JPH0533442B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention includes a plurality of rotating magnetic heads and reproduction signal amplification circuits mounted on a rotating cylinder, and amplifies and selects reproduction signals from a magnetic tape on the rotating side. The present invention relates to a magnetic recording/reproducing device characterized by the following.

Conventional structure and its problems Conventionally, when recording/reproducing on a magnetic tape using a plurality of rotating magnetic heads, as shown in FIG. Signals were exchanged between the rotating side and the rotating side via the rotating transformers 2a and 2b. In FIG. 1, 4a and 4b are reproduction signal amplification circuits, and 5 is a recording signal amplification circuit, each having a function of amplifying reproduction and recording signals. Also, 3
Recording/reproducing switching circuits a and 3b are connected between the rotary transformers 2a and 2b and the reproduced signal amplifying circuits 4a and 4b, and are controlled according to each recording/reproducing mode. Reference numeral 6 denotes a reproduction head switching circuit having a function of selecting a specific reproduction output from the signals amplified by the reproduction signal amplification circuits 4a and 4b. 8 is a recording head switching circuit configured to supply the signal amplified by the recording signal amplifying circuit 5 only to a specific rotating magnetic head;
a, 3b and the recording signal amplification circuit 5. The DC voltage circuit 7 supplies DC voltage for driving each of the circuits.

During reproduction, the reproduction outputs of the rotating magnetic heads 1a, 1b are transmitted to the recording/reproducing switching circuits 3a, 3b via the rotating transformers 2a, 2b. Here, the recording/reproduction switching circuits 3a, 3b detect that the recording/reproduction switching signal is the reproduction mode, connect the rotary transformers 2a, 2b and the reproduction signal amplification circuits 4a, 4b, and connect the recording head switching circuit 8. are separated from the rotating transformers 2a and 2b. That is, the reproduced signal is input only to the reproduced signal amplification circuits 4a and 4b, and is not affected by the recording head switching circuit 8 in any way. Furthermore, the signals amplified by the reproduction signal amplification circuits 4a and 4b are input to the reproduction head switching circuit 6,
Only a specific reproduction output is output according to the head switching signal.

Conversely, during recording, the recording/reproduction switching circuit 3a,
3b separates the circuits after the reproduced signal amplification circuits 4a and 4b from the rotary transformers 2a and 2b. The signal amplified by the recording signal amplification circuit 5 is transmitted only to a specific rotating magnetic head by the operation of the recording head switching circuit 8. In this way, multiple rotating magnetic heads and only one side of the rotating transformer are mounted on the rotating cylinder, and all processing such as amplification and selection of the reproduced signal is performed by each circuit on the stationary side. It is becoming. In the description of the conventional example, although FIG. 1 shows only two rotating magnetic heads, the basic structure remains the same even if there are three or more rotating magnetic heads.

However, in recent years, the number of rotating magnetic heads has tended to increase in order to realize special playback, audio recording, video inserts, long-time recording, etc. However, in the configuration of a conventional rotary magnetic head recording/reproducing system, since the rotary magnetic head and the rotary transformer correspond to each other on a one-to-one basis, the number of rotary transformer channels equal to the number of rotary magnetic heads is required. As a result, the shape of the rotating transformer becomes larger and the cost increases.
This has the disadvantage that it is not possible to provide sufficient spacing between channels, resulting in increased crosstalk.
Furthermore, in magnetic recording/reproducing apparatuses configured with existing formats, the diameter of the cylinder is regulated, so it is impossible to easily increase the number of channels of the rotary transformer. There is also a method of using a slip ring or the like as a means of transmitting signals between the rotating side and the stationary side, but the negative effects of mechanically generated noise at the contact portion cannot be avoided.

Furthermore, considering that higher image quality and digital recording will be required in the future, it will be essential to widen the bandwidth of the recording and reproducing system of the rotating magnetic head. Stray capacitance in wiring, line capacitance of the rotating transformer itself, and coupling capacitance become obstacles.

Therefore, the rotary transformer that was interposed between the reproduction signal amplification circuit of the rotary magnetic head was removed, and the rotary magnetic head and the reproduction signal amplification circuit were directly connected.
Consider a configuration in which the reproduction signal can be selected on the rotating side.
Examples thereof are shown in FIGS. 2 and 3. FIG. 2 is an exploded perspective view of a cylinder block in which each of the circuits described above is mounted on a rotating cylinder, and FIG. 3 is a circuit configuration diagram thereof.

In FIG. 3, 1a and 1b are rotating magnetic heads, 9 is a rotating cylinder, 13 is a fixed cylinder, 1
1 is a rotary transformer on the rotating side, and 12 is a rotary transformer on the stationary side, and the gap thereof is about 100 μm. 10 is a disk for attaching the rotary transformer 11 to the rotary cylinder 9. Also, 1
Reference numeral 8 indicates a circuit block mounted on the rotary cylinder, which transmits and receives recording/reproducing signals to and from the circuit magnetic heads 1a and 1b, and rotary transformers 11 and 1.
2 to the necessary circuits on the fixed side and recording/playback signals,
It sends and receives power and control signals.

FIG. 3 is a circuit configuration diagram specifically showing the configuration of the circuit block 18 of FIG. 2 (including a rotary transformer and a part of the circuit on the stationary side).

In FIG. 3, rotating magnetic heads 1a, 1b,
The connection relationships among the reproduction signal amplification circuits 4a, 4b, the recording signal amplification circuit 5, the reproduction head switching circuit 6, the recording head switching circuit 8, and the recording/reproduction switching circuits 3a, 3b, and the operation during recording/reproduction are the same as the conventional example described above. Basically no change. However, the rotating magnetic heads 1a, 1b are directly connected to reproduction signal amplification circuits 4a, 4b, and recording/reproduction switching circuits 3c, 3d are provided on the rotating side and fixed side of the rotary transformer, respectively. During reproduction, the recording/reproducing switching circuit 3c separates the rotary transformer 2a from the recording signal amplifying circuit 5, and transmits the output of the reproducing head switching circuit 6 to the fixed side via the rotary transformer 2a. During recording, the recording/reproduction switching circuit 3c, conversely, disconnects the reproduction head switching circuit 6 from the rotary transformer 2a, and transmits the recording signal transmitted from the fixed side to the recording signal amplification circuit 5. Similarly, the recording/reproduction switching circuit 3d also
The recording signal processing circuit on the fixed side is separated from the rotary transformer 2a during reproduction, and the reproduction signal processing circuit on the fixed side is separated from the rotary transformer 2a during recording. In the configuration of the recording/reproducing system as shown in FIG. 3, control signals for each switching circuit and a DC voltage circuit for each circuit are required on the rotation side.

Therefore, the alternating current signal having the information of the control signal is transmitted via the rotary transformer 2b to the recording/reproducing switching signal generating circuit 14, the head switching signal generating circuit 15, and the direct current voltage generating circuit 16 provided on the rotating side. A recording/reproduction switching signal, a head switching signal, and a DC voltage can be obtained by this. In other words, by mounting the playback signal amplification circuit and each switching circuit on the rotating side, it is possible to prevent an increase in the number of channels of the rotating transformer due to an increase in the number of rotating heads, and by directly connecting the rotating magnetic head and the amplifier circuit, the number of channels in the rotating transformer can be prevented from increasing. This has the advantage that a wideband recording/reproducing system of the magnetic head can be realized.

However, generally the driving voltage for each of the above circuits is 5V.
Therefore, the voltage amplitude of the AC signal transmitted via the rotary transformer 2b is several tens of _Vpp , whereas the voltage amplitude of the signal reproduced by the rotating magnetic heads 1a and 1b is several hundred _μVpp . That is, the disadvantage is that the AC signal jumps into the rotating magnetic head from the AC signal transmission channel or the wiring from the rotating side of the rotary transformer to the DC voltage generation circuit 16, interfering with the reproduced signal and causing noise beats etc. on the reproduced screen. have. Although FIGS. 2 and 3 show a case in which two rotating magnetic heads are mounted, the same can be said for a case in which three or more rotating magnetic heads are mounted. Further, although the conventional example shows a rotary transformer that faces each other in a plane, it is clear that the same thing can be said when a rotary transformer that faces each other circumferentially is used.

OBJECTS OF THE INVENTION The present invention aims to solve the above-mentioned problems. It is possible to cope with the increase in the number of rotating magnetic heads without increasing crosstalk between channels of recording and reproduction signals, and without causing interference with recording and reproduction signals due to the transmission of AC signals (10-odd _Vpp ). A magnetic recording system that can overcome the obstacles to wideband performance caused by the wiring capacity, the line capacitance of the rotating transformer, and the coupling capacitance that exist between the rotating magnetic head and the input end of the reproduced signal amplification circuit in the recording/reproducing system of the magnetic head. The purpose is to provide a playback device.

Configuration of the Invention In order to achieve the above object, the present invention provides recording/
a plurality of rotating magnetic heads for reproduction; a first recording/reproducing switching circuit connected between the rotating magnetic heads and an amplifier circuit for switching recording/reproducing; and a reproduction head switching circuit for switching the output of the amplifier circuit; , a second recording/reproduction switching circuit connected between the reproduction head switching circuit and the rotary transformer;
and a second recording/playback switching circuit,
a recording head switching circuit that switches the rotating magnetic head during recording; a recording/reproduction switching signal generation circuit and a head switching signal generation circuit that supply a recording/reproduction switching signal and a head switching signal to each of the switching circuits;
A rotating cylinder block is constituted by a DC voltage generation circuit that supplies DC voltage to each of the above circuits, and the AC signals transmitted to the recording/reproduction switching signal generation circuit, head switching signal generation circuit, and DC voltage generation circuit are It is configured to be transmitted through the channel furthest from the rotating magnetic head of the rotating transformer, thereby preventing the DC voltage generation circuit from interfering with the recording/reproducing signal of the rotating magnetic head. .

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below based on the drawings. FIG. 4 is a sectional view of a cylinder unit (excluding the fixed cylinder) showing one embodiment of the present invention.
The circuit configuration diagram in this embodiment is the same as that shown in FIG. 3 above. Furthermore, in terms of circuit operation, the playback/recording signal amplification circuits 4a, 4b, 5 and the recording/playback switching circuits 3a, 3 mounted on the rotary cylinder are
b, 3c, the operation of the recording/reproducing head switches 8, 6 amplifies and switches signals on the rotating side, and also supplies power and control signals to each of the above circuits using an alternating current that is transmitted via the rotating transformer. This is done using signals, and is similar to that shown in FIG. 3 above.

In Fig. 4, the rotating magnetic heads 1a and 1b have several 100 μV _pp (the signal level is particularly low during playback).
On the other hand, in the channel of the rotary transformer 2b, which transmits and receives power/control signals, a signal of more than 10 _Vpp is transmitted.

Furthermore, when transmitting power from the fixed side to the rotating side using a rotating transformer, the DC voltage generation circuit 1
6, harmonic components (about several _Vpp ) are present in the winding on the rotating side of the rotary transformer 2b and in the wiring from the winding to the DC voltage generating circuit 16. That is, when transmitting power using a rotary transformer, the transmission channel of the rotary transformer and the wiring from the transmission channel of the rotary transformer to the DC voltage generation circuit 16 are connected to the rotary magnetic head 1.
A direct intrusion of AC signals (power/control signals) to a and 1b occurs, causing interference to the recording/reproduction signal. Therefore, by setting the transmission channel of the alternating current signal to the inner channel of the rotary transformer 2b, which is the inner one of the two transmission channels of the rotary transformer that is remote from the rotary magnetic heads 1a and 1b, the Disturbance to the magnetic head can be reduced and a sealing effect on the rotating magnetic head can be provided.

In addition, in this embodiment, there are two rotating magnetic heads.
Although we are considering the case of 3 or more, the same can be said for the case of 3 or more. Furthermore, it is clear that the same thing can be said not only to the planarly opposed type rotary transformer but also to the circumferentially opposed type rotary transformer.

In other words, by setting the power transmission channel to the channel furthest from the rotating magnetic head of the rotary transformer, it is possible to reduce interference to the recording/reproduction signal via the rotating magnetic head due to power transmission, and to It is possible to realize multiple systems and wideband rotating magnetic head systems.

Effects of the Invention As is clear from the above description, the present invention provides a signal processing circuit between the rotating transformer and the rotating magnetic head, and sets the power transmission channel to the channel farthest from the rotating magnetic head of the rotating transformer. This configuration has the effect that the rotary transformer can be made smaller with respect to the rotary cylinder of the multihead, without increasing interference with the recording/reproduction signal that accompanies power transmission. Furthermore, since the reproduction signal amplification circuit is mounted on the rotary cylinder side, the head and amplifier can be connected with a very short line, which minimizes stray capacitance on the input side of the amplifier, resulting in a wide signal transmission band. Also, during playback, the weak signals discarded by the head are amplified to an appropriate level before being transmitted via the rotating transformer, so there is almost no S/N deterioration due to transmission loss of the rotating transformer. This also has the effect of being able to obtain a high S/N ratio.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram of a main part of a conventional magnetic recording and reproducing device, and FIGS. 2 and 3 are exploded perspective views of a cylinder portion of a conventional magnetic recording and reproducing device, and a circuit configuration of a main part mounted on a rotating cylinder. 4 are sectional views of a cylinder portion showing an embodiment of the present invention. 1a, 1b...Rotating magnetic head, 2a, 2b...
... Rotating transformer, 3a, 3b, 3c, 3d... Recording/reproduction switching circuit, 6... Playback head switching circuit,
8... Recording head switching circuit, 9... Rotating cylinder, 10... Disk, 11, 12... Rotating transformer, 13... Fixed cylinder, 14... Recording/playback switching signal generation circuit, 15... Head switching signal Generation circuit, 16...DC voltage generation circuit, 18...Circuit block on the rotating cylinder.

Claims (1)

[Claims] 1. A plurality of rotating magnetic heads for recording/reproducing;
a first recording/reproducing switching circuit connected between the rotating magnetic head and the amplifier circuit for switching recording/reproducing; a reproducing head switching circuit for switching the output of the amplifying circuit; a first recording/reproducing switching circuit connected between the rotating magnetic head and the amplifier circuit; a recording head switching circuit connected between the first and second recording/reproducing switching circuits and switching the rotating magnetic head during recording; A rotating cylinder block is constituted by a recording/playback switching signal generation circuit and a head switching signal generation circuit that supply a recording/playback switching signal and a head switching signal to the circuit, and a DC voltage generation circuit that supplies DC voltage to each of the above circuits. , recording to the above recording/reproduction switching signal generation circuit, head switching signal generation circuit, and DC voltage generation circuit.
A magnetic recording/reproducing device in which the channel farthest from the rotating magnetic head of the rotary transformer is used to transmit an alternating current signal having reproduction/head switching information. 2. Claim 1, characterized in that the rotary transformer has a planar configuration in which the magnetic core opposing portion uses the innermost channel for transmitting AC signals.
The magnetic recording and reproducing device described in 2. 3. The magnetic recording and reproducing apparatus according to claim 1, wherein the rotary transformer has a concentric circular configuration in which the magnetic core opposing portions are arranged, and the lowermost channel is used for transmitting the alternating current signal.