in FIG. 3 to which another conventional technique proposed to solve the problems of the technique shown in FIG. 2 is attached, the phosphor coated on the fluorescent surface has a line shape instead of a dot shape. In other words, the shadow mask is a mark form type.

As described above, the mark form-type shadow mask shown in FIG. 3 is changed to a lattice structure of an electron beam transmission hole that is formed in a dot shape in the shadow mask of FIG. 2. In addition, the arrangement of the electron gun was also changed inline, and the average size of the electron beam transmission holes perforated in the shadow mask was 0.5 to 0.7 mm in width and 0.7 to 0.8 mm in length.

In this case, in the case of using the mark form-type shadow mask as shown in FIG. 3, the electron beam is at an angle due to the deflection of the electron beam at the periphery of the screen compared to the incident area of the electron beam colliding with the fluorescent surface near the center of the screen. Because of the bending, the incidence area is widened. Therefore, if the size of the electron beam transmission hole at the periphery is maintained at the same size as the vicinity of the center, the problem of emitting adjacent phosphors together occurs, thereby making the size of the electron beam transmission hole at the periphery smaller.

However, as described above, when the size of the transmission hole decreases, the number of electrons colliding with the fluorescent surface decreases, so that the brightness of the screen is lower than that of the central portion of the screen.

As a tension type shadow mask shown in FIG. 4 to which the conventional technique for solving the problems caused by the mark form-type shadow mask shown in FIG. 3 is attached, the transmission of the electron beam is limited only in the transverse direction. Therefore, there is an advantage that the brightness of the periphery is considerably improved compared to the mark form-type shadow mask shown in FIG. 3.

In addition, the tension type shadow mask shown in FIG. 4 can be fixed with longitudinal tension in the construction of a planar CRT, which has a considerably strong advantage for micro-phonic.

However, when the tension type is applied to the CRT having the curvature, the shadow mask must also have a certain curvature, and thus the tension type fixed only in the longitudinal tension has no means for transverse direction and thus does not have a lateral fixation means. μ-phonic) phenomenon is so severe that the tension type cannot be applied to the CRT with curvature.

Therefore, the mark form or tension type should be applied according to the produced product in the production of the television product, and thus the overall disadvantage that the accompanying disadvantages should be basically taken.

An object of the present invention for solving the above problems, while utilizing the advantages of the tension type, when the tension type shadow mask is fixed to the longitudinal direction only when applied to the CRT having a certain curvature by a small tension for curvature formation Applied to flat CRT or curved CRT by combining the advantages of the Mark Formed and Tension types, which form a band for preventing vibration in the transverse direction to prevent easily deforming or aggravating the micro-phonic phenomenon. To provide a shadow mask that can be used.

1 is a configuration diagram of a general CRT

2 is an exemplary diagram for explaining a relationship between a shadow mask and a fluorescent surface in a CRT having a delta electron gun;

3 is an exemplary view for explaining a relationship between a mark form-type shadow mask and a fluorescent surface in a CRT having an inline electron gun;

4 is an exemplary view for explaining a relationship between a tension type shadow mask and a fluorescent surface in a CRT having an inline electron gun;

5 is a partial illustration of a shadow mask according to the present invention

In order to achieve the above object, a feature of the present invention is that a plurality of electron beam blocking films having a predetermined thickness are formed in the longitudinal direction, and each electron beam blocking film is a shadow mask in a form of maintaining a predetermined interval, and connecting the electron beam blocking films in a horizontal direction. A plurality of banding films are formed at intervals of 7 to 8 mm, and the banding films have durability against tension of 7 to 10 kg.

Hereinafter, the configuration according to an embodiment of the present invention with reference to the accompanying drawings in detail as follows.

First, the technical idea to be applied in the present invention, the tension type limiting the electron beam only in the transverse direction has an advantage in the planar CRT but the reason why very severe micro-phonic phenomenon occurs in the CRT having curvature If the electron beam blocking film formed only on the longitudinal axis is bent to have a certain curvature, it is easily vibrated by the shock in the lateral direction. Therefore, if a dustproof means for preventing the vibration is provided, the micro-phonic can be maintained while maintaining the advantages of the tension type. It was conceived that the phenomenon could be suppressed.

Therefore, as shown in FIG. 5, a vibration mask is prevented from rotating in a tension type shadow mask, that is, a shadow mask having a predetermined thickness and forming a plurality of electron beam blocking films (TSMs) formed in the longitudinal direction. As a dustproof means for forming a banding film (FSMB) for connecting the electron beam blocking film (TSM) in the transverse direction.

At this time, the banding film (FSMB) is formed at an interval of 7 to 8mm, because the formation of a diameter of 0.7 to 0.8mm vertically in the conventional mark form type, by maintaining the interval of about 10 times, the tension type In order to perform the dustproof function while taking advantage of the advantages.

In addition, the banding film FSMB has a durability in tension in the longitudinal direction, that is, 7 to 10 kg, which is normally used when the tension type shadow mask is fixed to the flat plate CRT in case it is applied to the flat plate CRT. Have it.

By providing a shadow mask according to the present invention as described above, while the tension type shadow mask is applied to the CRT having a certain curvature, the tension mask is bent to form curvature when it is fixed under tension only in the longitudinal direction. Accordingly, it can be prevented from being easily deformed by a small impact or aggravating a micro-phonic phenomenon, and can be applied to both a flat CRT and a curved CRT.

Claims (2)

In a shadow mask in which a plurality of electron beam blocking films TSM having a predetermined thickness are formed in the longitudinal direction and each electron beam blocking film TSM maintains a predetermined interval, A shadow mask, characterized in that for forming a plurality of banding film (FSMB) for connecting the electron beam blocking film (TSM) in the horizontal direction at intervals of 7 to 8mm. The method of claim 1, The banding film (FSMB) is a shadow mask, characterized in that it has a durability to the tension of 7 to 10kg.