JPH0434701A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To eliminate the need for a special transmission means and to reduce the cost by providing a power supply circuit and a modulation circuit receiving a control signal so as to convert power of the power supply circuit into a modulated voltage to the outside of a rotor and providing a constant voltage circuit converting the modulated voltage sent to the rotor into a constant voltage and a demodulating circuit demodulating the control signal from the modulated voltage into the rotor. CONSTITUTION:To the outside of a rotor, a modulation circuit 2 is provided, which modulates a power supplied from a power supply circuit 1 by a control signal VA controlling the changeover of recording/reproduction and/or controlling the position of a magnetic head in response to the recording or reproduction mode. Then a constant voltage circuit 4 converting the modulated voltage sent via a transmission means 3 into a control voltage required as the power supply for circuits in the rotor and a demodulation circuit 6 demodulating a control signal VB from the modulated voltage are provided to the rotor. Thus, the power voltage and the control signal are included in the modulated voltage given from the modulation circuit 2 to the rotor, a rotary transformer 3 is used in common for the power supply and the control signal as the transmission means and no special transmission means for transmitting the control signal is not required and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary head type magnetic recording/reproducing device in which a magnetic head, a pre-up, etc. are mounted on a rotating body (rotating drum) side.

[Prior Art] Conventionally, this type of magnetic recording/reproducing device has been disclosed in, for example, Japanese Patent Application Laid-Open No.
As shown in Publication No. 5406 and Japanese Unexamined Patent Publication No. 62-175905, a magnetic head, a reproduction signal amplification circuit, a detection circuit for detecting a control signal having recording/reproduction switching information, etc. is provided on the rotating body side. Equipped with a recording/reproduction switching circuit and a head switching circuit that operate according to control signals, a constant voltage circuit that generates the power supply voltage for each of these circuits, etc. The fixed side is equipped with a power supply circuit that supplies power to the rotating body and a control signal. In addition to being equipped with a control circuit for transmitting power, a transmission means consisting of a low retrans, a slip ring, and a flan for power supply is provided between the stationary side and the rotating side. In order to separately transmit control signals, a transmission means consisting of a separate rotary transformer or a slip ring and a brush is provided.

[Problems to be Solved by the Invention] However, in the conventional magnetic recording and reproducing device having the above configuration, a special transmission separate from the transmission means for power supply is required to transmit the control signal from the stationary side to the rotating body side. Since a means is required, the number of parts increases and the space also increases, which not only increases costs but also causes deterioration in reliability. Further, as the number of magnetic heads increases, the number of rotary transformers and channels also increases, and the above-mentioned problems become even more noticeable.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a magnetic recording and reproducing device that can eliminate the need for special transmission means for transmitting control signals to the rotating body side. shall be.

[Means for Solving the Problems] In order to achieve the above object, a magnetic recording/reproducing device according to the present invention is provided with a magnetic head and an up-circuit for amplifying recording or reproduction signals on the rotating body side, and a power source is installed outside the rotating body. In a magnetic recording and reproducing device having a circuit and a transmission means for supplying power from the power supply circuit to the rotating body side, controlling switching of recording and reproduction of power supplied from the power supply circuit to the outside of the rotary body, and/or a modulation circuit that modulates the position of the magnetic head with a control signal according to the recording/reproducing mode, and transmits the modulated voltage transmitted through the transmission means into the rotating body. The present invention is characterized in that it includes a constant voltage circuit that converts to a constant voltage necessary as a power source for the circuit, and a demodulation circuit that demodulates the control signal from the modulated voltage.

[Operation] In the present invention, the modulation circuit provided outside the rotating body converts the power supplied from the power supply circuit into a modulated voltage using a control signal, transmits it to the rotating body side via the transmission means, and In this case, a constant voltage circuit converts the modulated voltage into a predetermined constant voltage to obtain circuit power, and a demodulation circuit demodulates a control signal from the modulated voltage.

[Embodiment] Hereinafter, one embodiment of the magnetic recording/reproducing apparatus of the present invention will be described based on the drawings. FIG. 1 shows a schematic configuration diagram of the magnetic recording and reproducing apparatus in this embodiment. In the figure, outside the rotating body, there is a power supply circuit 1 and a control signal 1 for transmitting the power supplied from the power supply circuit 1 to the rotating body side. Changed mI by 9! The modulation circuit 2 converts the voltage into a control signal V, for example. It is designed to output a high frequency voltage that has been FM modulated. This high frequency voltage is transmitted into the rotating body via the low retransistor 3. Here, this control signal includes a signal that controls the switching of recording and playback, a signal that controls the position of the magnetic head according to each recording and playback mode (slow motion, frame advance, etc.), and a signal that controls the switching of recording and playback. This may include a timing signal for instructing the insertion of the data.

On the other hand, inside the rotating body, there is a constant voltage circuit 4 that rectifies the FM-modulated high-frequency voltage and converts it into a constant voltage necessary as a pre-up 5 for reproduction signals and a power source for recording up (not shown). A demodulation circuit 6 that demodulates the FM-modulated high-frequency voltage and outputs it as a control signal ■8
The control signal (1) 8 is used as a control signal for switching between a plurality of magnetic heads mounted on the rotating body, switching between recording and reproduction, and the like.

Therefore, according to this embodiment, the modulated voltage applied from the modulation circuit 2 to the rotating body side includes the i[voltage and the control signal, and the low retransformer 3 is used as the power source and control signal transmission means. It can be shared, and special transmission means for transmitting control signals is not required.

In the above embodiment, the voltage output from the modulation circuit 2 is AM-modulated by the control signal 9;
It may be any type, such as one that is M-modulated or one that takes several types of frequencies (although the mode of modulation is not limited in the answer).

Next, FIG. 2 shows another embodiment of the present invention, in which a transmission means 7 consisting of a slip ring and a brush is used as a transmission means for transmitting the output of the modulation circuit 2 from the outside of the rotating body to the inside of the rotating body. In addition to further improving reliability,
A resistor R is used as a demodulation circuit that demodulates the control signal inside the rotating body.
1, R2, and a comparator 8.

This embodiment will be described below with reference to the timing chart shown in FIG. Power is supplied from the power supply circuit 1 to the modulation circuit 2, and a control signal 8 is supplied to the modulation circuit 2. Here, the control signal (2) is a binary digital signal of high level and low level. The modulation circuit 2 outputs 1 when the control signal v9 is at a high level, and outputs VY when the control signal v9 is at a low level. Here, if the voltage required as a power source for the pre-up 5 is v2, the voltage values vX and vY are set so that v,>v2 and v,>v2 hold.

The output voltage of the modulation circuit 2 is guided to a constant voltage circuit 4 inside the rotating body via a transmission means 7 consisting of a slip ring and a brush. This constant voltage circuit 4 uses a three-terminal regulator to output a power supply voltage (2) necessary for the pre-up 5 and supplies it to the pre-up 5. The output voltage of the modulation circuit 2 is divided by two resistors R1 and R2 connected in series, and the divided voltage is converted to a reference voltage (2) by a comparator 8. It is converted into a binary digital signal by comparing it with .

This operation allows the control signal (1)8 to be easily demodulated. That is, the comparator 8 is at the reference voltage ■. Since the control signal VB becomes high level when the input voltage has a larger value, it operates as a demodulation circuit. Note that 1[ of the comparator 8 can also serve as a power source for the pre-up 5.

[Effects of the Invention] As is clear from the detailed explanation above, according to the magnetic recording/reproducing apparatus of the present invention, a power supply circuit is provided outside the rotating body, and the power of the power supply circuit is converted into a modulated voltage by a control signal. A modulation circuit is provided, and a constant voltage circuit that converts the modulated voltage transmitted via the transmission means into a predetermined constant voltage and a demodulation circuit that demodulates a control signal from the modulated voltage are provided in the rotating body. Therefore, there is no need for a special transmission means for transmitting control signals, and it can be used in common with the power supply transmission means.Therefore, the number of parts can be reduced as a whole, reducing costs, as well as reducing space and weight. Effects such as reduction also occur.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing another embodiment of the present invention, and FIG. 3 is a diagram of output waveforms of each part in FIG. Fig. 1 1... Power supply circuit, 2... Modulation circuit, 3... Transmission means consisting of a rotary transformer, 4... Constant voltage circuit, 5
. . . Pre-up, 6. Demodulation circuit, 7. Transmission means consisting of a slip ring and brush, 8. Comparator operating as a demodulation circuit. Inventor: Akira Obayashi Patent applicant: Victor Japan Co., Ltd.

Claims (1)

[Claims] (1) A magnetic head equipped with a magnetic head and a booster for amplifying recording or reproduction signals on the rotating body side, a power supply circuit outside the rotating body, and a transmission means for supplying power from the power supply circuit to the rotating body side. In the recording and reproducing apparatus, modulation is performed in which power supplied from the power supply circuit to the outside of the rotating body is modulated by a control signal that controls switching of recording and reproduction and/or controls the position of the magnetic head according to the recording and reproduction mode. a constant voltage circuit that converts the modulated voltage transmitted into the rotating body via the transmission means into a constant voltage necessary as a power source for a circuit in the rotating body; and a constant voltage circuit that converts the modulated voltage transmitted into the rotating body via the transmission means, A magnetic recording/reproducing device characterized by being provided with a demodulation circuit that demodulates a signal.