JPS5996509A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To increase the number of rotary magnetic heads without increasing the number of channels of a rotary transformer by transmitting/receiving signals between a rotary cylinder circuit and a fixed cylinder circuit through the rotary transformer and setting up power frequency within the transmission band of the rotary transformer and at the low frequency part of a recording/reproducing signal. CONSTITUTION:A reproducing signal from a rotary magnetic head 1a is amplified through an alteration switch 6 and transmitted to the fixed cylinder side through a head selecting circuit 14 and a rotary transformer 19. At the recording, a recording signal is amplified through a rotary transformer 18 and transmitted to heads 1a, 1b through the alteration switches 6, 7. In case of the recording system of a low frequency- converted color signal, the band of a recording/reproducing signal occupies several hundred KHz to several MHz. Therefore a signal included in said band is applied to the rotary transformers 18, 19. It is preferable to set up the channels of rotary transformers 20, 21 to a band other than said band. When a signal amplifier circuit is set up on a rotary cylinder, the transmission frequency of electric power to be supplied to a power supply circuit on the rotary cylinder should be set up close to the lower limit frequency of the low frequency-converted color signal and within the transmission band of the rotary transformers.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording/reproducing device (with only one of the reproducing and recording functions) equipped with a plurality of rotating magnetic heads and a recording/reproducing signal amplification circuit on a rotating cylinder. (including those that also have).

Conventional configuration and its problems Conventionally, in order to record and reproduce signals on a magnetic tape using a plurality of rotating magnetic heads, a rotating magnetic head (ia) (lb) as shown in FIG. Rotating transformers (3) and (4) provided in one-to-one correspondence with (2) (
5) to the recording signal amplification circuit (9) on the fixed ring side.
and reproduction signal amplification circuit CIIθυ@ and rotating magnetic head (
Signals are being exchanged between 1a), (1b), and (2).

(6) (7) (8) 03 is a recording/reproduction changeover switch, which is operated by a signal from the recording/reproduction changeover circuit OQ. a< is a head selection circuit, which selects a reproduction signal. Note that α9 is the recording signal amplification circuit (9)
and a reproduction signal amplification circuit 40] (6), a power supply circuit for the head selection circuit Q, and the recording/reproduction switching circuit αQ. In this way, a plurality of heads and only one side of the rotary transformer are mounted on the rotary cylinder, and all signal processing is performed on the fixed side via the rotary transformer.

However, in recent years, the number of rotating magnetic heads has been increasing in order to achieve special playback or long-time recording, and in the conventional configuration of a recording/reproducing system for a rotating magnetic head, the rotating magnetic head and rotating transformer are arranged one-to-one. In order to correspond to the number of rotating magnetic heads, it is necessary to have as many channels of rotating transformers as there are rotating magnetic heads. Therefore, the rotary transformer becomes larger and the cost increases. In other words, in an off-the-shelf format VTR with a fixed cylinder diameter, the number of channels in the rotary transformer cannot be easily increased, so for example, a VHS system V'I'R has more than a 4-head configuration. has not been realized. However, the wiring from the rotating magnetic head to the recording/endogenous signal amplification circuit and the rotating transformer σ) floating volume M (due to the widening of the recording/reproducing system of the rotating magnetic head - it has the disadvantage of not being able to be viewed at a glance). te 0ru.

OBJECTS OF THE INVENTION The present invention aims to solve the above-mentioned problems, and provides a magnetic recording and reproducing device in which the number of rotating magnetic heads can be arbitrarily increased without increasing the number of channels of the rotating transformer. The purpose is to install a recording/reproduction signal amplification circuit, a transducer (circuit, control circuit, and power supply circuit) on the top of the top, and connect it to the power supply circuit via a rotating transformer. It is intended to transmit alternating current (No. 1), which may interfere with the recording/reproduction signal number, and may cause the connection path from the rotary magnet to the amplifier circuit to be extremely high power). Magnetic head recording 1j
This aims to achieve the reduction of 41) the number of biological systems.

Structure of the Invention In order to achieve the above object, the present invention provides a rotating magnetic head for recording and reproducing signals on a magnetic tape, and a recording/reproducing head connected to the rotary magnetic head via a recording/reproducing switching circuit. a signal amplification circuit; a head selection circuit that selects the reproduction output of an arbitrary rotating magnetic head from the output of the reproduction signal amplification circuit; a control circuit that supplies control signals for the recording and reproduction switching circuit and the head selection circuit; and the recording and reproduction circuit. Signal amplification circuit.

A recording signal is sent to the head selection circuit, the power supply circuit of the control circuit, and the recording signal amplification circuit, the power supply circuit, and the control circuit, respectively.
It is comprised of a rotating transformer that supplies power and control signals from each required circuit on the fixed cylinder side, and supplies the output of the destination selection circuit to the required circuits on the fixed cylinder side for tF, and supplies power to the power supply circuit. For transmission, the power frequency is set within the transmission band of the rotating transformer and in the low-frequency region of the recording band of the magnetic recording/reproducing device. It can cope with multiplexing and wideband recording/reproducing systems.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Second
As shown in the figure, the rotary transformer has four transmission channels, Q barrel is for the channel that transmits the recording signal to the recording signal amplification circuit (9), and C1l is for the channel that transmits the recording signal to the recording signal amplification circuit (9), and C1l is the one for the channel that transmits the recording signal to the recording signal amplification circuit (9). (E) is a channel that transmits power to the power supply circuit QO, <21) is a control circuit (17), a head selection circuit Q4, and a recording/reproduction changeover switch.

((1) (7) (8) (to) The channel that transmits the control signal that controls
is operated by the output from the control circuit 0'7). (II
(lυθo is a reproduction signal amplification circuit, (9) is a recording signal amplification circuit, (1a) (1b) (2) is a rotating magnetic head, α
9 is a power supply circuit for each circuit on the rotating cylinder.

Considering the signal flow, during reproduction, the reproduction signal obtained from the rotating magnetic head (1a) passes through the recording/reproduction changeover switch (6), is amplified by the reproduction amplification circuit 0 (step 0), and is amplified by the head selection circuit 04. ) and the rotating transformer OI to the fixed cylinder side. Conversely, during recording, the recording signal supplied from the required circuit on the fixed cylinder side passes through the rotary transformer 081, is amplified by the recording signal amplification circuit (9), and is sent to the rotary magnetic head via the recording/reproduction changeover switch (6) (7). (1a) and (1b).

If we consider a magnetic recording and reproducing device that uses a low-band conversion color signal recording method, the frequency band used for recording and playback signals is as shown in FIG. It consists of a low frequency carrier FM signal (carrier frequency is fc) of a luminance signal, and generally occupies the range from several hundred KHz to several MHz. Therefore, the rotating transformer (
) and 01 transmission channels have a frequency of several hundred KHz to several MHz.
2 signals will be applied. Due to the structure of a rotary transformer, crosstalk interference from adjacent channels is unavoidable, and in this case, the signal transmission channel must be connected to the power transmission channel of the rotary transformer to the power supply circuit or the rotary transformer to the control circuit (17). ) is desirably set to a signal band other than the above signal band.

In addition, if the loss in the core of a rotating transformer that actually sends and receives signals is generally considered to be sufficiently small,
This is represented by an equal circuit as shown in FIG. In FIG. 4, (A) is an input terminal, and (C) is an output terminal. Also, the threat is the effective resistance on the primary side, (c) is the effective resistance on the secondary side,
(C) is the primary side leakage inductance, 2) is the secondary side leakage inductance, (A) is the mutual inductance, (E)
is the load connected to the output terminal (7). Now, considering the transmission characteristics of the rotating transformer, J
: When the signal source frequency is between fl and -f-2 (approximately equal to the signal frequency band of the low-pass conversion color signal recording method), the transmission characteristics are flat, but when it is lower than chi1 and -f-2, the transmission characteristics are flat. If it is higher than Fs, the transmission characteristics are deteriorated and it is not suitable for signal transmission. That is, from FIG. 5, in order to efficiently transmit power using a rotary transformer, the power frequency must be set between 1 and 2.

Considering the above matters and looking at the signal frequency band of the low-frequency conversion color signal recording method and the transmission characteristics of the rotating transformer, in the above embodiment, when the recording/reproducing signal amplification circuit is mounted on the rotating cylinder, The transmission frequency of the power supplied to the necessarily necessary power supply circuit on the rotating cylinder should be set near the lower limit frequency of the low-frequency conversion color signal and within the transmission band of the rotating transformer. Furthermore, within the transmission band of the rotary transformer, it goes without saying that the power transmission frequency should be set below the lower limit frequency of the low frequency conversion color signal.

In the above description, the recording method is limited to the low-frequency conversion color signal recording method, and the recording and reproduction signal amplification circuits are mounted on the rotating cylinder, but other recording methods (
V'l, for example, characterized in that the luminance and color signals are transmitted via different channels of a rotating transformer.
Of course, the above-mentioned conditions can also be applied to cases where only the reproduced signal amplification circuit is mounted on the rotary cylinder (e.g. ' R, etc.) and the rotary cylinder.

Effects of the Invention The present invention provides a recording/reproducing switching circuit on a rotary cylinder;
It is equipped with a recording/reproducing signal amplification circuit, a head selection circuit, a control circuit, and a power supply circuit, and transmits and receives signals between each circuit of the rotating cylinder and fixed cylinder via a rotating transformer. Furthermore, the power frequency is transmitted through the rotating transformer. By setting within the band and in the low frequency part of the recording/playback signal of the magnetic recording/playback device, the number of rotating magnetic heads can be increased due to special playback, long-time recording, etc. without increasing the number of channels of the rotating transformer. (including rotary magnetic heads with new functions such as rotary magnetic heads for erasing only), as well as the conventional method of performing special playback by switching the rotary magnetic heads within the same field. , and has the advantage that there is little interference with recording/reproduction signals and that the efficiency of supplying power to the power supply circuit can be increased. Furthermore, 17r! It has the advantage of eliminating the wiring from the rotating magnetic head to the recording/reproducing (Pl' 3 amplifier circuit) and the floating rotating transformer, making it possible to achieve a wider band and lower loss in the recording/reproducing system of the rotating magnetic head. ing.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a recording/reproducing system of a conventional rotary magnetic head, Fig. 2 is a block diagram showing a recording/reproducing system of a rotary magnetic head which is an embodiment of the present invention, and Fig. 8 is a block diagram showing a recording/reproducing system of a rotary magnetic head according to an embodiment of the present invention. A diagram showing the signal frequency band of the converted color signal recording method, Figure 4 shows the circuit of the rotating transformer, Figure 2, Figure 3, f3fc frt-tr).

Claims (1)

[Claims] 1. A plurality of rotating magnetic heads on a rotating cylinder for recording and reproducing signals on a magnetic tape, and a recording/reproducing signal amplification circuit connected to the rotating magnetic heads via a recording/reproducing switching circuit. a head selection circuit that selects the reproduction signal output of an arbitrary rotating magnetic head based on the output of the recording and reproduction signal amplification circuit; a control circuit that controls the recording and reproduction switching circuit and the head selection circuit; and operating each of the circuits. a first channel for taking out the output of the head selection circuit to the fixed side; a second channel for supplying an AC signal to the power supply circuit; and a second channel for supplying a control signal to the control circuit. A magnetic recording/reproducing device characterized in that a rotary transformer having eight channels is provided in a cylinder. 2. The magnetism according to claim 1, characterized in that the transmission frequency of the electric power supplied from the required circuit on the fixed cylinder to the power supply circuit on the rotating cylinder is set at the lower end of the transmission band of the rotating transformer. Recording and playback device.