JP2002358912A - Cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct horizontal deflection field acting in an unbalanced manner on a side beam and a center beam for satisfying convergence performance, aim at stabilization of convergence performance and unification of an electron gun, and respond to a quick design change. SOLUTION: With the cathode-ray tube supplying high voltage to an electron gun 1 placed at a neck part of a glass bulb through an inner conductive film 12 formed on the inside face of the glass bulb and forming three both-side and center-electron beams arrayed almost in parallel on one horizontal face, the resistance value of the inner conductive film of the neck part on which horizontal deflection field acts by a deflection yoke 11 deflecting the electron beams is differentiated from that at the deflection field part acting on the side beams to that acting on the center beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cathode ray tube,
In particular, it relates to a cathode ray tube used at a high horizontal deflection frequency.

[0002]

2. Description of the Related Art As a countermeasure against misconvergence when a horizontal deflection frequency is increased, a shield electrode structure is disclosed in, for example, Japanese Patent No. 2760783. 5 and 6
Is a conventional in-line type electron gun for a cathode ray tube (hereinafter, referred to as a gun) provided with a screen member in a shield cup of a shield electrode.
FIG. 5A is a front view of the electron beam viewed from the upstream side, FIG. 5B is a side view thereof,
FIG. 6 is a perspective view of the partition member.

In FIG. 1, reference numeral 1 denotes an electron gun, and 2 denotes a cylindrically formed shield cup, which is provided at an end of the electron gun 1 in the direction of electron beam travel, and has a center and both sides substantially parallel in a horizontal plane. It has electron beam passage holes 3s, 3c, 3s through which the electron beam passes and a peripheral wall 2a extending in the electron beam traveling direction. The shield cup 2 is formed of a non-magnetic metal in a cylindrical shape, and is disposed at the end of the electron gun 1 on the fluorescent screen side to shield an electron beam from electrostatic charges charged on the inner surface of the color cathode ray glass bulb.

[0004] Reference numeral 3c denotes a central electron beam (hereinafter, referred to as a center beam) passage hole among the three electron beams, and 3s.
Is a hole through which electron beams (hereinafter referred to as side beams) on both sides are shown, and 4 is a partition member attached to the shield cup 2 and is formed of a non-magnetic metal. It has a pair of partitions 5, 6 extending in the traveling direction.

[0005] In recent years, the horizontal deflection frequency has tended to increase as the in-line type cathode ray tube has become higher in definition. However, in line with this higher frequency and higher performance requirements, the convergence between the center beam and the side beam arranged in a straight line has been increasing. There was a problem that performance could not be satisfied.

The problem of the convergence performance is that the horizontal deflection magnetic field generated by the deflection yoke mounted near the connection between the funnel of the cathode ray tube and the neck tube is perpendicular to the side surface of the electron gun 1 around the shield cup 2. Pass. Therefore, an eddy current is generated on the side surface of the component centering on the shield cup 2 in accordance with the change of the magnetic flux. Therefore, it is considered that a new magnetic flux is generated so as to cancel the change of the magnetic flux, and the magnetic flux acting on the electron beam changes with a time delay compared to the case where the shield cup 2 is not provided.

Usually, since the electron gun parts are elliptical or cylindrical, the eddy current generated from the horizontal deflection magnetic field passing vertically through the center beam and the side beam is not uniform, and the horizontal deflection magnetic field has a pincushion shape. Because
The eddy current acting on the side beam becomes weak because it has a certain angle from the direction perpendicular to the magnetic flux. The time delay between the center beam and the side beam causes misconvergence, and the screen 7C scanned by the center beam as shown in FIG.
However, it is shifted to the right as compared with the screen 7S scanned by the side beam. This misconvergence cannot be ignored with the recent increase in horizontal deflection frequency.

Usually, in order to improve the convergence characteristics, a pair of non-magnetic metal partitions 5, 6 are formed on both sides of the side beam passage holes 3s in the arrangement direction.
Is provided to reduce the horizontal deflection magnetic field acting on the side beams due to the eddy current generated in the partitions 5, 6, so that the horizontal deflection magnetic fields acting on the three electron beams in the in-line arrangement are equalized.

[0009]

The conventional electron gun for a cathode ray tube is constructed as described above, and the partitions 5 and 6 constituting the partition member 4 are separated from the flat portion having the electron beam passage hole of the partition member 4. It is bent at 90 degrees, has a plate thickness of about 0.3 mm to 0.6 mm, and has a length extending in the electron beam traveling direction of about 4 mm to 8 mm. Therefore, the screen tends to be deformed by external human or mechanical contact after the screen is fixed, and if deformed, eddy currents generated in the screen parts 5 and 6 tend to vary, and convergence tends to occur in characteristics. .

[0010] Therefore, in the subsequent steps, it is necessary to perform the work with great care so as not to deform the partitions 5 and 6. Further, since the partition member 4 is welded to the bottom 2b of the shield cup 2 with a welding margin 9, the shield cup 2
The partition member 4 must be welded in advance and attached to the sub-assembled electron gun 1, and its shape must be determined at the stage of designing the electron gun. Therefore, when the use of the horizontal deflection magnetic field is increased and the deflection yoke is changed due to the change of the horizontal deflection magnetic field, the electron gun must be redesigned, resulting in a large time loss.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In order to satisfy convergence performance without using an electron gun partitioning part, the present invention acts unbalanced on a side beam and a center beam. An object is to correct a horizontal deflection magnetic field, improve misconvergence, and satisfy convergence performance.

[0012]

A cathode ray tube according to the present invention has an internal conductive film formed on an inner surface of a glass bulb, and is disposed at a neck portion of the glass bulb through the internal conductive film.
In a cathode ray tube that supplies a high voltage to an electron gun that forms a total of three electron beams at the center and on both sides substantially parallel in one horizontal plane, a deflection yoke that deflects the electron beam acts on the inside of a neck portion where a horizontal deflection magnetic field acts. It is characterized in that the resistance value of the film is different between the deflection magnetic field portion acting on the side beam and the deflection magnetic field portion acting on the central electron beam.

In the cathode ray tube according to the present invention, an inner conductive film is formed on the inner surface of the glass bulb, and the inner conductive film is disposed at the neck of the glass bulb through the inner conductive film. In a cathode ray tube for supplying a high voltage to an electron gun for forming three electron beams, a deflection yoke for deflecting the electron beam is used to deflect the resistance value of the internal conductive film at the neck where a horizontal deflection magnetic field is applied to the side beam. The magnetic field portion is different from the deflection magnetic field portion acting on the central electron beam, and a metal deposition film is formed on the outer surface or the inner surface of the neck portion of the deflection magnetic field portion acting on the side beam. Things.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, the present invention will be described with reference to the drawings showing the first embodiment. FIG. 1 is a configuration diagram of a cathode ray tube. A deflection yoke 11 for generating a horizontal deflection magnetic field and a vertical deflection magnetic field for deflecting the electron beam emitted from the in-line type electron gun 1 is provided in the cathode ray tube 10.
Is attached.

FIG. 2 is a partially enlarged view of FIG. 1, and shows the positional relationship among the electron gun 1, the deflection yoke 11, and the internal conductive film 12. As shown in FIG. An inner conductive film 12 for supplying a high voltage applied from an anode 13 to the electron gun 1 is formed on the inner surface of the neck portion of the cathode ray tube 10.
Overlap with the portion on which the horizontal deflection magnetic field acts.

FIG. 3 is a cross-sectional view taken along line AA of the overlapping portion of the internal conductive film 12 with the horizontal deflection magnetic field. S is an electron gun 1
Are the inner side beams of the three electron beams emitted from, and C is the center beam. Reference numeral 11 denotes a deflection coil, and arrow 14 denotes a pin-shaped magnetic field generated by the coil. 12S is an internal conductive film portion where a horizontal deflection magnetic field acting on the side beam S intersects, and 12C is an internal conductive film portion where a deflection magnetic field acting on the center beam intersects and has different resistance values. Usually, the eddy current acting on the center beam is larger than that of the side beam as described above.
To smaller.

The internal conductive film thus configured generates relatively more eddy currents acting on the side beams than the center beam, and can equalize the eddy currents acting on the center beam and the side beams. The horizontal deflection magnetic fields acting on the three electron beams can be made equal.

Further, since the screen is not used in the electron gun, the screen is not deformed by human or mechanical contact after the screen is fixed.
Quality stabilization of desired convergence performance is achieved.

Embodiment 2 FIG. In the second embodiment, a conductive portion is formed by depositing a metal on a neck portion and the first embodiment.
Is a combination of FIG. 4 is a cross-sectional view in which a metal deposition film is formed on a portion acting on a side beam.
In FIG. 4, reference numeral 15 denotes a metal deposition film. An eddy current can be generated in the deposited film by the horizontal deflection magnetic field applied to the side beam emitted from the electron gun. Since the metal deposited film 15 is formed on the portion acting on the side beam, the difference in resistance between the center and both ends can be increased, and the balance adjustment range can be further increased. Although FIG. 4 showing the second embodiment has a metal deposited film formed on the outer surface of the neck portion, a similar effect can be obtained by forming the deposited film on the inner surface of the neck portion.

[0020]

As described above, the quality is stabilized without using an electron gun partition member necessary for improving the convergence performance in the electron gun, and a design change involving a change in the horizontal deflection magnetic field, and An early introduction of performance improvement can be expected for variations. In addition, introduction of multiple types of deflection yoke,
Even if the convergence performance changes with a change in the horizontal deflection magnetic field such as an increase in the horizontal deflection frequency, the unification of the electron guns can be easily achieved, and the effect of reducing the loss due to the stock of the electron guns can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a cathode ray tube according to a first embodiment.

FIG. 2 is a partially enlarged view of FIG. 1 showing the cathode ray tube of the first embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. 2 of the first embodiment.

FIG. 4 is a sectional view of a second embodiment.

5A is a front view of a conventional electron gun, and FIG.
(B) is a side view.

FIG. 6 is a perspective view showing a conventional partition member.

FIG. 7 is an explanatory view showing a conventional misconvergence.

[Explanation of symbols]

Reference Signs List 10 cathode ray tube, 11 deflection yoke, 12 internal conductive film, 15 deposited film

Claims (2)

[Claims] 1. An internal conductive film is formed on an inner surface of a glass bulb, and the electron conductive film is disposed on a neck portion of the glass bulb through the internal conductive film to form a total of three electron beams substantially parallel to a center and both sides in a horizontal plane. A cathode ray tube for supplying a high voltage to the electron gun; a deflection yoke for deflecting the electron beam, a deflection yoke for deflecting the electron beam; And a deflection magnetic field portion acting on a center beam. 2. An internal conductive film is formed on the inner surface of the glass bulb, and the electron conductive film is formed on the neck portion of the glass bulb through the internal conductive film to form a total of three electron beams at the center and both sides substantially parallel in a horizontal plane. A cathode ray tube for supplying a high voltage to the electron gun; a deflection yoke for deflecting the electron beam, a deflection yoke for deflecting the electron beam; A cathode ray tube, wherein a metal deposition film is formed on an outer surface or an inner surface of the neck portion of the deflection magnetic field portions acting on the electron beams on both sides, differently from a deflection magnetic field portion acting on the center beam. .