JPS59191238A - Deflection yoke - Google Patents

Abstract

PURPOSE:To make compensation or reduction of coma aberration and G drag at a screen corner part by providing at least one pair of auxiliary coils at the electron gun side of a deflection yoke and at left and right positions inside vertical deflection coils and by allowing an electrical current to flow in the reverse direction to that of the vertical deflecting current. CONSTITUTION:At a location inside a vertical deflection coil 3 and on the electron gun side, at leat one pair of auxiliary coils 15 of a ring shape wound almost on the same curved surface or of a similar shape are provided at left and right of the deflection yoke, and are constituted so that an electrical current reverse to the vertical deflection current flowing in the vertical deflection coils may flow in these auxiliary coils. Namely, wire connection is made in such a way that the direction of magnetic field made by the vertical deflection coils inside the core and on the electron beam side may be reverse to the direction of magnetic field made by the auxiliary coils inside the core and on the electron beam side. Accordingly, both or one of misconvergence caused by coma aberration and G drag can be compensated or reduced with a single deflection yoke.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a deflection yoke used by being attached to a cathode ray tube of a television receiver, and more particularly to a deflection yoke for correcting coma aberration.

[↓μ↓]

In the self-convergence deflection yoke used for color cathode ray tubes equipped with in-line electron guns,
As is well known, convergence correction is performed by changing the magnetic field created by the horizontal deflection coil into a pincushion-shaped magnetic field and the magnetic field created by the vertical deflection coil into a barrel-shaped magnetic field. Among the above, the barrel-shaped magnetic field of the vertical deflection coil is:
As shown in FIG. 2, the vertical centerline 9 of the deflection yoke
Since the nearby windings are sparser than those at both ends, the electron beam 8 for green (G) located at the center 1 is for red (R) located at both ends.

The amount of vertical deflection is substantially reduced compared to the electron beam 8 for blue (B), and as shown in the raster pattern in FIG. This results in a misconvergence called so-called coma aberration, which moves to the inside.

Conventionally, as means for correcting this type of coma aberration, the fourth
A magnetic piece called a magnetic field control element 14 as shown in FIG. 5 is placed at the tip of the electron gun 16 of the cathode ray tube (hereinafter referred to as CPT) 19 shown in the figure.5. A method is generally used in which the deflection magnetic field is concentrated near the G electron gun located at the center to relatively increase the amount of G deflection compared to R/H.

By the way, in this method, there is a factor in which the above-mentioned coma aberration fluctuates due to an error in the combination of the CPR and the deflection yoke, and this may result in manufacturing variations. Furthermore, as a phenomenon that is thought to be caused by the difference in the deflection center of the R/B electron beam deflected by the magnetic field created by the deflection yoke and the G electron beam deflected in advance by the magnetic field control element 14 described above, there is a phenomenon shown in FIG. As shown in 18, as the center G electron beam is deflected to the corner of the screen, the amount of deflection decreases compared to the R/B electron beam.

convergence (hereinafter referred to as G-sag), which leads to deterioration of convergence quality.

Now, as a means for adjusting the above-mentioned coma aberration (in the vertical direction in this example), as shown in FIG.

Although a method of arranging magnetic pieces 20 above and below the rear end of the deflection yoke 1 is known, this method cannot increase the amount of deflection that weakens the vertical deflection magnetic field produced by the deflection yoke. Furthermore, as mentioned above, the vertical coma aberration is caused by the small amount of deflection in and around the center of the vertical deflection coil, so it would be better to concentrate the windings in this area. If this is done, the entire magnetic field created by the vertical deflection coil changes to a pincushion-shaped magnetic field, which has the disadvantage of extremely worsening the .epsilon.

[Purpose of the invention]

An object of the present invention is to realize a deflection yoke that corrects or reduces coma aberration with the deflection yoke alone, and also corrects or reduces G sag at the corners of the screen, in order to eliminate the drawbacks of the prior art described above. The goal is to provide a means for

[Summary of the invention]

In order to achieve the above object, the deflection yoke according to the present invention is provided with at least one pair of auxiliary coils on the electron gun side at a position in the left and right direction inside the vertical deflection coil, and a current in the direction opposite to the vertical deflection current is applied to the deflection yoke. This reduces the amount of deflection of the R/B electron beams located at both ends, corrects aberrations between the G li and the child beam located relatively at the center, and It also has a function to correct G sag.

[Embodiments of the invention]

An embodiment of the present invention using a semi-toroidal type deflection yoke (horizontal deflection coil is hollow type, vertical deflection coil is toroidal type) shown in the drawings will be described below. The appearance of the conventional deflection yoke 1 is as shown in FIG. 1, the deflection yoke according to the embodiment of the present invention is shown in FIG. As shown in the figure. Further, a configuration diagram of the deflection yoke according to the present invention is shown in FIG.

As shown in FIG. 10, the deflection yoke according to the present invention has a ring shape or a ring shape wound around the vertical deflection coil 5 (core 4) at a position on the electron gun side within the substantially same curved surface. At least one pair of auxiliary coils 15 each having a shape such as It is something.

In other words, deflection wires are connected so that the direction of the magnetic field created by the vertical deflection coil on the electron beam side inside the core and the direction of the magnetic field created on the electron beam side inside the core by the auxiliary coil are opposite to each other. It's York.

Next, I will explain the principle behind this correction.

First, regarding the cross section of the deflection yoke according to the present invention (11th
Figure (however, only the vertical deflection coil portion is shown) VC is also considered. Pertains to the present invention.

As shown in FIG. 11, the auxiliary coil 15 is provided inside the vertical deflection coil at a position where it acts on the magnetic field at both ends of the vertical deflection coil winding. This auxiliary coil 15 is connected so that a current flows in the opposite direction to the vertical deflection coil of the main deflection, and its effect is as shown by the deflection force 10 in FIG. A strip that has the effect of moving the electron beam in the opposite direction (indicated by e in the figure) and in the opposite direction (indicated by e in the figure).

This auxiliary coil acts partially on the deflection magnetic field created by the main deflection vertical deflection coil near both ends of the coil (in other words, in the range that affects the R/B electron beam trajectory). As shown in FIGS. 11 and 12, this structure has the function of reducing the amount of deflection of the R/B electron beam passing near the auxiliary coil 15.

In addition, the Lorentz force of the force that reduces the amount of deflection of the R/B electron beam by the auxiliary coil 15 increases as the electron beam approaches the deflection coil, so the electron beam is deflected toward the corner of the screen. As it is done,
The amount of deflection of the R/B electron beam tends to further decrease.

Therefore, by providing the auxiliary coil 15 according to the present invention, the amount of deflection of the relative fG electron beam with respect to the R/B electron beam increases as shown in FIG. 12, and the coma aberration 17 is corrected. In addition, misconvergence related to G sag 18 due to the difference between the raster caused by the R/B electron beam and the raster caused by the G electron beam (C) is corrected even in the corner areas of the screen. Due to the above effect, barrel-shaped deflection distortion may occur on the screen, but it is well known that this can be corrected by conventional techniques such as 1. winding distribution of the deflection coil and addition of magnets.) Therefore, by implementing the present invention, the 15th
As shown in the figure, the deflection yoke alone can correct or reduce misconvergence caused by comatic aberration and G sag, or both, resulting in a good raster image. It is a means.

〔Effect of the invention〕

According to the present invention, the magnetic field control element for coma aberration correction on the CPT side is not required or simplified, and misconvergence caused by changes in coma aberration due to G sag and combination errors between the CPT and the deflection yoke is reduced. It can be a practically effective means.

[Brief explanation of drawings]

Figure 1 is a perspective view of a conventional deflection yoke, Figure 2 is a sectional view of a vertical deflection coil, Figure 3 is an explanatory diagram showing coma aberration, and Figure 4 is the positional relationship between the deflection yoke and the electron gun. FIG. 5 is an explanatory diagram showing a magnetic field control element provided near the conventional (, F T electron gun), FIG. 6 is a pattern diagram of misconvergence after coma aberration correction by the magnetic field control element, FIG. 70 is a perspective view of a conventional deflection yoke having a coma aberration adjustment function, FIG. 8 (al is a plan view of the deflection yoke according to the present invention, and FIG. 9 is a perspective view of the auxiliary coil, which is the main part of the present invention, FIG. 10 is a developed view of the structure of the deflection yoke according to the present invention, and FIG. 11 is the vertical deflection coil of FIG. 8 and the auxiliary coil. FIG. 12 is a rear view of the coil, FIG. 12 is a pattern diagram showing changes in the horizontal line raster due to the auxiliary coil of the present invention, and FIG. 13 is a pattern diagram of misconvergence when the present invention is implemented. 1! Deflection yoke, 2: Horizontal deflection coil, 31 Vertical deflection coil, 4+ core, 5I separator (molded product), 6 Toclip, 7; Vertical deflection magnetic field line, 8: Electron beam, 9
: Vertical center line (Y axis), 10 + deflection force, 11
iC'7'T screen, 12°IR, G, B horizontal line raster,
151 is the secondary gun body, 14: magnetic field control element, 15; auxiliary coil, 16 is the horizontal direction 17) center line (X axis), 17s Co-r aberration, 181G sagging component, 19: CPT, 20 + magnetic piece, 21 : Center line of deflection yoke. Hand 1 Figure 2 Figure Sheep 3 Figure 4-4 Figure Sheep 5 Figure Haya 8 Figure Sheep /θ Figure Hand 〃 Figure

Claims (1)

[Claims] 1. On the electron gun side of the deflection yoke, an auxiliary coil having a ring shape or a similar shape with a portion wound approximately parallel to the conductor of the vertical deflection coil at a position in the left and right direction inside the vertical deflection coil. 1. A deflection yoke characterized in that at least one pair of yoke are provided, and a current in a direction opposite to the vertical deflection current is passed through the yoke.