JP2001307656A - Cathode-ray tube and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems as an erroneous focusing of electron on a panel face, or as a spot distortion of electron on the panel face, in a case of applying an identical electron gun on cathode-ray tubes of different sizes. SOLUTION: A cathode-ray tube is composed of flowing components; a cathode-ray tube bulb 1 used as a tube body, an in-line type electron gun 6 equipped inside a neck portion 4 of the cathode-ray tube bulb 1, and two four-pole magnets 10 and 11 positioned at one end (a neck end side) and the other end (a panel side) bordering a main electric field lens 9 of the electron gun in the direction of a central axis of the cathode-ray tube bulb 1. Through the two four-pole magnets 10 and 11, an orbit of the electron beam (the side beam) can be controlled one by one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube having an in-line type electron gun and a display device such as a television receiver or a computer display using the cathode ray tube.

[0002]

2. Description of the Related Art Generally, in a color cathode ray tube, three electron beams emitted from an electron gun, ie, B (blue),
By deflecting the traveling directions of the three electron beams that cause the G (green) and R (red) phosphors to emit light up, down, left, and right,
Images are assembled on the screen (panel surface) of the cathode ray tube. In the case of an electron gun equipped with an in-line type electron gun, three electron beams are used in which an electron beam for emitting green phosphor is used as a center beam, and an electron beam for emitting red and blue phosphors is used as a side beam. The image is emitted in an inline shape (horizontal straight line) to assemble the image on the screen.

FIG. 6 is a schematic plan view showing the structure of a conventional cathode ray tube having an in-line type electron gun. In FIG. 6, a cathode ray tube bulb 1 includes a panel unit 2 and a funnel unit 3.
And a neck portion 4. Funnel 3
A deflection yoke 5 is attached to a portion (cone portion) extending from the to the neck portion 4. The neck 4 has an electron gun 6.
Is decorated. Further, the outer peripheral portion of the neck portion 4
The pole magnet 7 is mounted.

The electron gun 6 has three cathodes Kb, Kg, and Kr corresponding to B, G, and R, respectively.
Electrons are emitted from b, Kg, and Kr, respectively. A control electrode group 8 including a plurality of grid electrodes is incorporated in the electron gun 6. Each of the grid electrodes constituting the control electrode group 8 is provided with three beam passage holes.

In the cathode ray tube having the above configuration, the magnetic field of the quadrupole magnet 7 acts on the side beams on both sides of the three electron beams emitted from the three cathodes Kb, Kg, and Kr in the electron gun 6. Thereby, three electron beams pass through the optimal position (usually the center of the lens) of the main electric field lens 9 formed in the control electrode group 8,
In addition, control is performed so that three electron beams are concentrated (convergence) on the panel surface of the cathode ray tube bulb 1.
Further, by applying a magnetic field (vertical deflection magnetic field, horizontal deflection magnetic field) of the deflection yoke 5 to the three electron beams emitted from the electron gun 6, the three electron beams scan the entire area of the panel surface. Controlling.

[0006]

By the way, in general, a cathode ray tube has a 14-inch, 21-inch, or 2-inch depending on the screen size.
There are various sizes such as 9 type, 32 type and 36 type. In the cathode ray tubes having different sizes as described above, not only the screen size but also the distances L1 and L2 from the cathode position of the electron gun 6 to the panel surface are different. For this reason, conventionally, the electron gun 6
Is adjusted so that the three electron beams reach the panel surface with an optimal trajectory.

However, in such a technical idea, a dedicated electron gun has to be designed, manufactured and managed for each size of the cathode ray tube, so that the design cost, the manufacturing and management costs are increased, and the cost is disadvantageous. Situation.

If the same electron gun is used for cathode ray tubes of different sizes, the following problems occur. That is,
For example, when a 21-type cathode ray tube is compared with a 32-type cathode ray tube, the distance from the cathode position of the electron gun to the panel surface is, as shown in FIG.
The distance L2 of the 32-inch type is longer than that of the type-1. Therefore, when the trajectory of the electron beam is adjusted according to the 21-type using an electron gun optimally designed for the 21-type, the three electron beams are shifted to the panel surface position P1 of the 21-type as shown by the solid line in FIG. , And reaches the 32-inch panel surface position P2. Therefore, in the 32 type cathode ray tube, so-called misconvergence occurs in which three electron beams are not concentrated on the panel surface.

Therefore, in the 32 type cathode ray tube, as shown by the broken lines in the figure, three electron beams are applied to the panel surface position P2.
When the magnetic field of the quadrupole magnet 7 is adjusted so as to concentrate at the center, the center beam at the center passes through the optimum position (center) of the main electric field lens 9g, but the side beams on both sides are at the optimum positions (main position) of the main electric field lenses 9b and 9r. It passes through a position (outside the lens) that deviates from (center). Therefore, the spot of the side beam reaching the panel surface position P2 is distorted under the influence of the coma aberration of the main electric field lenses 9b and 9r. More specifically, when there is no influence of coma aberration, the spots of the three electron beams B, G, and R become almost perfect circles as shown in FIG. 8A, the spots of the side beams B and R on both sides are distorted in a state where they are extended outward as shown in FIG. 8 (II).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to concentrate electron beams on a panel surface when using the same electron gun for cathode ray tubes of different sizes. It is an object of the present invention to provide a cathode ray tube capable of simultaneously eliminating displacement and spot distortion of an electron beam, and a display device using the same.

[0011]

In a cathode ray tube according to the present invention, a cathode ray tube bulb, an in-line type electron gun provided in the cathode ray tube bulb, and a main part of the electron gun in a central axis direction of the cathode ray tube bulb. The configuration includes two quadrupole magnets disposed on one and the other side of the position of the electric field lens. Further, the display device according to the present invention uses the cathode ray tube having the above configuration.

In the cathode ray tube and the display device having the above-mentioned structure, the trajectories of the side beams on both sides of the three electron beams emitted in-line from the electron gun are adjusted to the beam incidence side and the beam emission side of the main electric field lens. Thus, it is possible to individually adjust each of them by using a four-pole magnet. Thereby, for example, when an electron gun optimally designed for a predetermined size is used in a cathode ray tube having a larger size, first, the electron gun is arranged there on the beam incident side of the main electric field lens of the electron gun. The beam trajectory is adjusted by the quadrupole magnet so that the side beam passes through the optimum position of the main electric field lens. Further, on the beam exit side of the main electric field lens, the side beam is adjusted by the quadrupole magnet disposed there to the cathode ray tube valve. By adjusting the beam trajectory so as to concentrate on the panel surface, it is possible to avoid the occurrence of beam spot distortion and misconvergence on the panel surface.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the present embodiment, the same parts as those of the above-described related art will be denoted by the same reference numerals and described.

FIG. 1 is a schematic plan view showing the configuration of a cathode ray tube according to an embodiment of the present invention. In FIG. 1, a cathode ray tube bulb (cathode ray tube main body) 1 is formed of, for example, transparent glass, and includes a panel section 2 and a funnel section 3.
And a neck portion 4. Funnel 3
A deflection yoke 5 is mounted on the cone part extending from the nose to the neck part 4. The neck portion 4 has an in-line type electron gun 6 therein. Further, two quadrupole magnets 10 and 11 are mounted on the outer peripheral portion of the neck portion 4.

The electron gun 6 has three cathodes Kb, Kg, and Kr corresponding to B, G, and R, respectively.
Electrons are emitted from b, Kg, and Kr, respectively. A control electrode group 8 including a plurality of grid electrodes is incorporated in the electron gun 6. By applying a predetermined voltage to each of the plurality of grid electrodes, a main electric field lens 9 is formed inside the control electrode group 8 at a predetermined position in the grid arrangement direction. Each grid electrode forming the control electrode group 8 is provided with three beam passage holes. As an example, the third grid electrode G3 shown in FIG. 2I is provided with three beam passage holes Hb, Hg, Hr corresponding to the B, G, and R electron beams.

On the other hand, the two quadrupole magnets 10, 1
Reference numeral 1 denotes one (neck end side) and the other (panel side) of the cathode ray tube bulb 1 in the central axis direction (left-right direction in FIG. 1) with the position of the main electric field lens 9 as a boundary.
More specifically, in the central axis direction (tube axis direction) of the cathode ray tube bulb 1, the four pole magnet 10 on the neck end side is used.
Is the main electric field lens 9 from the cathodes Kb, Kg, Kr.
The four-pole magnet 11 on the panel side is disposed on the way of the electron beam from the main electric field lens 9 to the deflection yoke 5 (ie, on the beam incident side of the main electric field lens 9). It is arranged on the beam exit side of the main electric field lens 9). These quadrupole magnets 10 and 11 are attached to the neck part 4 of the cathode ray tube bulb 1 as a neck assembly part, for example. Hereinafter, for convenience of description, the quadrupole magnet 10 on the neck end side is referred to as a first magnet 10 and the quadrupole magnet 11 on the panel side is referred to as a second magnet 11.

The first and second magnets 10 and 11 are, for example, constituted by four-pole ring magnets. For example, as shown in FIG. 2 (II), the four-pole ring magnet is configured by superposing two circular ring-shaped magnets (permanent magnets) M1 and M2. It forms four magnetic poles. The two magnets M <b> 1 and M <b> 2 are mounted on the cathode ray tube bulb 1 in a state where their inner peripheral parts are fitted to the outer peripheral part of the neck part 4. In addition, 4
In the polar ring magnet, by rotating the two magnets M1 and M2 in the circumferential direction as appropriate,
The magnetic field intensity can be arbitrarily varied.

The cathode ray tube having such a structure is provided in the panel section 2.
It is incorporated in an apparatus housing together with various accessory parts necessary for reproducing a color image (or a black and white image) on the inner phosphor screen, thereby constituting a display device such as a television receiver or a computer display.

Next, as an operation function of the cathode ray tube having the above-described configuration, for example, when an electron gun optimally designed with a 21 type cathode ray tube is used with a 32 type cathode ray tube, the cathode ray tube of the present embodiment is replaced with a 32 type cathode ray tube. An example in which the present invention is applied to a cathode ray tube will be described.

First, as shown in FIG. 1, the distances L1 and L2 from the cathode position of the electron gun 6 to the panel surface are different between the 21-type cathode ray tube and the 32-type cathode ray tube. Specifically, L1 ≒ 35 cm for 21 type, L for 32 type
It becomes 2ｃｍ50cm, and 32 type is 1.5 more than 21 type
It is almost twice as long.

In such a case, in a 32 type cathode ray tube (cathode ray tube to which the present embodiment is applied), three electron beams emitted in-line from three cathodes Kb, Kg, Kr are applied to a main electric field lens. The magnetic field of the first magnet 10 acts on the beam incident side 9. When the magnetic field of the first magnet 10 in this case is viewed from the panel side, FIG.
(I). At this time, the magnetic field φ1 acting on the side beam B becomes an upward magnetic field, and the magnetic field φ2 acting on the side beam R becomes a downward magnetic field. By these magnetic fields φ1 and φ2, the side beams B and R receive forces F1 and F2 in directions approaching each other. As a result, the trajectories of the side beams B and R are adjusted so as to pass through the optimum positions of the main electric field lenses 9b, 9g and 9r together with the center beam G as shown by the solid line in FIG.

At this time, as described above, the first magnet 1
If the configuration is such that the magnetic field strength of 0 can be varied, it is possible to correct the trajectory shift of the electron beam due to an assembly error of the cathode ray tube or the like.

However, if the side beams B and R proceed along the orbit (trajectory indicated by broken lines in the figure), the electron beam may be concentrated (horizontal misconvergence) at the 32-inch panel surface position P2. become.

Then, a magnetic field of the second magnet 11 is applied to the electron beam passing through the main electric field lens 9 of the electron gun 6 on the beam emission side of the main electric field lens 9. FIG. 4 (II) shows the magnetic field of the second magnet 11 in this case as viewed from the panel side. At this time, the magnetic field φ3 acting on the side beam B becomes a downward magnetic field, and the magnetic field φ4 acting on the side beam R becomes an upward magnetic field. By these magnetic fields φ3, φ4, the side beams B, R receive forces F3, F4 in directions away from each other.
Thereby, the trajectories of the side beams B and R are adjusted so as to converge (convergence) at the 32-inch panel surface position P2 together with the center beam G as shown by the solid line in FIG.

At this time, as described above, the second magnet 1
If the magnetic field intensity can be changed, the orbital deviation of the electron beam due to an assembling error of the cathode ray tube or the like can be corrected, and the electron beam is concentrated according to the panel surface position corresponding to the size of the cathode ray tube. The position can be adjusted. Therefore, even if the configuration of the present embodiment is applied to a 21-type cathode ray tube, it is necessary to adjust the magnetic field strength so that the force applied to the side beams B and R by the magnetic field of the second magnet 11 becomes almost zero. Thus, the operation can be performed without any problem.

As described above, in the cathode ray tube of the present embodiment, by adjusting the trajectories of the side beams B and R by the first and second magnets 10 and 11, three electron beams are provided as shown by the solid lines in FIG. After passing the beams through the optimum positions of the main electric field lenses 9b, 9g, 9r, respectively,
It can be concentrated at the panel surface position P2 of the second type. As a result, three electron guns optimally designed with a 21-type cathode ray tube were used.
When used with a type 2 cathode ray tube, without causing misconvergence in the horizontal direction on the panel surface,
An optimum beam spot can be obtained.

Such an effect can be similarly obtained, for example, when a 21-type electron gun is used in a 25-type or 29-type cathode ray tube. From this, regarding the electron gun for 21 type, a plurality of types (25 type, 2 type,
(9 type, 32 type, etc.). Incidentally, the common electron gun is not limited to the 21 type.

Further, the main electric field lens 9 of the electron gun 6
When the diameters of the electron beams B, G, and R passing therethrough are sufficiently small with respect to the diameters of b, 9g, and 9r, that is, even when the trajectory of the electron beam deviates slightly from the optimal lens position (center of the lens), the coma aberration. In an electron gun hardly affected by the above, the aspect ratio of the beam spot can be easily changed by the action of the magnetic field by the first and second magnets 10 and 11.

In the above embodiment, a four-pole ring magnet is exemplified as the configuration of the four-pole magnet. However, the present invention is not limited to this. For example, as shown in FIG. Magnetic material) Electromagnetic four-pole coil 1 formed by winding coils 13A and 13B around 12A and 12B, respectively
4 may be adopted and attached to the outer peripheral side of the neck portion 4.

When the above-described electromagnetic quadrupole coil 14 is employed, magnetic fields φ5 and φ6 can be generated by applying a DC current to each of the coils 13A and 13B with both ends of each of the cores 13A and 13B as magnetic poles. At this time, the directions of the magnetic fields φ5 and φ6 can be reversed by reversing the direction of the current flowing through the coils 13A and 13B. Regarding the strength of the magnetic fields φ5 and φ6, the coils 13A,
By controlling (adjusting) the level of the current flowing through 13B, the level can be changed arbitrarily.

[0031]

As described above, according to the present invention, four pole magnets are provided on one side and the other side on the boundary of the position of the main electric field lens of the electron gun in the direction of the central axis of the cathode ray tube bulb. When the same electron gun is used for the cathode ray tube, it is possible to simultaneously eliminate the deviation of the electron beam concentration on the panel surface and the spot distortion of the electron beam. This makes it possible to use the same electron gun for cathode ray tubes of different sizes without deteriorating the display image, etc., and it is necessary to design, manufacture, and manage the electron gun for each cathode ray tube size. Disappears. Also,
There is no need to change the design of the electron gun to adjust the beam trajectory according to the size of the cathode ray tube. As a result, the cost of the cathode ray tube can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a configuration of a cathode ray tube according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of components provided in the cathode ray tube of the embodiment.

FIG. 3 is a diagram illustrating the trajectory of an electron beam in the cathode ray tube of the embodiment.

FIG. 4 is a diagram illustrating a magnetic field of a four-pole magnet.

FIG. 5 is a diagram illustrating another configuration example of a four-pole magnet.

FIG. 6 is a schematic plan view showing a configuration of a conventional cathode ray tube.

FIG. 7 is a diagram illustrating the trajectory of an electron beam in a conventional cathode ray tube.

FIG. 8 is a diagram illustrating spot distortion of an electron beam.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 cathode ray tube bulb 2 panel part 3 funnel part 4 neck part 5 deflection yoke 6 electron gun 9
Main electric field lens, 10: first magnet (quadrupole magnet), 11: second magnet (quadrupole magnet)

Claims (3)

[Claims] 1. A cathode ray tube bulb, an in-line type electron gun provided in the cathode ray tube bulb, and one and the other arranged with a main electric field lens position of the electron gun in a center axis direction of the cathode ray tube bulb. Done 2
A cathode ray tube comprising: a four-pole magnet. 2. The cathode ray tube according to claim 1, wherein at least one of the two quadrupole magnets has means for varying the magnetic field strength. 3. A cathode ray tube bulb, an in-line type electron gun provided in the cathode ray tube bulb, and one and the other arranged at a position of a main electric field lens of the electron gun in a center axis direction of the cathode ray tube bulb. Done 2
A display device comprising a cathode ray tube having two four-pole magnets.