JPH10275318A - Magnetic reproducing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly speedily reproduce a signal from a digitally recorded VTR tape. SOLUTION: Plural fixed reproducing heads (1), (2) and (3) are disposed so as to take out recording information in their positions at the same intervals on a line (a head fitting axis) orthogonal to recording tracks of a magnetic tape. Then, under the tape traveling state, the recording information taken out by the individual reproducing heads is written once in a storage device, and out of these written signals, signals written with a time lag in order read out by a prescribed time length to become a continuous signal, so that recording information on an arbitrary recording track is reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic reproducing method and apparatus capable of reproducing recorded information from a magnetic tape (VTR tape) recorded by a VTR at a high speed.

[0002]

2. Description of the Related Art One of the television program production services by a digital method is a non-linear editing service (non-linear system). In order to use this system, a recorded VTR tape (material) must be reproduced and copied to a non-linear system.

[0003] Currently, VT digitally recorded uncompressed.
As technologies for reproducing recorded information from R tape at high speed, products that have recently reached the practical stage include “Digital β Cam-SX” released by Sony Corporation and Matsushita Electric Industrial Co., Ltd. "DVC-Pro", etc.
These are all reproducing heads (VTR heads) during reproduction.
Is rotated at a high speed to reproduce a signal of about four times speed. Also, these products are MP
Since the image signal is recorded by compressing the image signal to about one-fourth by a data compression technique such as EG, a recording / reproducing rate is low, and there is still room for speeding up the rotating mechanism. I have.

[0004]

However, in the above-mentioned products, the digital format of recorded information is extremely specified, and high-speed reproduction cannot be performed in any format. In addition, in the current D3-VTR or the like that records an uncompressed signal, the rotation speed is already close to the limit. It is.

[0005] As described above, the VT recorded at present without compression is
Since there is no means for reproducing a signal from an R tape at a high speed corresponding to any format, copying the material from a VTR tape to a non-linear system requires the same reproduction time as during recording. Therefore,
The introduction of expensive nonlinear systems does not necessarily improve the total editing efficiency, including copying.

An object of the present invention is to provide a magnetic reproducing method and apparatus capable of reproducing a signal from a digitally recorded VTR tape at a high speed in order to overcome this problem. It opens the way to the realization of a system that can reproduce signals from digital format tape at high speed.

[0007]

According to the present invention, there is provided a magnetic reproducing method for reproducing recorded information from a magnetic tape recorded by a VTR using a plurality of fixed reproducing heads. The plurality of fixed reproducing heads are arranged so that recording information is respectively taken out at equal intervals on a line perpendicular to the recording track of the magnetic tape, and the recording medium taken out by each of the reproducing heads in a tape running state. By writing information to the recording device and reading out the signals written with a time lag sequentially among the written signals for each of the reproducing heads for a predetermined length of time to make them continuous signals, It is characterized in that recorded information of a track is reproduced.

Further, the magnetic reproducing method of the present invention is a method of reproducing recorded information from a magnetic tape recorded by a VTR using a plurality of fixed reproducing heads, wherein the information is recorded on a line perpendicular to a recording track of the magnetic tape. From evenly spaced positions,
While moving the respective positions in the longitudinal direction of the tape and arranging the plurality of fixed reproduction heads so that recording information is respectively taken out at positions intersecting the head mounting axis parallel to the recording track, in a tape running state, Writing the recorded information taken out by each of the reproducing heads into a storage device, and reading out the simultaneously written signals among the signals written for each of the reproducing heads for a predetermined time length to form continuous signals; Thus, recorded information of an arbitrary recording track is reproduced.

A magnetic reproducing apparatus according to the present invention is an apparatus for reproducing recorded information from a magnetic tape recorded by a VTR using a plurality of fixed reproducing heads. In the tape running state with the plurality of fixed playback heads arranged so that the recording information is respectively taken out at equal intervals, writing the recording information taken out by each of the playback heads,
Of the signals written for each of the reproducing heads, the signals written sequentially with a time lag are read out for each predetermined time length to be continuous signals, thereby reproducing the record information of an arbitrary recording track. And at least a storage device.

According to a third aspect of the present invention, there is provided the magnetic reproducing apparatus according to the third aspect, wherein the plurality of fixed reproducing heads are arranged so that both ends of respective recording signals constituting adjacent recording tracks are arranged in the longitudinal direction of the magnetic tape. To project on a line perpendicular to the recording track, and a shorter one of two line segments cut off corresponding to both ends thereof is a,
When the width of the fixed reproducing heads is b, the fixed reproducing heads are arranged at equal intervals equal to ab = c or shorter than c.

The magnetic reproducing apparatus according to the present invention is an apparatus for reproducing recorded information from a magnetic tape recorded by a VTR using a plurality of fixed reproducing heads, wherein the information is recorded on a line perpendicular to a recording track of the magnetic tape. From evenly spaced positions,
In the tape running state, the plurality of fixed playback heads arranged so that each position is moved in the tape longitudinal direction and recording information is respectively taken out at a position intersecting a head mounting axis parallel to the recording track, Writing the recording information taken out by each of the reproducing heads,
A storage device that reproduces recorded information of an arbitrary recording track is at least provided by reading out simultaneously written signals among the written signals for each of the reproducing heads and reading out the signals for each predetermined time length to form continuous signals. It is characterized by having.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on embodiments of the present invention with reference to the accompanying drawings. For example, the present invention uses several hundreds of fixed read heads,
The information recorded on the TR tape is fetched in the tape running direction, and the fetched information (signals) are sequentially joined to restore the signal recorded on each recording track as a continuous signal.

As described above, in the reproducing apparatus of the present invention, it is necessary to arrange several hundred extremely fine reproducing heads in the width direction of the tape. Using a (Magnetoresistive) head makes it possible to process heads in the order of microns and to accumulate hundreds of heads, which makes it possible to rotate a rotating reproducing head at high speed as conventionally thought. It is possible to reproduce a signal recorded at an arbitrary speed without depending on an appropriate head speed. Therefore, if the magnetic reproducing device of the present invention is used,
When performing non-linear system editing work, the material can be copied to the non-linear system in a very short time.

In the current VTR, recording is performed with a magnetic head having a predetermined azimuth angle (± α) in order to prevent interference of reproduced signals. Here, recording is performed using a fixed head according to the present invention. In order to facilitate understanding of the principle of signal reading, a signal extracting operation will be described for a case where the azimuth angle is zero (that is, azimuth recording is not performed).

FIG. 1 schematically shows a recording pattern on a magnetic tape (VTR tape) and an arrangement example of a reproducing head according to the present invention when the azimuth angle is zero. In the figure, only three fixed reproducing heads (only heads are shown in the figure) are shown, but there are cases where the number reaches several hundred as described above. Further, FIG. 1 shows only two recording tracks on the tape, but these are naturally infinitely adjacent to each other.

In one embodiment of the present invention, a plurality of fixed reproducing heads are arranged on a head mounting axis (see FIG. 1), and the head mounting axis is a line perpendicular to the recording track on the tape. That is, it is a line inclined by the track inclination angle θ with respect to the width direction of the magnetic tape. In other embodiments of the present invention, a plurality of fixed reproducing heads are not arranged on the above-mentioned head mounting axis, but the arrangement of the plurality of fixed reproducing heads in that case will be described later.

The operation of signal extraction by the plurality of fixed reproducing heads will be described below in the case where the reproducing head is arranged on the head mounting shaft shown in FIG. Now, it is assumed that the signal of the upper recording track of the two recording tracks is extracted. As shown in the drawing, signals in the range indicated by l can be extracted by the reproducing head, signals in the range indicated by m can be extracted by the reproducing head, and signals in the range indicated by n can be extracted by the reproducing head. It can be seen that the signals on the recording tracks can be completely extracted by these fixed reproducing heads by adding additional heads above the reproducing head and below the reproducing head on the mounting shaft.

In FIG. 1, the distance c between the heads is a length of a line segment projected on the head mounting axis by moving both ends of the recording signal forming the recording track in the longitudinal direction of the magnetic tape. (Μm) and the width of the reproducing head is b (μm)
Then, it can be expressed by the following equation (1). c ≦ ab (μm) (1) Further, the arrangement interval of the reproducing heads is set to the maximum value of c (that is,
By setting (the interval at which the equal sign of the equation (1) holds), all signals on the magnetic tape can be extracted with the minimum number of heads.

Next, even when the azimuth angle is not zero, the head mounting axis may be arranged on a line orthogonal to the recording track on the tape, similarly to the case where the azimuth angle is zero. This will be described with reference to FIG.

FIG. 2 shows a case where a signal is extracted by applying the present invention to a normal magnetic tape (including one recorded by a digital D3-VTR) recorded at an azimuth angle ± α. . In particular, in the case of D3-VTR,
The azimuth angle indicated by ± α is ± 20 degrees, and the track inclination angle θ is 5 degrees. Also in this case, by arranging the reproducing head on the head mounting axis inclined by the track inclination angle θ (= 5 degrees) with respect to the width direction of the magnetic tape (this agrees with the recording track at right angles), All the signals on each recording track can be taken out under the same conditions (sensitivity) by the fixed reproduction head.

The reason is that, since the recording track has an inclination angle of θ, the recording signal on the track, as shown in FIG.
(3) Equation (θ + α) axis (2) (θ−α) axis Recorded with the angle of (3). Therefore, by setting the mounting axis of the reproducing head to the illustrated axis represented by a line inclined by the track inclination angle θ with respect to the width direction of the magnetic tape,
The angle at which the recording signal intersects with the reproducing head (strictly speaking, the angle at which the recording signal intersects with the gap of the reproducing head in each direction)
As shown in the following equations (4) and (5), (θ + α) −θ = + α (4) (θ−α) −θ = −α (5) It is possible to extract signals under the same conditions.

In the case of azimuth recording, as shown in FIG. 3, which schematically shows a recording pattern on a magnetic tape and an arrangement example of a reproducing head according to the present invention, as shown in FIG. The length a of a line segment obtained by moving both ends of the magnetic tape in the longitudinal direction of the magnetic tape and projecting it on the head mounting axis is a recording track recorded at an azimuth angle α and a recording track recorded at an azimuth angle −α. Now, Figure 3
As can be seen from FIG. 2, the lengths of the line segments obtained by moving both ends of the recording signal of the recording track in the longitudinal direction of the magnetic tape and projecting them on the line in the width direction of the tape are h1 and h2 (h, respectively).
Since 1 <h2), two values are taken.

In this case, the shorter value of the line segment length a (that is, the value of a corresponding to the line segment length h1) is adopted.
The arrangement interval of the reproducing heads may be set to a value of c that satisfies the expression (1). Conversely, by making such settings, all recording signals can be extracted.

In order to obtain a continuous signal for each recording track (corresponding to reproducing the recording information of an arbitrary recording track) from the recording signals extracted as described above, as described with reference to FIG. Playback head,
, Must be sequentially connected in a time-division manner.

FIG. 4 shows this situation over time. As can be seen from FIG. When a signal on a specific recording track is reproduced, the signals at the start point and the end point of the recording signal extraction by one reproducing head, if that head, each head must be overlapped and the same signal must be reproduced simultaneously. Take it out. 2. The bit length extracted from the recording signal extraction start point to the end point is
It has a unique bit length depending on the arrangement of the reproducing head.

FIG. 5 shows that when a plurality of fixed reproducing heads take out signals of a specific recording track from a magnetic tape in the order shown in FIG. 4, one reproducing head continuously outputs signals for one recording track. As an example, what kind of information the time length and the timing for taking out are taken into the magnetic tape is shown. However, this is merely an example, and may be performed by another method.

First, there is a time length t in which one reproducing head continuously takes out a signal for one recording track. As shown in FIG. 5, the effective track width is L (mm). When the number of fixed reproducing heads is n and the running speed (tape speed) of the magnetic tape is v (mm / sec), it is given by the following equation (6). t = L / (n · v · tan θ) (sec) (6) When the above-described equation (1) for giving the reproducing head interval is applied, the following equation (7) is obtained. t <(ab) · 10 ⁻³ / (v · tan θ) (sec) (7) However, the unit of a and b is μm, and v is mm.

As shown in FIG. 5, since a time code for editing and a control track (CTL) signal for tracking are recorded on the magnetic tape, signal processing is performed based on these signals. , The signal indicating the time length t can be reproduced.

A plurality of fixed reproducing heads simultaneously take out recording signals from each recording track in units of the time length t, and
These fetched signals are once written as signal pieces into a μ-CPU controlled storage device called a block junction (to be described later), and a large number of the time lengths t (the respective reproducing head directions, time The control system for obtaining a continuous reproduction signal of a sequential recording track from the signal fragment of the direction）) takes out the written signal fragment from another adjacent reproduction head every time the time length t elapses. The writing and reading of the storage device are controlled so as to be connected to the read signal pieces and read.

FIG. 6 is a block diagram showing an embodiment of the magnetic reproducing apparatus of the present invention for performing the above-described control and obtaining a continuous reproduced signal. In the embodiments described below, signals are reproduced at high speed from a digitally recorded magnetic tape. In FIG. 6, a signal taken out from a recording track of a magnetic tape by each reproducing head 1 forms a waveform, and is then passed through a waveform shaping circuit 2 for restoring "1" and "0" signals by a clock signal. Block joint 5
For example, 32 to 64 adapted to the storage device constituting
The signal is sent to a serial / parallel conversion (S / P conversion) circuit 3 for conversion into a bit parallel signal.

As soon as the conversion into the parallel signal is completed, S
The / P conversion circuit 3 outputs a write request to the block joining section 5. From S / P conversion circuit 3 to block junction 5
The solid line indicates the parallel signal, and the broken line indicates the write request signal.

The block connecting section 5 is composed of a storage device controlled by the μ-CPU, and is taken out by all the reproducing heads 1 into all the memory areas specified by the memory addresses, and S / P-converted signals are written therein. . In FIG. 6, the storage state of the signal in the memory area is indicated by a broken line including a partial solid line extending in the horizontal direction for each reproducing head, and the horizontal direction represents time. , Are signal pieces having a time length t continuously taken out by the above-described reproducing heads for one recording track. A section indicated by a solid line indicates that a signal extracted from a specific recording track by each reproducing head is stored at the address. Therefore, by sequentially reading out the signal pieces stored in the portion indicated by the solid line (in the order of the reproducing head) to obtain continuous signals, the signal of a specific recording track is completely restored as a continuous signal. At this time, since the same signal is always included before and after the point corresponding to the head switching (see FIG. 5), it is necessary to remove unnecessary signals. The same applies to the restoration of the signal of another recording track.

In the block joining section 5, the address sequence of writing and reading to and from the memory follows a predetermined program, and the timing is such that the control track (see FIG. 5) recorded on the magnetic tape is shown in FIG. 4
A signal obtained by scanning with a CTL head (abbreviation of a CTL signal reproducing head) (when this signal is also supplied to the block joining section 5, the waveform shaping circuit 2 and S / P conversion circuit is a parallel signal of "1" and "0"). The reproduction signal is sequentially restored in this manner. However, if the memory becomes full with the written signal (signal piece), the signal written at the old time should have been already read. It is assumed that writing is performed again from the area of the first address. As described above, the block junction is an endless storage device for writing and reading signals.

In this embodiment, the block joint 5
And three signals processing circuits (for example, the signal processing circuits 10 surrounded by a dashed frame in FIG. 6) are used, and the signals taken out from all the reproducing heads (for example, 192 to 384) are divided into three groups. Process. Each is a unit for processing a signal in units of 64 to 128 reproducing heads. By dividing the signal into a plurality of units and processing the signals, the concentration of the wire on each unit is reduced, and the speed of the entire system is increased.

Such a circuit that combines the outputs of three identical signal processing circuits 10 (readout signals from the respective block joints 5) to finally produce a continuous information signal (video signal) is entirely formed. This is the joint 6. An arrow indicated by a two-way broken line connecting the entire joint 6 and the block joint 5 in each signal processing circuit 10 causes the entire joint 6 to notify each signal processing circuit 10 of "start of reproduction" and the like. The signal processing circuit 10 gives a trigger to start S / P conversion, parallel signal fetching, and the like, and sends a signal write request from each signal processing circuit 10 to the entire junction 6.

Further, the signal processing circuit 10 starts operation simultaneously by using this signal and the control track signal as a trigger to synchronize the signal processing circuits 10 and each signal processing circuit 10 processes a signal on the same recording track. Will be able to do it. The solid arrows from the block joints 5 to the entire joints 6 in the respective signal processing circuits 10 are lines for supplying the signals that have been joined at the respective block joints 5 to the entire joint 6. The entire joint 6 is composed of a μ-CPU, has a memory like the block joint 5, and writes a signal (here, a signal piece) connected by each block joint 5 into the memory. , And finally output a continuous signal by reading in a pre-programmed order. This signal is sent to a parallel / serial (P / S) conversion circuit 7, and a high-speed reproduced video signal in the form of a serial signal (when the magnetic tape is run at high speed) is obtained. The VTR start information supplied to the entire joint 6 is information such as "reproduction start" obtained from the system.

In the above description, a plurality of fixed reproducing heads (reproducing heads) are arranged at regular intervals on a line orthogonal to the recording track of the magnetic tape. However, in the magnetic reproducing method and apparatus of the present invention, a plurality of fixed reproducing heads (reproducing heads) are provided. The fixed reproducing heads may be moved in the longitudinal direction of the tape from equidistant positions on a line perpendicular to the recording tracks of the magnetic tape to be arranged at positions perpendicular to the head mounting axis.

FIGS. 7 and 8 show charts of the arrangement of the reproducing heads in the magnetic reproducing apparatus of the present invention having the above-mentioned configuration and a chart showing when some of the arranged reproducing heads are used. In FIG. 7, the head mounting axis in this case is a line parallel to the recording track (in FIG. 7, the head indicated by the broken line does not exist). In this case, as can be seen from FIG. 8, a conventional rotary head type magnetic recording / reproducing system in which all the heads reproduce a recording signal of a certain track, and after completing the recording signal, start reproducing the next track. The operation is similar to the signal reproduction by the device. However, even in this configuration, the tape running speed of the magnetic tape can be adjusted arbitrarily, and a conventional rotary head type magnetic recording / reproducing apparatus (for example, a digital D-3)
VTR) enables high-speed reproduction that cannot be achieved.

Even when a reproducing head (reproducing head) is arranged as shown in FIG. 7, the hardware shown in FIG. 6 can be applied to the configuration of an apparatus for reproducing a video that is finally continuous from a magnetic tape (see FIG. 6). However, the software that determines the signal reading order is different.) In this case, the signal pieces on the same recording track indicated by the solid lines at the block connection portion can be understood with reference to FIG. 8 (in the case of FIG. 6, FIG. 4).
Should correspond to one column). Accordingly, signal joining becomes easy, but the arrangement of a large number of reproducing heads with high accuracy on the head mounting axis is better if they are arranged on an axis perpendicular to the recording track (in the case of FIG. 3). it is conceivable that.

[0040]

According to the prior art for reproducing a signal from a magnetic tape at a high speed, the rotation of a reproducing head (rotating head) and the speed of a tape running system are increased, and the signal is reproduced by the recorded head itself. Depending on the method, 1/4
A device that reproduces a signal that has been compressed to a degree at a quadruple speed has just entered a practical stage. Further, in order to reproduce a signal recorded in an uncompressed state at a high speed, the magnetic tape and the head system are seriously damaged, and it is difficult to realize the signal in the future.

According to the present invention, signal reproduction is shared by hundreds of reproduction heads, and reproduction is performed by a fixed head. Therefore, damage to the tape head system is small, and it is simple, inexpensive, and in principle. The present invention enables a signal to be reproduced at an arbitrary speed, thereby realizing high-speed copying to a non-linear system, which has been a concern, and greatly contributing to an improvement in efficiency in the total editing work.

[Brief description of the drawings]

FIG. 1 schematically shows a recording pattern on a magnetic tape and an arrangement example of a reproducing head according to the present invention when the azimuth angle is zero.

FIG. 2 shows a case where the present invention is applied to a normal magnetic tape recorded at an azimuth angle ± α to perform signal extraction.

FIG. 3 schematically shows a recording pattern on a magnetic tape and an arrangement example of a reproducing head according to the present invention when the azimuth angle is ± α.

FIG. 4 shows a situation where signals taken out from the reproducing heads are sequentially connected in a time-division manner.

FIG. 5 shows an example in which a time length and a timing in which one reproduction head continuously takes out a signal for one recording track are recorded on a magnetic tape (recorded as a CTL signal).

FIG. 6 is a block diagram showing one embodiment of the magnetic reproducing apparatus of the present invention.

FIG. 7 shows an example in which a plurality of fixed reproducing heads are moved in the longitudinal direction of the tape from equidistant positions on a line orthogonal to the recording tracks of the magnetic tape and arranged at positions intersecting the head mounting axis. I have.

FIG. 8 shows a situation in which, when a plurality of fixed reproducing heads are arranged according to FIG. 7, the signals respectively taken out from the reproducing heads are sequentially connected.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 reproduction head (head) 2 waveform shaping circuit 3 serial / parallel (S / P) converter 4 control track (CTL) head 5 block junction (storage device) 6 whole junction 7 parallel / serial (S / P) conversion Unit 10 Signal processing circuit

Claims (5)

[Claims] 1. A method for reproducing recorded information from a magnetic tape recorded by a VTR using a plurality of fixed reproducing heads, wherein the recorded information is recorded at equal intervals on a line orthogonal to a recording track of the magnetic tape. The plurality of fixed playback heads are arranged so as to be respectively taken out, and in a tape running state, the recording information taken out by each of the playback heads is written to a recording device, and the written signal for each of the playback heads is written. A method for reading recorded information of an arbitrary recording track by reading out a signal written with a time lag sequentially for each predetermined time length and forming a continuous signal. . 2. A method for reproducing recorded information from a magnetic tape recorded by a VTR by using a plurality of fixed reproducing heads, wherein each of the information is read from equally spaced positions on a line orthogonal to a recording track of the magnetic tape. The plurality of fixed reproducing heads are arranged such that the position is moved in the longitudinal direction of the tape so that recording information is respectively taken out at a position intersecting a head mounting axis parallel to the recording track, and in the tape running state, By writing the recording information taken out by the reproducing head to a storage device, and reading out the simultaneously written signals among the signals written for each of the reproducing heads for a predetermined time length into continuous signals, A magnetic reproducing method characterized by reproducing recorded information of an arbitrary recording track. 3. An apparatus for reproducing recorded information from a magnetic tape recorded by a VTR using a plurality of fixed reproducing heads, wherein the recorded information is recorded at equally spaced positions on a line perpendicular to the recording tracks of the magnetic tape. In the tape running state with the plurality of fixed playback heads arranged so as to be respectively taken out, the recording information taken out by each of the playback heads is written, and among the signals written for each of the playback heads, sequentially. A magnetic reproducing apparatus comprising at least a storage device for reproducing recorded information of an arbitrary recording track by reading out a signal written with a time lag for each predetermined time length and forming a continuous signal. . 4. The magnetic reproducing apparatus according to claim 3, wherein
The plurality of fixed reproducing heads move both ends of respective recording signals constituting recording tracks adjacent to each other in the longitudinal direction of the magnetic tape and project them on a line orthogonal to the recording tracks, and cut out corresponding to the both ends. A is the shorter of the two line segments obtained, and b is the width of the fixed read head.
Wherein the magnetic reproducing devices are arranged at equal intervals with an interval equal to or shorter than ab = c. 5. A device for reproducing recorded information from a magnetic tape recorded by a VTR using a plurality of fixed reproducing heads, wherein each of the devices reproduces recorded information from an equidistant position on a line orthogonal to a recording track of the magnetic tape. A plurality of fixed reproducing heads arranged so that recording information is respectively taken out at a position intersecting a head mounting axis parallel to the recording track by moving the position in the longitudinal direction of the tape; By writing the recording information taken out by the reproducing head and reading out the simultaneously written signals among the written signals of the respective reproducing heads for a predetermined time length so as to be continuous signals, any desired recording can be performed. A magnetic reproducing apparatus comprising at least a storage device for reproducing recorded information of a track.