JPS61233402A - Rotary head type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To simplify the structure and to reduce the cost of a rotary type magnetic recording/reproducing device by sharing a single rotary transformer with plural magnetic heads and performing the transfer of signals among these heads via the rotary transformer. CONSTITUTION:A rotary head mechanism 21 has such a structure where a rotary drum 23 containing two rotary heads A' and B' is combined rotatably with a fixed drum 22 and a rotary transformer 24 shared with both heads A' and B' is formed with a status core 26 attached with a shared coil 25 on the drum 22 and a rotary core 28 containing a shared coil 27 of the drum 23. That is, the winding angle theta of a tape T must be set at >=180 deg. in case both heads A' and B' are set at different positions with a 180 deg. space. As a result, it is avoided that the signals reproduced by both heads according to the revolutions of the drum 23 are read at a time from the tape T.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a rotary head type magnetic recording/reproducing device.

<Overview> The present invention provides a rotary head with a simple structure in which a single rotary transformer is shared by a plurality of rotary heads, and signals are received and received by each rotary head via the shared rotary transformer. The present invention provides a magnetic recording/reproducing device of the type shown in FIG.

<Prior Art> The reproducing circuit system and rotary head mechanism of a conventional magnetic recording/reproducing apparatus of this type, particularly a magnetic recording/reproducing apparatus for PCM signals, and the rotary head mechanism thereof are shown in FIGS. 5 and 6. In this case, a rotary transformer 3.4 is provided individually for the rotary heads A and B on the rotary drum 2, which is rotatably combined with the fixed drum I, and the magnetic tape is reproduced by each rotary head A and B. Rotating transformer for each signal 3.
4 and channel switch 7 via preamplifier 5.6
According to the positions of the rotary heads A and B detected by the phase detection head 8 from the channel switch, the signal is supplied to the demodulator 9 at the next stage for demodulation, and then the TBC (Tim
The wow and flutter component is removed by the eBa5e Corrector circuit 10, and the error is corrected by the decoder 11.
2L, +2R and low pass filter l 3L, l 3R
It is designed to convert into an analog signal through the

Note that 14 is a synchronization signal generator.

<Problems to be solved by the present invention> Therefore, in the conventional device described above, it is necessary to provide a rotary transformer and a preamplifier for each rotary head, and it is necessary to eliminate crosstalk between the coils CA and CB of each rotary transformer. It is necessary to provide the groove 15, which makes the structure complicated and increases the cost.

Means for Solving the Problems> The present invention was invented in view of the above-mentioned drawbacks of the conventional device, and it transmits and receives signals to and from a rotating head that traces on a magnetic tape via a rotating transformer. A rotary head type in which one rotary transformer is shared by multiple magnetic heads, and signals are sent and received to and from each magnetic head via the shared rotary transformer. The present invention provides a magnetic recording and reproducing device.

<Operation> Therefore, according to the present invention, one rotary transformer is shared by a plurality of rotary heads to transmit and receive recording or reproduction signals.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block electric circuit diagram showing a reproducing system of a PCM signal magnetic recording and reproducing apparatus as an embodiment of the rotary head type magnetic recording and reproducing apparatus of the present invention, and FIG. 2 is a block diagram of the rotary head mechanism in the same apparatus. It is a schematic sectional view.

In these figures, the rotating head mechanism 21 rotatably combines a rotating drum 23 with two rotating heads A' and B' attached to a fixed drum 22, and a common coil 25 on the fixed drum 22 is fitted. Stator core 26
and a rotor core 28 into which the common coil 27 of the rotating drum 23 is fitted, forming a common rotating transformer 24 for the two rotating heads A' and B'.

29 is a preamplifier connected to the shared coil 25 in the rotary transformer 24, and 30 is a demodulator.

31' is a TBC for electrically correcting wow and flutter.
(Time Ba5e Corrector) circuit, 3
2 is a decoder which detects and corrects code errors in the digital signal supplied from the TBC circuit 31 and separates it into L and R channels; 83L and 83R are decoders 32;
Converters 34L and 34R are low-pass filters for converting digital signals from the digital signal into analog signals.

Note that 35 is a phase detection head, and 36 is a synchronization signal generator.

The present invention is constructed as a constriction, but in order to implement this and reproduce the signal well, the following conditions regarding the corners of the tape T to be wound around the rotating drum 23 are required. .

That is, the rotating head has two positions A' and B' as in the above embodiment.
When the tape T is installed at positions separated by 180° as shown in FIG. 3, the angle θ of the winding of the tape T must be 180° or less.

In this way, by setting the angle θ, the tape T is wound around each rotary head A', according to the rotation of the rotary drum 23.
The signals reproduced from B' are not read from tape T at the same time, and their envelopes have a waveform as shown in FIG.

Each reproduced signal having such a waveform passes through the rotary transformer 24 alternately, and then passes through the preamplifier 29 and the demodulator 30.
．． The signal passes through a TBC circuit 31 to a decoder 32, where it is error-corrected and separated into L and R channels, and converted into an analog signal by converters 38L and 33R, followed by a low-pass filter 34L.

It is output as L and R signals from 84R.

<Effects> Since the present invention has a constriction-like structure, it is possible to reduce the number of rotary transformers to one, and there is no need to provide grooves for removing crosstalk in such a rotary transformer, making it possible to manufacture the transformer at low cost. It becomes possible.

[Brief explanation of the drawing]

Fig. 1 is a block electrical circuit diagram showing one embodiment of the magnetic recording/reproducing device according to the present invention, Fig. 2 is a schematic cross-sectional view of the rotary head mechanism in a 1° device, and Fig. 3 is the same as above. Figure 4 is a waveform diagram showing the envelope of the read waveform of the rotary head in the above apparatus, and Figure 5 is an example of a conventional magnetic recording/reproducing apparatus. A block electrical diagram showing
FIG. 6 is a schematic cross-sectional view of the rotary head mechanism in such a conventional device. 24: Rotating transformer, A'CB'): Rotating head. Agent: Patent attorney Aihiko Fuku (and 2 others)
16 Figure 1 Diagram showing the angle of the S-girdle of the tape Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. In a device that records or reproduces signals by transmitting and receiving signals to and from a rotary head that traces on a magnetic tape via a rotary transformer, one rotation for a plurality of rotary heads. A rotary head type magnetic recording and reproducing device which uses a common transformer and sends and receives signals to and from each rotary head via the shared rotary transformer.