JPH07110986A - Information reproducing apparatus - Google Patents

Abstract

PURPOSE:To obtain an information reproducing apparatus in which a tracking pulling-in operation and a frame synchronization operation are performed at high speed to a multisegment-recorded tape and whose responsivity is excellent. CONSTITUTION:A tape drive part 7 runs a tape. A tracking-error detection part 5 detects a tracking error on the basis of the reproducing signal of a head 2a on a cylinder 3. A pilot discrimination part 6 detects and discriminates a pilot signal which is contained mainly in the reproducing signal of a head 2b. A tracking part 12 adjusts the tape drive of a tape drive part 7 on the basis of a tracking-error signal and a discrimination signal, and it controls a tracking operation. A track-number detection part 14 detects a track number contained in the reproducing signal. A correction-amount detection part 15 compares a reproduced track number with a reference frame number, and it outputs the number of phase-difference tracks. A phase correction part 16 corrects the phase of a reproducing frame by the tape drive part in such a way that a phase-difference track number becomes a prescribed value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reproducing apparatus for reproducing an information signal recorded as a diagonal track on a magnetic tape by a rotary head.

[0002]

2. Description of the Related Art In an information reproducing apparatus such as a video tape recorder for reproducing an information signal recorded on a tape as an oblique track, a helical scan is usually performed by a rotary head. At that time, in order to obtain a reproduction signal correctly, tracking control is required to control the scanning position so that the head traces each track accurately. The ATF method is known as one means for this.
For example, Japanese Unexamined Patent Publication No. 4-285746 discloses an example in which two types of tracking pilot signals having different frequencies are frequency-multiplexed with a data signal and recorded on a track on a tape, and the tracking control is performed using this. There is. Further, the tape reproduction phase is corrected so that the reproduction frame detected by the track number recorded on the track is synchronized with the reference frame.

[0003]

In such an information reproducing apparatus, when the reproduction is started, it is necessary to perform the pulling operation of the tracking control. If the transient response time to complete the pull-in operation at this time is long, the time from the operation to instruct playback start to the actual playback start becomes longer,
This will deteriorate the responsiveness of the device. By the way, in the conventional information reproducing apparatus using the pilot signal,
Since the tracking error detection characteristics are S-shaped characteristics having zero-cross points (equilibrium points) having different polarities, when pulling-in is started from an unstable zero-crossing point where the control polarities do not match, it takes a long time to complete pulling-in. .
As a result, there is a problem that it takes a long time to see the synchronization of the frame phase.

In view of the above problems, it is an object of the present invention to provide an information reproducing apparatus having excellent responsiveness by shortening a transition time to a reproducing state by speeding up tracking pull-in and frame synchronization.

[0005]

In order to solve the above-mentioned problems, an information reproducing apparatus of the present invention has a cyclically M track (where M is an even number of 4 or more) cycles of two or more different frequencies. Tracking pilot signals are selectively recorded, and 1-frame data is recorded on the H track (here, H track
Is an information reproducing apparatus for reproducing a signal by rotationally scanning a head mounted on a rotary cylinder with respect to a tape medium segment-recorded by dividing into 5 or more and a non-integer multiple of M). A tape driving means for driving the tape medium, a first head attached to the rotary cylinder, and a scanning locus of the first head attached to the rotary cylinder and one track or approximately one track. A tracking pilot signal amplitude is detected from the reproduction signal of the second head that scans at a position displaced in the width direction and the reproduction signal of the first head, and based on this, the tracking pilot mainly included in the reproduction signal of the first head. From the reproduction signal of the second head, and pilot detection / identification means for obtaining an identification signal identifying
Tracking error detection means for detecting the tracking pilot signal amplitude recorded on both tracks adjacent to the scanning track and creating and outputting a tracking error signal based on the tracking pilot signal amplitude, and the tape driving means by the tracking error signal and the identification signal. Tracking means for operating and performing tracking control; reference signal generating means for generating a reference frame signal; and the first head or the second head
Track number detecting means for detecting the track number in the 1-frame data included in the reproduction signal from the head of the head to obtain a number detection signal, and the phase detection track number by comparing the number detection signal with the reference frame signal. And a phase correction means for correcting the phase using the tape driving means so that the number of the phase difference tracks of the correction amount detection means becomes a predetermined value.

In the information reproducing apparatus of the present invention, two or more kinds of tracking pilot signals having different frequencies are selectively recorded cyclically in a cycle of M tracks (where M is an even number of 4 or more). Moreover, a head mounted on a rotary cylinder is rotationally scanned with respect to a tape medium in which one frame data is divided into H tracks (where H is 5 or more and an integer that is a non-integer multiple of M) and is segment-recorded. An information reproducing device for reproducing a signal by performing a tape drive means for driving the tape medium, a first head attached to the rotary cylinder, and a first head attached to the rotary cylinder. Head scanning locus and 1
A second head that scans a track or a position displaced by approximately one track in the track width direction, and a tracking pilot signal amplitude is detected from a reproduction signal of the first head, and reproduction of the first head is performed based on the detected amplitude. Pilot detection / identification means for obtaining an identification signal for identifying the tracking pilot signal mainly contained in the signal, and the tracking pilot signal amplitude recorded on both tracks adjacent to the scanning track from the reproduction signal of the second head, Tracking error detecting means for producing and outputting a tracking error signal based on this; tracking means for operating the tape driving means by the tracking error signal to perform tracking control; and reference signal generating means for generating a reference frame signal, Whether the first head or the second head Track number detecting means for detecting a track number in the 1-frame data included in the reproduction signal to obtain a number detection signal, and comparing the number detection signal with the reference frame signal to detect the number of phase difference tracks. Correction amount detecting means; and phase correcting means for correcting the phase by using the tracking means and the tape driving means so that the phase difference track number becomes a predetermined value based on the phase difference track number and the identification signal. It was done.

[0007]

With the above-described structure, the present invention can perform tracking control by selecting a tracking polarity that is stable at the reproduction position based on the identification signal and the tracking error signal detected from the reproduction signal. Further, even after the reproduction phase is corrected to set the number of phase difference tracks to a predetermined value, the tracking polarity can be adjusted to the corrected reproduction phase and stable tracking control can be immediately performed.

Further, the identification signal and the number of phase difference tracks are detected, the reproduction phase is corrected based on the detected number of phase difference tracks, and the corrected reproduction phase is stabilized by the identification signal and the number of phase difference tracks. The tracking polarity can be selected.

[0009]

Embodiments of the information reproducing apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an information reproducing apparatus according to an embodiment of the present invention. In the figure, 1 is a magnetic tape, 2a and 2b are magnetic heads having different azimuth angles, 3 is a cylinder, 4 is a cylinder control unit, 5 is a tracking error detection unit, 6 is a pilot detection identification unit, and 8 is a capstan. A control unit, 9 is a capstan motor, 10 is a capstan, 11 is a pinch roller, 12 is a tracking unit, 13 is a switch, 14 is a track number detection unit, 15 is a correction amount detection unit, 16 is a phase correction unit, and 17 is a phase correction unit. It is a reference signal generator. The block 7 surrounded by a broken line constitutes a tape drive unit. Next, the information reproducing apparatus configured as described above will be described.

First, the tracking control operation will be described. The heads 2a and 2b are mounted on the cylinder 3 at positions facing each other by 180 degrees at the same height with respect to the rotating surface. The cylinder 3 is rotated by a built-in motor (not shown), and the heads 2a and 2b scan the tape 1 wound around it. The cylinder control unit 4 controls the speed phase of the cylinder 3 so that the rotation of the cylinder is synchronized with the reference rotation signal 28 supplied from the reference signal generation unit 17. Further, the cylinder control unit 4 detects the rotation phase of the cylinder and outputs a head switching signal (hereinafter abbreviated as HSW signal) 23 for identifying the head during tape scanning. The HSW signal is a binary signal with a duty of 50%, and at a high level, the head 2a corresponds to a period in which the head 2b scans the tape at a low level.

FIG. 2 schematically shows a track pattern recorded on the tape 1. The symbols "f1" and "f2" shown in each diagonal track indicate the type of the tracking pilot signal recorded in the data superposed on the track. That is, the first tracking pilot signal (f1) and the second tracking pilot signal (f2) having a frequency different from the first tracking pilot signal are alternately recorded every other track. Further, "-" indicates that the tracking pilot signal is not recorded.

Also, the numerical value shown at the bottom of the track indicates the track number recorded in the track. In this example, one frame of data is divided and recorded in segments of 10 tracks, and each track is identified by track numbers 0-9. The track number is recorded at a specific place in the track data. Further, since the cycle (4 tracks) in which the frequency of the tracking pilot signal makes one round is not in an integral multiple relationship with the number of tracks (10 tracks) forming the frame, the tracking pilot signal at the beginning of the frame is "-, f1". A frame starting with
Frames starting with "-, f2" appear alternately. Also, the tracks with even track numbers are heads 2a.
And the tracks of odd track numbers have the same azimuth angle as the head 2b.

Tape 1 having tracks formed in this way
Is wound around the cylinder 3 for a period of about 180 degrees, sandwiched between the capstan 10 and the pinch roller 11, and runs in the longitudinal direction thereof. The speed of the rotation of the capstan motor 9 directly connected to the capstan 10 is controlled by the capstan controller 8 so that the tape 1 advances by one track during the half rotation period of the cylinder 3.

The tracking error detector 5 detects the relative shift amount between the head and the track from the tracking pilot signal included in the reproduction signal 22 from the head 2a,
The tracking error signal 24 corresponding to this is output.
FIG. 4C shows the amplitude of the tracking pilot signal included in the reproduction signal when the scanning position of the head is taken on the horizontal axis. The broken line indicates the track boundary, and the type of recorded tracking pilot signal is shown on the upper part. The tracking error detector detects the amplitudes of the f1 and f2 components included in this reproduced signal, and outputs the difference (f1 component amplitude−f2 component amplitude) as a tracking error signal 24. The specific configuration is as shown by the broken line portion 5 in FIG. That is, the detectors 40 and 41 for detecting the amplitudes of the f1 and f2 components and the difference device 42 for obtaining the difference between the detection outputs are included. Further, for example, the detector 40
Is composed of a bandpass filter having a center frequency at frequency f1 and an AM detection circuit for detecting the output amplitude of the bandpass filter. The same applies to the detector 41. The tracking error signal is shown in FIG.
The detection characteristic as shown in (d) is shown.

The tracking unit 12 processes the tracking error signal 24 and supplies it to the tape drive unit 7 to perform tracking control so that the tracking error signal 24 is finally set to zero. However, as is apparent from the track pattern of FIG. 2, the tracking pilot arrangements of the adjacent tracks are alternated for each scanning of the head 2a, so that the polarities of the tracking error signals are reversed like the scanning positions a1 and a2 shown in FIG. To do. Therefore, in order to make the control polarity constant, the polarity of the tracking error signal is inverted (switched between inverted and non-inverted) every scanning of the head 2a, and then added to the speed control system of the capstan in the tape drive unit 7.

By the way, the scanning state shown in the lower part of FIG. 4, that is, the head 2a has a1, a2, ..., And the head 2b has b.
Depending on which scan a1 or a2 is inverted and used in the state of sequentially scanning positions 1, b2, ..., Even if the tracking error signal is 0 as well, the polarity is completely inverted as a control system. To do. That is, one is stable, but the other is unstable, and if left unattended, a pulling operation occurs up to a position of two tracks and opposite polarity, and finally a stable state is achieved. In addition, in that case, a very long time is required as compared with the case where the tracking error signal pulls in a linear range with respect to the head position deviation. It cannot be determined from the reproduction signal 22 from the head 2a whether it is at a stable point or at an unstable point.

However, in the reproduction signal 21 of the head 2b, the tracking pilot f1 is generated at the scanning position b1.
However, since the tracking pilot f2 is dominant at the scanning position b2, it is possible to distinguish between these two states. The pilot detection / identification unit 6 receives the reproduction signal 21 from the head 2b, identifies the tracking pilot signal mainly contained therein, and identifies the result as an identification signal 25.
Output as. The configuration is, for example, as shown in FIG.
(Equal to the above) and a pilot identification unit 12 that determines the level (positive / negative) and outputs the result as an identification signal. The detection characteristics of the resulting identification signal are
For example, it becomes as shown in FIG. That is, it is shown that f1 is dominant at the high level and f2 is dominant at the low level. Further, the pilot detection / identification unit 12 holds the output near the scanning end of the head 2a during the period in which the reproduction signal from the head 2b is not obtained, that is, during the scanning period of the head 2a.

The tracking unit 12 switches the control polarity according to the value of the identification signal 25. An example of the configuration of the tracking unit 12 is shown by the broken line portion 12 in FIG. Inversion / non-inversion is not performed every cylinder rotation, and the identification signal 2
5 and the switching phase is corrected so that inversion / non-inversion switching has a predetermined relationship. The polarity of the tracking error signal 24 is inverted by the inversion circuit 43, the tracking error signals before and after the inversion circuit are switched by the switch 44, and the switch output 32 is sent to the tape drive unit 7. The HSW signal 23 is input to the frequency dividing circuit 45, is divided into a frequency of 1/2, and switches the switch 44 through the ex-or gate 46. As a result, the polarity is switched every time the head 2a is scanned, and the tracking error signal becomes a signal having a constant polarity. Therefore, it is assumed that the addition polarity of the tracking error signal in the tape drive unit 7 is set so that the tracking control becomes stable when the output 49 of the gate 46 has the same phase as the identification signal 25. Also,
Here, it is assumed that the input signal 26 has a fixed value. Gate 4
The output 49 of 6 is compared with the identification signal 25 by the comparison circuit 48. If the phases do not match, the tracking control is unstable. Therefore, the comparator circuit output 50 is inverted to invert the other input of the gate 46 and the switching polarity, that is, the tracking error signal 32 sent to the tape drive unit 7. Reverse the polarity of.

At this time, when the identification signal 25 and the inversion / non-inversion switching do not have a predetermined relationship, the switching polarity is corrected after confirming that the state has been maintained for a certain period. Good. Although not shown, this is a comparison circuit 48 for comparing a pulse signal (for example, a reference rotation signal) having a predetermined rate.
It is a logic that can be easily realized by a configuration in which the gate is output based on the result of the comparison, the gate output is counted by the counter, the predetermined count value corresponding to the confirmation period is decoded and detected, and the output of the comparison circuit is inverted. This makes it possible to avoid instability (erroneous determination due to noise) of the identification signal 25 when the tracking is deviated and the tracking pilot signal level in the reproduced signal is low, which is preferable from the viewpoint of operation stability. However, the entire pull-in operation time is required to be long only during the confirmation period.

A simpler configuration of the tracking section 12 is shown in FIG. Inversion / non-inversion is set directly from the value of the identification signal. With this configuration, the polarity reversal operation in the tracking unit is always in a stable control state.

Further, even when the scanning position is deviated from the positions a1 to b2 in FIG. 4, the identification signal 25 has the same value in the range of ± 1 track as shown in FIG. Always goes to the closer zero-cross point. That is, the tracking pull-in is always performed in the shortest path, and the time required for it is also shortest.

In the construction of the pilot detection and identification section 6, the tracking error detection section 51 of FIG. 5 is different from the tracking error detection section 5 only in its input, and the operation is the same. Moreover, in the configuration of this embodiment, the heads 2a and 2b alternately scan the tape. Therefore, the input may be switched to the time division like the reproduction signal 33, and the output may be used in the time division. As a result, these two blocks can be shared and the configuration can be simplified.

Next, the frame synchronization operation will be described. First, the track number detector 14 extracts the track number from the reproduction signal 33 and outputs the number detection signal 30. As the reproduction signal 33, the reproduction signals 21 and 22 from the two heads 2a and 2b are input to the switch 13, and the HSW signal 2
It is a signal switched by 3. The switch 13 always selects the reproduction signal from the head on the side reproducing the tape. The specific configuration method of the track number detection unit 14 is as follows.
Since it depends on the method of recording the track number on the track, its details are not mentioned here. In the case of a tape in which data is divided into small blocks (sync blocks) and recorded on a track, and a track number is recorded as ID information for each sync block, clock extraction and data reproduction (2 (Value conversion), sync detection, etc., and the track number information embedded in a specific location in the data is extracted.

In the correction amount detector 15, the number detection signal 30 and the reference frame signal 29 generated by the reference signal generator 17 are output.
Is input, the reproduction frame phase indicated by the number detection signal 30 and the phase of the reference frame signal 29 are phase-compared, and the difference between the comparison result and a predetermined phase difference (here, 0) is used as the phase difference track number 31. Output as. The simplest is Figure 7.
As described above, it can be realized by latching the number detection signal 30 with the reference frame signal 29. FIG. 6 shows the operation in that case. (A) is an HSW signal and (b) is a reference frame signal. (C) shows the number detection signal at every moment when the phase difference is 0 (here, the reproduction track number itself). The rising edge of the reference frame signal and the scanning period of track number 0 match. (D) to (g) show reproduction track numbers when the phase difference is not zero. The number of phase difference tracks in each case is shown by the numerical value at the right end.

Using these values, the phase correction unit 16 corrects the phase between the reproduction frame phase indicated by the number detection signal and the reference frame signal so that the phase becomes a predetermined value (here, the phase difference is 0). However, it is premised that the tracking control is performed stably. First, FIG. 6 (c)
If the phase difference is 0, as shown in, this does not need to be corrected. Next, if the number of phase difference tracks in (d) is 8, it is possible to synchronize by advancing the tape side by two tracks. However, the control polarity of the tracking error signal is inverted before and after correction. When the number of phase difference tracks in (e) is 6, it is possible to synchronize by advancing the tape phase by 4 tracks. In this case, the polarity of the tracking error signal 24 is the same before and after correction, and it is not necessary to operate it.
When the frame phase difference signal in (f) is 4, the tape phase can be delayed by 4 tracks for synchronization. Also in this case, the polarity of the tracking error signal does not change before and after the correction. When the number of phase difference tracks in (g) is 2, 2
It is possible to synchronize with the reference frame signal by delaying the tape phase only by the track. In this case, the control polarity of the tracking error signal is inverted before and after correction.

A specific means for performing the correction is not particularly limited, but an example of performing the correction by operating the target speed of the tape drive unit 7 will be described here with reference to FIGS. 8 and 9. FIG. 8 shows an example in which the reproduction frame phase is advanced by two tracks. (A) shows the reference rotation signal 28, (b) shows the target speed of the tape drive means, and (c) shows the actual tape speed change. In normal reproduction (× 1), the tape runs for two tracks in one cylinder rotation period, that is, in one cycle of the reference rotation signal, but it is the same by temporarily changing this to 3/2 times (× 1.5). You can advance 3 tracks in a period. Therefore, the tape speed is changed to 3/2 times only during the rotation period equal to the number of tracks to be advanced (in this case, two rotation periods = two reference rotation signal cycles). However, since the actual speed control system has some response delay as shown in (c), it is necessary to allow for a minute deviation.

On the contrary, FIG. 9 shows an example in which the reproduction frame phase is delayed by 4 tracks. The concept is the same as that of FIG. 8 except that the target speed is halved. The correction operation is completed by reducing the speed to 1/2 speed for four rotation periods.

The above series of operations of the phase correction unit 16 can be easily realized as a series of procedures by software by the processor. FIG. 10 is a flow chart showing an example of a procedure for starting reproduction when the phase correction unit 16 is composed of a microprocessor. First, in process 100, a speed command (× 1) corresponding to normal reproduction is given to the tape drive unit 7. Next, in process 101, tracking settling is determined. This may simply be configured to wait for a certain period of time, or the tracking error signal 24 may be read (not shown) to directly determine that the value is sufficiently small.

After confirming the settling, the process proceeds to step 102,
The phase difference track number 31 is read, and if the value is 0, the synchronization is completed and the process ends. If not 0, process 1
In 03, the correction time and speed are set from the number of phase difference tracks as described with reference to FIGS. For speed,
The signal 27 changes the target tape speed for the capstan controller 8. The correction time may be set using a built-in timer, or may be a software timer that counts the number of pulses of the reference rotation signal and the HSW signal on software, and the count value is set. Good.

If it is necessary to invert the polarity of the tracking error signal before and after the correction operation, the polarity setting signal 26 is inverted. This is useful when the configuration of FIG. 3A is used as the tracking unit and a delay element (logic for confirming continuity by the counter) is added to the comparison circuit 48. It is not necessary when the configuration of FIG. When the polarity setting signal 26 is inverted, the output of the ex-or gate 47 is inverted in FIG.
The transmission polarity from the output of 5 to the switch 44 is also inverted. That is, the polarity of the output 32 can be inverted. When it is known in advance that the polarity of the tracking error signal 24 is inverted at the corrected position, that is, when the number of phase difference tracks is 8 and 4 in the example of FIG. 6, the polarity setting signal 26
To invert the polarity. As a result, the influence of the delay in detection can be avoided, and the tracking control after correction can be stably pulled in.

Returning to FIG. 10, in process 104, process 10 is performed.
Wait for the time set in step 3, and proceed to step 105.
The speed target for the tape drive unit 7 is returned to x1. After that, the process returns to the process 101, the tracking settling is confirmed, and the number of the phase difference tracks is checked in the process 102. Note that the operation of the tracking control loop is stopped in the tape drive unit 6 (loop open state) from the viewpoint of stabilizing the correction operation while the tape speed is being changed.
However, it is preferable to perform only speed control.

As described above, according to this embodiment, 1
Tracking control is performed by selecting the tracking polarity so that the track is always pulled to a stable point closer to that position, based on the identification signal and the tracking error signal detected by the reproduction signal from the head that reproduces the position deviated from the track. The tracking control can be settled in a short time. Further, even after the reproduction phase is corrected to set the number of phase difference tracks to a predetermined value, the tracking polarity can be adjusted to the corrected reproduction phase and stable tracking control can be immediately performed. Therefore, the state can be swiftly changed from the start of the reproducing operation to the state in which the signal can be actually reproduced (the state in which the phases of the reference frame signal and the reproduction frame are synchronized).

Next, another embodiment will be described. Figure 1
1 is a block diagram showing a configuration in which the state transition is performed at a higher speed by simultaneously advancing the tracking pull-in process and the frame phase correction process in the configuration of FIG. In FIG. 11, the tracking unit 1
2. The configuration is the same as that of FIG. 1 except for the phase correction unit 16. FIG. 12 shows the configuration of the tracking error detector 5 and the tracking unit 12. FIG. 13 is a flowchart showing a procedure for starting reproduction when the phase correction unit 16 is composed of a microcomputer.

The cylinder control unit 4 controls the rotation of the cylinder 3 in synchronization with the reference rotation signal 28, the tape drive unit 7 runs the tape 1 at a constant speed, and the tracking error detection unit 5 detects the tracking error signal. The detection and identification of the tracking pilot signal by the pilot identification unit 6, the track number detection operation by the track number detection unit 14, and the phase difference track number 31 detection operation by the correction amount detection unit 15 are the same as in the example of FIG. is there. However, in operation, in this example, the identification signal and the number of phase difference tracks can be detected without waiting for tracking settling, and the phase correction operation is immediately performed, so it is necessary to add a function for that purpose. When the tracking is not settled, particularly when the tracking error is large, the reproduction signals 21 and 22 cannot be obtained normally, so that the track number detecting section 14 cannot detect the track number. Therefore, in order to prevent the subsequent malfunction, it is possible to determine that the number detection signal 30 is invalid in the undetectable state. For example, in this example, a value other than the correct track numbers 0 to 9 is output to indicate that the output is invalid. Similarly, the correction amount detector 1
In No. 5, when the number detection signal 30 is invalid, a value indicating invalidity is output as the number of phase difference tracks.

The operation of the phase corrector 16 will be described below with reference to the flowchart of FIG. First, in step 100, a speed command (×
Give 1). In process 107, the control polarity at the reproduction position is determined. That is, the identification signal 25 and the switching signal 5
Compare with 3. Before describing this determination operation, the configuration of the tracking unit 12 will be described. The tracking unit 12 has a configuration as shown in FIG. 12, and a signal obtained by dividing the HSW signal 23 by the frequency divider 45 into 1/2 is used as the ex-or gate 4.
The switch 44 is switched through the switch 6. The switching signal 53 is a signal indicating the switching polarity of the switch. Further, the polarity setting signal 26 is given to the other input of the ex-or gate, and the polarity of the switching signal can be inverted. Now, it is assumed that the control loop is set so that the tracking control becomes stable when the identification signal and the switching signal have a predetermined phase relationship, for example, the same phase. Processing 1
At 07, the switching signal 53 and the identification signal 25 are compared to determine the match / mismatch. If they do not match, it takes a long time to pull them in as they are. Therefore, the polarity is set by inverting the polarity setting signal 26.

Next, in step 106, the detection of the number of phase difference tracks is awaited. That is, it waits until the number of phase difference tracks that is not invalid is obtained. In the process 108, if the value of the phase difference track number 31 is 0, the synchronization is completed and the process moves to the process 110. Processing 1
10 will be described later. If it is not 0, in step 107, the correction time and speed are set from the number of phase difference tracks, as described in FIGS. Signal 27 for speed
The target tape speed is changed for the capstan controller 8. The correction time may be set using the built-in timer, or the reference rotation signal or H
A software timer for counting the number of pulses of the SW signal by software may be used and the count value may be set.

Further, here, the polarity setting signal 26 is operated according to the correction amount. That is, when the correction amount is ± 2 tracks, the tracking polarities are inverted before and after the correction, and when the correction amount is ± 4 tracks, the tracking polarities are preserved, so that the tracking is performed stably after the correction.
Specifically, the polarity setting signal is inverted when the correction amount is ± 2 tracks. When the correction amount is ± 4 tracks, the tracking control is stably performed after the correction with the same polarity, and thus no operation is necessary.

In the process 104, the time waited for the time set in the process 109, and in the process 105, the tape drive unit 7
The speed target for is returned to x1. After that, the process returns to step 106 to detect the correction amount, and the number of phase difference tracks is checked in step 108, and if it is 0 (if the correction operation is normally performed, it should be so), The process moves to step 110 and waits for tracking settling. That is, at this point the tracking control has not completely settled,
The tracking control settling is confirmed by, for example, waiting for a time corresponding to the response time of the tracking control loop, or by directly observing the tracking error signal and confirming its convergence. With the above, a series of phase correction operations is completed. From the viewpoint of stabilizing the correction operation, it is preferable that the operation of the tracking control loop in the tape drive unit 6 is stopped (loop open state) and only speed control is performed while the tape speed is being changed.

As described above, according to this embodiment, the pilot detection / identification unit detects the identification signal, and the track number detection unit and the correction amount detection unit detect the number of phase difference tracks, respectively.
The playback phase is corrected based on the number of detected phase difference tracks, and the tracking polarity that becomes stable in the corrected playback phase is selected and set according to the identification signal and the number of phase difference tracks. The phase correction operation can be performed with and the tracking control polarity can be stably pulled in at that position. Therefore, the state can be swiftly changed from the start of the reproducing operation to the state in which the signal can be actually reproduced (the state in which the phases of the reference frame signal and the reproduction frame are synchronized).

The present embodiment is only an example of the present invention. The number of tracks constituting one frame, the recording position of the tracking pilot signal, the method, the head arrangement on the drum, the number of heads, etc. can actually be variously configured.

The configurations of the tracking error detecting means and the tracking means are not limited to those shown in the embodiments. For example, the tracking means may be any one that operates the control polarity according to the recording pattern of the tracking pilot signal and based on the instruction of the phase correction means. Of course, a filter for improving the tracking characteristic such as an integral compensation filter may be included if necessary.

The pilot detection / identification means may be any means as long as it identifies a pilot signal mainly contained in a reproduced signal from a head scanning a position approximately one track away from the head used for tracking error detection. As shown in the example, a part of the configuration may be shared with the tracking error detection means, and the identification method itself is not particularly limited.

The correction algorithm in the phase correction means and the actual phase correction method are not limited to those shown in the embodiments. Various modifications can be made to other configurations.

[0044]

As described above, according to the present invention, two or more kinds of tracking pilot signals having different frequencies are selectively recorded cyclically in a cycle of M tracks (where M is an even number of 4 or more). And, the head mounted on the rotating cylinder is rotated with respect to the tape medium in which one frame data is divided into H tracks (where H is 5 or more and an integer which is a non-integer multiple of M) and is segment-recorded. An information reproducing apparatus for reproducing a signal by scanning, comprising: tape driving means for driving and driving the tape medium; a first head attached to the rotary cylinder; and a first head attached to the rotary cylinder. From the reproduction signal of the first head, and the second head that scans a position shifted by one track or approximately one track in the track width direction from the scanning track of the first head. Detects a ring pilot signal amplitude,
Based on this, pilot detection and identification means for obtaining an identification signal for identifying the tracking pilot signal mainly included in the reproduction signal of the first head, and the reproduction signal of the second head, to both tracks adjacent to the scanning track. Detect the recorded tracking pilot signal amplitude,
A tracking error detecting means for creating and outputting a tracking error signal based on this, a tracking means for operating the tape driving means by the tracking error signal and the identification signal to perform tracking control, and a reference signal for generating a reference frame signal. Generating means, track number detecting means for detecting a track number in the one-frame data included in a reproduction signal from the first head or the second head to obtain a number detection signal, and the number detection signal Correction amount detection means for detecting the number of phase difference tracks by comparing with the reference frame signal, and phase for phase correction using the tape drive means so that the number of phase difference tracks of the correction amount detection means becomes a predetermined value. Since the correction means is provided, the reproduction signal from the head that scans the positions shifted by one track from each other is reproduced. Tracking control can be performed by selecting the tracking polarity so that the position can always be pulled to a stable point closer from that position based on the identification signal and tracking error signal detected from Can be made. further,
Even after the reproduction phase is corrected to set the number of phase difference tracks to a predetermined value, the tracking polarity can be adjusted to the corrected reproduction phase and stable tracking control can be performed immediately. Therefore, the state can be swiftly changed from the start of the reproducing operation to the state in which the signal can be actually reproduced (the state in which the phases of the reference frame signal and the reproduction frame are synchronized).

Further, two or more kinds of tracking pilot signals of different frequencies are selectively recorded cyclically in a cycle of M tracks (where M is an even number of 4 or more), and one frame data is H tracks. (Here, H is 5 or more and an integer that is a non-integer multiple of M), and information for reproducing a signal by rotationally scanning a head mounted on a rotary cylinder with respect to a tape medium segment-recorded A reproducing apparatus, which is a tape driving means for driving and driving the tape medium, a first head attached to the rotary cylinder, a scan track of the first head attached to the rotary cylinder, and one track or Second scanning for scanning a position shifted by approximately one track in the track width direction
Detection of the tracking pilot signal amplitude from the reproduction signal of the first head and the reproduction signal of the first head, and based on this, an identification signal for identifying the tracking pilot signal mainly included in the reproduction signal of the first head is obtained. Means for detecting a tracking pilot signal amplitude recorded on both tracks adjacent to a scanning track from the reproduction signal of the second head, and creating and outputting a tracking error signal based on the tracking error signal; Included in the reproduction signal from the first head or the second head, tracking means for operating the tape drive means by a tracking error signal to perform tracking control, reference signal generation means for generating a reference frame signal. The track number in the 1-frame data is detected and Track number detecting means for obtaining a detection signal, correction amount detecting means for detecting the number of phase difference tracks by comparing the number detection signal with the reference frame signal, and the number based on the number of phase difference tracks and the identification signal. Since the tracking means and the phase correcting means for correcting the phase by using the tape driving means are provided so as to set the number of phase difference tracks to a predetermined value, the pilot detection identifying means detects the identification signal and the track number detecting means and the correction amount detection. The number of phase difference tracks is detected by the means, the reproduction phase is corrected based on the detected number of phase difference tracks, and the tracking polarity that becomes stable in the corrected reproduction phase is determined by the identification signal and the number of phase difference tracks. Can be set selectively. Therefore, after the tape is started, the phase correction operation can be performed in a short time, and the tracking control polarity can be stably pulled in at that position. Therefore, the state can be swiftly changed from the start of the reproducing operation to the state in which the signal can be actually reproduced (the state in which the phases of the reference frame signal and the reproduction frame are synchronized).

As described above, the information reproducing apparatus of the present invention provides the information reproducing apparatus excellent in responsiveness because the mode transition to the reproducing state is performed at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram of an information reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of a recording pattern of a tape applied to the present invention.

FIG. 3 is a block diagram showing a configuration example of a tracking error detection unit and a tracking unit according to the present invention.

FIG. 4 is a waveform diagram illustrating the operation of the pilot detection / identification unit according to the present invention.

FIG. 5 is a block diagram showing a configuration example of a pilot detection / identification unit according to the present invention.

FIG. 6 is a timing chart showing the operation of the correction amount detector according to the present invention.

FIG. 7 is a circuit diagram showing a configuration example of a correction amount detection unit according to the present invention.

FIG. 8 is a timing diagram showing a phase correction operation of a phase correction unit according to the present invention.

FIG. 9 is a timing diagram showing a phase correction operation of the phase correction unit according to the present invention.

FIG. 10 is a flowchart showing the operation of the phase correction unit according to the present invention.

FIG. 11 is a block diagram of an information reproducing apparatus according to another embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration example of a tracking error detection unit and a tracking unit according to the present invention.

FIG. 13 is a flowchart showing the operation of the phase correction unit according to the present invention.

[Explanation of symbols]

 1 tape 2a, 2b head 5 tracking error detection unit 6 pilot detection identification unit 7 tape drive unit 12 tracking unit 14 track number detection unit 15 correction amount detection unit 16 phase correction unit 17 reference signal generation unit

Claims (3)

[Claims] 1. A tracking pilot signal of two or more different frequencies is selectively recorded cyclically in a cycle of M tracks (where M is an even number of 4 or more), and 1 frame data is an H track. (Here, H is 5 or more, and M
Is an information reproducing device for reproducing a signal by rotationally scanning a head mounted on a rotating cylinder with respect to a tape medium segment-recorded by dividing the tape medium by A tape drive unit for driving, a first head attached to the rotary cylinder, and a position attached to the rotary cylinder and displaced from the scanning locus of the first head by one track or approximately one track in the track width direction. Signal for detecting a tracking pilot signal amplitude from a reproduction signal of the first head and a reproduction signal of the first head, and an identification signal for identifying a tracking pilot signal mainly included in the reproduction signal of the first head based on the detection signal. From the reproduction signal of the second head and the pilot detection and identification means for obtaining Tsu detecting a tracking pilot signal amplitude recorded on click, the tracking error detecting means for producing outputs a tracking error signal based on this,
Tracking means for operating the tape driving means by the tracking error signal and the identification signal to perform tracking control, reference signal generating means for generating a reference frame signal, and reproduction from the first head or the second head. Track number detecting means for detecting a track number in the one-frame data included in the signal to obtain a number detection signal, and a correction amount for detecting the number of phase difference tracks by comparing the number detection signal with the reference frame signal. An information reproducing apparatus comprising: a detecting unit; and a phase correcting unit that corrects the phase by using the tape driving unit so that the number of the phase difference tracks of the correction amount detecting unit becomes a predetermined value. 2. Tracking pilot signals of two or more different frequencies are selectively recorded cyclically in a cycle of M tracks (where M is an even number of 4 or more), and 1 frame data is H tracks. (Here, H is 5 or more, and M
Is an information reproducing device for reproducing a signal by rotationally scanning a head mounted on a rotating cylinder with respect to a tape medium segment-recorded by dividing the tape medium by A tape drive unit for driving, a first head attached to the rotary cylinder, and a position attached to the rotary cylinder and displaced from the scanning locus of the first head by one track or approximately one track in the track width direction. Signal for detecting a tracking pilot signal amplitude from a reproduction signal of the first head and a reproduction signal of the first head, and an identification signal for identifying a tracking pilot signal mainly included in the reproduction signal of the first head based on the detection signal. From the reproduction signal of the second head and the pilot detection and identification means for obtaining Tsu detecting a tracking pilot signal amplitude recorded on click, the tracking error detecting means for producing outputs a tracking error signal based on this,
Tracking means for operating the tape drive means by the tracking error signal to perform tracking control; reference signal generation means for generating a reference frame signal;
Track number detecting means for detecting a track number in the one-frame data included in a reproduction signal from the first head or the second head to obtain a number detection signal;
Correction amount detecting means for detecting the number of phase difference tracks by comparing the number detection signal with the reference frame signal; and for setting the number of phase difference tracks to a predetermined value based on the number of phase difference tracks and the identification signal. An information reproducing apparatus comprising: the tracking means and a phase correction means for performing a phase correction using the tape driving means. 3. The phase correction means performs phase correction using the tape drive means so that the number of phase difference tracks becomes a predetermined value, and operates the control polarity of the tracking means based on the identification signal. The information reproducing apparatus according to claim 2,