JPH08107563A - Deflection yoke - Google Patents

Abstract

PURPOSE: To provide a deflection yoke capable of easily switching the magnetic field direction of a correcting magnetic field for correcting misconvergence. CONSTITUTION: Circuit elements for which correcting coils 24 to 27 and diodes 28 to 32 are connected are parallelly connected while the direction of the diodes are made reverse for both first impedance element and second impedance element of a square bridge citcuit. Then, between the circuit element of the first impedance element and the circiuit element of the second impedance element, one correcting coil connected to the diode in the mutually reverse direction is selected from each circuit element, two sets of lap wound correcting coil pairs are formed and the direction of a current made to flow to the correcting coil pairs is turned to the reverse direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke to be combined with a cathode ray tube used in a television receiver or the like.

[0002]

2. Description of the Related Art Generally, a deflection yoke is composed of two sets of deflection coils that face each other horizontally and vertically, and a sawtooth wave current is passed through each deflection coil to move an electron beam emitted from an electron gun up and down. , Deflect left and right. At that time, in the case of the self-convergence system in which the three electron beams of red (R), green (G), and blue (B) are made to coincide with each other by the magnetic field generated from the deflection yoke,
The horizontal deflection magnetic field has a pincushion magnetic field distribution, and the vertical deflection magnetic field has a barrel magnetic field distribution. With this configuration, theoretically, color shift of convergence on the screen, that is, misconvergence can be eliminated, but theoretical characteristics cannot be obtained due to manufacturing error of the cathode ray tube and the deflection yoke. Have difficulty.

In order to approach these characteristics, it is needless to say that the magnetic field distribution of the coil forming the deflection yoke is adjusted, and that a magnetic piece is attached to the deflection yoke and cannot be reproduced only by the magnetic field distribution of the coil. The deflection magnetic field has been corrected by making. However, since misconvergence that cannot be corrected occurs even in this way, it is often practiced to provide a correction coil in addition to the deflection yoke and to add various correction circuits to this correction coil to generate a correction magnetic field. It was

A conventional deflection yoke will be described below with reference to the drawings. FIG. 6 shows a correction circuit diagram of a conventional deflection yoke. As shown in FIG. 6, the diode 1
One end of each of the diode 2 and the diode 2 is connected to one end of the vertical deflection coil 3. Further, a variable resistor 4 having a variable portion connected to the other end of the diode 1 and one ends of a correction coil 5 and a resistor 6 are connected to both ends of the variable resistor 4, respectively, and the other ends of the correction coil 5 and the resistor 6 are connected to each other. Are connected. Further, a variable resistor 7 having a variable portion connected to the other end of the diode 2 and one ends of a correction coil 8 and a resistor 9 are connected to both ends of the variable resistor 7, respectively, and the other ends of the correction coil 8 and the resistor 9 are connected to each other. Are connected. Then, one end of the resistor 10 is connected to the midpoint where the correction coil 5 and the other end of the resistor 6 and the correction coil 8 and the other end of the resistor 9 are connected, and the other end is connected to one end of the vertical deflection coil 3. ing.

The operation of the conventional deflection yoke correction circuit will be described below. FIG. 7 is a diagram showing a screen of misconvergence generated by a conventional deflection yoke.
As shown in FIG. 7, electron guns that emit red (R), green (G), and blue (B) electron beams from the right side when viewed from the screen 11 side are arranged in a horizontal straight line and are emitted from these electron guns. The electron beam is deflected by the magnetic field generated by the deflection yoke, and the luminous body on the screen 11 is caused to emit light to form a screen. At that time, in the upper peripheral portion and the lower peripheral portion on the screen 11, the red 12 pattern is on the left side of the green 13 pattern on the screen and the blue 14 pattern is on the right side. The desired misconvergence has caused the misconvergences 15 and 16 which are equal to or more than the allowable values.

The correction of such misconvergence 15 and 16 will be described in detail below. First, in FIG. 6, when a vertical deflection current Iv is applied to the vertical deflection coil 3 in the direction of a solid arrow 17, it flows through the diode 1 and the resistor 10, and the voltage drop across the resistor 10 becomes the threshold voltage of the diode 1. When the diode 1 is turned on, a current flows through the correction coil 5 and the resistor 6 to generate a correction magnetic field from the correction coil 5 to correct the misconvergence 15. At that time, the vertical deflection current Iv controlled by the variable resistor 4 is passed through the correction coil 5 to generate a correction magnetic field. Also, the vertical deflection current I is applied to the vertical deflection coil 3 in the direction of the broken arrow 18.
When v flows, it flows through the diode 2 and the resistor 10, and the resistor 10
When the voltage drop across the voltage reaches the threshold voltage of the diode 2, the diode 2 turns on and the correction coil 8 and the resistor 9
A current flows through the correction coil 8 to generate a correction magnetic field, and the misconvergence 16 is corrected.

[0007]

In such a conventional deflection yoke as described above, sufficient correction can be made when blue is on the right side of red. However, in the case where blue is on the left side of red, the correction magnetic field for correcting misconvergence has the same magnetic field direction, and therefore blue cannot be moved to the right to correct misconvergence.
In order to move the blue color to the right, the connection is changed by reversing the winding direction of the correction coil so that the correction magnetic field in the same magnetic field direction goes to the opposite side, so it lacks versatility. Had the problem.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a deflection yoke capable of easily switching the magnetic field direction of a correction magnetic field for correcting misconvergence.

[0009]

In order to achieve this object, the deflection yoke of the present invention comprises a circuit element in which both the first impedance element and the second impedance element are connected in series with a correction coil and a diode. The correction coils are connected in parallel with their directions reversed, and a correction coil in which diodes of opposite directions are connected between the circuit element of the first impedance element and the circuit element of the second impedance element is provided from each circuit element. Each of them has a configuration in which two sets of double-wound correction coil pairs are formed by selection, and the directions of the currents flowing through the correction coil pairs flow in opposite directions.

Further, in the modified yoke of the present invention, the first variable impedance element and the second variable impedance element are two resistances determined by the position of the movable contact of one variable resistor, and the movable contact is the third impedance element. It has the structure connected with the connection point of a 4th impedance element.

The deflection yoke of the present invention has a structure in which both the third impedance element and the fourth impedance element are resistors.

The deflection yoke of the present invention has a structure in which the third impedance element and the fourth impedance element are both coils.

[0013]

In the deflection yoke of the present invention, both the first impedance element and the second impedance element are circuit elements in which the correction coil and the diode are connected in series and the diode is reversed in direction and connected in parallel. A correction coil in which diodes in opposite directions are connected between the circuit element of the first impedance element and the circuit element of the second impedance element is selected from each of the circuit elements, and two pairs of correction coil pairs are provided. Since the configuration is such that the direction of the current flowing through the correction coil pair flows in the opposite direction, the magnetic field direction of the correction magnetic field can be easily switched by changing the first variable impedance and the second variable impedance. it can.

Further, in the deflection yoke of the present invention, since the third impedance element and the fourth impedance element are both constituted by resistors or coils, it is possible to easily switch the magnetic field direction of the correction magnetic field for misconvergence.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a deflection yoke according to an embodiment of the present invention. In FIG. 1, 19 is a core made of divided ferrite, 20 is a vertical deflection coil wound around the core 19, 21 is an insulating frame that insulates the vertical deflection coil 20 from a horizontal deflection coil (not shown), 22 , 2
Reference numeral 3 is a U-shaped magnetic piece provided on the electron gun side of the insulating frame 21. A first correction coil 24 and a third correction coil 26 are wound around the magnetic piece 22 to form a correction coil pair,
A second correction coil 25 and a fourth correction coil 27 are wound around the magnetic piece 23 to form a correction coil pair.

FIG. 2 is a correction circuit diagram including a four-sided bridge circuit of the deflection yoke in one embodiment of the present invention. Figure 2
As shown in FIG. 2, the first diode 28 and the first correction coil 24 are connected in series, and the second diode 29 and the second correction coil 25, which are opposite in direction to the first diode 28, are connected. The circuit elements of the first impedance element are configured by connecting them in series and further connecting them in parallel.
A first variable impedance element, which is a first resistance portion determined by a movable contact F of a variable resistor 30 described later, is connected in series to the first impedance element. In addition, the third diode 31 and the third correction coil 26
Is connected in series, and the fourth diode 32 and the fourth correction coil 27, whose directions are opposite to those of the third diode 31, are connected in series, and the second diode is further connected in parallel.
It constitutes a circuit element of the impedance element. A second variable impedance element, which is a second resistance portion determined by the movable contact F of the variable resistor 30, is connected in series to the second impedance element. That is, the variable resistor 30 may have the first terminal A depending on the position of the movable contact F.
Between the movable contact F and the movable contact F, the movable contact F and the second terminal D
However, since the position of the movable contact F is selectable, any of the resistance parts can be changed, and the resistance part between the terminal B and the movable contact F is the first part.
It functions as a variable impedance element, and the resistance portion between the movable contact F and the contact C functions as a second variable impedance element. The movable contact F is a terminal E which is a connection point between the first resistance 33 which is the third impedance element and the second resistance 34 which is the fourth impedance element.
Are connected via a third resistor 35.

As described above, in this embodiment, the first impedance element, the first variable impedance element, the second variable impedance element, and the second impedance element are connected in this order, and the third impedance element and the third impedance element are also connected. A second connection body in which four impedance elements are sequentially connected is connected in parallel, and further, a connection point between the first variable impedance element and the second variable impedance element, a connection point between the third impedance element and the fourth impedance element are connected, and four sides are connected. It forms a bridge circuit.

The operation of the correction circuit having the four-sided bridge circuit configured as described above will be described. FIG. 3 is a time change diagram of the current flowing through the vertical deflection coil of the deflection yoke in one embodiment of the present invention. In FIG. 3, the vertical axis represents the vertical deflection current Iv, and the horizontal axis represents time. During the period from t1 to t2, the vertical deflection current Iv of the sawtooth wave has a solid arrow 3 in FIG.
In the six directions, in the period from t2 to t3, the broken line arrow 37 in FIG.
It flows in the direction. If the variable resistor 30 is selected so that the impedance ZAE between A and E and the impedance ZAF between A and F become equal, the vertical deflection current Iv passes through the vertical deflection coil 20 and is divided during the period from t1 to t2. And one of them flows into the first resistor 33. At this time, EF
The voltage drop VE between them becomes zero, and the vertical deflection current Iv does not flow through the third resistor 35. Therefore, the vertical deflection current Iv that flows through the first resistor 33 flows through the second resistor 34 as it is.
The other of the split vertical deflection current Iv is turned on when the first diode 28 is turned on at a voltage equal to or higher than the threshold value, and the vertical deflection current Iv flows through the first correction coil 24.

At this time, the vertical deflection current Iv flowing through the first correction coil 24 flows through the variable resistor 30 and is communicated with the third correction coil 26 and the fourth correction coil 27, but the fourth diode 32 is Since the current direction is the reverse direction, the vertical deflection current Iv flows through the third correction coil 26 connected to the third diode 31 whose current direction is the forward direction. By the way, the first correction coil 24 and the third correction coil 26 are
The current direction of the diode 28 and that of the third diode 31 coincide with each other, and the vertical deflection current Iv flowing through the two correction coils 24 and 26 is double-wound between the first correction coil 24 and the third correction coil 26. Are configured to flow in opposite directions. Then, the first correction coil 24 and the third
The magnetic field directions of the correction magnetic fields generated from the vertical deflection current Iv flowing through the correction coil 26 are generated in the directions opposite to each other, the generated correction magnetic fields are canceled, and no magnetic flux is generated in the magnetic piece 22. In this way, the magnetic field generated by the correction coil pair including the first correction coil 24 and the third correction coil 26 is canceled in this case.

Next, when the voltage exceeds the threshold value during the period from t2 to t3, the second diode 29 and the fourth diode 32 are turned on, and the second correction coil 25 and the fourth correction coil 27 are perpendicular to each other. Although the deflection current Iv flows, since the magnetic field directions of the correction magnetic fields generated by the second correction coil 25 and the fourth correction coil 27 are generated in the opposite directions as described above, the generated correction magnetic field is canceled and the magnetic piece 23. Does not generate magnetic flux.

Next, the correction in the case where misconvergence occurs in such a four-sided bridge circuit will be described. First, FIG. 4A is a diagram showing a case where a red misconvergence is on the left side in the upper and lower peripheral portions of the screen in the deflection yoke according to the embodiment of the present invention. In FIG. 4 (a),
It is assumed that, in the upper peripheral portion and the lower peripheral portion on the screen 38, a red 40 pattern is on the left side of the green 39 pattern on the screen, and a blue 41 pattern is on the right side.

With respect to such misconvergence, in the correction circuit of FIG. 2, first, when the movable contact F of the variable resistor 30 is moved from the central position to the terminal C side, AE
Between impedance ZAE and impedance between AF and Z
AF becomes ZAF> ZAE, and impedance ZDE between DE and impedance ZDF between DF is ZDE> ZDF.
Is set so that When set in this way, t1 to t
In the period of 2, the vertical deflection current Iv flows in the direction of the arrow 36, the first diode 28 is turned on by the threshold voltage through the vertical deflection coil 20, and the current is shunted to the first correction coil 24 and the first resistor 33. To be done. Since ZAF> ZAE, the current flowing through the first correction coil 24 in the vertical deflection current Iv is reduced, and a part of the current flowing through the first resistor 33 flows through the third resistor 35 to make the first correction. Since it merges with the current flowing through the coil 24 and flows into the third correction coil 26, the current flowing through the third correction coil 26 increases. As described above, the vertical deflection current Iv flows through the first correction coil 24 and the third correction coil 26, respectively. However, since a larger current flows through the third correction coil 26, the correction magnetic field generated is as shown in FIG.
As shown in (b).

FIG. 4B is a diagram showing a correction magnetic field which is corrected when the red misconvergence is on the left side in the upper peripheral portion of the screen in the deflection yoke according to the embodiment of the present invention.
As shown in FIG. 4B, when the vertical deflection current Iv flows in the third correction coil 26 more than in the first correction coil 24, the correction coil pair wound around the magnetic piece 22 moves in the direction of arrow 42 (from right to left). The electron beam 43 which has generated the correction magnetic field of (1) and is subjected to the correction magnetic field is deflected in the directions of the arrows 44 (G beam is directed downward, and B and R beams are directed obliquely downward and outward). The left-side red 40 and the right-side blue 41 of the misconvergence in the upper peripheral portion of the screen 38 of 4 (a) are corrected in the arrow direction toward the center green 39.

Further, during the period from t2 to t3, the vertical deflection current Iv
Flows in the direction of arrow 37, and when the voltage exceeds the threshold value of the fourth diode 32, the current is shunted to the fourth diode 32 and the second resistor 34. The current flowing through the fourth correction coil 27 increases and the current flowing through the second correction coil 25 decreases by the amount of the current flowing through the third resistor 35 that is shunted. In this way, the vertical deflection current Iv is applied to the second correction coil 25.
And the fourth correction coil 27, the current flowing in the fourth correction coil 27 is the second correction coil 25.
Since it is larger, the correction magnetic field generated is as shown in FIG.

FIG. 4C is a diagram showing a correction magnetic field which is corrected when the red misconvergence is on the left side in the lower peripheral portion of the screen in the deflection yoke according to the embodiment of the present invention.
As shown in FIG. 4C, when the vertical deflection current Iv flows through the fourth correction coil 27, the correction coil pair wound around the magnetic piece 23 generates a correction magnetic field in the direction of arrow 45 (from right to left). , The electron beam 43 which received the correction magnetic field is indicated by the arrow 4 respectively.
The misconvergence in the lower peripheral portion of the screen 38 in FIG. 4A is corrected by deflecting in six directions (G is directed upward, and B and R beams are directed obliquely upward and outward).

Next, FIG. 5A is a diagram showing a case where a blue misconvergence is on the left side in the upper and lower peripheral portions of the screen in the deflection yoke according to the embodiment of the present invention. In FIG. 5A, in the upper peripheral portion and the lower peripheral portion on the screen 47, a red 49 pattern is on the right side of the green 48 pattern on the screen, and a blue 50 pattern is on the left side. It is assumed that

With respect to such misconvergence, in the correction circuit of FIG. 2, first, the movable contact F of the variable resistor 30 is moved from the central position to the terminal B side.
Between impedance ZAE and impedance between AF and Z
AF becomes ZAF <ZAE, and impedance ZDE between DE and impedance ZDF between D and F becomes ZDE <ZDF.
Is set so that When set in this way, t1 to t
When the vertical deflection current Iv flows in the direction of the arrow 36 during the period of 2 and reaches a voltage equal to or higher than the threshold value of the first diode 28 through the vertical deflection coil 20, the first diode 28 is turned on and the first correction coil is turned on. It is divided into 24 and the first resistor 33. When shunted, the current flowing through the first correction coil 24 in the vertical deflection current Iv is ZAF due to the impedance relationship.
<Increases because of ZAE, but conversely the third correction coil 26
The current flowing through it decreases. Therefore, the first correction coil 2
The correction magnetic field generated from the correction coil pair in which the fourth correction oil 26 and the third correction oil 26 are wound is as shown in FIG.

FIG. 5B is a diagram showing a correction magnetic field which is corrected when the blue misconvergence is on the left side in the upper peripheral portion of the screen in the deflection yoke according to the embodiment of the present invention.
As shown in FIG. 5B, when the vertical deflection current Iv flows through the first correction coil 24, the correction coil pair wound around the magnetic piece 22 generates a correction magnetic field in the direction of arrow 51 (from left to right). , The electron beam 43 which received the correction magnetic field is indicated by the arrow 5 respectively.
It is deflected in two directions (the G beam is directed upward and the B and R beams are directed upward and inward respectively), and the red color 49 and the left side on the right side of the misconvergence of the screen of the upper peripheral portion of the screen 47 of FIG. The blue 50 pattern is corrected in the direction of the central green 48 arrow.

Further, the vertical deflection current Iv during the period from t2 to t3.
Flowing in the direction of arrow 36, when the voltage exceeds the threshold value of the fourth diode 32, the fourth diode 32 is turned on to be shunted to the fourth correction coil 27 and the second resistor 34, and shunted. The current flowing through the fourth correction coil 27 in the vertical deflection current Iv decreases and the current flowing through the second correction coil 25 increases from the relationship between the impedance and the impedance. The current flowing through the first resistor 33 and the second correction coil 2
The currents flowing through 5 merge and flow to the vertical deflection coil 20. In this way, the vertical deflection current Iv is applied to the second correction coil 25.
And a fourth correction coil 27 respectively, but a large amount of current flows in the second correction coil 25, so that the correction magnetic field generated from the correction coil pair in which these two correction coils 25 and 27 are wound is as follows. It becomes as shown in FIG.

FIG. 5C is a diagram showing a correction magnetic field that is corrected when the blue misconvergence is on the left side of the lower peripheral portion of the screen in the deflection yoke according to the embodiment of the present invention.
As shown in FIG. 5C, when the vertical deflection current Iv flows through the second correction coil 25, the correction coil pair wound around the magnetic piece 23 generates a correction magnetic field in the direction of arrow 53 (from left to right). , The electron beam 43 which received the correction magnetic field is indicated by the arrow 5 respectively.
The misconvergence in the lower peripheral portion of the screen 47 is corrected by being deflected in four directions (the G beam is directed downward, and the B and R beams are directed inward downward).

Further, the misconvergence is displayed on the screen 47.
However, the vertical deflection current Iv increases as the vertical deflection current Iv approaches the upper and lower peripheral portions of the screen 47, and the correction magnetic field generated by the correction coil increases, so that the correction amount becomes large. There is no problem at all. The magnetic field direction of the correction magnetic field for correcting the misconvergence can be easily switched by simply moving the movable contact F of the variable resistor 30.

By the way, in the above-described embodiment, the first resistor 33, the second resistor 34, and the third resistor 3 are used in the correction circuit.
5 was used respectively, but there is no particular difference in action and effect even if a coil is used instead of the resistance.

[0033]

As described above, in the deflection yoke of the present invention,
Each of the first impedance element and the second impedance element is a circuit element in which a correction coil and a diode are connected in series and is connected in parallel with the direction of the diode reversed, and the circuit element of the first impedance element and the second impedance element are connected in parallel. A correction coil in which diodes of opposite directions are connected between the circuit elements of the impedance element is selected from each of the circuit elements to form two sets of double-wound correction coils, and a current flowing through the correction coil pair. Since the direction of the current flows in the opposite direction, the first variable impedance and the second variable impedance
By changing the variable impedance, the magnetic field direction of the correction magnetic field can be easily switched, and the correction of misconvergence can be facilitated.

Further, in the deflection yoke of the present invention, since the third impedance element and the fourth impedance element are both resistors or coils, it is possible to easily switch the magnetic field direction of the correction magnetic field for misconvergence. is there.

[Brief description of drawings]

FIG. 1 is a front view of a deflection yoke according to an embodiment of the present invention.

FIG. 2 is a correction circuit diagram including a four-sided bridge circuit of a deflection yoke in one embodiment of the present invention.

FIG. 3 is a time change diagram of a current flowing in a vertical deflection coil of a deflection yoke according to an embodiment of the present invention.

FIG. 4 (a) is a deflection yoke according to an embodiment of the present invention in which red misconvergence is present on the left and right in the upper and lower peripheral portions of the screen, and FIG. 4 (b) is a deflection yoke according to an embodiment of the present invention. FIG. 6C shows a correction magnetic field that is corrected when the red misconvergence is on the left side in the upper peripheral part of the drawing. Figure showing the correction field to be corrected in the case

5A is a deflection yoke according to one embodiment of the present invention, in which blue misconvergence is present on the left and right in the upper and lower peripheral portions of the screen, and FIG. 5B is a deflection yoke according to one embodiment of the present invention. FIG. 6C shows a correction magnetic field to be corrected when blue misconvergence is on the left side in the upper peripheral part of the drawing. Figure showing the correction field to be corrected in the case

FIG. 6 is a correction circuit diagram of a conventional deflection yoke.

FIG. 7 is a diagram of a screen of misconvergence generated by a conventional deflection yoke.

[Explanation of symbols]

19 core 20 vertical deflection coil 21 insulating frame 22,23 magnetic piece 24, 25, 26, 27 correction coil 28, 29, 31, 32 diode 30 variable resistor 33, 34, 35 resistance 36, 37, 42, 44, 45 , 46, 51, 52, 5
3,54 Arrow 38,47 Screen 39,48 Green 40,49 Red 41,50 Blue 43 Electron beam

Claims (4)

[Claims] 1. A first connection body in which a first impedance element, a first variable impedance element, a second variable impedance element and a second impedance element are connected in order, and a second connection element in which a third impedance element and a fourth impedance element are connected. A connecting body is connected in parallel, and a connection point of the first variable impedance element and the second variable impedance element and a connection point of the third impedance element and the fourth impedance element are connected to form a four-sided bridge circuit. A deflection yoke configured by connecting a deflection coil to the four-sided bridge circuit, wherein each of the first impedance element and the second impedance element is a circuit element in which a correction coil and a diode are connected in series. The first impeder connected in parallel with the direction reversed. Correction element in which diodes opposite to each other are connected between the circuit element of the second element and the circuit element of the second impedance element are selected from each of the circuit elements, and two sets of double-wound correction coils are selected. A deflection yoke, characterized in that a pair of coils is formed and a current flowing through the correction coil pair flows in a reverse direction. 2. The first variable impedance element and the second variable impedance element are two resistances determined by the position of the movable contact of one variable resistor, and the movable contact is the third impedance element and the fourth variable impedance element. The deflection yoke according to claim 1, wherein the deflection yoke is connected to a connection point of the impedance element. 3. The deflection yoke according to claim 1, wherein both the third impedance element and the fourth impedance element are resistors. 4. The deflection yoke according to claim 1, wherein each of the third impedance element and the fourth impedance element is a coil.