JPH033103A - Reproducing method for rotating head type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To realize reproduction having high transmitting rate while keeping the standard rotating speed of a cylinder by arranging N sets of heads having positive and negative azimuth angles at specified intervals and executing the reproduction with the aid of making the speed of a tape N-fold. CONSTITUTION:Rotating heads 11 - 14 are constituted of the positive azimuth A heads 11 and 13 and the negative azimuth B heads 12 and 14 and alternately arranged on the rotating cylinder 1 at the intervals of 360 deg./2N=90 deg.. Besides, a timing generator 15 which generates a head switching sub-pulse is connected to a servo circuit 10. In such constitution, tracking is executed every track as in a conventional manner by using a head switching pulse even when the tape is reproduced by making the speed of the tape twofold of ordinary time at the time of reproducing. Besides, since the rotating speed of the cylinder is normally 2,000rpm in a reproducing signal zone, it is hardly changed even when the tape speed is made twofold and the excellent reproduction is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a rotary head type magnetic recording/reproducing device, namely a rotary head type digital audio tape recorder (hereinafter referred to as R-D).
The present invention relates to a playback method (referred to as AT), and particularly relates to double-speed playback that is faster than the normal playback speed.

(b) Prior art The structure and operation of the R-DAT will be explained below with reference to FIGS. 5 to 7. In Figure 5, (1) is 18
0°opposed positive azimuth head (A hand) (2)
and a rotating cylinder to which a negative azimuth head (B head) (3) is attached, and (4) a magnetic tape drawn out from a cassette (5), which is wound 90' around the cylinder (1) for recording. (6) is the head (2) (3)
) is electrically connected to a recording/playback amplifier, (7) is an EQ-PLL circuit that equalizes the waveform of the playback signal, (8) is a digital signal processing circuit, and (9) is an ATF processing for tracking control. circuit, (10) is the ATF processing circuit (9
) is a servo circuit that controls the mechanical system of the R-DAT device by receiving the output from the R-DAT device. The two helads (2), (3)
The signal reproduced from is amplified by the recording/reproducing amplifier (6) according to the head switching pulse shown in FIG.
The envelope signal shown in b) is obtained.

In addition, the output of the recording/playback amplifier (6) is input to the ATF processing circuit (9), and tracking information is sampled using the sampling signal shown in Fig. 6(c), and good tracking is achieved by the servo circuit (lO). are doing.

On the other hand, the output of the recording/playback amplifier (6) is EQ-P [, L
It is also supplied to the circuit (7), and this EQ-PLL circuit (7)
A reproduction data read clock is generated, and together with this clock, the reproduction data is sent to the digital signal processing circuit (8).
supplied to This digital signal processing circuit (8) takes in the reproduced signal (A-1) shown in FIG. 6 and performs an error check in the period (a), and then performs error correction in the period (b). Similarly, the reproduced signal (B-1) is transmitted during the period (c
), corrected during period (d), and output after period (e).

In the relationship between the track (41) on the tape (4) and the magnetic head (42) shown in FIG. 7, the head velocity vector when the tape is stationary is VD, and the head velocity vector with respect to the tape in the tape traveling direction is VD. vT, the head speed vector v8 seen from the tape is the vector VD and ■7
This determines the track angle θ of the recording track. Here, the track angle when the tape is stationary is θ
. Then, the following formula holds true.

(VD-CO5θ-VT)・tanθ*V(,-5in
θ. (1) (c) Problems to be solved by the invention In the above-mentioned R-DAT, the data transmission rate for reproduction in the on-track state has already been determined, and the transmission rate is increased. To achieve this, it is necessary to increase the tape speed and head speed by the same ratio, but it is extremely difficult to increase the transmission rate with R-DAT because the playback band and tarok frequency become high.

(d) Means for Solving the Problems The present invention provides a rotary head type magnetic recording/reproducing device in which digital information is recorded on each track of a tape helically scanned by a rotary head, in which the rotary head is a positive azimuth head ( It consists of a negative azimuth head (hereinafter referred to as the A head) and a negative azimuth head (hereinafter referred to as the B head).
At least N sets of 62 or more rotating heads are used, the A heads and B heads are arranged alternately on the rotating cylinder with an IM of 360°/2N, and the tape speed is increased to N times the normal speed. We propose a reproducing method for a rotary head type magnetic recording/reproducing device that is characterized by reproducing.

(e) Effect According to the above means, the standard cylinder rotational speed of R-DAT (
On-track reproduction at a high transmission rate is possible while keeping the speed >2,000 rpm.

(F) Embodiment An embodiment of the R-DAT device for realizing the reproducing method of the present invention is shown in FIG. 1 and will be explained. The same parts as in the conventional FIG. Explanation will be omitted. In the same figure, (11), (12), (13), and (14) are a rotating head consisting of two sets of A head and B head arranged alternately at 90° intervals on a rotating head cylinder (1), and a servo circuit. (10) has a configuration that can be applied even when the tape speed is, for example, twice the normal speed. In addition, (14) is based on the signal from the servo circuit (10), for example, as shown in FIG. 2(b).
This is a timing generator that creates the head switching sub-pulses shown in Fig.

Next, the rotation speed of the rotating cylinder (1) is 2, which is the same as normal.
The operation of reproducing the tape at twice the normal speed using OOOrpm will be explained. The four rotating heads (1
The signals picked up in steps 1), (12), (13), and (14) are reproduced by a recording/reproducing amplifier (6) into an envelope signal shown in FIG. 2(c). Regarding tracking, by using the head switching sub-pulse [see Figure 2 (b)] and creating the sampling pulse shown in Figure 2 (d), tracking can be performed for each track as in the past. can.

Furthermore, regarding the reproduced signal band, since the cylinder rotation speed is 2.000 rpm, which is the same as normal, the tape speed is 2.000 rpm.
Even if it is doubled, there is almost no change, and the EQ-PLL circuit (7
) may be the same as the conventional one.

Regarding signal processing, digital signal processing circuit (8)
In the period (a) and (b) shown in FIG. 2, the data of the envelope signals (AI-1) and (Bl-1) are taken in, respectively, and in the periods (C) and (d), the data of the envelope signal ( Correction processing of Al-1) and (Bl-1) is performed, and data is output in periods (e) and (f). Note that since the tape speed is twice the normal speed, the sampling frequency for outputting data is twice the normal speed. The envelope signal (A
I-1), (Bl-1) correction processing period (c), (d
) and the next envelope signal (,A2-1), (B2-
Although the data acquisition periods (c) and (d) in 1) overlap, there is no gap if parallel processing using memory is performed. Next, the relationship between the tracks on the magnetic tape and the magnetic head will be explained with reference to FIG. The head velocity vector VD when the tape is stopped is the same as that in Fig. 7, and the head velocity vector V
T° is twice the normal value, and therefore, the head speed vector ■□ during normal playback is shown as a broken line, whereas the head speed vector during double-speed playback in the present invention is shown as shown as ■□゛. Here, the head speed vector V during double-speed playback
If the inclination of D' with respect to the tape traveling direction is θ, the following equation holds true.

(V,・COSθ0-2・Vtl tanθ'=VD-
sinθO"" (2) Conventionally used R-DA
Since the T magnetic head has a head width that is 1.5 times the track width, the head position at the frontmost part of the track and the head position at the rearmost part of the track are as shown in Fig. 3, which reduces the level of the reproduced signal. It can be read without

The one shown in FIG. 4 is another embodiment. The circuit configuration of this embodiment is exactly the same, but by adjusting the rotating cylinder and the running mechanism, the angle at which the tape is tilted with respect to the running direction can be changed. By making the track angle of the recording track equal to 2 and the trunk angle during fast playback, the head can trace the middle of the track. Here, the track angle when the tape stops is θ.

Assuming that the tape speed is N times the normal speed, the following equation holds true.

(vo-cosθo'-N・Vt')・tanθ=Vo
-sin θ, +, , (3) Track angle θ when the tape is stopped that satisfies equation (3) above. By selecting "," the track angle of the head velocity vector (Vo) becomes exactly the same as the recording track angle .theta., which is very suitable.

(G) Effects of the Invention In the method of the present invention, even if a track recorded according to the R-DAT format is played back at N times the speed, the playback band hardly changes and all the data on the recorded track is kept in good condition. It can be played back quickly, the transmission rate is increased, and the R-
It is extremely suitable for use in a data recorder using DAT.

[Brief explanation of drawings]

1 to 4 are for explaining the method of the present invention, and FIG. 1 shows an R-DA for realizing the method of the present invention.
FIG. 2 is a block diagram showing the configuration of the T device, FIG. 2 is a diagram showing signal waveforms at various parts of the block diagram of the present invention, FIG. 3 is a diagram showing the relationship between the rotary head and the track in the method of the present invention, and FIG. 4 is a diagram showing another implementation. In the example, FIGS. 5 to 7, which are diagrams showing the relationship between the rotary head and the track, are for explaining the prior art. FIG. 5 is a block diagram showing the configuration of a conventional R-DAT device, and FIG. FIG. 6 is a diagram showing the signal waveforms of various parts of a conventional block diagram, and FIG. 7 is a diagram showing the relationship between the rotary head and the track of the conventional R-DAT device. (1)... Rotating head cylinder, (2) (3) (11
)(12)(13)(14)...rotating head, (4)
···Magnetic tape.

Claims (2)

[Claims] (1) In a rotary head type magnetic recording/reproducing device in which digital information is recorded on each track of a tape that is helically scanned by a rotary head, the rotary heads are a positive azimuth head (hereinafter referred to as A head) and a negative azimuth head. head (hereinafter referred to as B head), N sets of at least two or more rotating heads are used, and the A head and B head are arranged alternately on a rotating cylinder at an interval of 360°/2N. A reproducing method for a rotary head type magnetic recording/reproducing device, characterized in that the tape speed is further increased to N times the normal tape speed. (2) In a rotary head type magnetic recording/reproducing device in which digital information is recorded on each track of a tape that is helically scanned by a rotary head, the rotary head consists of an A head and a B head, and at least two or more sets. N sets of rotating heads are used, and three of the rotating heads are mounted on a rotating cylinder.
When A head and B head are arranged alternately at an interval of 60°/2N and the tape speed is N times the normal speed for playback, the track angle of the recording track on the tape is θ, and the head speed during normal playback is V_D, the tape speed is V_T, and by setting the value to satisfy the track angle θ_0 when the tape is stopped in the following equation, the track angle during N times speed playback is made equal to the track angle θ of the recording track. A reproducing method for a rotating head type magnetic recording/reproducing device characterized by: (V_D・COSθ_0−N・V_T)・tanθ=V
_D・sinθ.