KR20030067139A - Transposed scan CRT - Google Patents

Abstract

PURPOSE: A transposed scan cathode ray tube is provided to achieve improved resistance against impact and prevent a howling phenomenon by enhancing a structural strength of the shadow mask. CONSTITUTION: A transposed scan cathode ray tube comprises a panel having a flat outer surface and an inner surface with a predetermined curvature; an electron gun where three cathodes for generating red, green and blue electron beams are arranged in a vertical line; a screen where electron beams emitted from the electron gun produce colors by being collided against a phosphor screen; a deflection yoke including a vertical coil for forming a pin cushion magnetic field for deflecting electron beams in a shorter axis direction and a horizontal coil for forming a barrel deflection magnetic field for deflecting electron beams in a longer axis direction; and a shadow mask having an electron beam passing hole elongated in the longer axis direction. Formulas 1.5xD<MRx, 2.0xD<MRy, MRx<αxMRy and α>=4/3 are satisfied, wherein MRx is the longer axis radius of curvature passing through the center of the effective portion, MRy is the shorter axis radius of curvature passing through the center of the effective portion, D is the diagonal length of the effective portion of the screen, and α is a constant representing a width to length ratio of the screen.

Description

Vertical scanning cathode ray tube {Transposed scan CRT}

The present invention relates to a vertical scan type cathode ray tube, and more particularly, to a shadow mask of a vertical scan type cathode ray tube for improving the drop characteristics of the cathode ray tube.

1 is a vertical sectional view of a vertical scanning cathode ray tube.

As shown in FIG. 1, the vertical scanning cathode ray tube includes a panel 1 having a phosphor 3 coated on its inner surface, and electron beams 8 of three colors R (Red), G (Green), and B (Blue). An electron gun 4 in which three cathodes 9 and 10 are arranged in a vertical inline, a screen 2 in which the electron beam emitted from the electron gun hits a fluorescent surface to reproduce color, and for deflecting the electron beam in a uniaxial direction A shadow mask having a deflection yoke (5) composed of a vertical coil forming a pincushion magnetic field, a horizontal coil forming a barrel-shaped deflection magnetic field for deflecting the electron beam in the long axis direction, and long holes (7) of the long axis through which the electron beam passes. (6) and so on.

The cathode ray tube of FIG. 1 configured as described above is accelerated and focused while the electron beams of three colors R, G, and B, in which an electron beam is generated from the cathode, are sequentially passed through a plurality of electrodes, and then deflected. Scanned toward the screen 2 in a state deflected in the vertical and horizontal directions by the magnetic field of the yoke 5.

The electron beam scanned as described above passes through the long electron beam passing hole 7 at the long axis of the shadow mask 6, which serves as color screening, and emits the phosphor 3 coated on the inner surface of the panel 1, thereby reproducing an image. do.

In the case of the panel 1 of the vertical scanning cathode ray tube as shown in FIG. 1, the outer surface is flattened, and the inner surface tends to increase gradually in radius of curvature.

In addition, the curvature radius of the shadow mask 6 having a constant relationship with the curvature of the panel also follows the curvature of the panel.

Therefore, in FIG. 2, in the case of the conventional vertical scanning type cathode ray tube having a long axis radius of curvature Rx of the inner surface of the panel larger than the short axis radius of curvature Ry, the shadow mask diagram of FIG. Since the major axis radius of curvature MRy becomes larger than the minor axis radius of curvature MRy, the structural strength of the shadow mask 6 is poor, and thus, the drop characteristic, which is a characteristic of reliability, is weak.

Therefore, the present invention is to solve the above problems, and to improve the structural strength of the shadow mask of the vertical scanning cathode ray tube to improve the drop characteristics and to improve the howling and impact resistance characteristics.

1 is a vertical cross-sectional view of the vertical scanning cathode ray tube.

2 is a perspective view of a panel structure.

3 is a structural diagram of a shadow mask.

*** Explanation of symbols for the main parts of the drawing ***

2: screen 3: phosphor

6: Shadow mask 7: Electron beam passing hole in shadow mask.

Rx: Long axis radius of curvature of panel

Ry: the short curvature radius of the inner surface of the panel

MRx: Long-axis curvature radius of shadow mask

MRy: Short curvature radius of shadow mask

The present invention for achieving the object as described above, the outer surface is flat and the inner surface has a constant curvature, three cathodes generating electron beams of three colors R (Red), G (Green), B (Blue) Electron guns arranged in a vertical line, a screen in which the electron beam emitted from the electron gun hits a fluorescent surface to reproduce color, a vertical coil forming a pincushion magnetic field for deflecting the electron beam in the short axis direction, and a barrel-type deflection for deflecting the electron beam in the long axis direction In a vertical scanning cathode ray tube including a deflection yoke composed of a horizontal coil forming a magnetic field and a shadow mask having an electron beam passing hole elongated in a long axis direction, a long axis curvature passing through the center of an effective portion in which an image inside the shadow mask is displayed. The radius is MRx, the short curvature radius passing through the center of the effective portion is MRy, and the diagonal length of the effective surface of the screen is D. When any constant representing the aspect ratio of the screen is α, the following equation, 1.5 × D <MRx, 2.0 × D <MRy, MRx <α × MRy and α ≧ 4/3 is satisfied. It features.

Hereinafter, with reference to the accompanying drawings, the present invention to achieve the above object will be described in detail.

As shown in FIG. 1, an electron gun 4 in which three cathodes generating three electron beams 8, 9, and 10 of R (Red), G (Green), and B (Blue) are arranged in a vertical inline. And a screen (2) for reproducing color by the electron beam emitted from the electron gun hitting a fluorescent surface, a vertical coil for forming a pincushion magnetic field for deflecting the electron beam in a short axis direction, and a barrel-type deflection magnetic field for deflecting the electron beam in a long axis direction. It is a vertical scanning type cathode ray tube consisting of a deflection yoke (5) consisting of a horizontal coil forming a, and a shadow mask (6) formed with long holes (7) of long axis through which the electron beam passes.

In the conventional vertical scanning type cathode ray tube, since the vertical scanning is performed in FIG. 2, the curvature of the inner surface of the panel is designed to have a larger major axis radius of curvature Rx than the minor axis radius of curvature Ry, and the cathode ray tube is enlarged, As it is flattened, the radius of curvature Rx of the inner surface of the panel is further increased.

In addition, the difference in thickness according to the position of the panel is also increased, and when the electron beam is scanned in the vertical scanning type cathode ray tube, an image distortion occurs when the horizontal line is perpendicular to a short axis having a large change in thickness.

As described above, the curvature of the shadow mask having a constant relation with the curvature of the inner surface of the panel having a large long curvature radius Rx also increases the value of the curvature radius (MRx) in the long axis direction far from the center, thereby weakening the impact resistance of the shadow mask. .

According to the present invention, when the curvature of the outer surface of the panel is more than 5000 mm, the short axis radius (Ry) of the inner surface of the panel is larger than the long axis radius (Rx) to solve the problem of horizontal line distortion in the vertical scanning cathode ray tube as described above. In the case of large design, the radius of curvature of the shadow mask is designed so that the short curvature radius (MRy) is larger than the major axis radius curvature (MRx) so that the radius of curvature (MRx) of the long axis away from the center of the shadow mask is small. will be.

In FIG. 3, the long axis curvature radius MRx and the short axis curvature radius MRy of the shadow mask satisfy the following equations.

1.5 × D <MRx and 2.0 × D <MRy and MRx <α × MRy and α≥ 4/3

Where α is any constant representing the aspect ratio of the screen and D represents the diagonal length of the effective surface of the screen.

In the above range, the long-axis curvature radius MRx and the short-axis curvature radius MRy of the shadow mask are most preferably in the range of 1.5 × D <MRx <4.0 × D and 2.0 × D <MRy <6.0 × D.

If the long axis radius of curvature (MRx) of the shadow mask is MRx <1.5 × D and the short axis radius of curvature (MRy) is MRy <2.0 × D, the radius of curvature of the shadow mask is so small that the drop characteristic is advantageous. As a result, the panel's rate of magnification increases, which causes disadvantages such as Brightness Uniformity, White Uniformity, and visual discomfort.

On the contrary, when the long axis radius of curvature of the shadow mask (MRx) is MRx> 4.0 × D and the short axis radius of curvature (MRy) is MRy> 6.0 × D, the radius of curvature of the shadow mask becomes large and the drop characteristic becomes disadvantageous. .

The shadow mask designed by applying the scope of the present invention as described above has a short axis radius of curvature (MRy) larger than the long axis radius of curvature (MRx), so that the strength of the long axis (x-axis) and corner portions far from the center of the shadow mask and vulnerable to stiffness Can be reinforced.

Therefore, according to the present invention, by designing the short axis radius of the shadow mask larger than the long axis radius of curvature in the vertical scanning type cathode ray tube, the structural strength of the shadow mask is sufficiently secured to improve the drop characteristic, which is a reliability characteristic against external impact. , Impact resistance characteristics and howling prevention effect can be obtained.

Claims (3)

A panel having a flat outer surface and a constant curvature on the inner surface, an electron gun in which three cathodes are arranged in a vertical inline to generate three color electron beams of R (Red), G (Green), and B (Blue), and an electron beam emitted from the electron gun A deflection yoke composed of a screen for reproducing color by hitting the fluorescent surface, a vertical coil for forming a pincushion magnetic field for deflecting the electron beam in the short axis direction, and a horizontal yoke for forming a barrel-shaped deflection magnetic field for deflecting the electron beam in the major axis direction, and a long axis. In the vertical scanning type cathode ray tube comprising a shadow mask formed with a long electron beam through-hole, The long axis radius of curvature passing through the center of the effective portion where the image inside the shadow mask is displayed is referred to as MRx, the short axis radius of curvature passing through the center of the effective portion is referred to as MRy, and the diagonal length of the effective surface of the screen is referred to as D, When any constant representing the aspect ratio of the screen is α, the following formula, 1.5 × D <MRx, 2.0 × D <MRy, MRx <α × MRy, and α ≧ 4/3 are satisfied. Vertical scanning cathode ray tube. The method of claim 1, The MRx is preferably a vertical scan type cathode ray tube, characterized in that 1.5 × D <MRx <4.0 × D. The method of claim 1, The MRy is preferably a vertical scan type cathode ray tube, characterized in that 2.0 × D <MRy <6.0 × D.