JPH01221069A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To conduct a special reproduction without any noise by employing a general formula which can easily generate a preset waveform able to scan a track in the unit of field by setting a parameter freely from system control part in case of conducting a special reproduction from a tape on which signals are recorded in segment. CONSTITUTION:A desired program is loaded on a ROM 122, and among parameters, the following are set from the system control part 11: a multiple speed N=2times, a segment M=3tracks, a track width A=40mum, r.p.m. R=1800. A general formula comes to be: D=240XZ+4800X{T-0.05X(K-1)}, where Z=0.1, K=FIX(TX20)+1, 0.05X(K-1)<=T<=0.05XK. By counting up with a cylinder FG and pulse 3c and by giving the time T, the differential D of a piezoelectric element is determined each time. As a result, in case of reproducing at a double speed from a recording track recorded three track/1 field-wise, recording in the unit of field is made able. Therefore, a noiseless reproduction equal to that from one track/one-field-recording can easily be attained with arbitrary segment recording.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for realizing noiseless reproduced images during special reproduction, particularly in a magnetic recording/reproducing apparatus such as a VTR having an electromechanical transducer element for driving a head. The present invention relates to a magnetic recording/reproducing device characterized by pneumo-mechanical transducer driving.

Conventional technology Conventionally, recording is performed at one track/field, so in order to perform noiseless special playback using an electromechanical transducer such as a piezoelectric element, the rise of each head switching signal no matter how many times the playback is performed. It would have been better to create a preset voltage waveform with a certain slope based on 9 on the top or xi on the bottom and drive the electromechanical transducer. That is, since field management can be performed on a track-by-track basis, it does not matter which track is selected as long as the starting ends of the tracks are matched.

The above content will be explained using FIGS. 8 to 10.

FIG. 8 is a configuration diagram for driving an electromechanical transducer in a conventional example, in which 1 is a magnetic tape, 5A, 5B are bare magnetic heads each having a different azimuth angle, 6 is a linear head for reproducing a control track, 7A, 7B 8 is an electromechanical transducer on which magnetic heads sA and sB are mounted; 8 is a cylinder on which electromechanical transducers 7A and 7B are mounted; 9 is a cylinder motor that rotates the cylinder 8; 10 is a timing generation circuit that generates various timing signals; 11 is various parameters (double speed, number of segments, track width, rotation speed)
13 is a D/A converter; 14 is a drive circuit for driving the electromechanical transducer 7A or 7B; 16 is a capstan motor for moving the magnetic tape 1 at a set double speed; The electromechanical transducer 7A or 7 is triggered by various timings according to parameters set by the system control unit 11.
9 is a ROM that outputs preset waveform data for driving 1.B. Indicates a magnetization trajectory recorded in a track/field, 1 is a magnetic tape, 2 is a recording track recorded by a rotating magnetic head 5A or 6B, 3 is a control track where a control signal is recorded, and 4 is a time code track. .

The magnetic tape 1 is directed to the X1 direction, and the magnetic head 6A or 6B
move in the X2 direction. T1-T10 indicate trunks recorded in one track/field. Figure 10 (A)
are the recording track magnetization locus and rotary head trajectory of 1 track/field during 2x speed playback (1x speed: thick line, 2x
Double speed: Indicates the positional relationship with ) (shown with a broken line), T1-T1
Reference numeral 9 indicates the order of recorded tracks, and the shaded area indicates the track locus scanned during double-speed playback. The horizontal axis is time T, the vertical axis is the direction of movement of the magnetic tape, and the arrows are times 14, 12°t3.
...tl. magnetic head 6A or 5B
indicates the amount of displacement for driving the electromechanical transducer 7A or 7B to scan the shaded area.

In FIG. 10(B), the horizontal axis represents time and the vertical axis represents the amount of displacement, and the amount of displacement 1O-( -) and the head switching signal 1o generated by the timing generation circuit 10 from the control signal, -(b) is a diagram showing the timing relationship.

1O-(d) is 1O with time on the horizontal axis and applied voltage on the vertical axis.
- Electromechanical transducer 7A or 7B by the amount of displacement in (a)
The voltage applied at each time to drive is shown.

To explain in detail below, the cylinder motor 9 rotates the cylinder 8 equipped with the electromechanical transducers 7A and 7B at a certain rotation speed, and the linear head 6 moves the control track 3 onto the electromechanical transducers 7A and 7B. Consider a configuration in which recording track 2 is reproduced by magnetic heads sA and sB located at .

For example, when performing double speed playback, magnetic tape 1 advances at twice the speed of normal (1x speed) playback, so the 10th
The head trajectory is as shown by the broken line in Figure (A). Therefore, in order for the magnetic head 6A or 6B to scan the shaded area, for example, from time 0 to t1, a primary linear preset waveform having a displacement of 80 μm at time t1 is transmitted from the ROM 16 at the timing of the head switching signal 1o-(b). The signal is generated and subjected to D/A conversion by the D/A converter 13. D/
After A conversion, it is supplied to the drive circuit 14, and the output voltage 1O-(d) of the drive circuit 14 is applied to the electromechanical transducer 7A or 7B. As a result, when a recording track of 1 track/field is played back at double speed, the track in the shaded area (TI
, T3. T5. T7.・・・・・・・・・・・・) will be scanned.

Problems to be Solved by the Invention However, in recent years, the transition from analog to digital has progressed rapidly, and digitization has been carried out in all aspects of the VTR field. Development is underway. The amount of data increases due to digital recording, and high-density recording is required in order to record with the same amount of tape as before.

To this end, methods have been adopted to increase the relative speed between the tape and the head, and a method has been proposed in which field data is recorded across multiple tracks (hereinafter referred to as segment recording). Therefore, let us consider a case where special playback, for example, double speed playback, is performed on a track on which such segment recording has been performed using a method similar to the conventional method. FIG. 11 shows the positional relationship between the recording track magnetization trajectory of 3 tracks/field and the rotary head trajectory (1x speed double thick line, 2x speed: broken line) during double speed reproduction, and shows the positional relationship between Sαβ (α: 1 to 7, β
:1 to 3), α indicates the field unit of the recorded track, and β indicates the order within the field.

For example, S11 is the first track in the first field,
S12 each indicates the second track in the second field. Further, the horizontal axis indicates time T, and the vertical axis indicates the traveling direction of the magnetic tape. Therefore, when the electromechanical transducer 7A or 7B is driven in the same manner as the conventional method described above, the position shown in the shaded area in FIG. 11, that is, S11.813. S22. S31, S33.
S42°351.853. Since the tracks S62 and S71 are scanned (see FIG. 11), there is a problem that reproduction cannot be performed in units of one field, that is, in units of (811, 312, 513).

The present invention provides a general formula that can easily generate a preset waveform that can scan a track in units of one field by freely setting parameters from the system control section when performing special playback of a tape on which segment recording has been performed. The purpose of this invention is to provide a magnetic recording and reproducing device that can perform noiseless special reproduction.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a cylinder equipped with a rotating magnetic head mounted on an electromechanical transducer.
A magnetic tape is wound diagonally and information signals are recorded and reproduced on the magnetic tape as a group of discontinuous recording tracks, the special playback speed is N, the number of recording tracks constituting a field is M, and the track width is A. , when the rotation speed is H, special reproduction is performed by displacing the electromechanical transducer at time T by an amount expressed by the following formula.O Double speed: N [times] Segment: M [track] Track 1 O: A [μm] Rotation speed HR [rpm: 1 Time: T (SEC) Piezo element displacement: D [μm] (1) INT (N)≦N≦I NT (N) +
0.5D=2XA×M×Z+(N-1)×AxRX(T
-30×M×(K-1)/R)/15Z=((N-FI
X(N)) (K-1).

IFIX(N)-11] K=FIX(T×R/M/30)+1 (2) INT(N)+0.5≦N≦INT (N
)-HD=-2×A×M×Z×N/ABS(N)+(N
-1)xAx Rx(T-30xMx(K-1)/R
)/15Z=({FIX(N)+1-INI)(K-
1).

IFIX(N)l) K=FIX(T×R/M/30)+1 However: 30×M× (K -1)/R≦T≦soxMxK/R
M: Any positive integer INT(N): The largest integer not exceeding N value FIX(N
): Value obtained by cutting off the decimal part of the N value Z [α, β]: a
shows the remainder when divided by β.

According to the above-described configuration, the present invention calculates the amount of displacement using a general formula even when various parameters (double speed, number of segments, track width, rotation speed) are arbitrarily varied when performing special playback of a segment-recorded tape. By passing the algorithm,
The electromechanical transducer can be driven so as to easily scan the track on a field-by-field basis, and even segment-recorded tapes can be reproduced with the same image quality as before without noise.

Embodiment FIG. 1 is a block diagram for driving an electromechanical transducer in a magnetic recording/reproducing load according to an embodiment of the present invention. Reference numeral 12 is a block diagram for driving an electromechanical transducer by processing parameter settings and various timings from a system control section. This is a microcomputer that outputs preset data to drive the elements, 121 is an import that reads data and interrupt signals into the microcomputer 12, 122 is a ROM that loads the program that runs the microcomputer 12, and 123 is used for program processing, etc. The RAM 1124 is the CPU that controls the microcomputer 12.

126 indicates outboard to output preset data. Those with the same numbers as those in the narrow tube 8 in Figure 8 operate in the same way, so explanations will be omitted.

Figure 2 shows track width A = 40Cμm], number of segments M
= 3 () rack/field], rotation speed R = 1800
(rpm), the magnetic tape 1 is in the X direction, and the magnetic head 5A or 5B is in the X2 direction.
move in each direction. 811 to S41 indicate tracks recorded at 3 tracks/field, and the same numbers as in the soil temperature diagram 9 indicate the same meaning. Figure 3 (A) shows the recording track magnetization trajectory of 3 tracks/field during double speed playback. and the rotating head trajectory (1x speed: thick line, 2x speed: broken line).
811 to 871 are the order of the recorded tracks, and the shaded area is the track locus scanned during double speed reproduction. The horizontal axis is time T1, the vertical axis is the direction of movement of the magnetic tape, and the arrow is time 14,
12,13°...t. In the magnetic head 5
A or 5B indicates the amount of displacement for driving the electromechanical transducer 7A or 7B to scan the shaded area. Figure 3 (
B) shows time on the horizontal axis and displacement on the vertical axis.
Or displacement amount 3 at each time when 5B drives the electromechanical transducer 7A or 7B to scan the shaded area
3a is a diagram showing the timing relationship between the head switch M number 3b generated by the timing generation circuit 10 from the control signal and the FG pulse 3c of the cylinder motor 9. FIG. 3d shows the applied voltage at each time to drive the electromechanical transducer 7A or 7B by the amount of displacement of 3a, with time on the horizontal axis and applied voltage on the vertical axis. Fourth
The figure is a 70-chart showing the algorithm of the program loaded into the ROM 122.

A detailed explanation will be given below using FIGS. 1 to 4.

Now, the desired program is loaded into the ROM 122, and among the parameters, N = 2 [times], M = 3 () rack] -A
If =4Q (μm) and R = 1800 [rpm] are set in the system control section 11, the general formula becomes as follows.

D=240XZ+4800X(T-o, osx(K-1
)) (1,1) However, Z=(o, 1') K=FIX(TX20)+1 0.05X (K -1)≦T≦0.05XK f
be.

If the time T is given by counting up with the cylinder FG pulse 3C, the displacement *D can be determined sequentially.

The relationship between cylinder FG pulse 3C and time T is that rotation speed B = 1soo [rpm] and the number of teeth of T cylinder FG is 48.
T = (s o/18.00)/
48XC (However, C Nijilinda - FG)

First, as shown in FIG. 4, various parameters are set by the system control unit 11 through the input 121, and then an interrupt is generated through the import 121 at the rising edge or falling edge of the head switching signal 3b. . When an interrupt occurs, time T is given by counting up the cylinder FG pulse 3C through the import 121 and substituted into the general equation (1, 1). Time T
Based on CPU124) 121, ROM12
2. Calculate displacement using RAM 123 and outport 125. Calculation Hiroka is D through outboard 126
/A converter 13. Looking at the amount of displacement over time, it is 3a. For example, at time t1, cylinder FG
When the pulse count number C is 24, T is '/60 [5ec
). As a result, the displacement is 8° (in μ). D
After /A conversion, the voltage is supplied to the drive circuit 14, and the output voltage 3d of the drive a circuit 14 is applied to the anaerobic mechanical conversion element 7A or 7B. As a result, when a recording track of 3 tracks/field is played back at double speed, the shaded tracks (311, 9
12°313.331, S32.833,...
. . . ), it is possible to reproduce one field at a time.

Next, the case where the parameter N is changed to o, 1/4, and 1/2 will be described. FIG. 6(A) shows the positional relationship between the recording track magnetization trajectory of 3 tracks/field and the rotary head trajectory (1x speed: thick line, 2x speed: broken line) during 0x speed playback (still playback), 811 ~
S31 is the number of the recorded track, and the shaded area is the track locus scanned during 0x speed playback (still playback). The horizontal axis is the time T1, the vertical axis is the traveling direction of the magnetic tape, and the arrow is the time t1°t't...tl. In order for the magnetic head 6A or 2'3' to scan the diagonally shaded area, the electromechanical transducer 7
Indicates the amount of displacement for driving A or 7B.

FIG. 5(B) shows time on the horizontal axis and displacement on the vertical axis, and the amount of displacement at each time when the magnetic head 6A or 5B drives the electromechanical transducer 7A or 7B to scan the shaded area. 5a, a head switching signal 6b generated by the timing generation circuit 1o from the control signal;
1 is a diagram showing the timing relationship between cylinder motor 9 (7) and FG pulse 6C. 6d indicates the time on the horizontal axis, the applied voltage on the vertical axis, and the electromechanical transducer 7 by the displacement amount of p5a.
The applied voltage at each time for driving A or 7B is shown.

Figure 6 (A) shows 3 trunks/3 trunks during 1/4 speed playback.
Field recording track magnetization trajectory and rotating head trajectory (
1x speed: thick line, 2x speed: broken line), 811 to S31 are the item numbers of the recorded tracks, and the shaded area is the track locus scanned during 174x playback.

The horizontal axis is time T, the vertical axis is the traveling direction of the magnetic tape, and the arrow is time t.

12.13. ...tl. magnetic head 6
A or 5B indicates the displacement amount for driving the electromechanical transducer r, A or 7B to scan the shaded area. Figure 9 (B) shows time on the horizontal axis, displacement on the vertical axis, and magnetic head 6.
A or 6B is the displacement amount 6a at each time when the electromechanical transducer 7A or 7B is driven to scan the shaded area, and the head switching signal 6b generated by the timing generation circuit 10 from the control signal 1 The FG pulse of the cylinder motor 9 6C is a diagram showing the timing relationship with 6C. 6d shows the applied voltage at each time to drive the electromechanical transducer 7A or 7B by the displacement amount of white a, with the horizontal axis representing time and the vertical axis representing applied voltage. FIG. 7(A) shows the positional relationship between the recording track magnetization locus of 3 tracks/field and the rotary head locus (1× speed: thick line, 2@speed: broken line) during 1/2 speed reproduction.
11 to S31 are the number numbers of the recorded tracks, and the shaded part is 1.
/ This is the track locus scanned during double speed playback. The horizontal axis is time T, the vertical axis is the direction of movement of the magnetic tape, and the arrow is time 1.
11...tl. In the magnetic head 5A
12'3' or 6B indicates the displacement amount for driving the electromechanical transducer 7A or 7B to scan the shaded area.

FIG. 7(B) shows time on the horizontal axis and displacement on the vertical axis, and the displacement 7a at each time when the magnetic head 6A or 6B drives the electromechanical transducer 7A or 7B to scan the shaded area, and the control Timing generation circuit 1 from signal
Head switching signal 7b generated from 0Vc,
7 is a diagram showing the timing relationship with the FG pulse 7c of the cylinder motor 9. FIG. 7d shows the applied voltage at each time to drive the electromechanical transducer 7A or 7B by the displacement amount of shift a, with the horizontal axis representing time and the vertical axis representing applied voltage. Even if the parameter N changes to 0, 1 /4, 1 /2, the algorithm calculated using the general formula is the same, so N
The amount of displacement can be easily determined using exactly the same principle as in the case of =2,
Can drive electromechanical transducers. Therefore, noiseless playback with the same image quality as conventional tapes can be easily achieved even on segment-recorded tapes. A detailed explanation will be omitted.

According to the present invention, the parameters [1x speed, number of segments (integer), track pitch, rotation speed]
Since we have introduced a general formula using , you can easily scan one field even if you change various parameters. Therefore, noiseless reproduction equivalent to one-track/field recording can be easily achieved in arbitrary segment recording, making it extremely effective as a magnetic recording and reproducing apparatus.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a configuration for driving an electromechanical transducer of a magnetic recording/reproducing device in an embodiment of the present invention, and Fig. 2 shows magnetization trajectories recorded in 3 tracks/field in an embodiment of the present invention. 3 is a timing diagram for explaining the operation in the case of double-speed playback in the embodiment of the present invention, FIG. 4 is a flow chart showing the program algorithm in the embodiment of the present invention, and the $S diagram FIG. 6 is a timing diagram showing the operation in the case of still playback among the embodiments of the invention. FIG. A timing diagram showing the operation in the case of 1/2 speed playback in the example, Fig. 8 is a block diagram of the drive system of the electromechanical transducer of the conventional example, and Fig. 9 shows the magnetization recorded in the same one track/field. A plan view showing the locus, FIG. 10 is a timing diagram showing the operation when playing back at double speed in the conventional example,
FIG. 11 is a timing chart showing the positional relationship between the recording track magnetization locus and the rotary head locus for three tracks/field in the conventional example, and the case of double speed reproduction. 1... Magnetic tape, 2... Recording track, 3... Control track, 4...
...Time code track, sA, sB...Magnetic head, 6...Linear head, yA, yB...
...Electromechanical conversion element, 8...Cylinder,
9... Cylinder motor, 10... Timing generation circuit, 11... System control unit, 12... Microcomputer, 13...
D/A converter, 14...1° drive circuit, 16.
...Capstan motor, 16...RO
M. Name of agent: Patent attorney Toshio Nakao and one other name
1 Figure /2-71Con R=
ノ80θ [rPm] Fig. 2 Fig. 3 Fig. 4 Fig. 5 (A> N = o L double ball] - Ichi T Fig. 6 Fig. 7 <, t+> - TN Figure 10

Claims (1)

[Claims] A magnetic tape is wound diagonally around a cylinder equipped with a rotating magnetic head mounted on an electromechanical transducer, and information signals are recorded and reproduced on the magnetic tape as a group of discontinuous recording tracks. , the special playback speed is N, the number of recording tracks constituting one field is M, the track width is A,
1. A magnetic recording/reproducing device characterized in that special reproduction is performed by displacing an electromechanical transducer at time T by an amount expressed by the following equation D when the rotational speed is R. Double speed: N [times] Segment: M [track] Track width: A [μm] Rotation speed: R [rpm] Time: T [SEC] Piezo element displacement: D [μm] (1) INT (N)≦N ≦INT(N)+0.5D=2
×A×M×Z+(N-1)×A×R×{Y-30×M×(K-1)/R}/15Z=[{N
-FIX(N)}(K-1), |FIX(N)-1|] K=FIX(T×R/M/30)+1 (2) INT(N)+0.5≦N≦INT(N )+1D
=-2×A×M×Z×N/ABS(N)+(N-1)×
A×R×{T-30×M×(K-1)/R}/15Z=
[{FIX(N)+1-|N|}(K-1), |FIX
(N) |] K=FIX(T×R/M/30)+1 However: 30×M×(K-1)/R≦T≦30×M×K/RM:
Any positive integer INT(N): The largest integer not exceeding the N value FIX(N): The value obtained by rounding down the decimal point of the N value Z[α
, β]: Indicates the remainder when α is divided by β.