JPH0580780B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a deflection yoke device that is attached to a color cathode ray tube and deflects an electron beam.

(Prior Art) In order to reduce misconvergence, a cathode ray tube in which three electron beams are arranged in-line has a horizontal deflection magnetic field configured as a pincushion type magnetic field and a vertical deflection magnetic field configured as a barrel type magnetic field. However, when using such a deflection magnetic field, when deflecting the corners of the screen, for example, in the horizontal deflection magnetic field, the pincushion magnetic field becomes stronger as the distance from the center of the screen increases. The farther the electron beam is located, the more strongly it is deflected in the vertical direction, resulting in cross misconvergence as shown in Figure 1.
Produces PQv.

For this reason, it is possible to eliminate the vertical misconvergence PQv at the screen corners by changing the shape of the deflection yoke coil and the conductor distribution.
Horizontal misconvergence X _H on both sides of the screen in the horizontal direction and horizontal misconvergence Y _H on the top and bottom of the screen in the vertical direction newly occur.

For example, if the horizontal deflection magnetic field is modified to have a strong pincushion tendency, misconvergence PQv can be reduced while suppressing the occurrence of misconvergence _XH , but if the vertical deflection magnetic field is modified to have a strong barrel tendency, This will cause convergence Y _H or increase misconvergence PQv.

Further, since these misconvergence are closely related to coma aberration, deflection distortion, landing, deflection sensitivity, etc., it is extremely difficult to eliminate it by correcting the deflection coil.

For this reason, it has been considered to add a deflection yoke circuit element to correct the deflection current and eliminate cross misconvergence.

For example, in Japanese Patent Publication No. 52-33451, each of a pair of horizontal deflection coils and a primary winding are connected in series, the secondary windings connected in anti-series are connected in series with a vertical deflection coil, and these are connected in series. A deflection current control device is disclosed that biases with a magnet to change the inductance of a primary winding.

(Problem to be Solved by the Invention) However, when the above-mentioned control device is added to the deflection yoke, crosstalk occurs between the horizontal deflection circuit and the vertical deflection circuit, worsening interlaced scanning, or This may worsen the current linearity. Furthermore, in the above-mentioned control device, when the primary coil for passing the horizontal deflection current and the secondary coil for passing the vertical deflection current are wound in an overlapping manner,
Mutual induced voltage may occur, resulting in synchronization failure, and between the primary and secondary coils.
A voltage difference of about 1K volts may occur, so
There is also a risk that the horizontal deflection circuit and the vertical deflection circuit may be short-circuited.

(Means for Solving the Problems) The present invention provides a deflection yoke configured to control the deflection current and eliminate cross misconvergence by adding to the deflection yoke a circuit element that improves the above-mentioned points. It is provided to

(Example) Examples of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic sectional view of a dynamic impedance device according to the present invention, and FIG. 2 is a side view thereof. A cylindrical vertical bobbin 1 has flanges 1a and 1b at both ends, and a control coil 2 is wound around the bobbin with a predetermined number of turns. The control coil 2 is connected in series with a vertical deflection coil 3, as shown in FIG. 3, and is supplied with a vertical deflection current from a vertical deflection circuit 4. Inside the vertical bobbin 1, there is a fifth
King-shaped cores 5 and 6 as shown in the figure are arranged side by side. The king-shaped core 5 has rod-shaped magnetic cores 5a and 5b on the upper and lower sides, and a total of three circular flanges 5 at both ends and between the rod-shaped magnetic cores 5a and 5b.
c, 5d, and 5e, and has two upper and lower winding portions 5x, 5y. Also, the Oji-shaped core 6 has a similar structure. When these O-shaped cores 5 and 6 are inserted into the bobbin 1, the flanges 5c and 5
d, 5e, 6d, and 6e are in contact with the inner surface of the bobbin 1, and the flanges 5c and 6c, the flanges 5d and 6d, and the flanges 5e and 6e are in contact to form gaps 9, 10, and 11. These square-shaped cores 5 and 6 function as the magnetic core of the control coil 2, and the magnetic flux generated from the control coil 2 passes, for example, from the bottom to the top in the drawing.

Impedance coils 13 and 14 are wound around the square cores 5 and 6. That is, the king-shaped core 5
The coil 13 is divided into two parts and windings 13a and 13b are formed on the winding part 5x of the square-shaped core 5 and the winding 6x of the square-shaped core 6, respectively. The coil 14 is divided into two parts and windings 14a and 14b are formed in the winding part 6y of No. 6, respectively. The impedance coils 13 and 14 are connected in series with horizontal deflection coils 15 and 16, respectively, and each is supplied with a horizontal deflection current from a horizontal deflection circuit 17.

Permanent magnets 18 are placed on the flanges 5c and 6c of the square-shaped cores 5 and 6, and permanent magnets 19 are placed on the flanges 5d and 6d, and these magnets 18 and 19 are arranged so that the same magnetic poles face each other. 5,
A DC magnetic field is applied to 6.

(Operation) The operation of the above configuration will be described. When a horizontal deflection current I _H flows through the impedance coils 13 and 14 and a vertical deflection current I _V flows through the control coil 2, a magnetic flux is generated in the direction shown by the arrow in FIG. That is, a control magnetic flux φ _V passing through the double-shaped cores 5 and 6 is generated by the control coil 2 in the direction of the arrow shown by the dashed line, and
King-shaped core 5 by impedance coil 13
The flange 5c, the magnetic core 5a, the flange 5d and the O-shaped core 6
The magnetic flux φ _H1 constituted by the flange 6d, magnetic core 6a, and flange 6c and the impedance coil 14 cause the flange 5e, magnetic core 5b, and flange 5c of the square-shaped core 5 to be connected to the collar of the square-shaped core 6. 6d, the magnetic core 6b, and the flange portion 6e generate a magnetic flux φ _H2 in the direction of the arrow shown by the solid line.
That is, the winding directions of the impedance coils 13 and 14 are determined so that the magnetic flux φ _H1 and the magnetic flux φ _H2 are generated in opposite directions. In addition, the magnets 18 and 19 apply a DC bias magnetic field to the magnetic cores 5a, 6a, 5b, and 6b, and the bias magnetic fluxes φ _M1 and _M2 passing through the magnetic cores are
form a magnetic path from the flanges 5d and 6d through the space and back to the magnet, and the directions are opposite.

The directions of the magnetic fluxes φ _V , φ _H1 , and φ _H2 generated from the impedance coils 13 and 14 and the control coil 2 change every half cycle of the deflection current. That is, the first
The arrow φ _V in the figure changes each time the screen is scanned up and down, and the arrows φ _H1 and φ _H2 change each time the screen is scanned left and right.

Looking at the state of the magnetic flux indicated by the arrows in FIG. 1, the magnetic cores 5b and 6b are biased to φ _M2 +φV, increasing the magnetic resistance of the magnetic path. Therefore, this is equivalent to a decrease in the magnetic permeability of the magnetic core relative to the impedance coils 14a, 14b, and the inductance of the coils 14a, 14b decreases. For this reason, the coil 14
Since the impedances of a and 14b are small, the horizontal deflection current flowing through the horizontal deflection coil 16 is not affected by the impedance coil.

On the other hand, 5a and 6a are biased to φ-φ _M1 , and the magnetic resistance of the magnetic path becomes small. Therefore, for the impedance coil 13, this is equivalent to an increase in the magnetic permeability of the magnetic core, and the inductance of the coil 13 increases. Therefore, since the impedance of the coil 13 becomes large, the horizontal deflection current flowing through the horizontal deflection coil 15 becomes small.

The above operation is a phenomenon seen at a specific time point in the vertical deflection cycle, and in reality, the horizontal deflection current flowing through the horizontal deflection coils 15 and 16 is controlled according to the cycle of the vertical deflection current.

As described above, since a current whose amplitude is modulated in the vertical deflection period flows through the horizontal deflection coils 15 and 16, the horizontal deflection magnetic fields generated from the horizontal deflection coils 15 and 16 have a difference in field strength. This state is shown in FIG. This is the electron beam R, G, B
is deflected upwards on the screen, but
In fact, the conventional magnetic field distribution shown by a is affected by a strong pincushion-shaped magnetic field as shown by the dotted line b.
This beam deflection operation corrects the cross misconvergence PQ _V as shown in FIG.

When the magnetic path 23 formed by the upper half of the O-shaped core 5 and the upper half of the O-shaped core 6 and the magnetic path 24 created by the lower half of the O-shaped core 5 and the lower half of the O-shaped core 6 are not homogeneous. In this case, the horizontal deflection currents flowing through the horizontal deflection coils 15 and 16 become unbalanced, causing new misconvergence. In this case, by moving the magnet 18 or 19 along the flange surface,
Or flange 5c, 6c or 5e, 6e and magnet 1
Adjustment can be made by inserting a polyester film or the like between 8 or 19 to create a gap. In addition, in order to increase the contact area between the double-shaped cores 5 and 6, as shown in FIG.
The linear portions 21 may be formed by polishing the circumferences of e, 6c, 6d, and 6e. Further, as shown in FIG. 7, the flange portion 22 may have a square shape.

(Effects) As described above, in the deflection yoke device of the present invention, a vertical deflection current corrected by the saturation characteristics of the magnetic core flows in the vertical deflection coil, and a vertical deflection current whose amplitude is modulated by the vertical deflection period flows in the horizontal deflection coil. Since a horizontal current flows, the cross-mistake convergence PQ _V that occurs when only the deflection coil is used is corrected to within tolerance, and the three electron beams are concentrated over the entire screen with high precision.

Furthermore, in the dynamic impedance device according to the present invention, the impedance coil is arranged inside the control coil, and the magnetic fluxes φ _H1 and φ _H2 pass through a closed magnetic path, so they do not interlink with the control coil. The horizontal deflection period and voltage are not cut off in the control coil. Therefore, disadvantages such as vertical synchronization shift do not occur.

Further, since sufficient insulation space and insulation means are provided between the impedance coil and the control coil, there is no possibility that the horizontal deflection circuit and the vertical deflection circuit will be short-circuited even if a potential difference of about 1K volts occurs. Furthermore, in order to form a magnetic path, two
Since a square-shaped core having two winding portions is used, the inductance of the control coil is more stable than when two drum cores are stacked one above the other. In other words, when two drum cores are stacked one above the other, there is a gap between them, but
In the case of a square-shaped core, such a gap does not exist, so the inductance of the control coil is stable.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a dynamic impedance device according to the deflection yoke device of the present invention, FIG. 2 is a side view of the device shown in FIG. 1, and FIG. 3 is a circuit connection diagram of the deflection yoke device of the present invention. Figure 4 is a diagram showing an example of the horizontal deflection magnetic field of the deflection yoke device of the present invention, Figure 5 is a side view of the core used in the device of the present invention, and Figures 6 and 7 are the core flange portions used in the device of the present invention. FIG. In the figure, 1 is a vertical bobbin, 2 is a control coil, 3 is a vertical deflection coil, 5 and 6 are square cores, 5a, 5
b, 6a, 6b are magnetic cores, 5c, 5d, 5e, 6
c, 6d, 6e are collar parts, 13, 13a, 13b,
14, 14a, 14b are impedance coils,
15 and 16 are horizontal deflection coils, and 18 and 19 are magnets.

Claims (1)

[Claims] 1. It has a pair of horizontal deflection coils and a pair of vertical deflection coils, an impedance coil is connected in series to the horizontal deflection coil, and the series circuit is connected in parallel to the horizontal deflection circuit, and the impedance coil is connected to the horizontal deflection coil in parallel. Control coils are connected in series and connected to a vertical deflection circuit, and the control coils are wound around a cylindrical bobbin, and two O-shaped cores having two upper and lower winding portions are connected to the bobbin. The impedance coils are placed side by side on the inside to form two closed magnetic paths between adjacent winding portions, and the impedance coils are placed in each of the closed magnetic paths to generate magnetic fluxes in mutually canceling directions within the closed magnetic paths. A deflection yoke device characterized in that the deflection yoke device is constructed by arranging magnets having the same polarity and facing each other in the closed magnetic path and applying a DC magnetic bias.