JPH1186380A - Rotary magnetic head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary magnetic head device capable of being miniaturized in the case of reproducing signals recorded on a tape like information recording medium by using plural reproducing heads. SOLUTION: This device is a rotary magnetic head device 10 reproducing signals recorded on a tape like information recording medium TP by using plural reproducing heads RH1, RH2, RH3, RH4. A reproduced signal selection means 200 is provided with magnets 980, 981 to be provided on a fixed drum 1 and plural magnetic sensing sensors 201A, 201B to be provided on a rotary drum 2 in order to output signals by sensing magnetic fluxes of the magnets 980, 981 of the fixed drum 1 at the time the rotary drum 2 is revolved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary magnetic head device having a non-contact type transmission device used for an information recording device such as a video tape recorder, for example, which is recorded on a tape-shaped information recording medium. The present invention relates to a rotating magnetic head device capable of reproducing signals of a plurality of recording tracks using a plurality of reproducing heads regardless of the arrangement of recording tracks on an information recording medium.

[0002]

2. Description of the Related Art As a device for recording information on a magnetic tape or reproducing information from a magnetic tape, there are a video tape recorder, a tape streamer and the like. Such a type of information recording apparatus includes a rotary magnetic head device for recording a signal on a magnetic tape and reproducing a signal from the magnetic tape. The rotating magnetic head device has a rotating drum and a fixed drum, and the rotating drum has a recording head and a reproducing head. The recording head is a head for recording a signal on the magnetic tape, and the reproducing head is used for reproducing a signal recorded on the magnetic tape.

The rotating drum holds the recording head and the reproducing head, and rotates the motor with respect to the fixed drum to scan the recording head or the reproducing head against the magnetic tape, for example, by a helical scan method. Thus, information can be recorded on the magnetic tape or the information on the magnetic tape can be reproduced. By employing such a helical scan method, high-density recording of signals on a magnetic tape is possible, and the relative speed between the magnetic tape and the magnetic head can be increased. In the helical scan type rotary magnetic head device, since the recording head and the reproducing head are housed in the rotary drum, it is necessary to exchange signals and power between the rotary drum and the fixed drum in a non-contact manner. . For example, there is a case where a reproduction signal obtained from the reproduction head is transmitted from the rotary drum side to the fixed drum side in a non-contact manner, or a power supply for a circuit board is supplied from the fixed drum side to the rotary drum side.

In recent years, by setting a plurality of reproducing heads on a rotating drum and rotating the plurality of reproducing heads at a high speed, a recording track recorded on a tape-shaped information recording medium is so-called non-recording. Reproduction is performed by a tracking method. The non-tracking reproduction method is as follows.

FIG. 20 shows a tape-shaped information recording medium, for example, a magnetic tape TP such as a video tape.
TCn are sequentially formed. As shown in FIG. 20A, information is recorded in adjacent TC1 to TCn in + azimuth and -azimuth. In a generally used tracking reproduction method, a plurality of reproduction heads set on a rotating drum of a magnetic head device are used to record each recording track T.
The information of each recording track is reproduced along the scan direction SC along C1 to TCn. However, in recent years, recording tracks have been narrowed to increase the recording density, and the width of each recording track has been reduced. Therefore,
In the case where each reproducing head reproduces information of each recording track by accurately tracing in the scanning direction SC of the recording track by a tracking method as in the related art, the accuracy of the guide of the reproducing head and the reproducing head of the rotating drum are required. Posture errors and the like have a great effect, and it is very difficult to accurately reproduce data by the tracking method.

In view of this, the above-mentioned non-tracking reproduction method has been proposed. For example, as shown in FIG. If the track is not parallel to the track forming direction DD and is inclined, that is, if the trace of the reproducing head when reproducing from the recording track is inclined, the area reproduced by a certain azimuth head is limited. Regardless, this method scans the rotating drum with the number of recording heads, for example, twice the number of recording heads, so that all the recording tracks can be recorded by the adjacent + azimuth reproducing head and -azimuth reproducing head. Can be traced. For example, paying attention to the reproduction trace of a certain recorded track, when double density scanning is performed, where the amplitude cannot be read due to the reverse azimuth in the odd-numbered scan, the portion that cannot be read is the next even-numbered scan. With the same rotational phase, the azimuth is the same, and the information of the recording track can be read without fail. When this is repeated for several scans, the data of one recording track is divided into several times, and as shown in FIG. 20C, each recording section constituting all data of the recording track, for example, RA1, RA2, etc. , The information IDs of all the recording tracks can be reproduced. Such a method is a non-tracking reproduction method.

[0007]

However, in order to realize such a non-tracking reproducing method, a plurality of reproducing heads, for example, four reproducing heads are required. With the increase of
The number of channels for signal transmission of the rotary transformer set in the rotary magnetic head device also increases to four. Therefore, the size of the rotary drum and the fixed drum of the rotary magnetic head device is inevitably increased, which causes an increase in cost. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a rotary magnetic head device that can be downsized when a signal recorded on a tape-shaped information recording medium is reproduced using a plurality of reproduction heads. I have.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided a tape-shaped information recording apparatus comprising a transmission device for transmitting a power supply and a signal between a rotating body and a fixed body in a non-contact manner. A rotating magnetic head device that reproduces a signal recorded on a medium using a plurality of reproducing heads, a rotating drum having a rotating body of a transmitting device and a plurality of reproducing heads, and a fixed drum having a stationary body of the transmitting device And reproducing signal selecting means for selecting a reproducing signal from each reproducing head based on the periodic signal when reproducing the signal using a plurality of reproducing heads, and sequentially arranging the reproducing signals from each reproducing head. The reproduction signal selecting means includes a magnet set on the fixed drum and a plurality of magnets set on the rotary drum for sensing a magnetic flux of the magnet of the fixed drum and outputting a periodic signal when the rotary drum rotates. Magnetic The rotary magnetic head apparatus comprising: the knowledge sensor, a, is achieved.

According to the present invention, when a signal recorded on a tape-shaped information recording medium is reproduced by using a plurality of reproducing heads, the magnet of the reproducing signal selecting means is provided on the fixed drum side, and a plurality of magnetic sensing elements are provided. The sensor rotates with the rotating drum. As a result, the magnetic sensor rotates with respect to the magnet, so that the magnetic sensor can output a periodic signal accompanying the rotation of the rotating drum by detecting the magnetic force of the magnet. Thereby, the reproduction signal selecting means can select the reproduction signals from the respective reproduction heads and sequentially arrange them based on the periodic signal.

According to the present invention, there is provided a transmission device for transmitting a power supply and a signal between a rotating body and a fixed body in a non-contact manner, and is recorded on a tape-shaped information recording medium. A rotary magnetic head device that reproduces signals of a plurality of recording tracks using a plurality of reproducing heads regardless of the arrangement of the recording tracks on an information recording medium, comprising: a rotating body of a transmission device; and a rotating drum having a plurality of reproducing heads. A fixed drum having a fixed body of a transmission device, and a playback signal from each playback head selected based on a periodic signal when signals of a plurality of recording tracks are played back using a plurality of playback heads. Playback signal selection means for sequentially arranging playback signals from the fixed drum, the playback signal selection means comprising a magnet set on the fixed drum and a magnet of the fixed drum when the rotating drum rotates. To output a periodic signal by sensing the bundle, by a rotary magnetic head device, characterized in that it comprises a plurality of magnetically sensitive sensors which is set to the rotary drum, it is achieved.

According to the present invention, when a signal recorded on a tape-shaped information recording medium is reproduced by using a plurality of reproducing heads, the magnet of the reproducing signal selecting means is provided on the fixed drum side, and a plurality of magnetic sensors are provided. The sensor rotates with the rotating drum. As a result, the magnetic sensor rotates with respect to the magnet, so that the magnetic sensor can output a periodic signal accompanying the rotation of the rotating drum by detecting the magnetic force of the magnet. Thereby, the reproduction signal selecting means can select the reproduction signals from the respective reproduction heads and sequentially arrange them based on the periodic signal. Accordingly, the number of channels in the rotary magnetic head device can be greatly reduced, and the rotary magnetic head device can be downsized.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 shows a preferred embodiment of a rotary magnetic head device having a non-contact transmission device according to the present invention. FIG. 2 shows an example of an information recording device provided with the rotary magnetic head device 10. The rotary magnetic head device 10 of the information recording apparatus includes a plurality of reproduction heads RH1 to RH4 regardless of the arrangement of the recording tracks of the magnetic tape, for example.
That is, a so-called non-tracking reproducing method for reproducing by using is used. Rotary magnetic head device 10 shown in FIGS. 1 and 2
Is applied to video tape recorders, data streamers, digital audio systems, etc. to record signals on a magnetic tape TP, which is a tape-shaped recording medium, and to reproduce information recorded on the magnetic tape TP. Used.

The rotary magnetic head device 10 shown in FIGS.
It has a fixed drum 1, a rotating drum 2, and a motor M. The rotating drum 2 includes, for example, four reproduction heads RH1.
(R +), RH2 (R +), RH3 (R-) and RH4
(R-) and two recording heads WH1 and WH2. Each of the reproducing heads RH1, RH2, RH3, RH4 has a phase difference of, for example, 90 degrees, and the recording heads WH1, WH
2 has a phase difference of 180 degrees. The rotating drum 2
By the operation of the motor M, the fixed drum 1 rotates in the direction of arrow R. The rotating drum 2, the recording head, and the reproducing head rotate in the R direction. The magnetic tape TP is sent obliquely from the inlet side IN to the outlet side OUT along the tape running direction E along the lead guide portion 3 of the fixed drum 1.

In the information recording apparatus shown in FIG. 2, the magnetic tape TP is brought into close contact with the rotating drum 2 and the fixed drum 1 from the supply reel 4 via the rollers 4a, 4b and 4c by a predetermined angle, and the rollers 4d, 4e, 4f, After 4 g, it can be wound on the take-up reel 5. In correspondence with roller 4f,
A capstan 4h is provided, and the capstan 4h is rotated by a capstan motor M1. As a result, when the motor M operates and the rotary drum 2 rotates in the R direction, the recording head and the reproducing head
Is contacted and guided by a helical scan method.
The magnetic tape TP runs obliquely along the lead guide 3 of the fixed drum 1.

FIGS. 3 and 4 show structural examples of the rotary magnetic head device 10. FIG. Rotary magnetic head device 10 shown in FIG.
Has a rotary transformer T which is a non-contact type transmission device, and the rotary transformer T is disposed between the rotary drum 2 and the fixed drum 1. That is, the rotary transformer T is built in the rotary magnetic head device 10. The rotating magnetic head device 10 is also called a rotating drum device, and includes two bearings 1 in a sleeve 1 a of the fixed drum 1.
b is arranged. A stator core 2, which is a fixed body of the rotary transformer T, is provided on a sleeve 1 a of the fixed drum 1.
0 is fixed.

The rotary drum 2 has a flange 2a, and the flange 2a is fixed to the upper end of the shaft 5 by press-fitting or bonding. The lower end of the shaft 5 is the rotor MR of the motor M.
It is fixed to. The motor M has a rotor MR and a stator MS. For example, a driving magnet 6 is disposed on the rotor MR, and a driving coil 7 is disposed on the stator MS. By energizing the coil 7 in a predetermined pattern, the rotor MR of the motor M rotates continuously. The intermediate portion of the shaft 5 is rotatably supported by bearings 1b, 1b. Inside the flange 2a,
A rotor core 30, which is a rotating body of the rotary transformer T, is fixed.

The rotary transformer T shown in FIG. 3 includes a stator core 20 (fixed body) and a rotor core 30 (rotary body), each of which is a disc-shaped core as shown in FIG. Made of material. The stator core 20 and the rotor core 30 are formed in a ring shape so that the sleeve 1a in FIG. Signal transmission channels CH1 to CH4 are arranged on the inner surface of stator core 20 (upper surface in FIG. 3) and the inner surface of rotor core 30 (lower surface in FIG. 3) about axis 5, respectively, as described later. Have been. The wiring portions forming these channels CH1 to CH4 can be formed by winding a normal insulated wire in a ring shape, or can employ a printed wiring board. Thus, when the coil 7 of the stator MS of the motor M is energized, the rotor MR of the motor M, the shaft 5, the flange 2a, the rotating drum 2 and the rotor core 30 of the rotary transformer T rotate with respect to the fixed drum 1 and the stator core 20. The rotor core 30 and the stator core 20 are arranged to face each other in a non-contact manner.

On the other hand, the rotary magnetic head device 10 shown in FIG.
A cylindrical stator core 120 as shown in FIG. 6 is fixed to the fixed drum 1. The rotor core 130 of the rotary transformer T1 is fixed to the flange 2a of the rotary drum 2. Stator core 120 and rotor core 13
Numerals 0 are arranged coaxially about the axis 5, and the outer diameter of the stator core 120 is set smaller than the inner diameter of the rotor core 130. Thereby, the stator core 120
And the inner surface of the rotor core 130 are arranged in a non-contact manner with a predetermined gap. The channels CH1 to CH4 of the rotary magnetic head device 10 of FIG. 4 are formed in a ring shape in the axial direction.

When the coil 7 of the stator MS of the motor M is energized in a predetermined energizing pattern, the rotor MR of the motor M, the shaft 5, the flange 2a, and the rotor core 130 of the rotary transformer T1 are fixed to the fixed drum 1 and the stator core 120.
And rotates in a non-contact manner at a predetermined interval. As the non-contact type transmission device, both a planar rotary transformer T as shown in FIGS. 3 and 5 and a cylindrical rotary transformer T1 as shown in FIGS. 4 and 6 can be applied.

Next, an example of the wiring structure of the rotary transformer T shown in FIGS. 3 and 5 will be described with reference to FIG.
The rotary transformer T shown in FIG.
0 are arranged to face each other, and a predetermined gap CM is set. On the inner surface 21 of the stator core 20, for example, four grooves 21a, 21b, 21c, and 21d are formed coaxially from the inner peripheral side to the outer peripheral side about the central axis CL. Similarly, the grooves 31 a, 31 b, 31 c, and coaxially around the center axis CL are also provided on the inner surface 31 of the rotor core 30.
31d are formed. These grooves 21a to 21d
And the grooves 31a to 31d are at positions facing each other.

A reproduction signal transmission ring RR is disposed in the grooves 21a and 31a, and a recording signal transmission ring WR is disposed in the grooves 21b and 31b. The recording signal transmission ring WR is disposed in the grooves 21c and 31c, and the power transmission ring PR is disposed in the grooves 21d and 31d. Each of the reproduction signal transmission ring RR, the recording signal transmission ring WR, the recording signal transmission ring WR, and the power transmission ring PR is formed by, for example, winding an insulated wire rod a plurality of times in a ring shape. The rotor core 30 and the stator core 20 themselves are made of a magnetically permeable material such as ferrite in a disk shape or a ring shape. The reproduction signal transmission ring RR and the recording signal transmission ring WR are signal transmission systems,
The power transmission ring PR is a power supply system.

Next, with reference to FIGS. 8 and 9, the rotary transformer T and its peripheral functions will be described. The rotary transformer T shown in FIG. 8 differs from the rotary transformer T shown in FIG. 7 in the illustrated method, and channels CH1 to CH4 are drawn in the vertical direction in FIG. As shown in FIGS. 8 and 7, in the rotary transformer T, the power transmission ring P
That is, the power supply area of R and the signal area of the reproduction signal transmission ring RR and the signal area of the recording signal transmission ring WR exist separately. The region of the power transmission ring PR and the reproduction signal transmission ring RR are separated by the region of the two recording signal transmission rings WR, WR. The recording signal transmission rings WR, WR serve as a crosstalk prevention unit of the rotor core 30 and a crosstalk prevention unit of the stator core 20 for preventing crosstalk between the region of the power transmission ring PR and the reproduction signal transmission ring RR.

In FIG. 8, the power transmission ring PR of the stator core 20 in the power transmission ring PR of the channel CH4 is connected to the oscillator 4 via the power drive 40.
1 and the switching means 50. The high frequency direct current generated by the oscillator 41 is converted into an alternating current, and the power drive 40 gives the alternating current to the power transmission ring PR of the stator core 20. The power transmission ring PR of the stator core 20 is
0 is transmitted to the power transmission ring PR in a non-contact manner, and the transmitted AC current is rectified by the rectifier 42 to become a DC current.
3a sets the desired voltage. Regulator 43
The current set to the voltage from a is preferably the reproduction amplifier 43A of the reproduction heads RH1, RH2, RH3, and RH4.
The read current is supplied to the read heads 43B, 43C, and 43D, and is used to amplify the read current obtained by the read head RH. Further, the current of the regulator 43a can be supplied to the reproduction signal selection means 200.

The four reproducing heads RH1, RH2, RH3 and RH4 set on the rotating drum are connected to reproducing amplifiers 43A to 43D, respectively, and can supply a reproducing signal RS to each of them. This playback amplifier 43
A to 43D separately amplify the applied reproduction signal RS. These reproduction amplifiers 43A to 43D can supply the reproduction signal transmission ring RR of the rotor core 30 arranged in the channel CH1 of the rotary transformer T. The reproduction signal transmission ring RR can transmit the reproduction signal to the reproduction signal transmission ring RR of the stator core 20 in a non-contact manner. The reproduction amplifiers 43A to 43D are connected to the reproduction signal selection unit 2
00, and the reproduction signal selecting means 200 supplies selection signals S1 to S4 to the respective reproduction amplifiers 43A to 43D.
Can be sent individually. Only the reproduction amplifier to which the reproduction signal is given can amplify the reproduction signal RS and send it to the reproduction signal transmission ring RR.

The reproduction signal selection means 200 shown in FIG. 8 appropriately selects the reproduction signals RS from the reproduction amplifiers 43A, 43B, 43C and 43D connected to the reproduction heads RH1, RH2, RH3 and RH4, and reproduces them. Signal transmission ring R
Send to R The reproduction signal selection means 200 has two Hall elements 201A and 201B, shaping circuits 202A and B, and switching means 203. Two Hall elements 2
As shown in FIG. 10, 01A and 201B are fixed with a phase of 90 degrees with respect to the lower surface of the rotating drum 2, for example. It should be noted that among the so-called Hall ICs formed by combining the Hall element 201A and the shaping circuit 202A, S → N →
For a magnetic field changing continuously from S to N, L → H → L →
It is also possible to use an alternating type Hall IC that generates a logic signal of H. On the fixed drum 1, two magnets 980 and 981 are arranged with a phase of 180 degrees. One magnet 980 and the other magnet 981 are positioned at positions where the positive and negative poles face each other in the diameter direction of the fixed drum 981.

FIGS. 11A and 11B show the case where the rotating element 2 is rotated by the fixed drum 1 when the Hall element 20 is rotated.
1A and 201B are magnets 98 on the fixed drum 1 side.
Hall element 201 when rotated with respect to 0,981
A and 201B show output waveforms. FIG. 11 (C),
(D) shows the outputs of the Hall elements 201A and 201B (FIG. 1).
1 (A) and (B) are shaped by the shaping circuit 202 in FIG. 8 to show the signals SMA and SMB shown in FIG.
11A and 11B, the Hall elements 201A and 201A
01B is the slice level L (+) and the slice level L
In (-), each is sliced. This slicing is performed by the shaping circuits 202A and 202B in FIG. As a result,
The shaped outputs of the Hall elements 201A and 201B are shown in FIG.
(C) and (D) are obtained.

FIG. 12 shows the Hall elements 201A, 201
Selection signals S1, S2, S3, S4 for selecting four reproduction amplifiers 43A, 43B, 43C, 43D using a 2-4 decoder based on the output of 1B (see FIG. 8).
Get. This 2-4 decoder is the switching means 203 of FIG. FIG. 13 shows an example of a truth table of the switching means 203. All are processed with negative logic.
In an example of the truth table shown in FIG. 13, Y0 bar corresponds to the selection signal S4, Y1 bar corresponds to the selection signal S1,
Y2 bar corresponds to the selection signal S3, and Y3 bar corresponds to the selection signal S2.

The switching means 203 is connected to the reproduction amplifier 43
By providing the selection signals S1 to S4 to A to 43D, respectively, the reproduction amplifiers 43A to 43D are selected according to the reproduction amplifier switching timing of FIG. For example, the reproduction amplifiers 43A to 43D can transmit the reproduction signals RS from the respective reproduction heads RH1 to RH4 to the reproduction signal transmission ring RR of the rotor core 30 in FIG. 8 at the timing shown in FIG. . 4 playback amplifiers 4
Since 3A to 43D are connected and sent to the reproduction signal transmission ring RR of the rotor core 30, the reproduction signals RSA arranged for one channel can be created as shown in FIG. 9B.

As shown in FIG. 8, the reproducing heads RH1 to RH
4 have a predetermined azimuth angle. That is, in the reproducing heads RH1 and RH2, the magnetic gap GP has a + azimuth angle θ,
3 and RH4 have a −azimuth angle θ. The reproducing heads RH1 and RH2 shown in FIG.
And the reproduction signals RS of the reproduction heads RH3 and RH4 reproduce an inverted azimuth recording track.
The reproducing heads RH1 (R +),
RH2 (R +) indicates that the magnetic gap GP has a + azimuth angle, and the read head RH3 (R-)
RH4 (R-) has a -azimuth angle. Further, the recording head WH1 (W +) in FIG.
The recording head WH2 (W
-) Indicates that it has a -azimuth angle.

As described above, in the embodiment shown in FIG. 8, the rotating drum 2 has a plurality of, for example, four reproducing heads RH1 to RH4.
For example, when the recording track recorded on the magnetic tape is reproduced by the non-tracking reproduction method by scanning at twice the normal density, the reproduction signal RS of each of the reproduction heads RH1 to RH4 is In accordance with the selection signals S1 to S4 of the reproduction signal selection means 200, the reproduction signals RS arranged in time series for one channel as shown in FIG.
A can be formed. Thereby, the reproduction signal transmission rings RR, RR in the rotary transformer T of FIG.
If one channel is provided, the reproduction signal RSA can be transmitted to the reproduction amplifier 44 of the stator core 20 in a non-contact manner.

The correction circuit 100 shown in FIG. 8 converts the reproduction signal RS amplified by the reproduction amplifier 44 in this manner, for example, according to the characteristics of each of the reproduction heads RH1 to RH4.
Can be corrected. For example, the correction circuit 100 in FIG. 8 adjusts the signal level, adjusts the frequency characteristics, and adjusts the phase characteristics of the signal to approximate them. However, this correction circuit 100 is provided in a stage subsequent to the reproduction amplifier 44 of the stator core 20,
Of course, it may be arranged before the reproduction signal transmission ring RR of the rotor core 30.

As shown in FIG. 1, the magnetic tape TP is helically wound at an angle of about 90 degrees by the rollers 4c and 4d, but is not limited to this. The two reproducing heads RH1 and RH2 are 90
The reproducing heads RH1 and RH2, which are arranged at a distance from each other and have two + azimuth angles, are aligned with respect to the rotary drum 2 so as to reproduce a signal shifted by one track. Similarly, the reproducing heads RH3 and RH4 having a negative azimuth angle are also aligned with respect to the rotating drum 2 so as to reproduce a signal shifted by one track.

The recording amplifier 4 on the fixed drum 1 side of FIG.
5 sends the recording current from the recording signal source to the recording signal transmission rings WR of the channels CH2 and CH3 of the stator core 20. When the recording signal WS is transmitted from the recording signal transmission ring WR of the stator core 20 to the recording signal transmission ring WR of the rotor core 30, the recording current is transmitted directly from the recording signal transmission ring WR of the rotor core 30 to the recording head WH. . As described above, since the recording head WH is directly connected to the recording signal transmission ring WR of the rotor core 30, the recording head WH and the recording signal transmission ring WR of the rotor core 30 in the low frequency region have a low frequency band. Can be reduced. The recording signal transmission rings WR, WR arranged in the channels CH2, CH3 can prevent crosstalk between the reproduction system of the channel CH1 and the power transmission system of the channel CH4. That is, the recording signal transmission ring W
R and WR reduce crosstalk from the power transmission system of channel CH4 to the reproduction signal system of channel CH1.

The switching means 50 in FIG. 8 is a switching means for turning on / off the operation of the oscillator 41. This switching means 50 includes an oscillator 41
Is turned on or off to turn on or off the oscillation operation for power supply. Thus, the oscillator 41
Is turned on / off for the following reason.
In other words, the switching unit 50 operates when the recording head WH is in contact with the magnetic tape TP (during signal recording).
The oscillator 41 is turned off, and when the magnetic head H is not in contact with the magnetic tape TP (during signal reproduction), the oscillator 41 is turned on. When the recording heads WH1 and WH2 are in contact with the magnetic tape TP,
When the signals H1 and WH2 are recording signals on the magnetic tape TP, the reproducing head RH does not reproduce the signals on the magnetic tape TP, so that the oscillator 41 supplies power to the reproducing amplifier 43 in FIG. Since there is no need, the oscillator 41 is turned off. On the other hand, when the recording heads WH1 and WH2 are not in contact with the magnetic tape TP, that is, when the reproducing heads RH1 to RH4 are
When the P signal is being reproduced, the oscillator 41 is turned on and the regulators 43a output the reproduction amplifiers 43A to 43A.
Power can be supplied to the 3D to amplify the reproduction signal RS of the reproduction head RH.

Therefore, when the recording head WH is the magnetic tape TP
Since the oscillator 41 is turned off in the state where the recording is performed while touching the channel, it is possible to reliably prevent the crosstalk from the power system of the channel CH4 to the reproduction signal system of the channel CH1 in FIG. When the DC current is converted into the AC current in the oscillator 41 and the AC current is converted again into the DC current in the rectifier 42, the AC current (A
C) so that the maximum frequency band of C) does not overlap the frequency band of the recording signal of channel CH2.
A method of preventing crosstalk from the power system No. 4 to the recording signal system of channel CH2 (the reproduction signal system of channel CH1) can also be adopted.

In the above-described embodiment, as shown in FIG. 8, four reproducing heads are set for the rotating drum. However, in the embodiment shown in FIGS. 14 to 17, the rotating drum 2 has two reproducing heads RH1 and RH2. The rotating magnetic head device 100 shown in FIG. 14 is different from the rotating magnetic head device 10 shown in FIG.
, Two reproducing heads RH1 and RH2 are set. In other respects, the rotary magnetic head device 100 of FIG. 14 is substantially the same as the rotary magnetic head device 10 of FIG.

FIG. 15 shows the rotary magnetic head device 1 of FIG.
The rotary transformer T and its peripheral portion at 00 are shown. The reproduction heads RH1 and RH2 can transmit reproduction signals to the reproduction signal transmission ring RR of the rotor core 30 via the reproduction amplifiers 43A and 43B, respectively. The reproduction signal selection means 200 includes one Hall element 20
1C, a shaping circuit 202 and a switching means 203. As shown in FIG.
Are fixed to the rotating drum 2. On the other hand, the two magnets 980 and 981 are fixed on the fixed drum 1 with a phase difference of 180 degrees. Magnet 9
In the reference numerals 80 and 981, the positive pole and the negative pole are located at the same position in the diameter direction of the fixed drum 1. Moreover, these magnets 980 and 981 have their + and-poles fixed in parallel on the upper surface 1 h of the fixed drum 1.

When the rotating drum 2 rotates with respect to the fixed drum 1, the Hall element 201C rotates with respect to the magnets 980 and 981 of the fixed drum 1, and the Hall element 20C rotates.
1C generates a magnetic flux waveform as shown in FIG. The waveform of the magnetic flux is sliced by the slice level L (+) and the slice level L (-). This slicing operation is performed by the shaping circuit 202 in FIG. As a result, as shown in FIG. 17B, the shaped output SM of the Hall element 201C enters the switching means 203 of FIG. 15, and the switching means 203 converts the selection signals S1 and S2, which are the switching timing signals of the reproduction amplifier, into the figure. This is given to the fifteen reproduction amplifiers 43A and 43B at the switching timing shown in FIG. Thereby, the reproducing heads RH1,
The reproduction signals RS from the RH2 are sequentially arranged, and the reproduction amplifiers 44 are transmitted via one reproduction signal transmission ring RR.
Can be sent to the side without contact.

FIGS. 18 and 19 show the magnet 108 set on the fixed drum 1 in the embodiment of FIG.
The arrangement forms of 0 and 1081 are different. These magnets 1080 and 1081 are set upright with respect to the fixed drum 1. For example, one magnet 1080 has its + pole side fixed to the upper surface 1 h of the fixed drum 1. On the other hand, another magnet 1081 is
The pole side is fixed to the surface 1h of the fixed drum 1. By doing so, the shape of the magnetic flux of the Hall element in FIG. 19A is slightly changed as compared with FIG. 17A. The embodiment of FIGS. 18 and 19 is substantially the same as the embodiment of FIGS. 16 and 17 in other respects.

The embodiment of the present invention has been described with reference to the planar opposed rotary transformer T shown in FIG. However, the present invention is not limited to this, and the above-described embodiment can be applied to the cylindrical rotary transformer T1 shown in FIGS.

In the embodiments shown in FIGS. 8 and 15, since the power is supplied from the power system to the reproduction amplifiers 43A to 43D of the reproduction system, the reproduction head R
As H, for example, a magnetoresistive element head (MR) can be employed. Magneto-resistive element head for reproduction (M
R) requires a bias current at all times to obtain a reproduction signal.
By sending a bias to .about.43D, the magnetoresistive element head can be operated to obtain a reproduced signal. This magnetoresistive element head is a head that causes a change in resistance when a magnetic field changes. The head can convert a change in a signal magnetic field (input signal) into a change in resistance and extract it as a change in a reproduction output signal (voltage). It is. This magnetoresistive element head can obtain a high and stable reproduction output signal without depending on the speed of the magnetic tape TP.

In the embodiment of the present invention, the times when the reproducing heads RH1, RH2, 4H3 and RH4 of FIG. 8 are in contact with the tape-shaped information recording medium do not overlap each other, and the reproducing heads RH1 and RH2 , RH3, RH
4 is connected to a reproduction amplifier. The reproduction signal RS is amplified by this amplifier and then sequentially arranged by the reproduction signal selection means 200 which functions as a switch circuit to become a reproduction signal of one channel. After the reproduction signal of the one channel is obtained, the reproduction signal of the one channel is transmitted to the signal processing unit side through the rotary transformer in a non-contact manner. That is, since the plurality of reproduction heads RH1, RH2, RH3, and RH4 have a temporally exclusive contact with the tape-shaped information recording medium, the reproduction signal RS is switched to one channel by switching after amplification. It is possible to This is the same in the embodiment of FIG.

As described above, in the embodiment of the present invention, a recording track recorded on a tape-shaped information recording medium is reproduced by, for example, non-tracking reproduction using a plurality of reproduction heads and one or more reproduction channels. In the case of reproducing information by the method, selective switching of reproduction signals from a plurality of reproduction heads is performed in a rotating drum, for example, the signals are aggregated into one channel or two channels, and then contactless using a rotary transformer T. Transmits the playback signal. Accordingly, it is not necessary to set a plurality of rotary transformers in the rotary magnetic head device, and the size and cost can be reduced. Further, the present invention is not limited to the non-tracking method, and can be applied to, for example, a tracking method.

In the embodiment of the present invention,
Although four reproducing heads are described as an example, the present invention is not limited to this, and the present invention can be applied to a case where two, three, or five or more reproducing heads are provided. Although two recording heads are shown, the present invention is not limited to this, and the present invention can be applied to the case of three or more recording heads or only one recording head. As the magnetic sensing sensor, a sensor other than the Hall element can be used.

[0046]

As described above, according to the present invention,
When a signal recorded on a tape-shaped information recording medium is reproduced using a plurality of reproducing heads, the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a rotary magnetic head device of the present invention.

FIG. 2 is a plan view showing an example of an information recording device including the rotary magnetic head device of FIG.

FIG. 3 is a diagram showing a configuration example of the rotary magnetic head device of FIG. 1 and showing a case where a built-in rotary transformer is of a flat facing type.

FIG. 4 is a diagram showing a configuration example of the rotary magnetic head device of FIG. 1 and showing a case where a built-in rotary transformer is cylindrical.

FIG. 5 is a perspective view showing the rotary transformer of FIG. 3;

FIG. 6 is a perspective view showing the rotary transformer of FIG. 4;

FIG. 7 is a partially omitted cross-sectional view showing a configuration example of the rotary transformer in FIG. 5;

FIG. 8 is a view showing a state of the rotary transformer and its peripheral portion of the first embodiment of the rotary magnetic head device of FIG. 1;

9 is a diagram showing an example of the arrangement of each reproducing head and recording head and an example of an arrangement of reproduced signals of the reproducing head in the embodiment of FIG. 8;

FIG. 10 is a perspective view showing a mounting example of a magnet and a magnetic sensor of the reproduction signal selection means in the embodiment of the present invention.

11 is a diagram showing an example of the reproduction switching timing of the reproduction amplifier in the mounting example of FIG. 10;

FIG. 12 is a diagram showing an example of switching means for realizing the reproduction timing of FIG.

FIG. 13 is a diagram showing an example of a truth table of the switching unit of FIG. 12;

FIG. 14 is a perspective view showing another embodiment of the rotary magnetic head device of the present invention.

FIG. 15 is a diagram showing the rotary transformer and its periphery in the embodiment of FIG. 14;

FIG. 16 is a diagram showing an example of the arrangement of magnets and magnetic sensing sensors of the reproduction signal selecting means in the embodiment of FIG. 14;

FIG. 17 is a diagram showing an example of the switching timing of the reproduction amplifier in the case of FIG. 16;

FIG. 18 is a perspective view showing an example of arrangement of a magnet and a magnetic sensor of a reproduction signal selection unit according to still another embodiment of the present invention.

FIG. 19 is a diagram showing an example of switching the reproduction timing of the reproduction amplifier in FIG. 18;

FIG. 20 is a view for explaining a conventional non-tracking reproduction method.

[Explanation of symbols]

1 ... fixed drum, 2 ... rotating drum, 10 ...
Rotary magnetic head device, 20: stator core (fixed body), 30: rotor core (rotary body), 200:
Reproduction signal selection means, 201: magnetic sensors (rotation detection means), 201A, 201B, 201C: Hall elements (magnetic detection sensors), 202A, B: shaping circuits (rotation detection means), 980, 981 , 1080, 108
1 ... magnet, T ... rotary transformer (non-contact type transmission device), T1 ... rotary transformer (non-contact type transmission device), T ... magnetic tape, RH1, RH
2, RH3, RH4 ... reproducing head, WH1, WH2
··· Recording head, RR ··· Reproduction signal transmission ring (rotating body signal wiring section, fixed body signal wiring section), WR ··· Recording signal transmission ring (rotating body signal wiring section and fixed body signal wiring section), PR: Power transmission ring (rotating body power supply wiring section, fixed body power supply wiring section)

Claims (5)

[Claims] A transmission device for transmitting a power supply and a signal between a rotating body and a fixed body in a non-contact manner, wherein a signal recorded on a tape-shaped information recording medium is transmitted using a plurality of reproducing heads. A rotary drum having a rotating body of a transmission device and a plurality of playback heads; a fixed drum having a fixed body of the transmission device; and a playback device for playing back signals using a plurality of playback heads. Reproduction signal selection means for selecting a reproduction signal from each reproduction head based on the periodic signal and sequentially arranging the reproduction signals from each reproduction head, wherein the reproduction signal selection means comprises a magnet set on a fixed drum. And a plurality of magnetic sensing sensors set on the rotating drum for sensing a magnetic flux of a magnet of the fixed drum and outputting a periodic signal when the rotating drum rotates. Magnetic head device. 2. The rotating magnetic head device according to claim 1, wherein the magnetic sensor comprises a Hall element and a shaping circuit connected to the Hall element. 3. The rotary magnetic head device according to claim 1, wherein one magnetic sensing sensor is arranged on the rotating drum and two magnets are arranged on the fixed drum for reproducing signals by two reproducing heads. . 4. The rotating magnetic head device according to claim 1, wherein two magnetic sensing sensors are arranged on the rotating drum and two magnets are arranged on the fixed drum for reproducing signals by the four reproducing heads. . 5. A transmission device for transmitting a power supply and a signal between a rotating body and a fixed body in a non-contact manner, and transmits signals of a plurality of recording tracks recorded on a tape-shaped information recording medium to information. A rotating magnetic head device for reproducing data using a plurality of reproducing heads regardless of the arrangement of recording tracks on a recording medium, comprising: a rotating body of a transmitting device, a rotating drum having a plurality of reproducing heads, and a stationary device having a fixed body of the transmitting device When reproducing signals on a drum and a plurality of recording tracks using a plurality of reproducing heads, a reproducing signal from each reproducing head is selected based on a periodic signal, and the reproducing signals from each reproducing head are sequentially arranged. A signal selection unit, and the reproduction signal selection unit senses a magnet set on the fixed drum and a magnetic flux of the fixed drum magnet when the rotating drum rotates, and outputs a periodic signal. And a plurality of magnetic sensing sensors set on the rotating drum for applying force.