JPS62170133A - Deflecting yoke - Google Patents

Abstract

PURPOSE:To control the deflection amount of a raster and thereby enable the fundamental pincushion distortion and the higher order pincushion distortion produced on the screen of a wide angle deflection cathode-ray tube to be corrected by providing auxiliary coils for the vertical deflection in a deflection yoke. CONSTITUTION:The pieces of magnetic material 6 are arranged at the upper and lower portions of a deflecting yoke 1, wound vertical auxiliary coils 7 solenoidally on nearly in parallel with the vertical deflecting coils 3 and a vertical deflecting current or its branch current is made flow through this vertical auxiliary coils 7. For this reason, the vertical auxiliary coils 7 produce the lines of magnetic force 9, increase the deflecting force 10 in the direction of the vertical axis acting on the electron beam at the neighborhood of the vertical auxiliary coils 7 and correct the fundamental pincushion distortion of a raster on a cathode-ray tube screen. Furthermore, the auxiliary coil 7 being divided into three parts 7a-7c and the winding direction of each auxiliary coil or the direction of current being constituted so as to be in opposite direction to each other, so each of the auxiliary coils 7a-7c produces magnetic fields 9a-9c respectively and thereby can correct the higher order pincushion distortion on the cathod-ray tube acreen.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a cathode ray tube (picture tube), which is disposed between the screen side and the electron gun side, and which horizontally directs the electron beam emitted from the electron gun. , relates to a deflection yoke equipped with horizontal and vertical deflection coils for deflecting vertically and projecting it toward the screen.More specifically, it deals with basic pincushion distortion and high-order distortion that occur on wide-angle deflection cathode ray tube screens. The present invention relates to such a deflection yoke, which is provided with means for effectively correcting pincushion distortion.

[Background of the invention]

Examples of a deflection yoke in which an auxiliary coil is provided in addition to the main horizontal (or vertical) deflection coil are disclosed in JP-A-56-82553, JP-A-57-151155, and JP-B-Sho 58-9541. Examples include those described in .

However, the coil provided on the deflection yoke screen side as disclosed in Japanese Patent Application Laid-Open No. 56-82553 is limited to (local) color purity correction of the cathode ray tube, and is used only for wide angle deflection cathode ray tube screens. No consideration was given to correcting pincushion distortion occurring in the upper region.

Furthermore, in Japanese Patent Application Laid-open No. 57-151155, 4
As a means for correcting the following vertical pincushion distortion, a technique has been disclosed in which various shapes of saddle-shaped horizontal deflection coils are specified to correct the fourth-order vertical pincushion distortion generated by the horizontal deflection magnetic field component. It is limited to vertical pincushion distortion, and there is no description of correction means for higher-order distortion or basic pincushion distortion. Also, the correction magnetic field is limited to that related to horizontal deflection magnetic fields, and there is no mention of vertical deflection magnetic fields. It was something that had not been done yet.

Next, Japanese Patent Publication No. 58-9541 shows an example in which an auxiliary deflection coil is connected in series with a crescent-shaped deflection coil. It is limited to correction of convergence patterns, and furthermore, as the specification states, ``There is no risk of co-occurrence of raster differences,'' no consideration is given to the amount of correction for pincushion distortion. This was something that had not been done.

[Purpose of the invention]

An object of the present invention is to provide a deflection yoke capable of correcting pincushion distortion that is likely to occur in wide-angle deflection cathode ray tubes, that is, its basic distortion and higher-order pincushion distortion (distortion that cannot be approximately approximated by a quadratic curve). be.

[Summary of the invention]

The deflection yoke according to the present invention is arranged in a picture tube between the screen side and the electron gun side, and deflects the electron beam emitted from the electron gun in horizontal and vertical directions so that it hits the screen side. A deflection yoke equipped with horizontal and vertical deflection coils for the purpose of the present invention, wherein magnetic pieces are provided in pairs at the upper and lower parts of the front of the yoke as viewed from the screen side, and the magnetic pieces are provided with horizontal and vertical deflection coils for the vertical deflection. The device is characterized in that an auxiliary coil connected in parallel or in series with the coil is wound, and raster pincushion distortion occurring on the screen is corrected by a vertical deflection current flowing through the auxiliary coil.

[Embodiments of the invention]

The present invention will now be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention.

In the same figure, ■ is a deflection yoke, 2 is a horizontal deflection coil,
3 is a vertical deflection coil, 4 is a core, 5 is a molded product,
6 is a magnetic material piece, and 7 is a vertical auxiliary coil.

FIG. 1A is a plan view of the vertical auxiliary coil 7 wound around the magnetic piece 6 in FIG. 1. Figures 1B and 1C are circuit diagrams showing the connection relationships of the vertical auxiliary coil 7, respectively. Figure 1B shows an example in which the vertical auxiliary coil 7 is connected in series with the vertical deflection coil 3, and Figure 1C is a circuit diagram in which the vertical auxiliary coil 7 is connected in series with the vertical deflection coil 3. An example is shown below. In addition, in FIG. 1C, 8 is a variable resistor.

As seen in these figures, the deflection yoke 1 as an embodiment of the present invention has magnetic pieces 6 arranged at the top and bottom of the front as seen from the screen side, and a solenoid-shaped magnetic piece 6. A vertical auxiliary coil 7 is wound approximately parallel to the vertical deflection coil 3.

The vertical deflection current or a branch thereof is made to flow through the vertical auxiliary coil 7. Further, the magnetic piece 6 is installed on the screen side of the deflection yoke l, so that the function of the magnetic piece 6 to shunt the main vertical deflection magnetic field generated by the vertical deflection coil 3 is minimized.

Therefore, the vertical auxiliary coil 7 has the function of generating magnetic lines of force 9 as shown in FIG. 2 and increasing the deflection force 10 in the vertical axis direction acting on the electron beam (not shown) in the vicinity of the vertical auxiliary coil 7. Motsu. This makes it possible to correct the raster basic pincushion distortion 11 on the cathode ray tube surface as shown in FIG. 3(a).

Further, as shown in FIG. 4, the vertical auxiliary coil 7 is 7a,
Divided into 7b and 7c, the winding direction or current direction of each auxiliary coil is opposite to each other, such as 7a in the 13a direction, 7b in the 13b direction, and 7C in the 13c direction. If configured, each auxiliary coil 7a, 7b, 7
c are magnetic fields 9a, 9b, 9, respectively, as shown in FIG.
c and the deflection force 1 due to them on the electron beam
0a, 10b, and 10c are similarly shown in FIG. 5, and it is possible to correct the raster high-order pincushion distortion 12 on the cathode ray tube surface as shown in FIG. 3(b).

As shown in FIG. 1C, when the vertical deflection coil 3 and the vertical auxiliary coil 7 are connected in parallel, a resistor 8 is installed on the side of the vertical auxiliary coil 7 to control the shunt ratio between the vertical deflection coil 3 and the vertical deflection coil 3.
(or a variable resistor), it is possible to adjust or control the amount of correction of raster pincushion distortion on the cathode ray tube surface.

In addition, the vertical auxiliary coil 7 used in the present invention is adapted to the shape of the pincushion distortion that must be corrected, as shown in FIG. 3(b), where the distortion near the center of the screen is larger than that at both ends of the screen. In the case of a high-order pincushion distortion 12, for example, as shown in FIG. It is also effective to adopt a shape of the vertical auxiliary coil 7 that is convex toward the side (or convex toward the electron gun side, although not shown), or convex in both directions as shown in FIG. 6(b).

In addition, the vertical auxiliary coil needs to be able to appropriately form a correction magnetic field in a shape that follows the shape of the pincushion distortion that needs to be corrected. By dividing the vertical auxiliary coil 7 into two or three pieces including the magnetic material piece 6 as shown in FIG. It is possible to correct it.

As a next modified example, as shown in FIG. 9, both ends of the magnetic piece 6 are bent in the direction of the center axis of the deflection yoke in order to effectively guide the correction magnetic field created by the vertical auxiliary coil 7 to the electron beam side. It is possible to consider a structure in which the bent portion 14 is formed by

The principle of distortion correction for pincushion distortion using such a vertical auxiliary coil is the same as described above, but the bending portion 14 brings the distance between the magnetic piece 6 and the electron beam closer, improving the correction efficiency. can be done.

In yet another embodiment, the vertical auxiliary coil 7 is
It is possible to consider the shapes shown in FIG. 1 and FIG. 11, respectively.

FIG. 10 shows a device in which a protrusion 15 extending from both ends of the magnetic piece 6 toward the screen is provided, and a vertical auxiliary coil 7 is provided on the protrusion 15.

The feature of the embodiment using such a vertical auxiliary coil is that the vertical deflection coil 3 wound around the main core (not shown) and the vertical auxiliary coil 7 wound around the protrusion 15 of the magnetic piece 6 provided inside the deflection yoke are mutually connected. The reason is that the wires are wound approximately at right angles to.

Note that 13 indicates the direction of the current flowing through the vertical auxiliary coil 7.

With this configuration, the auxiliary magnetic field for vertical deflection created by the vertical auxiliary coil 7 is formed approximately at right angles to the main vertical deflection magnetic field, so that the magnetic field created by the vertical auxiliary coil does not adversely affect the main vertical deflection magnetic field. For example, the occurrence of a situation in which convergence performance deteriorates can be minimized.

In FIG. 11, the distance between the protrusions 15 is reduced, and the shape of the correction magnetic field is changed.

Next, FIG. 12 shows a front view of an embodiment in which the vertical auxiliary coil shown in FIG. 10 is attached to the deflection yoke. Explain the principle of

As seen in FIG. 12, vertical auxiliary coils 7a, 7b
are wound and wired around protrusions 15a and 15b at both ends of the magnetic piece 6, respectively, and each coil 7a and 7b has a coil 13a in FIG. 12A.

The wires are wound or connected so that currents in opposite directions flow as shown in 13b, respectively, and generate magnetic fields in opposite directions, and the vertical auxiliary coils? a.

The magnetic field (magnetic force lines 9) generated by the magnetic field 7b is formed from one protrusion 15b extending toward the screen toward the other protrusion 15a.

This magnetic field has a generally pincushion-shaped magnetic field and can form a pincushion distortion correction magnetic field. (This generates a deflection force of 10 for the electron beam, making it possible to correct pincushion distortion.) In addition, FIG. For example, the coil current direction 1 as shown in the same figure.
3a to 13d and magnetic fields (magnetic lines of force 9a to 9c), the effect of increasing the amount of deflection of the electron beam at the center of the screen and decreasing the amount of deflection at both ends of the screen can be obtained. This is effective for correcting high-order pincushion distortion as shown in b).

FIG. 14 also shows the main body portion of the magnetic piece 6 and the protruding portion 15.
Although a vertical auxiliary coil 7 is shown wound on both sides, it is clear from the above explanation that pincushion distortion can also be effectively corrected by this.

It goes without saying that 13 indicates the direction of the current flowing through each coil, and 9 indicates the lines of magnetic force.

For reference, FIG. 15 shows the effect of correcting pincushion distortion by the vertical auxiliary coil 7 shown in FIG. 1A.

FIG. 15(a) shows the vertical auxiliary coil 7 used in the experiment.
Figure (b) is a graph showing how the pincushion distortion is corrected when the vertical auxiliary coil 7 is attached to the deflection yoke l, which shows that the pincushion distortion can be corrected by the present invention. will be understood.

Figure 15(c) is a diagram used to explain the definition of pincushion distortion.As shown in the figure, the vertical length of the screen is d, the maximum dimension of the superstructure is a, and the maximum dimension of the superstructure is b. It is well known that , is defined as .

〔Effect of the invention〕

According to the present invention, by providing an auxiliary coil for vertical deflection in the deflection yoke, it is possible to control the amount of raster deflection. It has the effect of correcting pincushion distortion and can provide good screen performance.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention, Fig. 1A is a plan view of the vertical auxiliary coil in Fig. 1, Fig. 1B, Fig. 1
Figure C is a circuit diagram showing the connection relationship of the vertical auxiliary coils, Figure 2 is a diagram explaining the principle of the distortion correction effect by the vertical auxiliary coil provided according to the present invention, and Figure 3 (a) is a basic pincushion of raster on the cathode ray tube surface. Explanatory diagram showing distortion, Fig. 3(b)
FIG. 4 is a plan view showing another example of the vertical auxiliary coil used in the present invention, and FIG.
FIG. 6(a) is an explanatory diagram of the magnetic field and deflection force generated when the auxiliary coil shown in FIG. 4 is used. (b) is a plan view showing still another example of the vertical auxiliary coil used in the present invention, FIGS. 7 and 8 are plan views showing another example of the vertical auxiliary coil used in the present invention, and FIG. 10 and 11 are respectively plan views showing still further vertical auxiliary coils, and FIG. 12 is a front view showing another embodiment of the present invention. , Fig. 12A is an explanatory diagram of the magnetic field generated from the vertical auxiliary coil in Fig. 12, Fig. 13, Fig. 1
4 is a plan view showing still other vertical auxiliary coils that can be used in the present invention, FIG. 15(a) is an explanatory diagram of the dimensional relationship of the vertical auxiliary coils used experimentally, and FIG. 15(b) is the experimental results. FIG. 15(c) is an explanatory diagram used to explain the definition of pincushion distortion. Explanation of symbols 1... Deflection yoke, 2... Horizontal deflection coil, 3...
・Vertical deflection coil, 4... Core, 5... Molded product, 6... Magnetic material piece, 7... Vertical auxiliary coil, 8
...Resistance, 9... Lines of magnetic force, 10... Deflection force, 11
...Basic pincushion distortion, 12...Higher order pincushion distortion, 13...
・Direction of current, 14...Bending portion, 15...Protrusion Agent Patent Attorney Akio Namiki Figure 1 Figure 1B Figure 1C Figure 2 Figure 3 Figure 4 Figure N5 Silk 6 Figure (a) (b) Diagram N7
Figure 8 Front 11g Figure 12 Figure 12A Figure 13

Claims (1)

[Claims] 1) In a picture tube, the device is disposed between the screen side and the electron gun side, and deflects the electron beam emitted from the electron gun in horizontal and vertical directions so as to strike the screen side. In a deflection yoke equipped with horizontal and vertical deflection coils for the purpose of 1. A deflection yoke, comprising: an auxiliary coil connected in parallel or series with the auxiliary coil, and a vertical deflection current flowing through the auxiliary coil to correct raster pincushion distortion occurring on a screen. 2) In the deflection yoke according to claim 1,
At least one portion of the auxiliary coil generates a magnetic field in the same direction as a vertical deflection magnetic field generated by the vertical deflection coil, and at least one other portion generates a magnetic field in the same direction as the vertical deflection magnetic field generated by the vertical deflection coil. A deflection yoke characterized by being wound so as to generate a magnetic field in the opposite direction to a vertical deflection magnetic field. 3) In the deflection yoke according to claim 1,
The deflection yoke is characterized in that the magnetic piece has a shape in which both ends thereof are bent inside the deflection yoke. 4) In the deflection yoke according to claim 1,
The magnetic piece has a protrusion that protrudes at an angle from the main body located in the front horizontal direction, and the auxiliary coil is attached to the protrusion at an angle of approximately 90 degrees with the winding direction of the vertical deflection coil. A deflection yoke characterized by consisting of a wound solenoid-shaped coil. 5) In the deflection yoke according to claim 1,
The magnetic piece consists of a main body positioned in the front horizontal direction and a protrusion protruding from the main body at an angle, and the auxiliary coil is wound around the main body and the protrusion, respectively, and has a diameter of about 90 mm. A deflection yoke characterized by comprising a plurality of solenoid-shaped coils forming an angle of 1.5 degrees.