JPH0240103A - Recording or reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a recording or reproducing device, and particularly to a recording or reproducing device in which a recording or reproducing head is mounted on a rotating body and information is recorded or reproduced by rotating the rotating body. Or it relates to a playback device.

[Prior art] As this type of device, a VTR (video tape recorder)
There is. Recently, the image quality of VTRs has been increasing, and various methods have been proposed.

One of the most effective methods is to widen the band or increase the frequency of recording/reproducing signals. In order to achieve this wide band, measures such as improving the magnetic head, improving the magnetic tape or replacing it with high-performance tape (metal tape or vapor-deposited tape), and increasing the relative speed of the magnetic head and magnetic tape will be taken. Broadband signals are now available. For this reason, it has become necessary to widen the band not only in the electromagnetic conversion system consisting of the magnetic head and the magnetic tape, but also in the signal processing circuit such as the recording/reproducing amplifier in the stage before the magnetic head.

However, although recording and reproducing amplifiers and rotary transformers that relay recording and reproducing signals are being improved, in the conventional configuration, the rotary transformer is interposed between the recording and reproducing amplifier and the magnetic head, so the wiring between the magnetic head and the recording and reproducing amplifier is cannot be shortened below a certain length.

Because this wiring is long, it becomes difficult for recording current to flow during recording due to the inductance component of the wiring. Furthermore, during reproduction, the high frequency characteristics deteriorate due to the stray capacitance of the wiring. Furthermore, since a weak signal must be transmitted through a long wire including a rotary transformer, noise is generated due to external induction and the signal itself is degraded.

In order to overcome these drawbacks, proposals have been made for VTRs in which a signal processing circuit such as a recording/reproducing amplifier is also mounted on the rotating drum on which the magnetic head is mounted. The circuit configuration of the main parts related to recording and reproduction of such a VTR is shown in FIG. 4 and will be explained.

As shown in FIG. 4, a reproduction signal processing circuit 8, a recording signal processing circuit 9,
One side portions 6b and 7b are provided, each of which includes the power supply circuit 10, the recording/reproduction switching circuit 11a, and the respective coils of the rotary transformer 6.7. Here, the reproduced signal processing circuit 8 performs processing such as waveform shaping, demodulation, and frequency conversion of the reproduced signal. Also, recording signal processing circuit 9
performs frequency conversion and modulation of the recording signal. The power supply circuit 10 supplies power to the entire signal processing circuit on the rotary tram section 20 side. Further, the recording/reproduction switching circuit 11a is a changeover switch 2d provided on the fixed drum/VTR main body 30 side.
and a changeover switch 2a provided on the rotating drum section 20 side.
It controls switching of 2C and switches between recording mode and reproduction mode. Furthermore, the recording/reproduction switching circuit 11a
A control signal for controlling the changeover switches 28 to 2C on the rotating drum section 20 side is superimposed on the output of the power supply circuit 10.

Further, the rotary transformer 6 relays recording signals or reproduction signals between the rotating drum section 20 and the fixed drum/VTR main body section 30. Further, the rotary transformer 7 is connected to the power supply circuit 10.
relays the power output by the switch 2 and relays the control signals of the changeover switches 2a to 2C.

On the other hand, the rotating drum section 20 has one side portions 6a and 7 which are composed of the magnetic head 1a of the electromagnetic conversion system 1, the reproduction amplifier 3, the recording amplifier 4, the coils of the rotary transformer 6.
a, recording/reproduction switching circuit 1it), control signal separation circuit 12
and a rectifier circuit 13 are provided.

As is well known, the magnetic head 1a slides into contact with the magnetic tape 1b to perform electromagnetic conversion of recording or reproduction signals. The reproduction amplifier 3 and the recording amplifier 4 amplify the reproduction signal and the recording signal, respectively. Further, the control signal separation circuit 12 separates the control signals of the changeover switches 2a to 2c from the output of the power supply circuit 10 relayed via the rotary transformer 7, and supplies the control signals to the recording/reproduction changeover circuit 11b. The output of is given to the rectifier circuit 13. The recording/reproduction switching circuit 11b controls the changeover switches 2a to 2c according to the input control signal. Further, the rectifier circuit 13 rectifies the AC output of the power supply circuit 10 into DC and supplies it to the reproduction amplifier 3 or the recording amplifier 4 via the changeover switch 2c.

When recording under such a configuration, selector switches 2a to
2d is switched to the lower side of the diagram, that is, to the recording amplifier 4 side and the recording signal processing circuit 9 side. The recording signal processed as described above by the recording signal processing circuit 9 is led to the recording amplifier 4 via the rotary transformer 6, where it is amplified and then applied to the magnetic head 1a for recording.

Further, during reproduction, the changeover switches 2a to 2d are switched to the upper side of the diagram, that is, to the reproduction amplifier 3 side and the reproduction signal processing circuit 8 side. The reproduction signal is then input from the magnetic head 1a to the reproduction amplifier 3, where it is amplified and then sent via the rotary transformer 6 to the reproduction signal processing circuit 8, where it undergoes the above-mentioned processing and is processed by the subsequent stage (not shown). Output to the circuit.

According to such a configuration, the magnetic head 1a, the reproduction amplifier 3, and the recording amplifier 4 are connected directly and at a short distance.

Therefore, during recording, the inductance component of the transmission path is reduced, and a recording current can flow up to a higher frequency with less power. In addition, the stray capacitance of the wiring between the head and the amplifier is reduced, improving high frequency characteristics during playback, and reducing signal loss due to external interference.

[Problems to be Solved by the Invention] However, in the configuration shown in FIG. 4, the power supply is relayed via a rotary transformer, so there are the following drawbacks.

That is, among the circuits on the rotating drum section 20 side, the recording amplifier 4 that supplies the recording current to the magnetic head 1a in particular requires a large amount of electric power, but the rotary transformer tends to have lower transmission efficiency in the low frequency region; It is difficult to supply sufficient power because power cannot be transmitted beyond the magnetic saturation of the core that constitutes the rotary transformer.

Furthermore, the magnetic flux flowing through the rotary transformer 7 for power supply is much larger than the magnetic flux flowing through the rotary transformer 6 for recording/reproducing signals, and leakage magnetic flux from the rotary transformer 7 jumps into the rotary transformer 6, causing the /N ratio will be lowered.

Therefore, the problem of the present invention is not limited to VTRs, but includes a recording or reproducing head and a signal processing circuit for processing input or output signals of this head mounted on a rotating body, and recording or reproducing information by rotating this rotating body. Or, in the playback device, ensure that sufficient power is supplied to the above-mentioned signal processing circuit, and
The objective is to improve the N ratio to enable good recording or reproduction.

[Means for Solving the Problems] In order to solve the above problems, according to the present invention, a recording or reproducing head and a signal processing circuit for processing an input or output signal of the head are mounted on a rotating body, and the rotating body In a recording or reproducing device that records or reproduces information by rotating a body, a coil is provided on the rotating body and a magnet is provided on the main body of the recording or reproducing device, and the coil and magnet generate electricity by the rotation of the rotating body. A configuration was adopted in which a power generator was configured to perform the signal processing, and power was supplied from the coil to the signal processing circuit.

Further, according to the present invention, in the recording or reproducing apparatus of the above type, a light receiving element is provided on one side of the rotating body and the recording or reproducing apparatus main body side, and a light emitting element is provided on the other side, and a photocoupler is configured by the light receiving element and the light emitting element. However, a predetermined signal is transmitted between the circuit on the main body side of the recording or reproducing apparatus and the signal processing circuit on the rotating body via the odocobra.

[Function] According to the former configuration, there is no restriction as in the case where power is supplied from the main body of the recording or reproducing device to the signal processing circuit on the rotating body via a rotary transformer, and the signal processing circuit on the rotating body is Sufficient power can be supplied to the processing circuit. Further, it is possible to avoid the problem of noise due to leakage magnetic flux from the rotary transformer when a rotary transformer is used.

In addition, according to the latter configuration, the predetermined signal is transmitted between the circuit on the main body side of the recording or reproducing device and the signal processing circuit on the rotating body via the photocoupler, so the predetermined signal is transmitted without using a rotary transformer. transmission and avoids the problems of using a rotary transformer.

[Example] Hereinafter, details of embodiments of the present invention will be described with reference to the drawings.

1 and 2 explain the configuration of the main parts related to recording and reproduction of a VTR according to an embodiment of the present invention. FIG. 1 shows the electrical circuit configuration, and FIG. 2 shows the recording and reproduction. The mechanical structure of the drum section is shown.

First, the electrical circuit configuration will be explained with reference to FIG. In FIG. 1, parts common or corresponding to those in FIG. 4 of the conventional example are given the same reference numerals, and explanations of the common parts will be omitted or only briefly mentioned.

The configuration shown in FIG. 1 differs from the conventional example shown in FIG. 4 in that only one rotary transformer is provided, and only a rotary transformer 6 for relaying recording or reproduction signals is provided. In addition, instead of supplying power from the fixed drum/VTR main unit 30 side to the rotating drum unit 20 side via a rotary transformer as in the conventional case, the rotating tram unit 20
A magnet 15b is provided on the fixed drum of the coil 15a1/fixed drum of the VTR body section 30 to constitute the generator 15, and the coil 15a of the generator 15 is connected to the rotating drum section 20.
The power is supplied to the signal processing circuit of the controller. The rotating drum section 20 is provided with a rectifier circuit 14 that rectifies the AC output of the generator 15 into DC and supplies it to the reproduction amplifier 3 or the recording amplifier 4 via the switching switch 2C.

In addition, in the configuration shown in FIG. 1, instead of transmitting the control signals of the changeover switches 2a to 2C via the rotary transformer, the light receiving element 16a1 is connected to the fixed drum/V of the rotating drum section 20.
A light emitting element 16b is provided on the fixed drum of the TR main body 30,
A photocoupler 16 is configured, and via the photocoupler 16, the recording/reproduction switching circuit 11a of the fixed drum/VTR main body section 30 is connected to the recording/reproduction switching circuit 11b of the rotating drum section 20.
Control signals for the changeover switches 2a to 2C are transmitted to the switches 2a to 2C.

Next, the structure of the drum section will be explained with reference to FIG.

In FIG. 2, a fixed drum 49 is fixed on a base (not shown) of the VTR. A shaft 50 is rotatably supported at the center of the fixed drum 49. A magnet 4 is located at the bottom of the shaft 50 in the fixed drum 49.
A rotor 48c is fixed to the lower surface of the rotor 8b.

A coil 48a is fixed to the lower part of the fixed tram 49 facing the magnet 48b, and the drive motor 4 is connected to the coil 48a, the magnet 48b, and the rotor 48c.
8 are made up. The shaft 50 is rotated by the drive motor 48 .

On the other hand, a rotating drum 46 is fixed to the upper part of the shaft 50, and is provided facing a fixed tram 49.

One side portion 6a of a rotary transformer 6 made of a coil is provided at the lower end of the rotating drum 46, and faces the one side portion 6b provided on the fixed drum 49 side to form the rotary transformer 6.

Further, a magnetic head I is provided at the lower end of the outer circumference of the rotating drum 46.
a and la are fixed.

Further, a recess 46a is formed in the lower central portion of the rotating drum 46. A light receiving element 16a is provided facing the inner surface of the recess 46a.

On the other hand, the upper center of the fixed drum 49 has a convex portion 4.
9a is formed, and a light emitting element 16b is provided so as to face the outer surface of this convex portion 49a and facing the light receiving element 16a. ing.

Further, a coil 1 is provided on the top surface of the recess 46a of the rotating drum 46.
5a, and a magnet 15b is provided at the upper end of the convex portion 49a of the fixed drum 49 so as to face the coil 15a, and the generator 15 described above is constituted by the coil 15a and the magnet 15b.

Furthermore, on the upper surface of the rotating drum 46, there is a reproducing amplifier 3 as shown in FIG.
, a recording amplifier 4, a recording/reproduction switching circuit iib, a rectifier circuit 14, and the like.

With this structure, during recording and reproduction, the drive motor 4
The shaft 50 is rotated by the drive of the rotary drum 4.
6 is rotated. This rotation causes the magnetic heads Ia, la
is in sliding contact with a magnetic tape (not shown) that is wound around the rotary drum 46 and fixed drum 49 and runs.

On the other hand, due to the rotation of the rotating drum 46, the coil 15a rotates with respect to the magnet 15b, generating electricity, and the coil 15a rotates with respect to the magnet 15b.
AC power is excited at a. This AC output is rectified into DC by the rectifier circuit 14 shown in FIG. 1, and is supplied to the reproduction amplifier 3 or the recording amplifier 4 via the changeover switch 2C.

The recording/reproducing switching circuit 11a in FIG. 1 is a selector switch 2d.
It generates a control signal for directly switching the switch, and also generates a control signal for switching the changeover switches 2a to 2C on the rotary tram section 20 side. This control signal is sent to the recording/reproduction switching circuit j on the rotating drum section 20 side via the photocoupler 16.
ib, and the changeover switches 2a to 2C are switched to the recording side or the reproduction side under the control of the circuit 11b.

During recording, the recording signal undergoes the above-mentioned processing in the recording signal processing circuit 9, is output, is input to the recording amplifier 4 via the rotary transformer 6, is amplified by the amplifier 4, and is applied to the magnetic head 1a, where it is applied to the magnetic head 1a for recording. will be done.

On the other hand, during playback, the playback signal input from the magnetic head 1a is amplified by the playback amplifier 3 and input to the playback signal processing circuit 8 via the rotary transformer 6, where it undergoes predetermined processing and is input to the circuit on the VTR main body side. be done.

According to this embodiment as described above, power is supplied to the signal processing circuit 45 of the rotating drum section 20 by the generator 15, so there is no restriction when using a rotary transformer, and there is no restriction on the signal processing circuit 45. Sufficient power supply can be provided, and recording and reproduction signals can be handled in a critical band or at high frequencies, and recording and reproduction can be performed satisfactorily. Further, since a rotary transformer is not used for power supply, it is possible to avoid noise problems caused by leakage magnetic flux of the rotary transformer for power supply, and it is possible to improve the S/N ratio of recording and reproduction signals. Furthermore, in this embodiment, the control signals of the changeover switches 2a to 2C are transmitted via the photocoupler 16, so the control signals can be transmitted without using a rotary transformer, and the above-mentioned control signals can be transmitted without using a rotary transformer. You can avoid problems.

In addition, in the above structure, the coil 15a of the generator 15
Magnet 15b and photocoupler 16 light receiving element 1
6a and the position where the light emitting element 16b is provided is not limited to the position shown in FIG. For example, it may be provided as shown in FIG. 3 as another embodiment. In the case of Fig. 3, the coil 15a
A recess 46b formed in the center of the upper surface of the rotating drum 46
The magnet 15b is mounted on the support member 5 in opposition to the magnet 15b.
1 and constitutes a generator 15. Further, a light receiving element 16a is also provided on the upper surface of the rotating drum 46, and a light emitting element 16b is provided opposite to this, thereby forming a photocoupler 16. Exactly the same effects can be obtained by such an arrangement.

In both cases of FIG. 2 and FIG. 3, since the coil is installed in the recess of the rotating drum, it does not protrude and worsen the space factor.

Therefore, the coil is less likely to be damaged during assembly, and since it is integrated with the rotating drum, it is easy to handle. It goes without saying that the above-mentioned configuration is not limited to VTRs, but can also be similarly applied to other recording or reproducing devices that record or reproduce information by mounting a recording or reproducing head and a signal processing circuit on a rotating body. be. Furthermore, in that case, the signal transmitted from the main body of the recording or reproducing apparatus to the rotating body via the photocoupler is, of course, not limited to the above-mentioned changeover switch signal. Also, contrary to the above, a light emitting element is provided on the rotating body side, and a light receiving element is provided on the recording or reproducing device main body side to form a photocoupler, and the signal processing circuit on the rotating body side is connected to the recording or reproducing device main body side via this photocoupler. It is also conceivable to transmit a predetermined signal to this circuit.

[Effects of the Invention] As is clear from the above description, according to the present invention, a recording or reproducing head and a signal processing circuit for processing input or output signals of the head are mounted on a rotating body, and the rotating body is rotated. In a recording or reproducing device for recording or reproducing information, a coil is provided on the rotating body and a magnet is provided on the main body of the recording or reproducing device, and the coil and magnet generate electricity by the rotation of the front rotating body. The apparatus is configured such that power is supplied from the coil to the signal processing circuit, and a light receiving element is provided on one side of the rotating body and the recording or reproducing apparatus main body side, and a light emitting element is provided on the other side, and the light receiving element and the light emitting element are provided on the other side. A photocoupler is configured with a light emitting element, and five predetermined signals are transmitted between a circuit on the recording or reproducing device main body side and a signal processing circuit on the rotating body via the photocoupler. As a result, it is possible to supply power to the signal processing circuit on the rotating body and transmit a specified signal without using a rotary transformer, and it is possible to supply sufficient power to the signal processing circuit on the rotating body and to transmit recording or playback signals. Excellent effects can be obtained in that the S/N ratio can be improved and recording or reproduction can be performed satisfactorily.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing the circuit configuration of the main parts related to recording and reproduction of a VTR according to an embodiment of the present invention, and FIG.
3 is a cross-sectional view showing the structure of the drum part according to another embodiment, and FIG. 4 is a cross-sectional view showing the structure of the drum part of the conventional V.
FIG. 2 is a block circuit diagram showing a circuit configuration of a main part of a TR. 1... Electromagnetic conversion system 1a... Magnetic head 1b.
... Magnetic tapes 2a to 2d... Selector switch 3... Playback amplifier 4... Recording amplifier 6...
Rotary transformer 8... Reproduction signal processing circuit 9... Recording signal processing circuit 11a, Ilb... Recording/reproduction switching circuit 14... Rectifier circuit 15... Generator 15a... Coil
15b...Magnet 16...Photocoupler 16
a... Light receiving element 16b... Light emitting element 45...
Signal processing circuit 46... Rotating drum 48... Drive motor 49... Fixed drum

Claims (1)

[Claims] 1) A recording or reproducing head and a signal processing circuit for processing an input or output signal of the head are mounted on a rotating body, and the rotating body is rotated to record or reproduce information. In the reproducing device, a coil is provided on the rotary body and a magnet is provided on the main body of the recording or reproducing device, the coil and the magnet constitute a generator that generates power by the rotation of the rotary body, and the signal processing circuit is connected from the coil to the signal processing circuit. A recording or reproducing device characterized in that it supplies power to. 2) A recording or reproducing apparatus in which a recording or reproducing head and a signal processing circuit for processing an input or output signal of the head are mounted on a rotating body, and the rotating body is rotated to record or reproduce information. A light receiving element is provided on one side of the body and the recording or reproducing apparatus main body side, and a light emitting element is provided on the other side, and the light receiving element and the light emitting element constitute a photocoupler, and the circuit on the recording or reproducing apparatus main body side and the above are connected via the photocoupler. A recording or reproducing device characterized in that a predetermined signal is transmitted between signal processing circuits on a rotating body.