JPS63308491A - Convergence correcting device - Google Patents

Abstract

PURPOSE:To correct an erroneous convergence due to the frame aberration of a vertical center beam without applying no influence to a side beam by disposing plural sets of coils forming the magnetic field of plural electrodes in the vicinity of the electron gun of a cathode-ray tube. CONSTITUTION:At the time of correcting the frame in a four pales magnetic field, the side beams 3b, 3r receive vertical force 3 according to the horizontal magnetic field of the four pales magnetic field formed by the correcting coil. Consequently, the side beams 3b, 3r are displaced from an X axis and incident on a vertical deflecting magnetic field 9 forming a barrel shape magnetic field, so that a second correcting coil for forming a two pales magnetic field 6 is disposed and superimposed on the four pales magnetic field 4 to have the distribution state of the magnetic field of the proper intensity. Thereby, the side beams 3b, 3r are made incident on the vertical deflecting magnetic field 9 without the displacement from the X axis to prevent the generation of the erroneous convergence and obtain the picture of good quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a convergence correction device used in an image display device that combines an in-line color cathode ray tube and a self-convergence type deflection yoke.

[Conventional technology]

In a color television receiver or color display device equipped with an in-line electron gun and a combination of a color cathode ray tube and a self-convergence type deflection yoke, the horizontal magnetic field of the deflection yoke generally has a pincushion-shaped magnetic field distribution. However, the vertical deflection field has a barrel-shaped field distribution.

It is known that this causes misconvergence of the center beam due to coma as shown in FIG. 9. - In order to correct the misconvergence mentioned above, as shown in FIG. Controller C and below FC
In many cases, a correction method was used in which magnetic pieces 102a and 102b (abbreviated as ) were attached to the electron guns B, G, and RL of the cathode ray tube 2.

In addition, in color cathode ray tubes where this FC is not installed in the electron gun, a correction coil that forms a 4-pole magnetic field or a 6-pole magnetic field is placed near the neck of the cathode ray tube, and the coil L is vertically deflected. Misconvergence caused by coma aberration in the vertical direction was corrected by passing a periodic sawtooth wave current.

[Problem that the invention seeks to solve]

However, when the horizontal deflection frequency is higher than that of ordinary televisions (for example, 6
4KHz) Eddy currents are generated in the FC due to the high frequency deflection magnetic field applied to the FC, and the calculated appropriate coma correction is impaired due to fluctuations in the FC's magnetic field due to the eddy currents.
There was a problem in that misconvergence occurred and the picture quality on the cathode ray tube deteriorated.

In addition, when using a cathode ray tube without FC, coma correction in the horizontal direction is performed by appropriately setting the magnetic field distribution in the tube axis direction of the horizontal deflection magnetic field when a saddle coil is used as the horizontal deflection coil. Correction is possible by

On the other hand, for coma correction in the vertical direction, a self-convergence type deflection yoke generally uses a vertical deflection coil (b) or a toroidal coil. Setting the distribution appropriately is very difficult. Therefore, a set of correction coils that generate a 4-pole magnetic field or a 6-pole magnetic field is disposed near the neck of the cathode ray tube 2, and a sawtooth wave current having a vertical deflection period is passed through the correction coils to perform correction. is used.

Here, when performing coma correction in the vertical direction by the above-mentioned correction coil (hereinafter referred to as correction coil), three electron beams 3b, 3 are generated by the magnetic field generated by the correction coil.
g and 3r each receive a deflecting force. That is, the three electron beams 3b, 3g,
When 3r is incident, the side beams 3b and 3r take trajectories displaced from the X axis due to the force of the magnetic field, and the side beams 3b and 3r at the top and bottom sides of the screen of the cathode ray tube 2 receive a horizontal force. The lateral convergence of will also change at the same time, resulting in misconvergence.

This misconvergence of the side beams 3b and 3r can be corrected by changing the vertical deflection magnetic field distribution in design, but from this correction, the vertical misconvergence of the side beams 3b and 3r at the four corners of the cathode ray tube screen can be corrected. It will occur. That is, the trilemma changes, causing a problem that it becomes difficult to maintain convergence quality over the entire screen.

Also, when performing optimal correction by varying the amount of correction of the coil to compensate for variations in comatic aberration caused by variations in mass production of deflection yokes and cathode ray tubes, the side beams 3b at the top and bottom sides of the screen are simultaneously adjusted.

3r lateral misconvergence occurs, resulting in a problem of deteriorating screen quality.

The purpose of this invention is to solve these problems and provide a convergence correction device with a simple configuration that corrects misconvergence caused by coma aberration of the center beam in the vertical direction without affecting the side beams in any way. do.

[Means for solving problems]

To achieve the above objective, the specific means used is an image display device consisting of a combination of an in-line cathode ray tube and a self-convergence type deflection yoke, in which multiple sets of coils that generate a multi-pole magnetic field are arranged near the electron gun of the cathode ray tube. The convergence correction device is characterized in that the coma aberration of the center beam is corrected for misconvergence that occurs when the center beam is vertically deflected by a composite magnetic field generated by combining the coils.

[Effect]

By using the above means, the electron beam emitted from the electron gun is corrected to a trajectory that does not cause coma aberration by the composite magnetic field generated by the plurality of coils b, and the occurrence of misconvergence is prevented and a high-quality image is obtained. can get.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 1 shows the magnetic field generated by the correction coil 1 and the three electron guns R installed in-line in the cathode ray tube 2.
, G, and B. FIG.

The correction coil 1 is wound around the E-type core 1a, and a sawtooth wave current IV having a vertical deflection period is passed through the correction coil 1.

The sawtooth wave current Jvl collectively generates six magnetic poles and a magnetic field distribution as shown in the figure. The distribution of the generated magnetic field and the strength of the magnetic field are determined by the number of turns of the correction coil 1a and the I of the sawtooth wave current.
It can be changed depending on the size of v.

Figures 2, 3, and 6 show the first embodiment of the present invention, and Figure 2 shows the magnetic field distribution when performing coma correction with a correction coil that generates a quadrupole magnetic field. It is something that As shown in FIG. 2, when coma correction is performed using a quadrupole magnetic field, the side beams 3b and 3r receive a vertical force 3 due to the horizontal magnetic field of the quadrupole magnetic field generated by the correction coil. As a result, as shown in Fig. 3, the side beams 3b and 3r are
Displaced from the axis and incident on the vertical deflection magnetic field 9 that generates a barrel-shaped magnetic field, the horizontal component of the cuff causes lateral misconvergence at the upper and lower sides of the cathode ray tube screen. As a countermeasure for this improvement, a bipolar magnetic field 6 as shown in Fig. 6 is used.
By disposing a second correction coil that generates a magnetic field and superimposing it on the quadrupole magnetic field 4 shown in FIG. 2 and the magnetic field distribution state of appropriate strength, the side beam 3b is ,
3r enters the vertical deflection magnetic field 9 without being displaced from the X axis. By using the above-mentioned means, it is possible to solve the misconvergence in which the convergence at the upper and lower sides of the cathode ray tube screen deviates, and to perform coma correction of the center beam. Also,
While keeping the ratio of the strength of the two-pole magnetic field and the four-pole magnetic field somewhat constant,
By changing the strength of each magnetic field, the side beam 3b
, 3r, it becomes possible to vary the coma correction amount of the center beam 3g.

Next, Fig. 4, Fig. 5, and Fig. 7 show a second embodiment of the present invention. Although the distribution is opposite to that of the quadrupole magnetic field 4 in the first embodiment, the side beams 3b and 3r receive a vertical component force 3, and as shown in FIG. Since the beam is displaced from the X axis and enters the vertical deflection magnetic field 9 and receives a horizontal component force 8, lateral misconvergence of the side beam occurs at the upper and lower sides of the screen of the cathode ray tube. Therefore, the two-pole magnetic field 6 of opposite polarity to the two-pole magnetic field used in the case of the four-pole magnetic field shown in the first embodiment is superimposed on the six-pole magnetic field 5 at an appropriate strength ratio as shown in FIG. Then, the barrel-shaped vertical deflection magnetic field enters the side beam without being displaced from the X-axis, so coma correction of the center beam can be performed without affecting the convergence of the side beam.

Furthermore, a combination of a 4-pole magnetic field and a 6-pole magnetic field ~ and a 2-pole magnetic field,
The ratio of the strength of each magnetic field is set to an appropriate amount so that the side beam does not displace from the X axis even in the combination of a 4-pole magnetic field and a 6-pole magnetic field. It becomes possible to perform coma correction of the center beam without deteriorating convergence.

The present invention is not limited to the above-mentioned embodiments, but can be implemented in various ways.

〔Effect of the invention〕

As explained above, by using the present invention, a composite magnetic field formed by a combination of any two or all combinations of the two-pole magnetic field, the four-pole magnetic field, and the six-pole magnetic field generated by the correction coil is used. Since it is possible to perform coma correction in the deflection direction, and the center beam can be corrected without affecting the side beam distortion, it is possible to correct the deterioration of the convergence of the side beams due to the trilemma, which changes the various conditions for achieving convergence.
Even when the correction amount is varied to optimize coma correction during mass production, the side beam convergence does not deteriorate, and the field controller (FC)
Appropriate convergence is achieved without being affected by the horizontal deflection frequency, and the screen quality of the cathode ray tube can be maintained at good quality.

Further, the correction coil according to the present invention has a simple shape and structure, and the cost required for its structure, installation, etc. is low.

The above effects provide a convergence correction device that has a simple configuration and corrects misconvergence due to coma aberration.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of one embodiment of the present invention, and FIG.
The figure is an explanatory diagram of coma correction by generation of a quadrupole magnetic field of the correction coil in the first embodiment, FIG. 3 is a diagram showing the deflection magnetic field received by the electron beam in the first embodiment, and FIG.
FIG. 6 is a diagram showing correction of an electron beam by generation of a dipole magnetic field of a correction coil in an embodiment. Further, FIG. 4 is an explanatory diagram of coma correction by the six-pole magnetic field of the correction coil in the second embodiment, and FIG. 7 shows the correction of the electron beam by the generation of the two-pole magnetic field of the correction coil in the second embodiment. In the figure, FIG. 8 shows a diagram in which the side beam is corrected and is incident on the vertical deflection magnetic field. 9 and 10 show examples of the prior art. ■...Correction coil 2...Cathode ray tube 3...
Vertical force received by the magnetic field of the correction coil 3r...Red electron beam (side beam) 3g...i
Electron beam (center beam) 3b... Blue electron beam (side beam) R, G, B... Electron gun 4...4
Polar magnetic field 5...6 polar magnetic field, field 6...2 polar magnetic field 7
...Horizontal component of the force exerted on the side beam from the vertical deflection magnetic field when coma correction is made with a 4-pole magnetic field 8...Horizontal component 9 of the force exerted on the side beam from the vertical deflection magnetic field when coma correction is made with a 6-pole magnetic field ...Vertical deflection magnetic field Figure 1 Figure 2 Figure 7 Figure 8 Procedure correction writing method) % formula % 1, Incident display 1988 Patent Application No. 1682 2, Name of the invention Convergence correction device 3, Relationship with the person making the amendment Patent applicant address 3-12-4 Moriya-cho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture
, Date of amendment order" June 28, 1986 (shipping date) 5. Column 6 for a brief explanation of the drawings of the specification subject to amendment, Contents of amendment (1) Specification, page 11, line 13 'Ari,' and '7th
``Figure 5 is a diagram showing the deflection magnetic field received by the electron beam h< in the second embodiment'' is inserted between ``Figure 5''.

Claims (1)

[Claims] In an image display device consisting of a combination of an in-line cathode ray tube and a self-convergence type deflection yoke, a plurality of coils that generate a multi-pole magnetic field are disposed near the electron gun of the cathode ray tube, and a composite magnetic field generated by the combination of the coils is used. A convergence correction device that corrects misconvergence that occurs when coma aberration of a center beam is vertically deflected.