JP2560844B2 - Cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is configured to exert a color selection function by projecting electron beams onto fluorescent films of a plurality of colors formed on the inner surface of a Paelface portion. The present invention relates to a cathode ray tube.

[Prior Art] FIG. 7 is a plan view in which a conventional shade mask type color cathode ray tube is partially cut away. In the figure, (1) is a vacuum envelope made of glass, which is composed of a panel face portion (2), a funnel portion (3) and a neck portion (4).

(5) is a phosphor film of a three-color mosaic of red, green and blue (hereinafter, referred to as R, G, B) formed on the inner surface of the panel face portion (2), and (6) is a slit-like or A sheer dough mask made of a thin iron plate in which a large number of dot-shaped electron beam transmitting holes (7) are formed, which is arranged at a predetermined interval from the fluorescent film (5) and is attached to a mounting frame (8) in the shape of a margin Has been.

(9) is an electron gun that emits an electron beam accelerated toward the fluorescent film (5) and is housed in the neck portion (4). Reference numeral (10) is a deflection coil provided on the outer peripheral portion of the boundary portion between the funnel portion (3) and the neck portion (4).

 Next, the operation of the above configuration will be described.

About 20% of the electron beam emitted from the electron gun (9) passes through each electron beam passage hole (7) of the shadow mask (6) and collides with the fluorescent film (5) of the panel face portion (2). It is issued and a predetermined image is displayed.

[Problems to be Solved by the Invention] Since the conventional cathode ray tube is configured as described above, in the operating state of the cathode ray tube, only a small amount of electron beam passes through the electron beam transmitting hole (7) of the show mask (6). Since it is 20%, the luminous efficiency is very poor. In addition, about 80% of the electron beam that does not pass through the electron beam transmission hole (7) collides with the shadow mask (6) and raises the temperature of the shadow mask (75) to 75 ° C to 80 ° C. 6) is thermally deformed, and as a result,
The relative positional relationship between the electron beam transmitted light (7) of the shear mask (6) and the phosphor mosaic of the phosphor film (5) is changed to reduce the color purity such as color shift on the screen, that is, the doming phenomenon, the brightness, and the image quality. There was a problem of leading to the decrease of.

The present invention has been made to solve the above problems, and eliminates the decrease in light emission efficiency due to the shadow mask that blocks the electron beam and the decrease in color purity due to thermal deformation of the shadow mask, resulting in a significant increase in brightness and image quality. An object is to provide a cathode ray tube that can be improved.

[Means for Solving the Problems] A large number of three-sided cone-shaped projections arranged at the front part of the vacuum envelope and protruding at an inner surface with a predetermined angle and coated with phosphors of different colors on the respective surfaces. A panel face portion in which a portion is formed,
An electron gun that is arranged near the tube axis at the rear of the vacuum envelope so as to face the inner surface of the panel face section and that emits three electron beams at predetermined angles with respect to the tube axis, and the inner surface of the panel face section. And an electrostatic deflection device for generating a magnetic field having a component parallel to the direction connecting the electron gun and the electron gun, and a solenoid for surrounding the electron beam and forming a magnetic field in the vacuum envelope to give a spiral motion to the electron beam. It is equipped with and.

[Operation] According to the present invention, since the color selection function can be exerted by setting the concavo-convex portion formed on the phosphor screen and the incident angle of the electron beam, 100% of the electron beam is projected onto the phosphor screen. The luminous efficiency can be improved, the doming phenomenon can be eliminated, and the luminance and color purity can be significantly improved.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view of a cathode ray tube according to an embodiment of the present invention, and FIG. 2 is a horizontal sectional view. In FIGS. 1 and 2, (16) is a vacuum envelope made of glass, which is formed integrally with the panel face portion (17). Reference numeral (11) is a three-color mosaic phosphor film of R, G, B formed on an uneven portion to be described later on the inner surface of the panel face portion (17).

(12) is a solenoid coil, which is the vacuum envelope (16)
Is wound around the outer periphery of the vacuum envelope (16) to form a magnetic field inside the vacuum envelope (16). (14) is, for example, three electron guns of R, G, and B arranged in a delta shape, each of which emits an electron beam at an angle of, for example, 60 ° with respect to the tube axis (a). (13) is an electrostatic deflection device, which is installed inside the vacuum envelope (16).

FIG. 3 is an enlarged view of the inner surface of the panel face portion (17). In FIG. 3, the solid line indicates the convex portion (18a) and the dotted line indicates the concave portion (1).
8b), each phosphor screen with R, G, and B attached is
For example, they have an angle of 90 ° to each other,
It has a shape in which a large number of rectangular parallelepipeds are arranged with one corner up.

FIG. 4 is an enlarged view of the G phosphor screen in FIG.
This is a 1-segment fluorescent screen viewed from the direction of incidence of the G electron beam, and (θ1) in the figure is set to 90 °.

 Next, the operation of the above configuration will be described.

R, G in FIG. 5 emitted from the electron gun (14),
The B3 electron beams (r), (g), and (b) are emitted at an angle of, for example, 60 ° with respect to the tube axis (a). Each electron beam (r) emitted in this way,
(G) and (b) are, as shown in the locus diagram of the xy plane,
Under the influence of the magnetic field (H) created by the solenoid coil (12), the process proceeds as if winding a vortex, and then the electrostatic deflection device (1
By 3), it is deflected parallel to the tube axis (a).

After that, each electron beam (r), (g), (b)
Light is incident from a direction substantially perpendicular to the R, G, and B phosphor screens, and only the corresponding phosphor screens emit light.

More specifically, since the electron beam emitted from the point O in FIG. 5 travels in the magnetic field (H) by the solenoid coil (12), the force in the radial direction can be understood as understood from Fleming's left-hand rule. Then, the process proceeds so as to draw a circle on the xy plane, and arrives at point A with almost the same vector as point O.

FIG. 6 is a simulation diagram of three electron beam trajectories, where FIG. 6A shows a non-deflected state, FIG. 6B shows a horizontal deflection state, and FIG. 6C shows a vertical deflection state. Further, FIG. 6D shows the state of simultaneous horizontal and vertical deflection, where O in FIG. 6 is the emission point of the electron beam and A is the arrival point.

[Effects of the Invention] As described above, according to the present invention, 100% of the electron beam can reach the phosphor screen without obstructing the electron beam, so that the luminous efficiency and the brightness can be significantly improved. it can. Moreover, since the shear mask is not required, the doming phenomenon does not occur, and the deterioration of the color purity due to the color shift can be prevented, and the image quality as a whole can be greatly improved.

[Brief description of drawings]

1 and 2 are a longitudinal sectional view and a lateral sectional view of the cathode ray tube, FIG. 3 is an enlarged inner view of a panel face portion of the cathode ray tube according to an embodiment of the present invention, and FIG.
An enlarged view of the segment, FIG. 5 is a trajectory diagram of the electron beam in the xy plane, FIGS. 6A to 6D are electron beam simulation diagrams, and FIG. 7 is a conventional color cathode ray tube. It is a top view which partially crossed. (11) …… Fluorescent film, (12) …… Solenoid coil, (1
3) ... Electrostatic deflector, (14) ... Electron gun, (17) ... Panel face, (18a) ... Convex, (18b) ... Concave. The same symbols in the drawings indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A large number of three-sided pyramidal protrusions are provided on the front portion of a vacuum envelope, projecting at a predetermined angle on the inner surface, and phosphors of different colors are applied to the respective surfaces. The panel face portion and the inner surface of the panel face portion are arranged in the vicinity of the tube axis in the rear part of the vacuum envelope so as to emit three electron beams at the predetermined angle with respect to the tube axis. An electron gun, an electrostatic deflector for generating a magnetic field having a component parallel to the direction connecting the inner surface of the panel face portion and the electron gun, and the vacuum envelope provided so as to surround the electron beam. A cathode ray tube, comprising: a solenoid for forming a magnetic field to give a spiral motion to the electron beam.