KR20030071128A - The Flat Color Cathode-ray Tube - Google Patents

Abstract

PURPOSE: A flat color CRT(Cathode Ray Tube) is provided to be capable of sorting colors and increasing deflection force by reducing the incidence angle of electron beam to a shadow mask using the first and second deflecting system. CONSTITUTION: A flat color CRT comprises a panel(1) having a fluorescent screen coated with fluorescent substance of red, green, and blue inside, a funnel(6) connected to the panel, an electron gun loaded at a neck part of the funnel for emitting electron beam to the fluorescent screen, a shadow mask arranged and spaced apart from the fluorescent screen for discriminating colors and a deflecting system. The deflecting system includes the first deflecting system(4) installed for enclosing the outside of the funnel and the second deflecting system(8) installed at the lateral portion of the fluorescent screen.

Description

The Flat Color Cathode-ray Tube}

The present invention relates to a flat color cathode ray tube, and more particularly, by installing a second deflection system other than the first deflection system, which is a deflection yoke, in the flat color cathode ray tube, color discrimination is possible by reducing the shadow mask incident angle of the electron beam. And a flat color cathode ray tube for increasing deflection force.

A typical cathode ray tube is a straight type as shown in Fig. 1, a panel 1 having R, G, B fluorescent surfaces 3 coated on its inner surface, a funnel 6 fused to a rear end of the panel, and a An electron gun 5 inserted into the neck portion to radiate the electron beam 7, a deflection yoke 4 for deflecting the electron beam 7, and an electron beam 7 passing through the panel at regular intervals. And a shadow mask 2 in which a plurality of holes are formed. The straight cathode ray tube is arranged to be almost orthogonal to the axis of the electron gun, the path of the electron beam before the fluorescent surface is deflected, and to form a raster while deflecting the electron beam. Very difficult to implement

It was invented to improve such a problem as a flat cathode ray tube as shown in Figure 2, wherein the flat cathode ray tube was placed at a position parallel to the axis of the electron gun to deflect the electron beam about 90 degrees to irradiate the fluorescent surface. The flat cathode ray tube is mounted in a monitor, door phone or portable television that requires a thin water receiver.

The flat cathode ray tube is composed of three parts, the neck portion, the funnel portion and the display body portion as shown in FIG. The neck portion is provided with an electron gun (5) which serves to emit a mono electron beam, the funnel portion is attached with a deflection yoke (4) for deflecting the electron beam, the display body portion is a screen coated with a fluorescent surface (3) And a display surface section where the image information can be actually viewed.

The flat cathode ray tube configured as described above may obtain image information through the following process. First, the electron beam emitted from the mono electron gun installed in the neck portion is deflected by the magnetic field generated by the deflection yoke, collides with the fluorescent surface to which the phosphor is applied to emit light, and image information can be viewed through the display surface portion provided in the front surface.

In addition, a deflection yoke for deflecting the electron beam is provided outside the funnel portion, and the deflection yoke includes a horizontal deflection coil 41, a vertical deflection coil 42, and a ferrite core 44 as shown in FIG. 3. The conventional deflection yoke generally flows a current having a frequency of 15.75 kHz or higher to the horizontal deflection coil 41 as shown in FIG. 4, and deflects the electron beam inside the cathode ray tube in a horizontal direction by using a magnetic field generated accordingly. In addition, the vertical deflection coil is supplied with a current having a frequency of 60 Hz and is deflected in the vertical direction by using a magnetic field generated accordingly. At this time, in case of making a magnetic field by flowing current through the deflection coil, it is difficult to deflect the electron beam to the front of the screen only by the magnetic field by the coil, and the efficiency of the magnetic field is minimized by using the ferrite core 44 of permeability to minimize the loss in the return path of the magnetic field. To increase the magnetic force.

The conventional flat cathode ray tube is a black and white cathode ray tube employing a mono electron gun, and it is difficult to implement a color, and even when a flat color cathode ray tube is implemented using a three-color electron gun, color separation is performed as shown in FIGS. 5 and 6. Since the incident angle of the electron beam incident through the shadow mask 2 becomes very large, it is very difficult to colorize the electron beam on the screen. In addition, as the incident angle increases, the degree of distortion of the spot shape of the electron beam is increased, thereby deteriorating the focus characteristic of the electron gun, and there is a problem in that color uniformity is inferior due to a large luminance difference between the screen center part and the peripheral part.

Accordingly, the present invention is to solve the above problems, by installing a second deflection system other than the first deflection system of the deflection yoke in the flat color cathode ray tube to reduce the incident angle of the shadow mask of the electron beam, color discrimination is possible. An object of the present invention is to provide a flat color cathode ray tube that increases the deflection force.

1 is a structural diagram of a typical straight cathode ray tube.

2 is a structural diagram of a conventional flat black and white cathode ray tube.

3 is a structural diagram of a general deflection yoke.

4 is a diagram showing a current flowing in a vertical deflection coil of a deflection yoke.

5 is a view showing an angle of incidence of an electron beam in a conventional flat monochrome cathode ray tube.

Fig. 6 is a diagram showing color screening in a conventional flat cathode ray tube.

7 is a structural diagram of a flat color cathode ray tube of the present invention.

8 is a view showing an angle of incidence of an electron beam in a flat color cathode ray tube of the present invention.

Fig. 9 is a diagram showing color screening in the flat color cathode ray tube of the present invention.

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

1 panel 2 shadow mask

3: fluorescent surface 4: deflection yoke (first deflection system)

6: funnel 8: second deflection system

Technical means of the present invention for achieving the above object is a panel having a fluorescent surface coated with phosphors of R, G, B on the inner surface, a funnel connected to the panel, the rear of the funnel at a predetermined angle with the panel A flat color cathode ray tube including an electron gun mounted on a bent neck portion to emit an electron beam toward the fluorescent surface, a shadow mask arranged at a predetermined interval with respect to the phosphor screen on the inner surface of the panel to serve as color screening, and a deflection system; The deflection system is characterized in that it comprises a first deflection system provided surrounding the outer side of the funnel, and a second deflection system provided on the side of the screen.

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

The flat color cathode ray tube of the present invention is mounted on the front of the cathode ray tube as shown in FIG. 7 and has a fluorescent surface coated with phosphors of R, G, and B on its inner surface, and a cathode ray coupled to the rear of the panel. A funnel 6 for keeping the inside of the tube in a vacuum state, an electron gun mounted to a neck portion bent at an angle with the panel to the rear of the funnel to emit an electron beam toward the fluorescent surface, and a phosphor screen on the inner surface of the panel A shadow mask arranged at regular intervals to serve as color screening, a first deflection system 4 deflecting the electron beam and surrounding the outer side of the funnel, a deflection device for increasing the vertical deflection force of the electron beam, and the It consists of a second deflection system 8 consisting of a deflection device which reduces the angle at which the electron beam is incident on the panel screen.

The color flat cathode ray tube of the present invention uses an inline electron gun, wherein the red (R), green (G), and blue (B) electron beams are arranged side by side horizontally. Accordingly, the first deflection system of the present invention applies a self-converging method using a non-uniform magnetic field to converge the three electron beams at one point of the fluorescent surface.

Also, the first deflection system includes a pair of horizontal deflection coils 41 for deflecting the electron beam emitted from the electron gun in the horizontal direction, and a pair of vertical deflection coils for deflecting the electron beam in the vertical direction. (42), and a conical ferrite core 44, which is used to reduce the loss of magnetic force generated by the current flowing through the horizontal / vertical deflection coil to improve deflection efficiency, and the horizontal / vertical deflection coil and ferrite. The holder 43 serves to determine the mounting position of the core, to fix and couple the mechanisms, and to insulate between the horizontal and vertical deflection coils, and to be installed on the neck side of the holder by a vertical barrel type magnetic field. COMA Free Coil (45), which improves the comma aberration generated, and is installed at the neck end of the holder to provide a cathode ray tube and the first deflection system. And a ring band 46 which is mechanically coupled, and a magnet 47 which is provided at the end of the opening of the first deflection system and used to correct raster distortion on the screen.

However, since the flat color cathode ray tube has a very short electric field and a large deflection angle, as shown in FIG. 6, a very large vertical deflection force is required to deflect the electron beam emitted from the electron gun on the screen. Not only it is difficult to implement the deflection force, but also the angle of incidence of the electron beam to the shadow mask 2 having the color screening function is very large, so it is very difficult to implement the screening function.

Therefore, the present invention is equipped with a second deflection system (8) in addition to the first deflection system to solve the above problems. As shown in FIG. 7, the second deflection system is installed in close proximity to one side of the screen adjacent to the neck and the other side of the screen opposite thereto, and the second deflection system is installed on one side of the screen adjacent to the neck (8-2). It serves to increase the vertical deflection force of, and to be installed on the other side of the screen opposite to (8-1) serves to reduce the incident angle of the electron beam.

Fig. 8 shows the deflection of the electron beam by the deflection system of the present invention. As shown, the second deflection system 8-2 installed on one side of the screen when the electron beam emitted from the electron gun is deflected by the first deflection system and the second deflection system provided on one side of the screen adjacent to the neck and near the fluorescent surface. The angle of incidence is reduced by the second deflection system 8-1 provided at a position opposite to the direction. As a result, color selection by the shadow mask 2 is possible as shown in FIG. 9.

In addition, since the second deflection system plays a role of deflecting the electron beam emitted from the electron gun in the vertical direction on the screen like the vertical deflection coil of the first deflection system, the current flowing through the second deflection system is perpendicular to the first deflection system. As shown in FIG. 9, the vertical deflection coil and the second deflection system of the first deflection system are connected in series so as to correspond to the current flowing through the deflection coil.

As described above, the flat color cathode ray tube according to the present invention, unlike the conventional black and white flat cathode ray tube, is provided with a shadow mask functioning for screening on the back of the screen and red (R), green (G), A thin colored cathode ray tube can be realized by forming a fluorescent surface coated with a blue (B) phosphor. In addition, a large-sized thin colored cathode ray tube can be realized by deflecting the electron beam by including a first deflection system that converges three electron beams at one point and a second deflection system that increases vertical deflection force.

In addition, by installing a second deflection system that reduces the angle of incidence, it is possible to reduce the angle of incidence of the electron beam incident on the shadow mask, so that color discrimination is possible even at ultra wide angles, and the reflection type in which the electron beam hits the surface of the fluorescent film and is reflected on the display surface It is possible to provide a thin color cathode ray tube with improved luminance because the electron beam directly collides with the fluorescent surface formed on the screen instead of the flat cathode ray tube.

Claims (4)

A panel having a fluorescent surface coated with phosphors of R, G, and B on its inner surface, a funnel connected to the panel, and a neck portion bent at an angle with the panel behind the funnel to emit an electron beam toward the fluorescent surface In the flat-colored cathode ray tube comprising an electron gun, a shadow mask arranged at a predetermined interval with respect to the phosphor screen on the inner surface of the panel and serving as color screening, and a deflection system, And said deflection system comprises a first deflection system arranged around the outer side of said funnel and a second deflection system provided on the side of the screen. The method of claim 1, The first deflection system includes a horizontal deflection coil for horizontally deflecting an electron beam, a vertical deflection coil for deflecting a vertical beam, a ferrite core for reducing magnetic losses generated from the horizontal deflection coil and a vertical deflection coil to increase magnetic efficiency, and the horizontal deflection coil. A flat color cathode ray tube, comprising: a holder for holding a coil, a vertical deflection coil, and a ferrite core at a predetermined position, and insulating between the horizontal deflection coil and the vertical deflection coil. The method of claim 1, Among the second deflection systems, a deflection device for increasing the vertical deflection force of the electron beam is installed near one side of the screen adjacent to the neck portion, and a deflection device for reducing the angle at which the electron beam is incident on the panel screen is used for vertical deflection of the electron beam. A flat-colored cathode ray tube, characterized in that it is installed in close proximity to the other side of the screen facing the deflecting device to increase the force. The method according to claim 1 and 2, And a current equal to the current flowing in the vertical deflection coil of the first deflection system flows in the second deflection system.