JP3189437B2 - Rotating head type digital signal recording apparatus, reproducing apparatus and recording / reproducing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head type digital signal recording apparatus, a reproducing apparatus and a recording / reproducing apparatus for recording, reproducing or recording / reproducing a digital signal such as a digital video signal on a magnetic tape using a rotary head. It is.

[0002]

2. Description of the Related Art Conventionally, a rotary head type digital signal recording / reproducing apparatus having a head as shown in FIG. 7 has been considered. In FIG. 7, a pair of recording / reproducing heads A having different azimuth angles (angles in the direction in which the gap extends) are shown.
1, B1 are arranged at close positions on the rotating drum D so as to have a predetermined step Ds. At a position 180 ° away from the pair of recording / reproducing heads A1, B1 on the rotary drum D, a pair of recording / reproducing heads A2, B2 having different azimuth angles have a predetermined step Ds. Are located. Here, the recording and reproducing heads A1 and A2
Have the same azimuth angle, and the recording and reproducing heads B1 and B2 have the same azimuth angle.

[0003] A magnetic tape (not shown) is wound around the rotary drum D on which the head is disposed at an angle of 180 ° or more, and is rotated in the direction of arrow P from the rotation direction of the rotary drum D. An oblique track is formed with respect to the magnetic tape running in a slightly inclined direction. FIG. 8 is a diagram showing a connection relationship from a recording / reproducing amplifier to a recording / reproducing head of the rotary head type digital signal recording / reproducing apparatus shown in FIG. Recording / reproducing head A1, A
Reference numerals 2, B1 and B2 are connected to recording / reproduction amplifiers 8 to 11 via coils 1 to 4 of channels 1 to 4 of a rotary transformer, respectively. And coil 1
And 2, short rings 5 and 6 for preventing crosstalk between channels between recording and reproducing heads A1 and A2, A2 and B1 and B1 and B2, respectively. , 7 are provided.

FIG. 9 is an operation timing chart at the time of recording of the rotary head type digital signal recording / reproducing apparatus shown in FIG. 7, and FIG. 10 is a diagram showing the relationship between the track pattern and the rotary head. Hereinafter, the recording operation of the conventional rotary head type digital signal recording / reproducing apparatus will be described with reference to FIGS. As shown in FIG.
The recording / reproducing heads A1, B1 every half rotation of the rotating drum D
And the pair of A2 and B2 are simultaneously turned on alternately. As a result, as shown in FIG. 10, the tracks _TA1 and _TB1 are formed by the pair of the recording and reproducing heads A1 and B1 in the first half rotation of the rotary drum D, and the recording and reproducing head A2 is formed in the next half rotation. , B2 form a track T _A2 , T _B2 . At this time, the track pitch Tp = Ds. Thereafter, in the same manner, T _A1 ,
_TB1 , _TA2 , _TB2 , ... are formed.

Here, recording and reproducing heads A1, B1 and A
The digital signal supplied to each pair of 2 and B2 is obtained by extending a single-system signal by two times on the time axis, converting the signal into two-system signals, and then inputting the signals to the recording / reproducing amplifiers 8 to 11. The outputs of the recording / reproducing amplifiers 8 to 11 are output from coils 1 to 4 of a rotary transformer, respectively.
, And are supplied to the recording and reproducing heads A1, A2, B1, and B2. At this time, the crosstalk between each channel via the coil of the rotary transformer is caused by the short ring 5
７7.

[0006] The operation at the time of reproduction has no particular difference except that the signal flow is opposite to that at the time of recording, and therefore the description is omitted.

[0007]

However, in the conventional rotary head type digital signal recording / reproducing apparatus, the tracks are formed at a pitch equal to the step of the recording / reproducing head arranged close to the apparatus. For example, when trying to form tracks with two types of track pitch,
A total of eight recording / reproducing heads are required, four for each type of track pitch. For this reason, there has been a problem that the cost increases and it is difficult to configure a multi-channel rotary transformer within a limited outer diameter.

Further, since one channel of a rotary transformer and a signal processing circuit such as a recording / reproducing amplifier are provided for each recording / reproducing head, when a head is added for variable speed reproduction or the like, the rotary transformer becomes a multi-channel. In addition, the number of signal processing circuits is increased, and the hardware configuration is technically difficult and the cost is increased. Further, when the rotating drum is rotated at a double speed to perform non-tracking reproduction with a small number of heads, technical difficulties such as an increase in power consumption, head wear, and an increase in noise occur.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it has been made possible to record, reproduce and reproduce tracks having a plurality of track pitches without increasing the number of recording / reproducing heads and the number of rotary transformer channels. An object of the present invention is to provide a rotary head type digital signal recording device, a reproducing device, and a recording / reproducing device capable of recording and reproducing.

Another object of the present invention is to provide a rotary head type digital signal recording apparatus, reproducing apparatus and recording / reproducing apparatus capable of increasing the number of heads without increasing the number of channels of a rotary transformer and the number of signal processing circuits. Aim.

[0011]

In order to solve the above problems, a first invention of the present application is directed to a first recording mode for recording at a first track pitch on a magnetic tape wound on a rotating drum, and In a rotary head type digital signal recording apparatus having a second recording mode for recording at a second track pitch smaller than one track pitch, four recording heads are arranged at 90 ° intervals on a rotating drum, and four recording heads are arranged. The timing at which the recording head performs the recording operation is sequentially delayed by 90 ° from the recording head preceding in the rotation direction of the rotary drum, and the running speed of the magnetic tape is switched according to the first and second recording modes. did.

Further, the second invention of the present application provides a first reproduction mode for reproducing a digital signal recorded at a first track pitch on a magnetic tape wound on a rotating drum,
A rotary head digital signal reproducing apparatus having a second reproduction mode for reproducing a digital signal recorded at a second track pitch smaller than the track pitch of
The four reproducing heads are arranged at 90 ° intervals on the rotating drum, and the timing at which the four reproducing heads perform the reproducing operation is
9 in order from the reproducing head preceding the rotating direction of the rotating drum.
The configuration is such that the running speed of the magnetic tape is switched in accordance with the first and second track pitches by delaying by 0 °.

Further, the third invention of the present application is directed to a first recording / reproducing mode for recording / reproducing at a first track pitch on / from a magnetic tape wound on a rotating drum, and a second track pitch smaller than the first track pitch. In a rotary head type digital signal recording / reproducing apparatus having a second recording / reproducing mode for recording / reproducing in the above, four recording / reproducing heads are arranged at 90 ° intervals on a rotating drum, and the four recording / reproducing heads perform recording / reproducing operations. Is delayed by 90 ° in order from the recording / reproducing head preceding in the rotation direction of the rotating drum,
Further, the running speed of the magnetic tape is switched according to the first and second recording modes.

In the fourth invention of the present application, the track width of the head according to the first, second or third invention is set to be equal to or larger than the first track pitch and equal to or smaller than twice the second track pitch. In the fifth invention of the present application, the track width of the head according to the first invention or the third invention is set to be equal to or less than the first track pitch, and a fixed erase head or a rotary erase head is provided.

[0015]

[0016]

According to the first to third aspects of the present invention, recording, reproduction or recording / reproduction can be performed at the first track pitch and the second track pitch by switching the running speed of the magnetic tape. According to the fourth aspect, crosstalk from an adjacent track can be prevented. According to the fifth aspect, recording with a guard band can be performed.

[0017]

FIG. 1 is a diagram showing the arrangement and configuration of the heads of a rotary head type digital signal recording / reproducing apparatus according to an embodiment of the present invention. In FIG. 1, a pair of recording / reproducing heads A1 and A2 having the same azimuth angle are arranged on the rotating drum D at the same height at 180 ° intervals. Further, a pair of recording / reproducing heads B1 and B2 having the same azimuth angle are arranged on the rotating drum D at the same height at 180 ° intervals. Further, the azimuth angles of the recording / reproducing heads A1 and A2 and the azimuth angles of the recording / reproducing heads B1 and B2 are different, and the height of the rotating drum D is the same.
They are arranged at 0 ° intervals. Each recording / reproducing head A
1, B1, A2, and B2 have the same track width Tw.

A magnetic tape (not shown) is wound around the rotary drum D on which the heads are arranged at an angle smaller than 180 °, for example, at an angle of 170 °, and rotates in the direction of arrow P. An oblique track is formed with respect to the magnetic tape running in a direction slightly inclined from the rotation direction of the rotary drum D.

FIG. 2 is a diagram showing a connection relationship from a recording / reproducing amplifier to a recording / reproducing head of a rotary head type digital signal recording / reproducing apparatus according to an embodiment of the present invention. The recording / reproducing heads A1, A2, B1, and B2 are connected to recording / reproducing amplifiers 8 to 11 via coils 1 to 4 of channels 1 to 4 of a rotary transformer, respectively. Further, between the coils 2 and 3, recording / reproducing heads A1, A
There is provided a short ring 6 for reducing crosstalk between channels between the pair 2 and the pair B1 and B2.

FIG. 3 is an operation timing chart at the time of recording of the rotary head type digital signal recording / reproducing apparatus according to the embodiment of the present invention, and FIG. 4 is a diagram showing the relationship between the track pattern and the rotary head. Hereinafter, the recording operation of the rotary head type digital signal recording / reproducing apparatus according to the embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 3, in the first half rotation of the rotating drum D,
The recording / reproducing head A1 is turned on for a period of, for example, 160 ° rotation while being in contact with the magnetic tape. The recording / reproducing head B1 is turned on at a timing rotated by 90 ° from the timing at which the recording / reproducing head A1 is turned on. In the next half rotation of the rotating drum D, the recording / reproducing head A2 is turned on for a period of, for example, 160 ° while being in contact with the magnetic tape. Also, the recording / reproducing head B1 is turned off at a timing of, for example, 160 ° rotation from the timing of turning on. Further, the recording / reproducing head B2 is connected to the recording / reproducing head A2.
Is turned on at a timing rotated by 90 ° from the timing at which is turned on. Hereinafter, in the same manner, 9
Recording / reproducing heads A1, B1, A arranged at 0 ° intervals
2 and B2 sequentially while contacting the magnetic tape, for example, 16
The recording is performed by turning ON only during the rotation of 0 °.

As a result, as shown in FIG. 4, the recording / reproducing heads A1, B1,
Tracks T _A1 , T _B1 T _A2 , and T _B2 are sequentially formed by _A2 and _B2 . At this time, the track pitch Tp = running speed of the magnetic tape. Thereafter, in the same manner,
T _A1 , T _B1 , T _A2 , T _B2 ,... _Are sequentially formed for each rotation.

Here, the track width Tw of the recording / reproducing head according to the embodiment of the present invention will be described. In this embodiment, the track pitch of the first recording mode (hereinafter, referred to as SP mode) is T _PS , the track pitch of the second recording mode (hereinafter, referred to as LP mode) is T _PL , and T _PS > T _PL . Then, in order to at the time of recording of the SP mode does not cause a guard band, Tw is required to be larger than the track pitch T _PS of SP mode. Further, an excessively large Tw, particularly cross talk from the adjacent tracks and second adjacent tracks in the LP mode is increased at the time of variable speed reproduction, since leading to image quality deterioration, twice the track pitch T _PL of Tw LP mode It is desirable to make the following. That is, Tw
Is not less than T _{PS and not} more than 2 × T _PL .

One example of specific numerical values is T _PS = 9 μm, T
_{When PL} = 6 μm, Tw is suitably about 10 μm.
However, in the apparatus provided with erasing means such as a fixed erasing head or rotary erase head, the occurrence of the guard band at the SP mode it will not be a problem, thus it is possible to Tw <T _PS. In the case of this apparatus, crosstalk from adjacent tracks is less likely to occur. Therefore, even if the azimuth angles of the recording / reproducing heads A1, B1, A2, and B2 are the same, there is little deterioration in image quality. When erasing is performed by one rotating erase head, the track width of the rotating erase head needs to be at least four times _TPS .

Recording / reproducing heads A1, B1 and A2, B2
The digital signals supplied to each pair are adjusted by a means similar to the conventional example so as to have a timing difference corresponding to a quarter rotation of the rotating drum,
Input to the recording / reproducing amplifiers 8 to 11. The outputs of the recording / reproducing amplifiers 8 to 11 are supplied to the recording and reproducing heads A1, B1, A2, and B2 through coils 1 to 4 of channels 1 to 4 of a rotary transformer, respectively. At this time, as shown in FIG.
The period in which N is set partially overlaps with the period in which the recording / reproducing heads B1 and B2 are turned on. Further, the recording / reproducing head A2 is turned on.
Also partially overlaps with the period when the recording / reproducing heads B1 and B2 are ON. However, the recording / reproducing heads A1, A2
Since the short ring 6 is provided between the pair of B1 and B2, crosstalk between channels via the coil of the rotary transformer is reduced.

As described above, in this embodiment, the four recording / reproducing heads A1, A2, B1, and B2 are mounted on the rotary drum D at equal intervals and at the same height. The patterns having the respective track pitches are formed according to the tape speed. Further, since the recording / reproducing heads A1 and A2 and B1 and B2 arranged at positions 180 ° apart from the rotary drum D are not turned on at the same time, the short circuit between the channels 1 and 2 provided in the conventional apparatus of FIG. A ring and a short ring between channels 3 and 4 become unnecessary, and the configuration of the rotary transformer is simplified.

FIG. 5 is a diagram showing a connection relationship from a recording / reproducing amplifier to a recording / reproducing head of a rotary head type digital signal recording / reproducing apparatus according to a second embodiment of the present invention. In this embodiment, the rotary transformer has two channels and three channels.
Switching circuits 10 and 11 are provided on the recording / reproducing amplifier side (stator) of the coils 2 and 3 of the channel.
It was configured such that both ends of the coil were short-circuited during a period when each of 2 and B1 was not in contact with the magnetic tape.

With such a configuration, while the amplifier sides of the coils 2 and 3 are short-circuited, they operate equivalently to the short ring, so that the short ring 6 in FIG. 2 can be omitted.

FIG. 6 is a diagram showing a connection relationship from a recording / reproducing amplifier to a recording / reproducing head of a rotary head type digital signal recording / reproducing apparatus according to a third embodiment of the present invention. In this embodiment, the coils of the recording / reproducing heads A1 and A2 arranged at the same height at 180 ° intervals on the rotating drum D and the rotor side of the coil 1 of one channel of the rotary transformer are connected in series, and the recording / reproducing is performed. The coils of the heads B1 and B2 and the rotor side of the two-channel coil 2 of the rotary transformer are connected in series. The recording / reproducing amplifier 13 is connected to the stator side of the coil 1, and the recording / reproducing amplifier 13 is connected to the stator side of the coil 2.
Further, between the coils 1 and 2, a recording / reproducing head A1,
A short ring 6 is provided for reducing crosstalk between channels between the pair A2 and the pair B1 and B2.

As shown in FIG. 3, since the recording / reproducing heads A1, A2 and B1 and B2 are not turned on at the same time, the signal processing circuits such as the rotary transformer and the recording / reproducing amplifier are shared. No signal crosstalk. Therefore, in this example, without increasing the number of channels of the rotary transformer and the number of signal processing circuits,
Additional heads are possible.

However, in the case of this example, it is necessary to change the number of windings of the coil of the recording / reproducing head. The reason is that the resonance frequency fo determined by the resonance of the coil of the recording / reproducing head, the inductance of the rotary transformer, and the input capacitance of the recording / reproducing amplifier must be higher than the frequency band of the recording signal. For example, by making the number of windings of the recording / reproducing head 1 / √2 times that in FIG. 1, the inductance of one recording / reproducing head is set to １ ／.
As a result, the output of the read signal of the recording / playback head is reduced by 3 dB, but the tape noise is also reduced by 3 dB, so that the S / N of the read signal is kept substantially equal to that in FIG.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible based on the spirit of the present invention, and they are not excluded from the scope of the present invention. For example, in the first to fifth inventions, the winding angle of the magnetic tape around the rotating drum may be 180 ° or more.

[0032]

As described above in detail, the first embodiment of the present invention is described.
According to the fifth to fifth aspects, it is possible to record and reproduce a plurality of types of tracks having different track pitches without increasing the number of heads, the number of channels of a rotary transformer, and the number of signal processing circuits.

[Brief description of the drawings]

FIG. 1 is a diagram showing an arrangement and a configuration of a head of a rotary head type digital signal recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a connection relationship from a recording / reproducing amplifier to a recording / reproducing head of a rotary head type digital signal recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 3 is an operation timing chart at the time of recording of a rotary head type digital signal recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between a track pattern and a rotary head of a rotary head type digital signal recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 5 is a diagram showing a connection relationship from a recording / reproducing amplifier to a recording / reproducing head of a rotary head type digital signal recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a connection relationship from a recording / reproducing amplifier to a recording / reproducing head of a rotary head type digital signal recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 7 is a diagram showing an arrangement and a configuration of a head of a conventional rotary head type digital signal recording / reproducing apparatus.

FIG. 8 is a diagram showing a connection relationship from a recording / reproducing amplifier to a recording / reproducing head of a conventional rotary head type digital signal recording / reproducing apparatus.

FIG. 9 is an operation timing chart at the time of recording of the conventional rotary head type digital signal recording / reproducing apparatus.

FIG. 10 is a diagram showing a relationship between a track pattern and a rotary head of a conventional rotary head type digital signal recording / reproducing apparatus.

[Explanation of symbols]

A1, A2, B1, B2: recording / reproducing head, D: rotary drum, 1-4: coil of rotary transformer

Claims (5)

(57) [Claims] A first recording mode for recording at a first track pitch on a magnetic tape wound on a rotating drum;
In a rotary head type digital signal recording apparatus having a second recording mode for recording at a second track pitch smaller than the first track pitch, four recording heads are arranged at 90 ° intervals on the rotating drum, The timing at which the four recording heads perform the recording operation is delayed by 90 ° in order from the recording head preceding in the rotation direction of the rotary drum, and the running of the magnetic tape is performed according to the first and second recording modes. A rotary head type digital signal recording device characterized by switching speeds. 2. A first reproduction mode for reproducing a digital signal recorded at a first track pitch on a magnetic tape wound on a rotary drum, and a second reproduction mode having a second track pitch smaller than the first track pitch. In a rotary head type digital signal reproducing apparatus having a second reproducing mode for reproducing recorded digital signals, four reproducing heads are arranged at 90 ° intervals on the rotating drum, and the four reproducing heads reproduce the digital signals. The timing of performing the operation is delayed by 90 ° in order from the reproduction head preceding the rotation direction of the rotary drum, and the running speed of the magnetic tape is switched according to the first and second track pitches. Rotating head type digital signal reproducing device. 3. A first recording / reproducing mode for recording / reproducing at a first track pitch on / from a magnetic tape wound around a rotating drum, and a second recording / reproducing mode for recording / reproducing at a second track pitch smaller than the first track pitch. In a rotary head type digital signal recording / reproducing apparatus having two recording / reproducing modes, four recording / reproducing heads are arranged on the rotating drum at 90 ° intervals, and the four recording / reproducing heads perform recording / reproducing operations. Rotating the magnetic tape in accordance with the first and second recording modes in order to delay the recording tape from the recording / reproducing head preceding in the rotation direction of the rotary drum by 90 °. Digital signal recording / reproducing device. 4. The track width of the four heads is equal to or greater than a first track pitch and is equal to or less than a second track pitch of two.
4. The rotary head type digital signal recording apparatus, reproducing apparatus or recording / reproducing apparatus according to claim 1, wherein the number is less than or equal to twice. 5. The rotary head type digital signal recording according to claim 1, wherein the track width of the four heads is equal to or smaller than the first track pitch, and a fixed erase head or a rotary erase head is provided. Device or recording / reproducing device.