JP3231121B2 - Non-tracking type playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-tracking type reproducing apparatus for scanning a recording track with a rotary head at twice the density of recording.

[0002]

2. Description of the Related Art Conventionally, a non-tracking type recording / reproducing apparatus is disclosed in, for example, "Nikkei Electronics" 19
92.3.30 (no. 550) p. 133-161
And so on.

An outline of the digital recording / reproducing apparatus will be described. FIG. 6 shows a rotary head device, 1 is a tape guide drum, and a magnetic tape 2 is wound around the tape guide drum 1 at an angle of about 100 degrees. 3A, 3B and 3A 'are rotary magnetic heads. The heads 3A and 3A 'have the same azimuth, and the heads 3A, 3A' and 3B have different azimuths, and the heads 3A and 3B are so-called double azimuth heads.

In such a rotary head device, at the time of recording, the heads 3A and 3B are used alternately for each rotation, and inclined recording tracks TA and TB are sequentially formed on the magnetic tape 2 as shown in FIG. Is done. In this case, each of the inclined tracks TA and TB is formed by supplying recording signals to the heads 3A and 3B during a 90 ° angular range in which the heads 3A and 3B scan the magnetic tape 2. The signal of one track is recorded while being divided into a plurality of blocks.
A track address and a block address are recorded for each block.

At the time of reproduction, the head 3
Since both A 'and 3B are used, even if the rotation speed is the same during recording and during reproduction, double-density scanning is performed during reproduction. FIG. 7 shows the scanning trajectories of the heads 3A 'and 3B.

FIG. 8 shows a circuit configuration of a reproducing system.
A reproduction signal S output from the heads 3A 'and 3B during reproduction
3A and S3B (shown in FIGS. 9A and 9B) are supplied to fixed terminals on the a and b sides of the changeover switch 5 via the reproduction amplifiers 4A and 4B, respectively. The changeover switch 5 is connected to the side a while the head 3A 'scans the magnetic tape 2, and is connected to the side b while the head 3B scans the magnetic tape 2.

A reproduction signal (shown in FIG. 9C) output from the changeover switch 5 is supplied to a reproduction signal processing circuit 8 via an amplifier 6 and a reproduction equalizer 7. In the processing circuit 8,
After the demodulation processing of the reproduction signal is performed, the data of each track is obtained by sequentially writing the data of each block to a predetermined address of the buffer memory corresponding to the track address and the block address. Then, the reproduction data of each track read from the buffer memory is subjected to error correction processing and output.

As described above, at the time of reproduction, the heads 3A 'and 3B scan the recording tracks TA and TB at double density, and the processing circuit 8 reconstructs signals of each track based on the track address and the block address. Head 3
A 'and 3B need not faithfully trace (track) the recording tracks TA and TB, respectively.

By the way, the tape running speed at the time of reproduction by the above-mentioned non-tracking type digital recording / reproducing apparatus is set to twice the normal speed, and the reproducing time is reduced to 1 by using a rotary head device as shown in FIG. / 2. 10, parts corresponding to those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 10, 9A, 9B, 9
A 'and 9B' are rotating magnetic heads arranged at 90 ° angular intervals. In this head configuration, the head 9
A and 9A 'have the same azimuth and heads 9B and 9A'
B ′ has the same azimuth, but the heads 9A, 9A ′ and 9
Azimuth different from B, 9B '.

In such a rotary head device, when the tape traveling speed is set to twice the normal speed, the heads 9A, 9
Even if the rotation speeds of B, 9A 'and 9B' are the same as those in the normal state, the scanning of the recording tracks TA and TB by the heads 9A, 9B, 9A 'and 9B' is twice as fast as during recording.

FIG. 11 shows a circuit configuration of a reproducing system, in which reproduced signals S9A and S9A output from the heads 9A and 9A 'are provided.
S9A '(shown in FIGS. 12A and 12B) is connected to the a side of the changeover switch 11A via the reproduction amplifiers 10A and 10A', respectively.
It is supplied to the fixed terminal on the b side. The changeover switch 11A is
The head 9A is connected to the side a during scanning of the magnetic tape 2, while the head 9A 'is connected to the side b during scanning of the magnetic tape 2. The output signal of the changeover switch 11A is connected to a fixed terminal on the a side of the changeover switch 12.

The reproduced signals S9B and S9B '(shown in FIGS. 12C and 12D) output from the heads 9B and 9B' are supplied to the a and b sides of the changeover switch 11B via the reproducing amplifiers 10B and 10B ', respectively. It is supplied to the fixed terminal. The changeover switch 11B is connected to the side a while the head 9B scans the magnetic tape 2, while the head 9B 'is
Is connected to the b side during the scanning period. The output signal of the changeover switch 11B is connected to a fixed terminal on the b side of the changeover switch 12.

The changeover switch 12 includes heads 9A and 9A '.
Is connected to the side a during scanning of the magnetic tape 2, while b is connected during scanning of the magnetic tape 2 by the heads 9 B and 9 B ′.
Connected to the side. A reproduction signal (shown in FIG. 12E) output from the changeover switch 12 is supplied to an amplifier 6 and a reproduction equalizer 7.
Is supplied to the reproduction signal processing circuit 8 via the controller and the reproduction data of each track is output.

[0015]

When the tape traveling speed is doubled, by using a rotary head device as shown in FIG. 10, the density is theoretically twice as high as at the time of recording as described above. Although the recording tracks TA and TB can be scanned, since the heads 9A and 9A 'or the heads 9B and 9B' are arranged apart from each other, it is difficult to completely pair the heads. There is a possibility that the recording tracks TA and TB cannot be scanned with high accuracy at twice the density of the recording tracks.

Therefore, the present invention provides a non-tracking type reproducing apparatus that scans a recording track with a rotary head at twice the density as at the time of recording, and uses the rotary head even when the tape speed is twice the normal speed. Thus, the recording track can be scanned at twice the density of the recording track.

[0017]

According to the present invention, a signal of one track is divided into a plurality of blocks and recorded, and each recording track on a tape on which a track address and a block address are recorded for each block is recorded. During normal playback, scanning is performed by a first rotary head having a first azimuth and a second rotary head having a second azimuth disposed at an angular interval of about 180 ° from the first rotary head, In a non-tracking type reproducing apparatus which performs scanning at twice the recording density and obtains signals of the respective tracks, the reproducing apparatus is adjacent to the first rotary head with a step of one track pitch relative to the first rotary head. Along with
A third rotating head having the first azimuth; a third rotating head adjacent to the second rotating head with a step of one track pitch with respect to the second rotating head;
When a fourth rotating head having a second azimuth arranged at an angular interval of about 180 ° and a second rotating head is provided, and the running speed of the tape is double that of the normal reproduction, the first to the fourth The reproduction signals from the rotary head No. 4 are rearranged based on the track addresses and block addresses to obtain the signals of the respective tracks.

[0018]

According to the present invention, when the running speed of the tape is doubled from the normal speed, the first rotating head having the first azimuth and the first rotating head are arranged at an angular interval of about 180 °. A second rotary head having a second azimuth, a third rotary head having a step of one track pitch with respect to the first rotary head, and having a first azimuth. , The second rotating head is adjacent to the second rotating head with a step of one track pitch, and is approximately one step away from the third rotating head.
Fourth rotary head having second azimuths arranged at an angular interval of 80 °, that is, four rotary heads 14A
Since the recording tracks TA and TB are scanned at .about.14B ',
Even if the tape running speed is twice as fast as in the normal case, it is possible to scan the recording track at twice the density as during recording.

[0019]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a rotary head device in this example. In FIG. 1, portions corresponding to those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, 14A, 14A ', 14
B and 14B 'are rotary magnetic heads. The heads 14A and 14A 'are disposed adjacent to each other, and
B and 14B 'are disposed adjacent to each other. Head 14
A, 14A 'and heads 14B, 14B' are approximately 1
They are arranged at an angular interval of 80 ° and have different azimuths. Also, the heads 14A and 14A 'are arranged so as to have a step difference by one track pitch TP in the axial direction as shown in FIG. Head 1
4B and 14B 'also have one track pitch TP in the axial direction.
It is arranged so that it is staggered and has a step.

In such a rotary head device, when the tape traveling speed is twice the normal speed, the head 14A,
Even if the rotation speeds of the heads 14A ', 14B, 14B' are the same as those at the normal time, the heads 14A, 14A ', 14B, 14B'
The scanning of the recording tracks TA and TB by B 'has twice the density as during recording, as shown in FIG.

In this case, since heads 14A and 14A 'are arranged adjacent to each other, these heads 14A and 14A'
4A 'can be accurately shifted in the axial direction by one track pitch TP. This corresponds to heads 14B and 14
The same applies to B '. Therefore, unlike the case where the rotary head device is configured as in the example of FIG. 10, there is no possibility that the pairing between the heads is not completely performed and the scanning cannot be performed with high density at twice the recording density.

Although not described above, the scanning at twice the recording density is the scanning of the recording track TA by the heads 14A and 14A 'and the scanning by the recording track TB by the heads 14B and 14B'. Therefore, the head 14
It is not necessary that the scanning trajectories B and 14B 'pass through the center of the scanning trajectories of the heads 14A and 14A'. In extreme cases, both scanning trajectories may completely overlap. In other words, the head 14
There is no need to perform pairing between A, 14A 'and heads 14B, 14B'.

FIG. 4 shows a circuit configuration of a reproducing system.
4, parts corresponding to those in FIG. 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The reproduced signals S14A and S14B output from the heads 14A and 14B (shown in FIGS. 5A and 5B) are supplied to the selector switch 16 via reproduction amplifiers 15A and 15B, respectively.
And fixed terminals on the side b. Selector switch 16
Is connected to the side a while the head 14A scans the magnetic tape 2 while it is connected to the side b while the head 14B scans the magnetic tape 2. The output signal of the changeover switch 16 (shown in FIG. 5C) is supplied to the amplifier 18 and the reproduction equalizer 2.
It is supplied to the fixed terminal on the a side of the changeover switch 23 via a series circuit of the 0 and 90 ° delay circuits 22 (shown in FIG. 5D).

The reproduced signals S14A 'and S14B' output from the heads 14A 'and 14B' (shown in FIGS. 5E and 5F) are supplied through the reproducing amplifiers 15A 'and 15B' to the a side of the change-over switch 17 and It is supplied to the fixed terminal on the b side. The changeover switch 17 is switched in conjunction with the changeover switch 16, and is connected to the side a while the head 14A 'scans the magnetic tape 2, while it is connected to the side b while the head 14B' scans the magnetic tape 2. You. The output signal (shown in FIG. 5G) of the changeover switch 17 is supplied to a fixed terminal on the b side of the changeover switch 23 via the amplifier 19 and the series circuit 23 of the reproduction equalizer 21.

The changeover switch 23 is connected to the heads 14A ', 1
4B 'is connected to the side b during scanning of the magnetic tape 2, while the heads 14A' and 14B are
Are connected to the a side during the period when is not scanned. Changeover switch 2
The reproduction signal (shown in FIG. 5H) output from the reproduction signal processing circuit 3 is supplied to a reproduction signal processing circuit 8, and reproduction data of each track is output.

[0028]

According to the present invention, when the running speed of the tape is doubled from the normal speed, not only the first and second rotary heads used at normal times but also adjacent steps with a step of one track pitch are used. Since the recording tracks are also scanned by using the third and fourth rotating heads arranged, the recording tracks can be scanned at twice the density at the time of recording. Thus, the signal recorded on the tape can be satisfactorily reproduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a rotary head device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining an arrangement of a head.

FIG. 3 is a diagram showing a recording track and a head scanning trajectory during reproduction according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a circuit configuration of a reproducing system according to one embodiment of the present invention.

FIG. 5 is a diagram illustrating signals of respective units in the example of FIG. 4;

FIG. 6 is a diagram showing a configuration of a rotary head device in a conventional non-tracking type digital recording / reproducing apparatus.

FIG. 7 is a diagram showing recording tracks and a head scanning trajectory during reproduction in a conventional non-tracking type digital recording / reproducing apparatus.

FIG. 8 is a block diagram showing a circuit configuration of a reproducing system of a conventional non-tracking type digital recording / reproducing apparatus.

FIG. 9 is a diagram illustrating signals of respective units in the example of FIG. 8;

FIG. 10 is a diagram illustrating a configuration of an example of a rotary head device.

11 is a block diagram showing a circuit configuration of a reproducing system when the rotary head device of the example of FIG. 10 is used.

FIG. 12 is a diagram illustrating signals of respective units in the example of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tape guide drum 2 Magnetic tape 8 Reproduction signal processing circuit 14A, 14A ', 14B, 14B' Rotating magnetic head 15A, 15A ', 15B, 15B' Reproduction amplifier 16, 17, 23 Changeover switch 20, 21, Reproduction equalizer 22 Delay circuit

Claims (1)

(57) [Claims] 1. A signal of one track is divided into a plurality of blocks and recorded, and each recording track on a tape on which a track address and a block address are recorded for each block is read by a first azimuth signal during normal reproduction. The first rotary head having the first rotary head and approximately 18
A non-tracking type reproducing apparatus that scans with a second rotary head having a second azimuth arranged at an angular interval of 0 ° and performs scanning at twice the density at the time of recording to obtain a signal of each track. A third rotary head adjacent to the first rotary head with a step of one track pitch with respect to the first rotary head and having the first azimuth;
A fourth azimuth having a second azimuth adjacent to the second rotary head with a step of one track pitch to the rotary head and having an angular interval of approximately 180 ° with the third rotary head; When a head is provided and when the running speed of the tape is made twice as high as that in the normal reproduction, the reproduction signals from the first to fourth rotary heads are rearranged based on the track address and the block address, and the respective tracks are reordered. A non-tracking type reproducing apparatus characterized in that a non-tracking type reproducing signal is obtained.