JP2002025468A - Picture tube discharge device, leakage flux reduction method of picture tube and video device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the magnetic flux leaking to the outside, without having to install a circuit for generating another magnetic field. SOLUTION: The picture tube discharge device comprises a deflecting coil, which generates a magnetic field for deflecting the electron beam of the picture tube, based on the drive current from the deflecting circuit and a transformer circuit, which is supplied with the drive current and comprises a coil that is wound in the direction, so as to cancel the leakage magnetic flux from the deflecting coil and supplies the high voltage to the picture tube. Since the flux leaking from the transformer circuit cancels the leakage flux from the deflecting coil, a shield material for covering the deflection coil or a circuit for generating another magnetic field is not required, the leakage flux from the deflecting coil can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a picture tube discharge device,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for reducing magnetic flux leakage of a picture tube discharge device, and more particularly to a picture tube discharge device for supplying a high voltage to a picture tube based on a drive current from a deflection circuit and deflecting an electron beam of the picture tube. The present invention relates to a method for reducing magnetic flux leakage of a discharge device and a video device.

[0002]

2. Description of the Related Art Conventionally, in a picture tube discharge device of this type, the periphery of the picture tube discharge device is covered with a shielding material such as a metal plate in order to reduce magnetic flux leaking from a deflection coil. Particularly, in a video device having a picture tube discharge device, a shield material is provided so that a magnetic field at a position of a magnetic head is reduced because a leakage magnetic flux from a deflection coil affects magnetic reproduction of a magnetic tape or the like. ing. Further, the one disclosed in JP-A-5-232891 is also known. This device is provided with a coil which is connected in series with a horizontal coil of a deflection yoke so that a horizontal deflection current flows. The coil is arranged and fixed in the vicinity of the deflection yoke so as to make the horizontal distribution of the magnetic field leaking from the deflection yoke by the magnetic field generated from the coil uniform.

[0003]

The above-mentioned conventional picture tube discharge device has the following problems. That is, in the former device, since the deflection coil cannot be completely covered with the shield material, the leakage magnetic flux is not completely shut off and is emitted to the outside. In the latter case, although the horizontal distribution of the magnetic field leaking from the deflection yoke can be made uniform, it is necessary to separately provide a coil for generating a magnetic field. In addition, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 2-7334, it is necessary to separately provide a coil for generating a magnetic field. The present invention has been made in view of the above problems, and does not require a shield material for covering the deflection coil or a circuit for separately generating a magnetic field, and can reduce a leakage magnetic flux from the deflection coil. An object of the present invention is to provide a method for reducing magnetic flux leakage of a picture tube discharge device and a video device.

[0004]

According to one aspect of the present invention, there is provided a deflection coil for generating a magnetic field for deflecting an electron beam of a picture tube based on a drive current from a deflection circuit; A transformer circuit is provided that has a coil that is supplied with a drive current and is wound in a direction to cancel the leakage magnetic flux from the deflection coil, and that supplies a high voltage to the picture tube.

In the invention according to claim 1 configured as described above, the transformer circuit generates a high voltage using the drive current of the deflection circuit, and supplies the high voltage to the picture tube. Then, an electron beam is generated in the picture tube by the high voltage.
The deflection coil generates a magnetic flux by using a drive current from the deflection circuit, generates a magnetic field in the picture tube, and deflects the electron beam. At that time, a small amount of leakage magnetic flux is generated from the deflection coil. Here, the drive current used by the transformer circuit is supplied to a coil provided in the transformer circuit. Then, since the deflection coil and the coil of the transformer circuit use the same drive current, the leakage magnetic flux generated from the deflection coil and the leakage magnetic flux generated from the coil of the transformer circuit both have the same frequency as the drive current. . And since the coil of the transformer circuit is wound in a direction to cancel the leakage magnetic flux from the deflection coil,
The leakage magnetic flux generated from the deflection coil is canceled by the same frequency leakage magnetic flux generated from the transformer circuit coil. Therefore, it is not necessary to provide a shield material for covering the deflection coil, and it is possible to reduce the magnetic flux leakage from the deflection coil. At this time, only a coil provided in a transformer circuit for supplying a high voltage to the picture tube is used, and there is no need to separately provide a circuit for generating a magnetic field.

Here, the deflection coil only needs to generate a magnetic field for deflecting the electron beam of the picture tube based on the drive current from the deflection circuit. For example, an electron beam may be deflected in a horizontal direction or an electron beam may be deflected in a vertical direction, and various configurations are possible. The transformer circuit only needs to have a coil to which a drive current is supplied and supply a high voltage to the picture tube. For example, a general-purpose flyback transformer may be used, or a high voltage output transistor may be used in combination with a transformer to generate a high voltage, and the configuration is various. .

[0007] Further, as an example of a configuration for changing the direction of a magnetic flux generated from a coil of a transformer circuit, the invention according to claim 2 is directed to the picture tube discharge device according to claim 1.
The transformer circuit is configured so as to be tiltable. In the invention according to claim 2 configured as described above, the transformer circuit having the coil can be tilted. By changing the inclination of the transformer circuit, the direction of the magnetic flux generated from the coil changes, so by setting the inclination of the transformer circuit to cancel the leakage magnetic flux from the deflection coil, the leakage magnetic flux from the deflection coil is reduced. It can be adjusted so that Further, by adjusting the inclination of the transformer circuit, it is possible to more reliably reduce the leakage magnetic flux from the deflection coil. Note that there are various configurations that allow the transformer circuit to be tiltable. For example, only the transformer circuit may be formed on an independent substrate, and the substrate may be rotatably supported at two ends, or one end of the substrate may be rotatably supported and the other end may be rotatably supported. It may be fixed inside the outer case.

Further, a configuration may be employed in which the intensity of the magnetic flux generated from the coil of the transformer circuit can be changed.
As an example of the specific configuration, the invention according to claim 3 is the picture tube discharge device according to claim 1 or 2, wherein the transformer circuit reduces leakage magnetic flux generated from the coil. The shield material is provided around the periphery. Claim 3 configured as described above.
According to the invention, the leakage magnetic flux generated from the coil of the transformer circuit is reduced by the shield material provided around. Then, since the strength of canceling out the leakage magnetic flux from the deflection coil changes according to the shield material, it is possible to make adjustments to further reduce the leakage magnetic flux.

Here, the shield material only needs to be able to reduce the leakage magnetic flux generated from the coil of the transformer circuit. As an example of the specific configuration, the invention according to claim 4 is the invention according to claim 3 In the picture tube discharge device, the shield material is formed of a tiltable plate material. In the invention according to claim 4 configured as described above, the leakage magnetic flux generated from the coil of the transformer circuit is reduced by the plate material that is the shield material provided around. This plate member can be tilted, and when the tilt is changed, the strength of the leakage magnetic flux generated from the coil of the transformer circuit changes. Therefore, the strength of canceling out the leakage magnetic flux from the deflection coil can be changed with a simple configuration, and the adjustment can be made so as to further reduce the leakage magnetic flux. Of course, the use of a tiltable plate material as the shield material is merely an example. For example, a metal foil or the like having an effect of blocking magnetic flux may be used, and various types are applicable.

By the way, as a specific application example of the picture tube discharge device, the invention according to claim 5 provides a magnetic field for deflecting the electron beam of the picture tube in a substantially horizontal direction based on a drive current from a horizontal deflection circuit. A horizontal deflection coil to generate,
It is provided with a flyback transformer that has a coil that is wound in a direction to supply the drive current and cancels the magnetic flux leakage from the horizontal deflection coil and that supplies a high voltage to the picture tube. That is, the present invention is also effective as a picture tube discharge device having the above specific configuration.

Further, as one example of the direction of the flyback transformer having the coil, the invention according to claim 6 is as follows.
6. The picture tube discharge device according to claim 5, wherein the flyback transformer has a core in which a core gap is formed and the coil is wound, and is substantially the same as a predetermined position of the horizontal deflection coil in a substantially vertical direction. The core gap is provided on a horizontal plane and the direction of the core gap is set to the direction of the predetermined position.

[0012] In the invention according to claim 6 configured as described above, when the horizontal deflection coil deflects the electron beam of the picture tube in a substantially horizontal direction, a magnetic field that changes in a substantially vertical direction is generated in the picture tube. The direction of the leakage magnetic flux at a predetermined position in the substantially vertical direction of the horizontal deflection coil is substantially vertical. On the other hand, the leakage magnetic flux generated from the flyback transformer generates a magnetic field that spreads in the direction of the core gap where the magnetic flux easily leaks. Here, since the direction of the core gap is substantially in the horizontal direction at the predetermined position, the direction of the leakage magnetic flux generated from the flyback transformer at the predetermined position is also substantially vertical. Since the coil of the flyback transformer is wound in such a direction as to cancel the leakage magnetic flux of the horizontal deflection coil, the magnetic field at a predetermined position in the substantially vertical direction due to the leakage magnetic flux from the horizontal deflection coil can be more effectively reduced. .

The method of reducing the leakage magnetic flux of the deflection coil in this way is not necessarily limited to a substantial device, and as an example, the invention according to claim 7 is as follows.
A coil provided in a transformer circuit that supplies a high voltage to the picture tube is wound in a direction to cancel a leakage magnetic flux from a deflection coil that generates a magnetic field that deflects the electron beam of the picture tube based on a drive current from the deflection circuit. The drive current is supplied to cancel the leakage magnetic flux of the deflection coil. That is, the present invention is not necessarily limited to a substantial device, and is also effective as a method.
Needless to say, it is also possible to make the device configuration according to the sixth aspect correspond to the method.

In addition, as a specific example of a device to which the picture tube discharge device is applied, the invention according to claim 8 supplies a high voltage to the picture tube based on a drive current from a deflection circuit and supplies the high voltage to the picture tube. A video output device having a picture tube discharge device for deflecting the electron beam, and a magnetic reproduction device capable of amplifying a video signal of a magnetic tape reproduced by a magnetic head and outputting the amplified signal to the picture tube. ,
The picture tube discharge device is provided with a deflection coil for generating a magnetic field for deflecting the electron beam of the picture tube based on the drive current from the deflection circuit, and a drive current supplied thereto, and a leakage magnetic flux from the deflection coil. And a transformer circuit for supplying a high voltage to the picture tube, the coil having a coil wound in such a direction as to cancel the magnetic field at the position of the magnetic head.

In the invention according to claim 8 configured as described above, the coil of the transformer circuit is wound in such a direction as to cancel the magnetic field at the position of the magnetic head due to the leakage magnetic flux from the deflection coil. Then, the magnetic field at the position of the magnetic head is reduced by being canceled out by the magnetic field due to the leakage magnetic flux of the same frequency generated from the coil of the transformer circuit. Therefore, when reproducing the magnetic tape, the influence of the magnetic flux leaking from the deflection coil is reduced, and the image quality of the reproduction screen can be improved.

Further, as a more specific example of a video device, the invention according to claim 9 is the video device according to claim 8, wherein the deflection coil is provided substantially above the magnetic head, and A horizontal deflection coil for generating a magnetic field for deflecting the electron beam of the picture tube in a substantially horizontal direction based on a drive current from a deflection circuit, wherein the transformer circuit is substantially on the same horizontal plane as the magnetic head, and The magnetic head is provided in a direction substantially perpendicular to the direction of irradiation of the electron beam with respect to the tube, and has a core formed with a core gap formed by winding the coil, and the direction of the core gap is set to the direction of the magnetic head. And a flyback transformer. That is, the present invention is also effective as a video device having the above specific configuration. Note that the present picture tube discharge device can be applied to a video device capable of performing magnetic recording with a magnetic head. In this case, the influence of the magnetic flux leakage from the deflection coil during recording on the magnetic tape is reduced, and the recording image quality of the magnetic tape is improved.

[0017]

As described above, according to the present invention, there is provided a picture tube discharge device capable of reducing a leakage magnetic flux from a deflection coil without requiring a shield material for covering the deflection coil or a circuit for separately generating a magnetic field. Can be provided. Also,
According to the second aspect of the present invention, by setting the inclination of the transformer circuit so as to cancel out the leakage magnetic flux from the deflection coil, it is possible to make an adjustment to reduce the leakage magnetic flux from the deflection coil. Further, according to the third aspect of the present invention, it is possible to perform adjustment so as to further reduce magnetic flux leakage from the deflection coil.

Further, according to the invention according to claim 4,
With a simple configuration, it is possible to make adjustments so as to further reduce the magnetic flux leakage from the deflection coil. Further, according to the fifth aspect of the present invention, there is provided a picture tube discharge device capable of reducing a leakage magnetic flux from a horizontal deflection coil without requiring a shield material for covering the horizontal deflection coil or a circuit for separately generating a magnetic field. Can be provided. Further, claim 6
According to the invention, the magnetic field in the substantially vertical direction of the horizontal deflection coil can be reduced more effectively.

Further, according to the invention of claim 7,
It is possible to provide a method of reducing a leakage magnetic flux of a picture tube discharge device which can reduce a leakage magnetic flux from the deflection coil without requiring a shield material for covering the deflection coil or a circuit for separately generating a magnetic field. Further, according to the eighth and ninth aspects of the invention, it is possible to provide a video device capable of reducing the influence on the magnetic head due to the leakage magnetic flux from the horizontal deflection coil.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a televideo 100 to which a picture tube discharge device according to an embodiment of the present invention is applied. In FIG.
The bus 50 includes a microcomputer 10 serving as main control means for centrally controlling internal devices, a tuner 20 for receiving television broadcast waves, and a television broadcast signal or a signal recorded on a video tape. A one-chip IC 30 for restoring and outputting a video signal and an audio signal and a video unit 40 for controlling reproduction of a magnetic tape and the like are connected. And these are via the IIC bus 50,
Predetermined data communication is performed by serial data communication. The microcomputer 10 controls the entire apparatus by the serial data communication to realize a function as a televideo.

The tuner 20 is a tuner employing a so-called voltage synthesizer, and can be controlled via an IIC bus 50. A normal tuner has a tuning voltage (V
0) and a VHF low band (V
L), a VHF high band (VH) and a UHF (U) band changeover switch, and a signal corresponding to a desired tuning frequency is received by appropriately setting these switches. The tuner 20 does not include these mechanical components, obtains these set values from the microcomputer 10 via the IIC bus 50, and transmits a television broadcast signal having a reception frequency corresponding to the set values via an antenna (not shown). To receive. At the same time, an intermediate frequency signal is generated from the television broadcast signal and output to the one-chip IC 30.

The intermediate frequency signal input to the one-chip IC 30 is input to an internal signal system circuit (not shown), where the intermediate frequency signal is amplified. The video signal is subjected to video detection after being subjected to intermediate frequency amplification, and is subjected to a predetermined color demodulation process based on the detected output to output an RGB signal. This R
The GB signal is input to the cathode amplifier 61, amplified as appropriate, and output to the picture tube 62. Further, the audio signal is extracted as a second audio intermediate frequency signal in the process of the intermediate frequency amplification, and the AUDIO signal is output from the one-chip IC 30 through FM detection. The AUDIO signal is input to an audio amplifier (not shown), and is appropriately amplified and supplied to a speaker (not shown).

Further, in the one-chip IC 30, the horizontal and vertical synchronizing signals are separated from the detection output and input to an internal synchronizing circuit (not shown). In the synchronization circuit, an oscillation output corresponding to the horizontal / vertical synchronization signal is input, and the respective oscillation outputs and the horizontal / vertical synchronization signal form a PLL loop. The signal whose phase is locked to the corresponding oscillation output by this PLL loop is saw-toothed,
It is output as a horizontal drive signal and a vertical drive signal. These drive signals are input to a horizontal deflection circuit 63 and a vertical deflection circuit 64, where a drive current for deflecting the electron beam of the picture tube 62 is created and supplied to the picture tube discharge device. The one-chip IC 30 can generate and output various signals based on the video reproduction signal input from the video unit 40. In this case, an RGB signal, an AUDIO signal, a horizontal drive signal, and a vertical drive signal are output without performing detection and demodulation.

The video unit 40 drives and controls a servomotor while receiving an extraction signal from a sensor in the video mechanism 41, and executes a tape feed or the like by a tape feed mechanism 41a. In addition, the magnetic tape is pulled out, a head signal is transmitted and received by using the magnetic head 41b that is in sliding contact with the magnetic tape, and the magnetic tape is reproduced.

The horizontal deflection circuit 63 generates a high frequency sawtooth voltage from a horizontal drive signal and supplies it to a horizontal deflection coil 71 constituting a picture tube discharge device 70. The horizontal deflection coil 71 is attached to the picture tube 62, and deflects the electron beam in the horizontal direction according to a horizontal drive current. On the other hand, the vertical deflection circuit 64 generates a vertical drive current converted into a relatively low-frequency sawtooth voltage from the vertical drive signal,
It is supplied to a vertical deflection coil 72 constituting a picture tube discharge device 70. A vertical deflection coil 72 is also attached to the picture tube 62, and deflects the electron beam in the vertical direction according to a vertical drive current.

The horizontal drive current generated in the horizontal deflection circuit 63 is also supplied to a flyback transformer 74 which is a transformer circuit constituting the picture tube discharge device 70. The flyback transformer 74 has a primary-side coil 74a wound around a core made of a magnetic material. Then, the horizontal drive current is input to the coil 74a, and a high voltage for causing the picture tube 62 to emit electrons is generated and output. This high voltage is converted to DC by a rectifier circuit (not shown),
2 is supplied. Then, the electron beam corresponding to the video signal is emitted while being deflected, and an image appears on the picture tube 62.

Although the deflection coil for deflecting the electron beam generates a magnetic field in the picture tube 62, the magnetic flux leaks to the outside. In the case of a televideo having a magnetic head, particularly, a high-frequency leakage magnetic flux generated from a horizontal deflection coil affects the magnetic head at the time of reproduction or the like, and causes a reduction in reproduction image quality or the like. Conventionally, the periphery of the picture tube discharge device is covered with a metal plate having an effect of reducing magnetic flux. However, it has been difficult to completely eliminate the influence of the leakage magnetic flux. Therefore, in the present embodiment, the coil 74a of the flyback transformer 74 is wound in such a direction as to cancel the magnetic field at the position of the magnetic head 41b due to the leakage magnetic flux from the horizontal deflection coil 71. The leakage magnetic flux from the horizontal deflection coil 71 is canceled by the leakage magnetic flux generated from the coil 74a. As shown in the rear view of FIG. 2, the magnetic head 41b is provided substantially vertically below the horizontal deflection coil 71, and the flyback transformer 74 is substantially on the same horizontal plane as the magnetic head 41b. Are provided in a direction substantially perpendicular to the magnetic head 41b with respect to the irradiation direction of the electron beam. As will be described later, the flyback transformer 74 is arranged in a direction that minimizes the magnetic field at the position of the magnetic head 41b.

FIG. 3 is a circuit diagram showing the main structure of the picture tube discharge device 70. In the figure, the picture tube discharge device 70
A horizontal deflection coil 71 connected to a horizontal deflection circuit 63 to receive a horizontal drive current at one end; a vertical deflection coil 72 connected to a vertical deflection circuit 64 to receive a vertical drive current at one end; A flyback transformer 74 which boosts the drive current and supplies the boosted drive current to the picture tube 62. Note that the other ends of the horizontal deflection coil 71 and the vertical deflection coil 72 are connected to ground via capacitors 71a and 72a, respectively, in order to cut off DC components flowing through these deflection coils.

The two input terminals of the flyback transformer 74 are connected to both ends of a primary coil 74a. One of these input terminals is connected to a horizontal deflection circuit 63, and the other is connected to ground via a DC component blocking capacitor 73. The core around which the coil 74a is wound has a secondary coil 7 having a larger number of turns than the coil 74a.
4b is wound, and a high voltage is supplied to the picture tube 62 with both ends of the coil 74b as output terminals.

When a horizontal drive current having a sawtooth waveform is supplied to the picture tube discharge device 70, the horizontal drive current is inputted to the flyback transformer 74, a high voltage is generated and supplied to the picture tube 62. . Then, in the picture tube 62, electrons are emitted based on the high voltage, and an electron beam is generated. On the other hand, from the horizontal deflection coil 71 to which the horizontal drive current is supplied, the same high-frequency magnetic flux as the horizontal drive current is generated. This magnetic flux generates a magnetic field which oscillates vertically in the picture tube 62, and deflects the electron beam horizontally. At this time, a small amount of leakage magnetic flux is generated from the horizontal deflection coil 71 in the vertical direction. Note that the vertical deflection coil 72 generates a small amount of leakage magnetic flux having the same relatively low frequency as the vertical drive current and oscillating in the horizontal direction. Further, since the horizontal drive current is input to the coil 74a of the flyback transformer 74, the same high frequency magnetic flux as the horizontal drive current is generated from the coil 74a and transmitted to the core in the flyback transformer 74. At this time, the generated magnetic flux slightly leaks outside. That is, the magnetic head 4
The magnetic field at the position 1b is generated by combining magnetic flux leakage from the horizontal deflection coil 71, the vertical deflection coil 72, and the flyback transformer 74.

As shown in the side view of FIG. 4, inside the flyback transformer 74, there is provided a core 74c having a core gap 74d and a substantially rectangular shape including the core gap 74d. . The coils 74a and 74b are wound around one side of the core 74c, and the core gap 74d is formed substantially at the center of one side opposite to the side around which the coils 74a and 74b are wound. The flyback transformer 74, which is substantially on the same horizontal plane as the magnetic head 41b, is arranged with the core gap 74d facing the direction of the magnetic head 41b.

Here, the leakage magnetic flux of a high frequency greatly affects the magnetic head 41b. Therefore, the coil 74a of the flyback transformer 74 is wound in such a direction that the high frequency leakage magnetic flux from the horizontal deflection coil 71 is canceled by the same frequency leakage magnetic flux generated from the flyback transformer 74. Then, the magnetic flux leaking from the horizontal deflection coil 71 is canceled by the magnetic flux leaking from the coil 74a having the same frequency, and the magnetic flux leaking outside the picture tube discharge device 70 is reduced. Therefore, it is not necessary to provide a shield material for covering the horizontal deflection coil 71, and it is possible to reduce the magnetic flux leakage from the horizontal deflection coil 71. At this time, only the coil 74a provided in the flyback transformer 74 for supplying a high voltage to the picture tube 62 is used, and there is no need to separately provide a circuit for generating a magnetic field.

When the horizontal deflection coil 71 deflects the electron beam of the picture tube 62 in a substantially horizontal direction, a magnetic field that changes in a substantially vertical direction is generated in the picture tube 62, as shown in FIGS. In addition, the direction of the leakage magnetic flux at the position of the magnetic head 41b provided substantially below the horizontal deflection coil 71 is substantially vertical. Further, the leakage magnetic flux generated from the flyback transformer 74 generates a magnetic field that spreads in the direction of the core gap 74d where the magnetic flux easily leaks. Here, since the core gap 74d is oriented substantially in the horizontal direction, the direction of the leakage magnetic flux generated from the flyback transformer 74 is also substantially vertical at the position of the magnetic head 41b arranged on the same horizontal plane. Then, the magnetic field at the position of the magnetic head 41 b due to the magnetic flux leaking from the horizontal deflection coil 71 is effectively canceled by the leak magnetic flux generated from the flyback transformer 74. Here, FIG. 5 is a schematic diagram showing an example of the magnetic flux generated from the horizontal deflection coil 71 and the flyback transformer 74 as viewed from the back of the televideo 100, and the curve with an arrow indicates the magnetic flux. FIG. 6 is a schematic diagram showing an example of a magnetic field generated from the horizontal deflection coil 71 and the flyback transformer 74 when viewed from the top of the televideo 100, and a portion surrounded by a dotted line is a magnetic field. Therefore, when the magnetic head 41b is provided substantially vertically below the horizontal deflection coil 71, the flyback transformer 74 is provided on substantially the same horizontal plane as the magnetic head 41b, and the direction of the core gap 74d is set to the direction of the magnetic head 41b. The horizontal deflection coil 71
The magnetic field in the magnetic head 41b due to the magnetic flux leakage from the magnetic head 41b can be reduced more effectively. When a high voltage is generated in the transformer circuit from the vertical drive current, the coil provided in the transformer circuit is wound in a direction to cancel the leakage magnetic flux from the vertical deflection coil, so that the coil leaks out of the picture tube discharge device. It is possible to reduce the magnetic flux.

In the present embodiment, the magnetic head 4
In order to make the magnetic field at the position 1b as small as possible, the strength of the leakage magnetic flux generated from the coil 74a of the flyback transformer 74 can be adjusted. FIG. 7 shows a flyback transformer 7 installed on a substrate 80.
4 and a shield material 81 surrounding the flyback transformer 74
FIG. In FIG.
Is formed of a metal member that reduces the transmitted magnetic flux. The shield member 81 is formed in a substantially U-shaped main body 81a.
And a metal plate 81b that is tiltably attached to the opening-side end of the main body 81a, and is installed so as to surround the flyback transformer 74 formed in a substantially rectangular parallelepiped shape. Then, the metal plate 81 is
The magnetic head 41b is located outside the b direction.
The magnetic flux leaked from the flyback transformer 74 is propagated to b through the metal plate 81b. When the inclination of the metal plate 81b is changed, the cross-sectional area of the metal plate 81b from the flyback transformer 74 in the direction of the magnetic head 41b changes according to the inclination. Changes. Therefore, it is possible to change the strength of canceling out the leakage magnetic flux from the deflection coil with a simple configuration, and it is possible to make an adjustment to further reduce the magnetic field at the position of the magnetic head.

The magnetic flux leaking from the horizontal deflection coil 71 is a wave propagating in the air, and the direction of the magnetic flux leaking from the flyback transformer 74 is adjusted to the direction of the wave. 74 is tiltable. FIG. 8 shows a flyback transformer 74.
FIG. 9 is a perspective view showing a state in which is mounted on a substrate 80. In the figure, a flyback transformer 74 is attached to an independent small, substantially rectangular substrate 82. Substrate 8
Substantially short columnar projections 82a, 82a are provided substantially at the center of two opposing sides of the two sides so as to be coaxial. Also, on the substrate 80, the projections 82a, 82a
Can be inserted from above, and two support members 82b, 82b each having a substantially U-shaped hole in a cross section perpendicular to the axial direction are attached. In the support member 82b, a screw hole 82c to be screwed with the screw 82d is formed in the horizontal direction and perpendicular to the axis.

When the projections 82a, 82a of the board 82 are inserted into the holes of the support members 82b, 82b, the flyback transformer 74 mounted on the board 82 can be tilted about the axis as a rotation axis. Then, the screws 82d, 82d are screwed into the screw holes 82c, 82c until they come into contact with the projections 82a, 82a in a state in which the direction of the leakage magnetic flux from the horizontal deflection coil 71 is adjusted.
Fixed on 0. That is, the inclination of the flyback transformer can be optimized to cancel the leakage magnetic flux from the deflection coil, and it is possible to adjust the flyback transformer so as to further reduce the magnetic field at the position of the magnetic head. If the flyback transformer can be rotated by 180 degrees or more, the same effect as changing the direction of the current flowing through the coil in the flyback transformer can be obtained.

Next, the operation of the picture tube discharge device 70 configured as described above will be described. FIG. 9 shows the magnetic head 4
It is a waveform diagram which shows a mode of a change of the magnetic field in the position of 1b. Since the leakage magnetic flux from the horizontal deflection coil 71 is a wave having a vertical amplitude as described above, FIG. 9 shows the waveform with the vertically upward positive magnetic field. The coil 74a of the flyback transformer 74 is wound so as to generate a magnetic flux in a direction opposite to the direction of the leakage magnetic flux from the horizontal deflection coil 71. The amplitude direction of the leakage magnetic flux from the flyback transformer 74 is
The inclination of the flyback transformer 74 is finely adjusted so as to be in the direction of the amplitude of the leakage magnetic flux from No. 1. Further, the metal plate is adjusted so that the magnetic field intensity at the position of the magnetic head 41b due to the leakage magnetic flux of the horizontal deflection coil 71 and the magnetic field intensity at the position of the magnetic head 41b due to the leakage magnetic flux of the flyback transformer 74 are substantially the same. The inclination of 81b is also adjusted.

When the horizontal drive current in the form of a sawtooth waveform is input to the horizontal deflection coil 71, a magnetic flux having the same frequency as the horizontal drive current and having a sawtooth amplitude is generated from the horizontal deflection coil 71. Then, the leakage magnetic flux from the horizontal deflection coil 71 becomes a wave that oscillates in the vertical direction,
The magnetic field at the position of the magnetic head 41b due to the leakage magnetic flux has a sawtooth waveform as shown in the upper part of FIG. On the other hand, a coil 74a of the flyback transformer 74 to which the same horizontal drive current is input also generates a magnetic flux having the same frequency as the horizontal drive current and having a sawtooth amplitude. Here, since the coil 74a is wound so as to have a direction opposite to the direction of the leakage magnetic flux from the horizontal deflection coil 71, the position of the magnetic head 41b derived from the leakage magnetic flux from the flyback transformer 74 is different. Is opposite to the direction of the magnetic field derived from the horizontal deflection coil 71 as shown in the middle part of FIG.

The magnetic field in the vertical direction at the position of the magnetic head 41b is a composite of the magnetic field derived from the leakage magnetic flux from the horizontal deflection coil 71 and the magnetic field derived from the leakage magnetic flux from the flyback transformer 74. . Then, as shown in the lower part of FIG. 9, the magnetic field derived from the leakage magnetic flux from the horizontal deflection coil 71 is canceled by the magnetic field derived from the leakage magnetic flux from the flyback transformer 74. That is, the leakage magnetic flux generated from the horizontal deflection coil is canceled by the leakage magnetic flux of the same frequency generated from the coil of the flyback transformer, and the magnetic field at the position of the magnetic head can be reduced. Therefore, when reproducing the magnetic tape, the influence of the magnetic flux leaking from the horizontal deflection coil is reduced, and the image quality of the reproduced screen can be improved.

As shown in FIGS. 5 and 6, the flyback transformer 74 is provided on substantially the same horizontal plane as the magnetic head 41b substantially below the horizontal deflection coil 71, and the core gap 74d, where magnetic flux easily leaks, is provided. Of the magnetic head 41b, the magnetic field in the magnetic head 41b due to the magnetic flux leaking from the horizontal deflection coil 71 can be reduced more effectively. Further, as shown in FIGS. 7 and 8, the flyback transformer 74 and the metal plate 81 are used.
Since the inclination of b is adjusted, the leakage magnetic flux from the flyback transformer 74 is a wave oscillating in the vertical direction, and the strength of the magnetic field at the position of the magnetic head 41b derived from the leakage magnetic flux from the flyback transformer 74 Is a magnetic head 41b derived from magnetic flux leakage from the horizontal deflection coil 71.
Is almost the same as the strength of the magnetic field at the position. Therefore, it is possible to more reliably reduce the leakage flux from the horizontal deflection coil and reduce the influence of the leakage flux to the magnetic head.

As described above, in the picture tube discharge device of the present embodiment, the leakage magnetic flux generated from the deflection coil is canceled by the leakage magnetic flux of the same frequency generated from the coil of the transformer circuit, and the magnetic flux leaking to the outside is reduced. Therefore, a picture tube discharge device, a method of reducing a leak magnetic flux of a picture tube discharge device, and a video device capable of reducing a leakage magnetic flux from the deflection coil without requiring a shield material for covering the deflection coil or a circuit for separately generating a magnetic field are required. Can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a televideo to which a picture tube discharge device according to an embodiment of the present invention is applied.

FIG. 2 is a rear view showing the horizontal deflection coil, the magnetic head, and the flyback transformer as viewed from the rear of the televideo.

FIG. 3 is a circuit diagram showing a main configuration of a picture tube discharge device.

FIG. 4 is a side view showing a core of the flyback transformer.

FIG. 5 is a schematic diagram showing an example of a magnetic flux generated from a horizontal deflection coil and a flyback transformer as viewed from the back of a televideo.

FIG. 6 is a schematic diagram showing an example of a magnetic field generated by a horizontal deflection coil and a flyback transformer as viewed from above a televideo.

FIG. 7 shows a flyback transformer installed on a substrate;
FIG. 4 is a perspective view showing a shield material surrounding a flyback transformer.

FIG. 8 is a perspective view showing how a flyback transformer is mounted on a substrate.

FIG. 9 is a waveform chart showing how a magnetic field changes at the position of a magnetic head.

[Explanation of symbols]

 Reference Signs List 10 microcomputer 20 tuner 30 one-chip IC 40 video unit 41 video mechanism 41a tape feed mechanism 41b magnetic head 50 IIC bus 61 cathode amplifier 62 picture tube 63 horizontal deflection circuit 64 vertical deflection circuit 70 picture tube discharge device 71 horizontal deflection coil 71a capacitor 72 vertical deflection coil 72a capacitor 73 capacitor 74 flyback transformer 74a coil 74b coil 74c core 74d core gap 80 substrate 81 shielding material 81a: Main body 81b: Metal plate 82: Substrate 82a: Protrusion 82b: Support member 82c: Screw hole 82d: Screw 100: Televideo

Claims (9)

[Claims] 1. A deflection coil for generating a magnetic field for deflecting an electron beam of a picture tube based on a drive current from a deflection circuit, and a winding wound in a direction to be supplied with the drive current and to cancel magnetic flux leakage from the deflection coil. A picture tube discharge device comprising: a turned coil; and a transformer circuit for supplying a high voltage to the picture tube. 2. The picture tube discharge device according to claim 1, wherein the transformer circuit is installed to be tiltable. 3. The picture tube discharge device according to claim 1, wherein the transformer circuit is provided with a shield member around the coil to reduce a leakage magnetic flux generated from the coil. Picture tube discharge device. 4. The picture tube discharge device according to claim 3, wherein the shield member is formed of a tiltable plate material. 5. A horizontal deflection coil for generating a magnetic field for deflecting an electron beam of a picture tube in a substantially horizontal direction based on a drive current from a horizontal deflection circuit; A picture tube discharge device comprising: a coil wound in a direction to cancel leakage magnetic flux; and a flyback transformer for supplying a high voltage to the picture tube. 6. The picture tube discharge device according to claim 5, wherein the flyback transformer has a core in which a core gap is formed and the coil is wound, and a substantially vertical direction of the horizontal deflection coil. Wherein the direction of the core gap is the same as the direction of the predetermined position. 7. A coil provided in a transformer circuit for supplying a high voltage to a picture tube, and a magnetic flux leaking from a deflection coil for generating a magnetic field for deflecting an electron beam of the picture tube based on a drive current from the deflection circuit. A method for reducing a leakage magnetic flux of a picture tube discharge device, wherein the leakage magnetic flux of the deflecting coil is canceled by supplying the same drive current by winding in the direction of the cancellation. 8. A video output device having a picture tube discharge device for supplying a high voltage to a picture tube based on a drive current from a deflection circuit and deflecting an electron beam of the picture tube, and a magnetic tape reproduced by a magnetic head And a magnetic reproducing device capable of amplifying the video signal of the picture tube and outputting the amplified signal to the picture tube. The picture tube discharge device comprises: an electron beam of the picture tube based on a drive current from the deflection circuit. A deflection coil for generating a magnetic field for deflecting the image, and a coil wound in a direction to cancel the magnetic field at the position of the magnetic head due to the leakage magnetic flux from the deflection coil while being supplied with the drive current. And a transformer circuit for supplying a high voltage to the tube. 9. The video device according to claim 8, wherein the deflection coil is provided substantially above the magnetic head, and substantially shifts the electron beam of the picture tube based on a drive current from a horizontal deflection circuit. A horizontal deflection coil for generating a magnetic field to be deflected in a horizontal direction, wherein the transformer circuit is on substantially the same horizontal plane as the magnetic head and is substantially perpendicular to the magnetic head with respect to the irradiation direction of the electron beam of the picture tube. And a flyback transformer having a core formed with a core gap and wound with the coil, and the direction of the core gap being oriented toward the magnetic head.