JP2002025474A - Deflection yoke and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy correction of the orthogonal distortions that appear on the screen. SOLUTION: The device comprises a correction coil 11, which is installed on the rear end side of the deflecting yoke and forms a two-pole correction magnetic field along the vertical axis direction of the yoke and a bridge circuit 13, which is connected in series with a vertical deflecting coil 7, so as to supply the correction coil 11 with a sawtooth form correcting currents Ia, Ib which are synchronized with a vertical deflecting current Iv. The bridge circuit 13 comprises a variable resistor VR, which is capable of changing the volume and direction of the correcting currents Ia, Ib.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cathode ray tube (CRT).
More particularly, the present invention relates to a deflection yoke used for a display device such as a television receiver or a computer display using the same.

[0002]

2. Description of the Related Art Generally, in a display device using a cathode ray tube, three electron beams emitted from an electron gun, that is, R beams are emitted.
Images are assembled on the screen (panel surface) of a cathode ray tube by deflecting the traveling directions of the three electron beams that cause the phosphors of each color (red), G (green), and B (blue) to emit light up, down, left, and right. ing. For deflection of the electron beam, a deflection yoke having a horizontal deflection coil and a vertical deflection coil (Deflection Yoke;
DY) is used. The deflection yoke is mounted on a portion called a cone from the neck of the cathode ray tube to the funnel.

On a screen of a cathode ray tube, scanning lines (horizontal lines) obtained by horizontal scanning of an electron beam are sequentially scanned (vertical scanning) from the upper side to the lower side of the screen to form one scanning line composed of many scanning lines. A surface, or raster, is formed.
Here, as shown in FIG. 10A, the raster 3 formed on the screen 2 of the display device 1 is orthogonal to the X axis which is the horizontal axis of the screen and the Y axis which is the vertical axis of the screen. (Θ = 90 °).

[0004]

However, in the assembled display device, there is a case where the orthogonal distortion of the raster is generated on the screen mainly due to the factor of the deflection yoke. The orthogonal distortion of the raster refers to a state where the raster 3 is not orthogonal to the X axis and the Y axis on the screen 2 of the display device 1 (θ ≠ 90 °), as shown in FIG. Such orthogonal distortion of the raster can be caused by, for example, deflection coils (horizontal deflection coils,
This is caused by the bias of the winding of the vertical deflection coil) or the displacement of the mounting position of the deflection coil itself.

In order to correct the orthogonal distortion of the raster, it is effective to perform so-called magnetic crosstalk adjustment that suppresses magnetic field interference between the horizontal deflection coil and the vertical deflection coil. However, for crosstalk adjustment after assembly is completed,
Since a complicated operation such as releasing the fixing of the component parts or finely adjusting the mounting position is involved, a very large number of man-hours are required. As a result, the production efficiency of the display device is significantly reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a deflection yoke capable of easily correcting orthogonal distortion of a raster and a display device using the same. is there.

[0007]

A deflection yoke according to the present invention is provided at a rear end side of a deflection yoke and forms a two-pole correction magnetic field along a vertical axis direction of the deflection yoke. A correction current supply means for supplying a sawtooth correction current synchronized with the vertical deflection current to the coil is provided. Further, the display device according to the present invention uses the deflection yoke having the above configuration.

In the deflection yoke and the display device using the same, the correction current supply means supplies the correction coil with a sawtooth-shaped correction current synchronized with the vertical deflection current, so that the rear end of the deflection yoke is provided. A two-pole correction magnetic field is formed along the vertical axis direction of the deflection yoke. The electron beam is displaced in the horizontal axis direction of the deflection yoke by the action of the correction magnetic field. At that time, since the direction of the correction magnetic field is reversed in the first half and the second half of the vertical deflection cycle,
In the first half of the vertical deflection cycle, the electron beam is displaced to one side in the horizontal axis direction, and in the second half of the vertical deflection cycle, the electron beam is displaced to the other side in the horizontal axis direction. As a result, the entire raster can be tilted on the screen.

Further, by adjusting the amount of the correction current flowing through the correction coil, it becomes possible to adjust the amount of inclination of the raster on the screen. Furthermore, by changing the direction of the correction current flowing through the correction coil, it is possible to control the inclination direction of the raster on the screen. Also, 2
By providing a set of correction coils and switching the supply destination of correction current in the first and second half of the vertical deflection cycle for each set of correction coils, the orthogonal distortion of the raster is individually corrected on the upper and lower sides of the screen Becomes possible.

[0010]

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

FIG. 1 is a plan view showing the structure of a cathode ray tube according to the present invention. As shown, the main body (glass bulb) of the cathode ray tube 1 is composed of a panel 2, a funnel 3, and a neck 4. On the inner surface of the panel portion 2, a phosphor screen (not shown) in which red, green, and blue phosphors are arranged in a pattern is formed. On the other hand, in the neck part 4,
An electron gun (not shown) serving as an electron beam emission source is provided therein. A deflection yoke 5 for deflecting an electron beam is mounted on a cone portion extending from the neck portion 4 to the funnel portion 3. The deflection yoke 5 is mounted and adjusted so that the center axis of the yoke coincides with the center axis of the cathode ray tube 1.

The cathode ray tube 1 having the above-described structure is incorporated in a housing (not shown) together with various accessories necessary for reproducing a color image (or a black and white image) on the phosphor screen on the inner surface of the panel section 2, thereby providing a television. A display device such as a John receiver or a computer display is configured.

The deflection yoke 5 is equipped with components such as a horizontal deflection coil 6, a vertical deflection coil 7, a separator 8, a DY core 9, and a ring magnet 10. The horizontal deflection coil 6 is wound in a saddle shape on the inner peripheral side of the separator 8,
The vertical deflection coil 7 is provided on the outer peripheral side of the separator 8 by the DY core 9.
Is wound in a toroidal shape. The separator 8 is made of an insulating material such as a resin, and has a substantially trumpet shape as a whole.

The vertical deflection coil 7 may be wound in a saddle shape. In FIG. 1, the horizontal deflection coil 6 is drawn out of the deflection yoke 5 and displayed so that the appearance of the horizontal deflection coil 6 can be confirmed.

The horizontal deflection coils 6 are arranged in pairs in the vertical axis direction (vertical direction) of the deflection yoke 5, and the vertical deflection coils 7 are also arranged in pairs in the vertical axis direction (vertical direction) of the deflection yoke 5. ing. On the trajectory of an electron beam emitted from an electron gun (not shown), the horizontal deflection coil 6 generates a magnetic field (horizontal deflection magnetic field) for deflecting the electron beam in the horizontal axis direction (left-right direction) of the screen. Numeral 7 generates a magnetic field (vertical deflection magnetic field) for deflecting the electron beam in the vertical axis direction (up and down direction) of the screen.

The DY core 9 is made of a magnetic material such as ferrite, and is formed in a trumpet shape with one opening in the yoke center axis direction larger than the other. This DY core 9
Has a function of enhancing the effectiveness of the magnetic field generated by the horizontal deflection coil 6 and the vertical deflection coil 7. Ring magnet 1
Numeral 0 is attached to the rear end of the deflection yoke 5 in order to correct a trajectory shift of the electron beam due to an assembly error of an electron gun (not shown).

Further, on the rear end side of the deflection yoke 5, a correction coil 11 is provided near the rear end of the horizontal deflection coil 6. The correction coil 11 is provided with the deflection yoke 5
To form a two-pole correction magnetic field along the vertical axis direction. The correction coil 11 is configured by two coils L1 and L2, as shown in FIG. These two coils L1 and L2 are arranged outside the neck portion 4 of the cathode ray tube in pairs in the Y-axis direction (vertical direction) which is the vertical axis of the deflection yoke 5 (or the cathode ray tube).

The specific configuration of the correction coil 11 is as follows.
Various forms can be adopted. For example, FIG.
As shown in (A), a case is conceivable in which two air-core coils L1 and L2 are paired up and down with an electron beam trajectory (dotted arrow) interposed therebetween. Further, as shown in FIG. 3B, a pair of magnetic bodies 12 facing each other on the Y axis
A case in which coils L1 and L2 are wound around A and 12B, respectively, is also conceivable.

FIG. 4 is a circuit diagram showing a coil connection state of the deflection yoke according to the embodiment of the present invention. As shown, the pair of vertical deflection coils 7 are connected in series with each other.
A vertical deflection current Iv is supplied to the pair of vertical deflection coils 7 by a vertical deflection circuit (not shown). Also, for a pair of vertical deflection coils 7,
A bridge circuit 13 is connected in series. The bridge circuit 13 sets one input terminal P1 to hot.
And the other input terminal P2 is connected in a bridge shape with the cool (cool) side.

In the bridge circuit 13, two fixed resistors (hereinafter simply referred to as resistors) R1 and R2 are connected in series with each other, and a connection point between the two resistors R1 and R2 is connected to one output of the bridge circuit 13. End P3. A variable resistor VR is connected between the input terminals P1 and P2 of the bridge circuit 13 in parallel with the two resistors R1 and R2. The output terminal is P4. And
Between the output terminals P3 and P4 of the bridge circuit 13, two coils L1 and L2 constituting the correction coil 11 are connected in series. In the bridge circuit 13, the resistance values of the resistors R1 and R2 are set so that the bridge can be balanced at the center position of the variable resistor VR.

Next, the operation of the coil circuit during the operation of the deflection yoke 5 will be described.

In general, the vertical deflection current Iv supplied to the vertical deflection coil 7 by a vertical deflection circuit (not shown) has a current direction (positive or negative) in the first half and the second half of the vertical deflection cycle.
Becomes an inverted sawtooth wave. Here, the vertical deflection current Iv
Assume a positive value in the first half of the vertical deflection period and a negative value in the second half.

The vertical deflection current (sawtooth wave current) Iv
Is also supplied to the bridge circuit 13 via the vertical deflection coil 7. At this time, during the first half of the vertical deflection cycle (ie, the period during which the vertical deflection current Iv is positive), a current flows from one input terminal P1 of the bridge circuit 13, and the second half of the vertical deflection cycle (ie, the vertical deflection current Iv). During the period in which is negative, a current flows from the other input terminal P2 of the bridge circuit 13.

Here, when a current flows from one input terminal P1 of the bridge circuit 13, if the slider S of the variable resistor VR is at the center position, the bridge circuit 13 enters a balanced state. Therefore, half of the current flowing from the input terminal P1 flows out of the input terminal P2 via the two resistors R1 and R2, and the other half flows into the variable resistor VR.
Out of the input terminal P2 via Therefore, the coil L connected between the output terminals P3 and P4 of the bridge circuit 13
No current flows through 1 and L2.

On the other hand, when the slider S of the variable resistor VR is slid to one side (left side in the figure) or the other side (right side in the figure), the balance of the bridge circuit 13 is lost and the coil L
1 and L2.

That is, when the slider S of the variable resistor VR is slid to one side (the left side in the figure), a current Ia flows through the coils L1 and L2 in the direction indicated by the solid arrows. At this time, the coil L
1, the amount of the current Ia flowing through L2 increases as the position of the slider S approaches one end (the left end in the figure). When the slider S of the variable resistor VR is slid to the other side (right side in the figure), a current Ib flows through the coils L1 and L2 in the direction of the dashed arrow. At this time, the amount of the current Ib flowing through the coils L1 and L2 increases as the position of the slider S approaches the other end (the right end in the drawing).

On the other hand, the other input terminal P of the bridge circuit 13
2, when the slider S of the variable resistor VR is at the center position, the bridge circuit 13 is in a balanced state in the same manner as described above, so that the coils L1, L2
No current flows through However, when the slider S of the variable resistor VR is slid to one side (left side in the figure), the coil L
The current Ib flows in the direction of the dashed arrow 1 and L2, and the amount of the current Ib increases as the position of the slider S approaches the other end (the left end in the figure). Also, when the slider S of the variable resistor VR is slid to the other side (right side in the figure), a current Ia flows through the coils L1 and L2 in the direction of the solid arrow, and the amount of the current Ia is At one end (right end in the figure)
It increases as it approaches.

As described above, the currents Ia and Ib flowing through the coils L1 and L2 are sawtooth-shaped currents synchronized with the vertical deflection cycle since the current supplied to the bridge circuit 13 is a vertical deflection current. Are the correction currents Ia, I
This is supplied to the correction coil 11 as b. The directions of the correction currents Ia and Ib flowing through the correction coil 11 (coils L1 and L2) are variable depending on whether the slider S of the variable resistor VR is slid to one side or the other side. The amounts of the currents Ia and Ib can be adjusted by how much the slider S is slid.

Next, the correction magnetic field formed when the correction currents Ia and Ib flow through the coils L1 and L2 as described above will be described.

The correction current Ia or Ib is applied to the coils L1 and L2.
Flows, on the rear end side of the deflection yoke, as shown in FIG. 5, a two-pole correction magnetic field φ1 or φ2 along the Y-axis direction on the trajectory of the electron beam G traveling in the neck portion 4 of the cathode ray tube. Is formed. More specifically, when the correction current Ia flows through the coils L1 and L2, a two-pole correction magnetic field φ1 is formed from the bottom to the top with the S pole on the coil L1 side and the N pole on the coil L2 side. When the correction current Ib flows through the coils L1 and L2, on the contrary, a two-pole correction magnetic field φ2 is formed from the top to the bottom with the coil L1 side as the N pole and the coil L2 side as the S pole. .

Incidentally, the directions of the correction magnetic fields φ1 and φ2 are determined by the winding directions of the coils L1 and L2 and the directions of the currents Ia and Ib flowing through the coils L1 and L2. Therefore, when the correction current Ia flows through the coils L1 and L2, a correction magnetic field φ2 is formed, and the correction magnetic field I2 flows through the coils L1 and L2.
It is also possible to configure so that the correction magnetic field φ1 is formed when b flows. Although only the green electron beam G is shown in FIG.
Numeral 2 similarly (equally) acts on each of the electron beams for red, green and blue.

Next, the principle of correcting the orthogonal distortion by the action of the correction magnetic fields φ1 and φ2 will be described.

First, the correction magnetic field φ is generated by the coils L1 and L2.
When 1 is formed, a force f1 in the horizontal axis (X-axis) direction is applied to the electron beam G as shown in FIG. 5, whereby the electron beam G is displaced to the right in the figure. Also,
When the correction magnetic field φ2 is formed by the coils L1 and L2, a force f2 is applied to the electron beam G in the horizontal axis (X-axis) direction, which is opposite to the previous direction, thereby displacing the electron beam G to the left in the drawing. .

Thus, when the slider S of the variable resistor VR shown in FIG. 4 is moved to one side (the left side in the figure), the first half of the vertical deflection cycle (ie, a positive deflection current is supplied to the vertical deflection coil 7). Current flows in the coils L1 and L2 during the
Since a flows, a upward correction magnetic field φ1 is formed on the trajectory of the electron beam, and the magnetic field acts to deflect the electron beam more to the right side of the screen. In the latter half of the vertical deflection cycle (that is, during the period in which a negative deflection current flows through the vertical deflection coil 7), the correction current Ib flows through the coils L1 and L2, so that the downward correction magnetic field φ2 Is formed, and the electron beam is more deflected to the left side of the screen by the action of the magnetic field. As a result, on the screen of the cathode ray tube, as shown in FIG.
The raster 3 is inclined clockwise on the upper side and the lower side of the screen 2.

On the other hand, when the slider S of the variable resistor VR shown in FIG. 4 is moved to the other side (the right side in the figure), the first half of the vertical deflection cycle (that is, a positive Since the correction current Ib flows through the coils L1 and L2 during the period in which the deflection current flows, a downward correction magnetic field φ2 is formed on the trajectory of the electron beam, and the magnetic field acts to deflect the electron beam more to the left side of the screen. . In the second half of the vertical deflection cycle (that is, a period during which a negative deflection current flows through the vertical deflection coil 7), the correction current Ia flows through the coils L1 and L2. Is formed, and the electron beam is more deflected to the right side of the screen by the action of the magnetic field. As a result, on the screen of the cathode ray tube, as shown in FIG.
The raster 3 is tilted counterclockwise on the upper side and the lower side of the screen 2.

From the above, when the orthogonal distortion of the raster is generated on the screen of the cathode ray tube, for example, in the state of FIG. 6A, the form is canceled (canceled), that is, FIG. By forming the correction magnetic fields φ1 and φ2 by the coils L1 and L2 so that the entire raster 3 is tilted in the counterclockwise direction, the orthogonal distortion of the raster can be corrected. In the case where the orthogonal distortion of the raster has occurred in the state of FIG.
By forming the correction magnetic fields φ1 and φ2 by the coils L1 and L2 so that the whole tilts clockwise, it is possible to correct the orthogonal distortion of the raster. Further, when the orthogonal distortion of the raster does not occur on the screen of the cathode ray tube, the slider S of the variable resistor VR is set to the center position and the bridge circuit 13 is set in the balanced state, so that the correction magnetic fields φ1 and φ2 are not changed. Since formation can be avoided, it is possible to maintain a state without orthogonal distortion.

Further, the position of the slider S of the variable resistor VR is operated to correct the correction currents Ia and Ib flowing through the coils L1 and L2.
, The magnetic field strength of the correction magnetic fields φ1 and φ2 can be arbitrarily changed. This makes it possible to adjust the amount of inclination (θa, θb in FIG. 6) of the raster 3 due to the correction magnetic fields φ1, φ2. for that reason,
Appropriate correction can be performed according to the amount of orthogonal distortion of the raster.

Further, depending on which side the slider S of the variable resistor VR is slid from the balanced state, the coils L1,
The directions of the correction currents Ia and Ib flowing through L2 can be changed, whereby the directions of the correction magnetic fields φ1 and φ2 can be changed (reversed). As a result, it is possible to control the inclination direction of the raster 3 on the screen by the correction magnetic fields φ1 and φ2. Therefore, appropriate correction can be performed according to the inclination direction of the orthogonal distortion of the raster.

Next, another embodiment of the present invention will be described with reference to FIGS.

FIG. 7 is a diagram showing the arrangement of correction coils according to another embodiment of the present invention. In FIG. 7, at the rear end side of the deflection yoke 5, a first correction coil 14 including two coils L3 and L4, and two coils L5 and L
6 is provided. That is, in this embodiment, two correction coils 1
4 and 15 are provided. In these two sets of correction coils 14, 15, the coils L3, L4 and the coils L5, L6 are respectively arranged outside the neck portion 4 of the cathode ray tube in pairs in the Y-axis direction (vertical direction).

As a specific configuration of each of the correction coils 14 and 15, it is possible to adopt the forms shown in FIGS. 3A and 3B. At this time, the coils L3, L5
And the coils L4 and L6 may be bifilar wound.

FIG. 8 is a circuit diagram showing a coil connection state of a deflection yoke according to another embodiment of the present invention. In FIG. 8, two bridge circuits 16 and 17 are connected in series to a pair of vertical deflection coils 7 with a common connection point P0. These two bridge circuits 16, 1
7 are connected in parallel with each other. One bridge circuit 16 is connected in a bridge shape with one input terminal P5 on the hot (Hot) side and the other input terminal P6 on the cool (Cool) side, and the other bridge circuit 17 has one input terminal P7 on the other. The hot side and the other input end P8 are connected in a bridge shape with the cool side being used.

In one bridge circuit 16, 2
Resistors R3 and R4 are connected in series with each other.
A connection point between the two resistors R3 and R4 is one output terminal P9 of the bridge circuit 16. A variable resistor VR1 is connected between the input terminals P5 and P6 of the bridge circuit 16 in parallel with the two resistors R3 and R4.
Is the other output terminal P10 of the bridge circuit 16. Two coils L3 and L4 constituting the correction coil 14 are connected in series between the output terminals P9 and P10 of the bridge circuit 16. In this bridge circuit 16, the resistors R3 and R4 are connected so that the bridge can be balanced at the center position of the variable resistor VR1.
Are set.

The other bridge circuit 17 has two resistors R
5, R6 and a variable resistor VR2.
P12 includes two coils L constituting the correction coil 15.
5, L6 are connected in series. In addition,
Since the basic configurations of the bridge circuits 16 and 17 are similar to each other, a detailed description of the bridge circuit 17 is omitted here.

Further, a diode D1 is connected between one input terminal P5 of the bridge circuit 16 and the connection point P0, and one input terminal P7 of the bridge circuit 17 is connected to the connection point P0.
The diode D2 is also connected between them. The anode of the diode D1 is connected to the connection point P0, and the cathode is connected to the input terminal P5. On the other hand, the anode of the diode D2 is connected to the input terminal P7, and the cathode is connected to the connection point P0. That is, the two diodes D1 and D2 are connected such that one is in the forward direction and the other is in the reverse direction with respect to the flow of the vertical deflection current Iv supplied to the vertical deflection coil 7. These two diodes D1 and D2 constitute switching means for switching the supply destination of the correction current in the first half and the second half of the vertical deflection cycle with respect to the two bridge circuits 16 and 17 including the correction coils 14 and 15, respectively. It is.

Subsequently, the vertical deflection current Iv supplied to the vertical deflection coil 7 is plus in the first half of the vertical deflection cycle,
The operation of the above-described coil circuit will be described with reference to a case where the latter half becomes negative.

First, in the first half of the vertical deflection cycle (that is, the period when the vertical deflection current Iv is positive), the diode D
Since a forward voltage is applied to 1 and a reverse voltage is applied to the diode D2, a current flows from one input terminal P5 of the bridge circuit 16. On the other hand, in the latter half of the vertical deflection cycle (that is, the period during which the vertical deflection current Iv is negative),
Since a reverse voltage is applied to the diode D1 and a forward voltage is applied to the diode D2, a current flows from the other input terminal P8 of the bridge circuit 17.

At this time, when the sliders S1 and S2 of the variable resistors VR1 and VR2 are at the center position, both the bridge circuits 16 and 17 are in a balanced state. Therefore, the current flowing from one input terminal P5 of the bridge circuit 16 in the first half of the vertical deflection cycle flows out of the other input terminal P6 without flowing through the coils L3 and L4. Also,
The current flowing from the other input terminal P8 of the bridge circuit 17 in the latter half of the vertical deflection cycle is also changed by the coils L5 and L6.
Out of one input terminal P7 without flowing to the input terminal P7. Therefore, no correction magnetic field is formed by the coils L3, L4 and L5, L6.

On the other hand, when the sliders S1 and S2 of the variable resistors VR1 and VR2 are slid to one side (left side in the figure) or the other side (right side in the figure), the bridge circuits 16 and 17 are moved.
, The current flows through the coils L3 and L4 in the first half of the vertical deflection cycle, and the current flows through the coils L5 and L6 in the second half of the vertical deflection cycle.

That is, when the sliders S1 and S2 of the variable resistors VR1 and VR2 are both slid to one side (the left side in the figure),
In the first half of the vertical deflection cycle, the current Ic flows through the coils L3 and L4 in the direction of the solid arrow, and in the second half of the vertical deflection cycle, the current Ie flows through the coils L5 and L6 in the direction of the broken arrow.
At this time, the amounts of the currents Ic and Ie flowing through the coils L3, L4 and L5, L6 increase as the positions of the sliders S1, S2 approach one end (the left end in the figure).

When the sliders S1 and S2 of the variable resistors VR1 and VR2 are both slid to the other side (right side in the figure),
In the first half of the vertical deflection cycle, the current Id flows through the coils L3 and L4 in the direction of the dashed arrow, and in the second half of the vertical deflection cycle, the current If flows through the coils L5 and L6 in the direction of the solid arrow.
At this time, the amounts of the currents Id and If flowing in the coils L3, L4 and L5, L6 increase as the positions of the sliders S1, S2 are closer to one end (the right end in the figure).

Further, when the slider S1 of the variable resistor VR1 is slid to one side (the left side in the figure) and the slider S2 of the variable resistor VR2 is slid to the other side (the right side in the figure), The current Ic flows through the coils L3 and L4 in the first half, and the current If flows through the coils L5 and L6 in the second half of the vertical deflection cycle. Conversely, when the slider S1 of the variable resistor VR1 is slid to the other side (the right side in the figure) and the slider S2 of the variable resistor VR2 is slid to the one side (the left side in the figure), the first half of the vertical deflection cycle is performed. The current Id flows through the coils L3 and L4 in the portion, and the current Ie flows through the coils L5 and L6 in the second half of the vertical deflection cycle.

Thus, the coils L3, L4 and L5, L
The currents Ic, Id and Ie, If flowing through each of the bridge circuits 16 and 17 are the same as the vertical deflection current Iv.
Therefore, each of them becomes a saw-tooth current synchronized with the vertical deflection period, and the saw-tooth currents are the correction currents Ic and Id.
, And Ie, If, the correction coil 14 (L
3, L4) and 15 (L5, L6).

The directions of the correction currents Ic and Id and Ie and If flowing through the correction coils 14 and 15 are determined by the variable resistance V
R1 and VR2 are variable depending on whether the sliders S1 and S2 are slid to one side or the other side, and the amounts of the correction currents Ic and Id and Ie and If are determined by the sliders S1 and S2.
It can be adjusted by how much S2 is slid.

Next, in another embodiment of the present invention, a correction magnetic field formed when the correction currents Ic, Id and Ie, If flow through the coils L3, L4 and L5, L6 as described above will be described. .

First, when the correction current Ic or Id flows through the coils L3 and L4, the rear end side of the deflection yoke 5, as shown in FIG. A two-pole correction magnetic field φ3 or φ4 along the Y-axis direction is formed on the orbit. Of these, the correction magnetic field φ3 has the same function as the above-described correction magnetic field φ1, and the correction magnetic field φ4 has the same function as the above-described correction magnetic field φ2 (see FIG. 5). Incidentally, the directions of the correction magnetic fields φ3 and φ4 are determined by the winding directions of the coils L3 and L4 and the directions of the currents Ic and Id flowing through the coils L3 and L4. Therefore, here, as an example, when the current Ic flows through the coils L3 and L4, the correction magnetic field φ3 is formed, and the current Id flows through the coils L3 and L4.
, A correction magnetic field φ4 is formed.

When the correction current Ie or If flows through the coils L5 and L6, a two-pole correction magnetic field φ3 or φ4 is formed at the rear end of the deflection yoke 5. Here, as an example, it is assumed that the correction magnetic field φ4 is formed when the current Ie flows through the coils L5 and L6, and the correction magnetic field φ3 is formed when the current If flows through the coils L5 and L6.

In such a case, when the sliders S1 and S2 of the variable resistors VR1 and VR2 are moved to one side (left side in the figure), a correction current Ic flows through the coils L3 and L4 in the first half of the vertical deflection cycle. In the latter half of the vertical deflection cycle, the correction current Ie flows through the coils L5 and L6. Thus, in the first half of the vertical deflection cycle, an upward correction magnetic field φ3 is formed on the trajectory of the electron beam G, and the electron beam is deflected more to the right side of the screen by the action of the magnetic field. In the second half of the vertical deflection cycle, a downward correction magnetic field φ4 is formed on the trajectory of the electron beam G, and the electron beam is more deflected to the left side of the screen by the action of the magnetic field. As a result, on the screen of the cathode ray tube, as shown in FIG. 9A, the raster 3 is tilted clockwise on the upper side and the lower side of the screen 2.

On the other hand, when the sliders S1 and S2 of the variable resistors VR1 and VR2 are moved to the other side (right side in the drawing), the correction current Id is supplied to the coils L3 and L4 in the first half of the vertical deflection cycle. In the latter half of the vertical deflection cycle, the correction current If flows through the coils L5 and L6. As a result, in the first half of the vertical deflection period, a downward correction magnetic field φ4 is formed on the trajectory of the electron beam G, and the electron beam is more deflected to the left side of the screen by the action of the magnetic field. In the latter half of the vertical deflection cycle, an upward correction magnetic field φ3 is formed on the trajectory of the electron beam G, and the electron beam is deflected more to the right side of the screen by the action of the magnetic field. As a result, on the screen of the cathode ray tube, as shown in FIG.

Further, when the slider S1 of the variable resistor VR1 is slid to one side (the left side in the figure) and the slider S2 of the variable resistor VR2 is slid to the other side (the right side in the figure), The current Ic flows through the coils L3 and L4 in the first half, and the current If flows through the coils L5 and L6 in the second half of the vertical deflection cycle. As a result, an upward correction magnetic field φ3 is formed on the trajectory of the electron beam G during the first and second half of the vertical deflection period, and the electron beam is more deflected to the right side of the screen by the action of the magnetic field. As a result, on the screen of the cathode ray tube, as shown by a solid line in FIG. 9C, the raster 3A tilts clockwise at the upper side of the screen 2 and the raster 3B tilts counterclockwise at the lower side of the screen 2. become.

When the slider S1 of the variable resistor VR1 is slid to the other side (right side in the figure) and the slider S2 of the variable resistor VR2 is slid to one side (left side in the figure), The current Id flows through the coils L3 and L4 in the first half, and the current Ie flows through the coils L5 and L6 in the second half of the vertical deflection cycle.
As a result, a downward correction magnetic field φ4 is formed on the trajectory of the electron beam G over the first and second half of the vertical deflection cycle, and the electron beam is more deflected to the left side of the screen by the action of the magnetic field. As a result, on the screen of the cathode ray tube,
As shown by the broken line in FIG. 9C, the raster 3A tilts counterclockwise at the upper side of the screen 2 and the raster 3A at the lower side of the screen 2.
B will be inclined clockwise.

As described above, according to another embodiment of the present invention, the orthogonal distortion of the raster on the upper side of the screen and the orthogonal distortion of the raster on the lower side of the screen can be corrected independently (individually). It becomes possible.

The positions of the sliders S1 and S2 of the variable resistors VR1 and VR2 are manipulated to operate the coils L3, L4 and L4.
By adjusting the amounts of the correction currents Ic, Id and Ie, If flowing in L5 and L6, the magnetic field strengths of the correction magnetic fields φ3 and φ4 are arbitrarily changed, and the inclination amount of the raster on the screen (θa, θb) can be adjusted separately for the upper and lower sides.

The correction currents Ic, Id and Ie, If flowing through the coils L3, L4 and L5, L6 depend on which side the sliders S1, S2 of the variable resistors VR1, VR2 are slid from the balanced state. And the formation of the correction magnetic fields φ3 and φ4 based on this makes it possible to separately control the upper and lower directions of the inclination of the raster on the screen.

In the above embodiment, the bridge circuit 13 including the correction coil 11 and the correction coils 14 and 1 are connected to the vertical deflection coil 7 to which the vertical deflection current is supplied.
5 are connected in series, so that the sawtooth-shaped correction current synchronized with the vertical deflection period is supplied to the correction coils 11, 14, and 15. However, the present invention is not limited thereto. However, the present invention is not limited to this, and it is also possible to adopt a configuration in which a correction current is supplied to the correction coils 11, 14, and 15 in a system different from the vertical deflection coil 7.

[0066]

As described above, according to the present invention, a sawtooth correction current synchronized with the vertical deflection period is supplied to the correction coil, thereby forming a two-pole correction magnetic field at the rear end side of the deflection yoke. By doing so, the raster can be tilted on the screen. This makes it possible to easily correct the orthogonal distortion of the raster.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of a cathode ray tube according to the present invention.

FIG. 2 is a diagram illustrating an arrangement state of a correction coil according to the embodiment of the present invention.

FIG. 3 is a diagram showing a specific configuration example of a correction coil.

FIG. 4 is a circuit diagram showing a coil connection state of the deflection yoke according to the embodiment of the present invention.

FIG. 5 is a diagram illustrating a correction magnetic field formed by a correction coil according to the embodiment of the present invention.

FIG. 6 is a diagram illustrating a change in a raster corresponding to the embodiment of the present invention.

FIG. 7 is a diagram showing an arrangement state of a correction coil according to another embodiment of the present invention.

FIG. 8 is a circuit diagram showing a coil connection state of a deflection yoke according to another embodiment of the present invention.

FIG. 9 is a diagram illustrating a correction magnetic field formed by a correction coil according to another embodiment of the present invention.

FIG. 10 is a diagram for explaining orthogonal distortion of a raster;

[Explanation of symbols]

4 ... neck part, 5 ... deflection yoke, 7 ... vertical deflection coil,
11, 14, 15 ... correction coil, 13, 16, 17 ... bridge circuit, L1, L2, L3, L4, L5, L6 ... coil, VR, VR1, VR2 ... variable resistor, D1, D2 ...
diode

Claims (7)

[Claims] 1. A correction coil provided at a rear end side of a deflection yoke to form a two-pole correction magnetic field along a vertical axis direction of the deflection yoke, and a sawtooth correction synchronized with a vertical deflection current to the correction coil. A deflection yoke comprising: a correction current supply unit that supplies a current. 2. The deflection yoke according to claim 1, further comprising current amount adjusting means for adjusting an amount of the correction current flowing through the correction coil. 3. The deflection yoke according to claim 1, further comprising current direction changing means for changing a direction of the correction current flowing through the correction coil. 4. It has two sets of said correction coils,
2. The deflection yoke according to claim 1, further comprising switching means for switching the supply destination of the correction current in the first half and the second half of the vertical deflection period for the two sets of correction coils. 5. The deflection yoke according to claim 4, further comprising current amount adjusting means for adjusting an amount of the correction current flowing through each set of correction coils. 6. The deflection yoke according to claim 4, further comprising current direction changing means for changing the direction of the correction current flowing through each of the sets of correction coils. 7. A correction coil provided on the rear end side of the deflection yoke to form a two-pole correction magnetic field along the vertical axis direction of the deflection yoke, and a saw-tooth correction synchronized with the vertical deflection current to the correction coil. A display device using a deflection yoke including a correction current supply unit for supplying a current.