JPH09259490A - Recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time for reproducing operation ands reduce error by making the tracking state of a reproducing head at the time of starting reproducing to be in off-tracked state in the amount corresponding to the value of timing error due to the error of mounting position. SOLUTION: When a recording head 15 is in an ideal tracking state against the recording operation, the position of the center of the reproducing head 16 is made as shown by a chain line TPC, which is off-tracked from the just tracking state in the amount shown as the offset OF. This offset OF is the width in the tracking direction corresponding to the error against the ideal state of the mounting position. Consequently, in this case, the timing error is added to a measured reference value on the timing ATF tracking at the inlet reproducing time, therefore, the on-tracking state as a timing ATF tracking servo is obtained at the position of the chain line TPC. Thus, the ideal positional state against the recording operation is maintained for the recording head 15, then the starting reproduction is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape recording / reproducing apparatus for scanning an inclined track by a helical scan method, and more particularly to tracking by controlling a relative speed between a running speed of a tape-shaped recording medium and a rotating speed of a rotary drum. The present invention relates to a recording / reproducing device that performs servo.

[0002]

2. Description of the Related Art For example, a digital audio tape player (DAT recorder / player) for recording and reproducing digital audio data on a magnetic tape, or a DAT system also using a magnetic tape is used as a data storage system for a computer. , Digital data storage devices (DDS devices) have been developed for recording and reproducing computer data.

In these devices, for example, 90
High density is achieved by running the tape with the magnetic tape wound at a wrap angle of 0 °, rotating the rotating drum, and performing recording / reproduction scanning by the helical scan method using the magnetic head on the rotating drum. It is possible to record.

In this case, inclined tracks TK _A and TK _B are formed on the tape as shown in FIG. 14, for example. The inclined tracks TK _A and TK _B are tracks formed by so-called azimuth solid recording by a pair of recording heads (A head HR _A and B head HR _B ) mounted on a rotating drum and having different azimuth directions, as shown in FIG. Is. The gaps GP of the recording heads HR _A and HR _B are provided with azimuth angles θ _A and θ _{B in} opposite directions, and therefore the tracks TK _A and TK _B are opposite azimuths as shown by the diagonal lines. With azimuth solid recording, when a certain track is recorded, the recording scan is performed so as to overwrite a part of the previous track,
The portion not overwritten is left as a track having a track width TP. Therefore, the track width TP is narrower than the head width of the recording heads HR _A and HR _B.

Incidentally, as a head configuration for recording / reproducing, there are a two-head system, a four-head system and the like. In the 4-head system, as shown in FIG. 16A, four heads are arranged at 90 ° intervals on the peripheral surface of the rotary head drum. That is, A
An azimuth recording head HR _A , an A azimuth reproducing head HP _A , a B azimuth recording head HR _B , and a B azimuth reproducing head HP _B. Also, the two-head method is shown in FIG.
180 ° on the peripheral surface of the rotary head drum as shown in 6 (b)
Two heads are arranged at intervals. Each head is also used as a recording / playback head, and an A azimuth recording / playback head HR
The P _A B azimuth recording reproducing head HRP _B of.

By the way, at the time of reproduction, the magnetic head must accurately trace the track TK on the tape. As a tracking control method, for example, D
In the DS reproducing device, a tracking servo control operation called a so-called timing ATF method is performed. The timing ATF method measures the time (tracking detection period) from the reference phase position of the rotating drum until the head detects a predetermined signal (timing detection signal) from the track, and compares the measured value with the reference value. Then, the error is used as servo error information.

Then, the servo error information is used to control the rotational speed of the capstan motor for running the tape to reflect it on the tape running speed. That is, the tape running speed is adjusted to adjust the relative speed between the drum rotation speed and the tape running speed so that a good tracking state can be obtained.

For example, when the scanning position of the magnetic head with respect to a certain track is in a position corresponding to the line (timing) shown as TR _{A in the} drawing as shown in FIG. 17, the phase position of the rotary drum is the reference position. Suppose that At the time when the reference phase position is reached during rotation of the drum, for example, a pulse signal is generated from a pulse generator (PG) arranged in the drum motor, so that the rotating drum becomes the reference phase position. Timing TR _A can be detected. After that, the magnetic head contacts the magnetic tape,
As the track TK _{A is} scanned, a timing detection signal is detected as reproduction data at a predetermined position P _TTP on the track. This timing detection signal is
It is assumed that a pulse is obtained at a position P _TTP that is predetermined based on the detection of the synchronizing signal and the address in the data.

In the figure, the track T is
Although three types of scanning with different tracking phase states with respect to K _A are shown, the period (tracking detection period) from the timing of the reference phase position of the rotating drum (position of line TR _A ) to the timing of reaching position P _TTP is: ,
, The scanning times are different as indicated by t1, t2 and t3.

As the tracking detection period, the time t1 obtained when the magnetic head is in a good tracking state with respect to the track TK, that is, in the state of tracing the center of the track TK _A as described above is used as a reference value in advance. Therefore, when the scanning is performed during tracking servo control and the time t1 is measured as the tracking detection period, the measured value and the reference value match. That is, in this case, there is no error between the measured value and the reference value, and a good tracking state is obtained. On the other hand, when scanning is performed in the tracking phase state such as or, the measurement value in the tracking detection period becomes t2 or t3, and there is an error compared with the reference value. In this case, it means that there is a tracking deviation corresponding to the error, and by reflecting this in the tape running speed, it is possible to execute the servo control toward the just tracking state.

In executing such timing ATF servo, it is necessary to obtain a reference value in advance. As mentioned above, this reference value is based on the timing of the reference phase position of the rotary drum in the just tracking state. It is a time value until the timing when the timing detection signal is obtained. Since the timing detection signal is generated, for example, based on the detection of the synchronization signal at a predetermined address on the track, its position P _TTP is fixed on each track of various tapes. It is unavoidable that a positional deviation occurs due to a mechanical error in the playback device. For this reason, when reproducing certain file data in the DDS reproducing device, the reference value of the tape (the file data track thereof) must be measured before reading the reproduction data.

To measure this reference value, scanning is performed on the track in various tracking phase states, an average value is calculated from the tracking detection period measured in each scanning, and this is used as the reference value. Processing is performed. For example, the image is shown in FIG. As shown in the drawing, for example, TJ1 to TJ for the track TK _A
When scanning is performed in a plurality of different tracking phase states as shown in FIG. 5, and an average value is calculated from each tracking detection period measured during those scanning, a tracking phase state near the tracking phase state TJ3 in the figure is obtained. The tracking detection period can be obtained. This can be considered as the tracking detection period in the just tracking state, and thus this should be set as the reference value.

[0013]

By the way, a DDS recording / reproducing apparatus or the like straddles two track areas (for example, a boundary area of two data files; hereinafter, such an area is referred to as an append portion) recorded at different times. Even in such a case, good reproduction is required.

Now, consider a case where new data is recorded (append recording) following an area (already recorded area) where a track as a data file has already been recorded on the tape. Now, as shown by the solid line in FIG. 20A, the track T as the file F1 is recorded on the tape.
Suppose K has already been recorded. File F at this time
In the case of append recording of the data as 2, the track TK as the file F1 is reproduced while applying the tracking servo (this kind of reproduction is referred to as run-up reproduction), and the file F1 is reproduced by this run-up reproduction.
By switching to the recording operation at the time when the reproduction of the last track of is finished, append recording of the data of the file F2 is performed as indicated by the broken track TK in the figure.

As described above, by starting the new recording after performing the running reproduction while applying the tracking servo in the already recorded portion, the track pitch can be properly maintained in the connecting area (append portion). However,
Considering the case of the 4-head system, the positional relationship between the recording head HR and the reproducing head HP must be in an ideal state in order to keep the track pitch constant in the append portion.

The ideal state of the arrangement positional relationship is shown in FIG. 19 (a).
The relationship is as shown in. Actually, the recording head HR and the reproducing head HP are separated by 90 ° as shown in FIG. 16A. However, when viewed from the scanning locus with respect to the track TK, the center CHP of the reproducing head HP is located in the track TK.
It is ideal that the end portion of the recording head HR coincides with the edge of the track TK when it coincides with the center of, that is, in the just tracking state. That is, the respective heads are arranged so that a difference in width W _RP can be obtained in the tracking direction between the center CHR of the recording head HR and the center CHP of the reproducing head HP.
This is understood from the azimuth solid recording as shown in FIG.

However, the positional relationship between the recording head HR and the reproducing head HP is shown in FIG. 19 due to manufacturing errors or the like.
It is difficult to maintain the tracking positional relationship as shown in (a) with high accuracy.
A center shift as shown in (c) occurs. That is, the center CHR of the recording head HR and the reproducing head HP
The width between the center CHP and the center CHP does not become the width W _{RP in the} ideal state, and the width W _RP 1 and the width W _RP 2 include an error.

In consideration of such a situation, even if the running reproduction is first performed and the recording is started during the append recording as described above, the track pitch (track width) varies at the append portion. . That is, since the run-up reproduction is performed only in the just tracking state of the reproducing head HP, if the ideal state of FIG. 19A is used, recording is started by the recording head HR in the tracking state and the azimuth solid pattern as shown in FIG. Even if you record
The track width TP is kept constant, but FIG.
When the center deviation as shown in (c) exists, the edge of the recorded track deviates from the original position in the track width direction, and thus the track width changes at the append portion.

For example, when the state shown in FIG. 19C is taken as an example, a track TK having a track width TP2 with respect to a constant track width TP1 is generated in the append portion as shown in FIG. 20B. It will be.

Considering the case where the reproduction operation reaches the append portion during reproduction of the data recorded in this way,
Due to the influence of the fluctuation of the track width, a good ATF tracking servo cannot be executed, which causes a lot of reproduction errors in the append section. Therefore, a situation occurs in which the reproduction is retried many times, which leads to a long reproduction operation and a decrease in reliability of the reproduction apparatus.

Next, regarding the two-head system, the case of append recording will be considered. In the case of the two-head system, the recording / playback head HRP is used. Therefore, the head for running playback and the head for recording are the same, and there is no possibility of center deviation due to mechanical error. However, since the ideal tracking state is different between reproduction and recording, the track width varies in the append area.

At the time of reproduction, as shown in FIG. 21, the just tracking, that is, the ideal state is when the center of the recording / reproducing head HRP coincides with the center of the track TK. However, during recording, since azimuth solid recording as shown in FIG. 15 is performed, it is required that the edge of the recording / reproducing head HRP coincides with the edge of the track TK.

Since the tracking servo is applied in the run-up reproduction, the ideal state at the time of reproduction is maintained as shown as in FIG. 22, but if the recording operation is switched as it is, in the tracking state shown as, that is, in the file F1 area. Since the recording is performed in the just tracking state of, the track width TP1 is constant in the append portion.
On the other hand, a track TK having a track width TP3 is generated. Therefore, the same problem occurs as in the case of the 4-head system.

[0024]

In view of the above problems, the present invention keeps the track width constant even in the append area so that a smooth playback operation can be realized especially in the append section during playback. The purpose is to do.

For this reason, the recording head and the reproducing head are provided as a recording / reproducing apparatus in which the recording head and the reproducing head are separated from each other as in the above-described four-head method, and the tracking servo is performed by the so-called timing ATF method at the time of reproducing. Storage means is provided for storing a timing error value due to an attachment position error that affects the tracking direction of the head. Further, when new data is recorded following the data recorded area of the tape-shaped recording medium, the tracking operation is performed using the measurement reference value measured in the data recorded area and the timing error value stored in the storage means. Set a reference value for the recording head, and while performing the tracking servo using the reference value in the data recorded area, the reproducing head performs the run-back reproduction operation, and when the area to be recorded is reached, the recording head starts the recording operation. A recording control means is provided for performing such control. In other words, the tracking state of the read head during run-up playback is set to the off-track state by an amount corresponding to the timing error value due to the mounting position error that affects the tracking direction of the write head and the read head. The position should be ideal in the track width direction.

The operation of the recording / reproducing head as a recording / reproducing apparatus configured such that recording / reproducing is performed by a recording / reproducing head as in the above-described two-head system, and tracking servo is performed by a so-called timing ATF system during reproduction. A storage means is provided for storing a timing value corresponding to a variation in the tracking state that should be changed when switching from reproduction to recording. Further, when new data is recorded following the data recorded area of the tape-shaped recording medium, the tracking operation of the tracking operation is performed using the measurement reference value measured in the data recorded area and the timing value stored in the storage means. Set a reference value for the recording / reproducing head while performing tracking servo using the reference value in the data recorded area, and when the area to be recorded is reached, the recording operation by the recording / reproducing head is performed. Recording control means for controlling the start is provided. In other words, the tracking state of the recording / reproducing head during run-up reproduction is set to the off-track state by the amount of fluctuation that should be ideal when switching to the recording operation, so that the recording / reproducing head is ideally arranged in the track width direction at the start of recording. The correct position.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a recording / reproducing apparatus of the present invention will be described below. In this example, a DDS recording / reproducing apparatus is used, but the so-called DDS method is more detailed in DD.
Three systems, S, DDS2 and DDS3, have been developed. The DDS recording / reproducing apparatus of this example is DDS / DDS2.
More compatible with DDS3, which uses a format that enables higher density recording. The present invention can be applied to a recording / reproducing system adopting ATF tracking other than the DDS recording / reproducing device. The description will be made in the following order. 1. DDS3 system track format 2. Configuration of recording / reproducing apparatus 3. 3. Configuration and operation for timing ATF 4. Recording operation 5. Storage operation of timing error value 6. Operation during append recording 7.2 Application example with head system

1. Track Format of DDS3 Method The track format of the DDS3 method will be described with reference to FIGS. FIG. 12 shows a helical scan type track formed on the magnetic tape 90.

Each track is formed as a track having a track width TW by so-called azimuth solid recording by a recording head (not shown). Adjacent tracks are regarded as reverse azimuth tracks. That is, the tracks TK _A in one azimuth direction and the tracks TK _B in the other azimuth direction are alternately formed. During reproduction, the reproducing head 16 scans the track. Although the head width HW of the reproducing head 16 is set wider than the track width TP, crosstalk from adjacent tracks is prevented by the so-called azimuth effect.

In the DDS format, a pair of adjacent tracks TK _A and TK _B are called 1 frame and 2
Two frames are a unit called one group. And an ECC frame is provided behind the group. An amble frame is provided after the ECC frame.
However, the number of frames of this amble frame is not specified and may not be provided. ECC frames and amble frames will define the boundaries of the groups on the tape 90. In each group, index information for partitioning a series of data is added to the last frame in the group.

The data format in one track is shown in FIG. As shown in FIG. 13A, a margin area is formed at both ends of one track, and the area sandwiched between the margin areas is the main data area. The main data area is divided into fragments of 96 units to which fragment addresses 0 to 95 are given. One fragment consists of 133 bytes, and its contents are shown in FIG.
It is shown in (b) and (c).

As shown in FIG. 13B, each 78-unit fragment having a fragment address of 9 to 86 is provided with a 1-byte sync signal area at the beginning, and a sync signal in a predetermined pulse form is recorded. To be done. A 6-byte address and subcode area are provided following the sync signal area. A fragment address is recorded in 1 byte, and a subcode is recorded in 5 bytes.

Next, 2 bytes are used as a header parity area, and further 112 bytes are used as a data area. Actual data is recorded in this data area. The last 12 bytes of the fragment are used as the ECC area. A so-called C1 correction code is recorded in this ECC area.
The C1 correction code is an error correction code for the data in the fragment, that is, the correction process is completed in fragment units.

Fragment addresses 0-8 and 87-
Each fragment of 18 units up to 95 is shown in FIG.
As shown in FIG. 13C, a sync signal area, an address and subcode area, a header parity area, and an ECC area are provided as in the fragment of FIG. 13B. However, 112 bytes, which was the data area in the fragment of FIG. 13B, is the ECC area, and the C2 correction code is recorded. The C2 correction code is a code of a correction series that is completed within one track.

A C3 correction code is further added as a correction code. This will be recorded in the ECC frame shown in FIG. This C3 correction code is 1
It is the code of the correction sequence that is completed within the group. Also, C
By confirming the error status by the 1-correction code and the C3-correction code, it is possible to confirm in which part the error has occurred in one track, but the C2-correction code is recorded by being interleaved in one track. The error occurrence position within one track cannot be confirmed from the error situation caused by the C2 correction code.

2. Configuration of Recording / Reproducing Apparatus FIG. 1 shows the configuration of the recording / reproducing apparatus of this example. The interface unit 1 is a unit that is connected to an external host computer (not shown) to exchange data. At the time of recording, the data from the host computer is received and supplied to the index adding circuit 2 and the sub code generator 8. At the time of reproduction, the operation of outputting the data reproduced from the magnetic tape 90 to the host computer is performed.

At the time of recording, the index adding circuit 2
Performs a process of adding index information to the input data for each group described above. The data to which the index information is added is the C3 encoder 3,
Error correction codes of C3 series, C2 series, and C1 series are added in the C2 encoder 4 and the C1 encoder 5, respectively. Each of the C3 encoder 3, the C2 encoder 4, and the C1 encoder 5 temporarily stores data in the memory 6 for each data unit forming one group and performs processing. Then, the C3 encoder 3 generates an error correction code C3 for the data string corresponding to the track width direction and adds it as the data of the last ECC frame of the data of one group. Further, the C2 encoder 4 generates the error correction code C2 of the data string corresponding to the track direction, and
0-8 fragments and 87-9 as shown in (c)
The error correction code C2 within 5 fragments is used. Further, the C1 encoder 5 generates an error correction code C1 in fragment units.

The data to which the error correction codes C1, C2 and C3 are added is supplied to the sub code adding circuit 7. The subcode generation unit 8 generates various subcode data and fragment addresses based on the data supplied from the interface unit 1 and supplies them to the subcode addition circuit 7. The generated sub-codes include, for example, separate counter information indicating a data delimiter, record counter information indicating the number of records, an area ID indicating each area defined on the tape format, a frame number, and a group count indicating the number of recording units. Information, checksum, etc.,
These are generated together with the fragment address in the subcode generating section 8.

The subcode adding circuit 7 adds these subcodes and fragment addresses for each data unit corresponding to one fragment. That is, FIG. 13 (b) (c)
Information to be recorded in the address / subcode area in is added.

Subsequently, in the header parity adding circuit 9, the CRC code recorded in the header parity area in FIGS. 13B and 13C is added. This CRC code is a 2-byte parity code for error detection for the subcode and fragment address.

Subsequently, in the 8/10 modulation circuit 10, so-called 8/10 modulation processing is performed in which the input data is converted from 8 bits into 10 bits in 1-byte units, and the synchronization signal addition circuit is applied to the modulation signal. At 11, a sync signal is added. This sync signal is the sync signal of the first byte of the fragment shown in FIGS. 13B and 13C.

Further, in the margin adding circuit 12, FIG.
As shown in (a), data corresponding to margin areas at both ends of the track is added, and at this stage, a recording data string conforming to the track format of FIG. 13 is generated. The recording data thus generated is supplied to the recording amplifier 13.

The signal amplified by the recording amplifier 13 is supplied to the recording head 15 in the rotary head drum HD via the rotary transformer 14, and the magnetic recording operation is performed on the magnetic tape 90 running by the recording head 15. The magnetic tape 90 is housed in a tape cassette 91, and the magnetic tape 90 is pulled out from the tape cassette 91 (recording / reproducing) and wound (loaded) around the rotary head drum 50. And capstan 2
The magnetic tape 90 is run at a constant speed by rotating the capstan 28 at a constant speed while being sandwiched by the pinch roller 29 and the pinch roller 29.

FIG. 2 shows an image of operation during recording and reproduction. The magnetic tape 90 pulled out from the tape cassette 91 is tilted in the height direction with respect to the rotary head drum 50 by the guide pins 51, 52, and 53, and the magnetic tape 90 is about nine.
While being wound in the section of 0 °, the capstan 28 and the pinch roller 29 travel at a constant speed. The rotary head drum 50 is rotated while slidingly contacting the magnetic tape 90, so that the recording operation by the recording head 15 forms a recording track on the magnetic tape 90 by the helical scan method as shown in FIG. Go.

Although only one recording head 15 and one reproducing head 16 are shown in FIG. 1, since the azimuth solid recording method is actually used, the azimuth angles are different as shown in FIG. Two recording heads 15
A, 15B, two reproducing heads with different azimuth angles 1
6A and 16B are arranged on the peripheral surface of the rotary drum in a state of being separated from each other by 180 °. Recording head 15A
The A azimuth angle θ _A in the reproducing head 16A and the B azimuth angle θ _B in the recording head 15B and the reproducing head 16B are angles as shown in FIG. At the time of recording, the recording head 15A and the recording head 15B alternately come into sliding contact with the magnetic tape 90, so that tracks TK _A and TK _B having different azimuth angles are alternately formed as shown in FIG.

At the time of reproduction, as shown in FIG. 2, the magnetic tape 90 wound around the rotary head drum 50 is run and the rotary head drum 50 is rotated, so that the reproducing heads 16A and 16B alternately record tracks. The trace is continued and the recorded data is read out.

Then, as shown in FIG. 1, the reproducing head 16 (1
The signals read by 6A and 16B) are supplied to the reproduction amplifier 18 via the rotary transformer 17. Although only one rotary transformer 14 for recording and one rotary transformer 18 for reproduction are actually shown, the rotary transformer 14 is not shown in FIG.
The rotary transformer 18 is provided corresponding to A and 15B, and the rotary transformer 18 is also provided corresponding to the reproducing heads 16A and 16B.

The signal amplified by the reproduction amplifier 18 is supplied to the sync signal detection circuit 19 and the sync signal is detected. Then, a reproduction clock synchronized with the synchronization signal detected by the internal PLL circuit is generated, and a signal (RF signal) amplified by the reproduction amplifier 18 by the reproduction clock.
Is binarized.

The 10-8 demodulator 20 performs a decoding operation on the 8-10 modulation at the time of recording on the binarized data, and restores the data in 8-bit units. The reproduced data demodulated into 8-bit unit data is subjected to a parity check of the subcode and the fragment address by the header parity check circuit 21 using the 2-byte header parity shown in FIGS. 13B and 13C. The data for which the parity check has been completed is supplied to the subcode separation circuit 22 and the timing detection pulse generation circuit 27.

The subcode separation circuit 22 extracts the fragment address and subcode data and supplies them to the system controller 31. The actual data other than the fragment address and the subcode data is sent to the C1 decoder 23, C2 decoder 24, and C3 decoder 25. The C1 decoder 23, C2 decoder 24, and C3 decoder 25 perform error correction processing on the C1 series, C2 series, and C3 series, respectively. C1 decoder 23, C
Each of the 2 decoder 24 and the C3 decoder 25 temporarily stores data in the memory 6 for each group and performs processing. Then, the C1 decoder 23 performs the correction process based on the error correction code C1 on a fragment basis, and the C2 decoder 24 performs the correction process using the error correction code C2 of the data string corresponding to the track direction. Further, the C3 decoder 25 uses the error correction code C3 to perform error correction processing in fragment units.

The index information of the data for which the error correction process has been completed is separated by the index separation circuit 26 and sent to the interface section 1. Then, it is output from the interface unit 1 to an external host computer.

The system controller 31 is formed by a microcomputer that controls the entire apparatus. That is, it controls the signal processing operation during recording / reproduction, the tape running operation, the rotating operation of the rotary head drum 50, and the like. Further, the servo circuit 30 actually performs the tape running operation and the rotary head drum 5 based on an instruction from the system controller 31.
The rotation operation of 0 will be executed. The servo circuit 30 can be formed by a microcomputer, and may be integrated with the system controller 31 as a circuit system having the function of the microcomputer as the system controller 31.

The rotating operation of the rotary head drum 50 is executed by the drum motor 33. A drum PG (pulse generator) 36 and a drum FG (frequency generator) 37 are attached to the rotary head drum 50, and pulses from this drum PG 36 are supplied to the servo circuit 30 via an amplifier 38. Also drum FG37
The pulse from is supplied to the servo circuit 30 via the amplifier 39. The servo circuit 30 includes a drum PG36 and a drum F.
A switching pulse can be generated according to the pulse from G37, and rotation phase information can be detected. The switching pulse is a signal that serves as a reference for switching processing corresponding to each of the so-called A azimuth head and B azimuth head.

The servo circuit 30 controls the drum PG36 to control the rotary head drum 50 at a constant speed.
Alternatively, rotation error information is obtained by detecting the rotation speed from the pulse from the drum FG 37 and comparing this with the reference rotation speed. Then, the drum servo signal S _D is generated based on the rotation error information, and the rotary head drum 50 is rotated at a constant speed by adjusting the drive signal applied from the drum motor driver 32 to the drum motor 33.

By controlling the rotation speed of the capstan 28, so-called tracking servo is performed. And in this example, as a tracking servo system,
The timing ATF method as described in FIG. 17 is adopted. The capstan 28 is a capstan motor 35.
Is driven to rotate. A capstan FG (frequency generator) 40 is attached to the capstan 28, and the pulse from the capstan FG 40 is supplied to the servo circuit 30 via the amplifier 41.

In order to rotate the capstan 28 at a constant speed, the servo circuit 30 detects the rotation speed of the capstan 28 by the pulse from the capstan FG 40 and compares it with the reference rotation speed to obtain the rotation error information. obtain. Then, based on the rotation error information, the capstan servo signal S
_Constant speed rotation is performed by generating _CP and adjusting the drive signal applied from the capstan motor driver 34 to the capstan motor 35.

In order to execute the tracking servo further, the servo circuit 30 monitors the reference phase position timing of the rotary head drum 50 which can be detected from the switching pulse and the timing detection pulse TTP supplied from the timing detection pulse generation circuit 27. Then, the period is measured as the tracking detection period. Then, the tracking error information is obtained by comparing the measurement value of the tracking detection period with a preset reference value, and the capstan servo signal S _CP is generated based on the tracking error information, and the capstan motor driver 34 causes the capstan motor driver 34 to generate the capstan servo signal S _CP. Tracking servo is performed by adjusting the drive signal applied to the motor 35 to increase or decrease the rotation speed of the capstan 28.

By the way, during the recording operation, the reference processing clock is generated based on the clock from the crystal oscillator 42. The processing of the recording circuit system from the index adding circuit 2 to the recording head 15 is executed based on the clock from the oscillator 42. Switching pulse S
The WP serves as a switching processing reference between the A channel and the B channel even during the recording operation, and this is also generated based on the clock from the oscillator 42.

3. Configuration and Operation for Timing ATF FIG. 3 shows the configuration of the circuit system for timing ATF operation. As a circuit system for the capstan servo including the timing ATF operation, a timing ATF processing unit 61, a switching pulse generation unit 62,
Free running counter 63, servo switch 64,
A capstan reference speed generator 65, a subtractor 66, a speed servo signal generator 67, and a delay amount register 69 are provided.

Although not directly related to the timing ATF operation at the time of reproduction, an EEP-ROM 68 for holding the timing error value used for the timing ATF operation at the time of appending reproduction at the time of append recording is provided. EEP-R
The timing error value stored in the OM 68 is a value according to the mounting position error between the recording head 15 and the reproducing head 16, and the value is measured in the adjustment work in the manufacturing process and is a value peculiar to each recording device. It is stored in the ROM 68.

In the case where the tracking servo is turned off and the capstan 28 is driven to rotate at a constant speed by the servo circuit 30 having the configuration shown in FIG. 3, the servo switch is _{turned on} by the servo on / off control signal TS _{ON / OFF} supplied from the system controller 31. 64 is turned off. In this case, the capstan reference speed generator 65 generates a signal corresponding to the speed desired to be set as the rotation speed of the capstan 28, and the signal is directly supplied to the speed servo signal generator 67 as the target speed signal CV. . In addition, the speed servo signal generator 6
7 is supplied with a pulse FG _C from the capstan FG 40, that is, a pulse having a frequency corresponding to the rotation speed of the capstan 28, and the speed servo signal generation unit 67 uses the pulse FG _C of the current capstan 28. Detect the rotation speed.

Then, the speed servo signal generator 67 compares the current rotation speed that can be detected from the pulse FG _C with the target speed signal CV indicating the target rotation speed, and uses the error as the capstan servo signal S _CP. It is supplied to the capstan motor driver 34. The capstan motor driver 34 drives the capstan motor 35 by, for example, a three-phase drive signal to rotate the capstan 28, but by controlling the motor drive voltage according to the capstan servo signal S _CP , the capstan 28 is The constant speed rotation servo is executed so as to converge on the target speed signal CV generated from the capstan reference speed generation unit 65.

Therefore, the capstan reference speed generator 65
If the target speed signal CV generated from the above is set to the tape running speed (1x speed) during normal recording / reproducing, the capstan 28 is rotated at a constant speed of 1x speed, and the target speed signal CV is set to 2x speed. Then, the capstan 28 is rotated at a constant speed at a double speed. That is, the tape running speed can be varied by changing the target speed signal CV generated from the capstan reference speed generating section 65. The target speed signal CV generated by the capstan reference speed generator 65 may be controlled by the system controller 31 according to the operating state at that time. For example, 1x speed during playback,
During fast-forward playback of the tape, the speed can be changed to x-times speed.

When performing tracking control during reproduction, the servo switch 64 is turned on. Then, the timing ATF processing unit 61 detects the tracking error SV and subtracts the tracking error SV from the value generated by the capstan reference speed generating unit 65 by the subtractor 66, thereby generating the target speed signal CV. That is, in this case, the target speed signal CV is increased / decreased according to the tracking error SV centering on a predetermined speed (eg, 1 × speed). Therefore, the tape running speed is accelerated / decelerated around a predetermined speed according to the tracking state, and is thereby converged to the just tracking state. When the tracking is stable, the tracking error SV becomes almost zero, so that the tape running continues at an almost predetermined speed.

The tracking error SV detection processing of the timing ATF processing section 61 is performed based on the timing detection pulse TTP from the timing detection pulse generation circuit 27 and the switching pulse SWP generated by the switching pulse generation section 62.

The timing detection pulse generation circuit 27 generates a timing detection pulse TTP from the data for which the header parity check has been completed from the header parity check circuit 21 as shown in FIG. The timing detection pulse TTP is a signal for measuring the tracking phase state, and is a pulse detected from a specific position on the track shown as the position P _TTP in FIG.

The timing detection pulse generation circuit 27 monitors the data read from the track TK of the tape 90 for the data detected from the sync signal area, the address / subcode area and the header parity area, that is, the fragment header data. Therefore, according to the fragment address corresponding to the position P _TTP , the timing detection pulse TTP is generated from the synchronization signal or the like at that time.

FIG. 4E shows an image of the reproduction RF signal read from the tracks TK _A and TK _B , and FIG.
(F) shows the timing detection pulse TTP generated by the timing detection pulse generation circuit 27. As can be seen from this figure, the timing detection pulse TTP is output at the timing corresponding to the reproduction scanning of a certain position P _TTP on the track during the reproduction scanning period of each track.

On the other hand, FIG. 4A shows an example of the pulse FG _D generated from the drum FG 37, and FIG. 4B shows an example of the pulse PG _D generated from the drum PG 36. Pulse F
Both G _D and pulse PG _D have a frequency corresponding to the rotation speed of the rotary head drum 50, and the pulse P
G _D is generated corresponding to a specific rotation phase position of the rotary head drum 50.

The switching pulse generator 62 generates the switching pulse SWP shown in FIG. 4D using the pulse FG _D and the pulse PG _D. For example, the rising edge of the pulse FG _D , which is the next timing after the detection of the pulse PG _D, is used as a reference, and the timing when the predetermined delay amount DL of FIG. 4C is applied thereto becomes the falling edge of the switching pulse SWP. The switching pulse SWP is generated.

The delay time DL is a delay time based on the value set in the delay amount register 69, and a delay amount appropriate for the reproduction process is set during reproduction. The delay time value set in the delay amount register 69 is the internal processing of the servo circuit 30 or the system controller 3
It can be rewritten by the control from 1. If the delay time value set in the delay amount register 69 is rewritten, the timing of the switching pulse SWP generated accordingly changes.

The switching pulse SWP becomes a signal which serves as a reference for switching between A channel (reproducing head 16A) / B channel (reproducing head 16B) for signal processing,
In addition to being supplied to the timing ATF processing unit 61 as shown in FIG. 3, it is also supplied to other various necessary circuit systems.

Switching pulse SW during reproduction
P is "L" level period becomes the processing period for reproducing data from the reproducing heads 16A, the scanning by the reproducing head 16A with respect to the track TK _A in this period performed, Figure 4 from the track TK _A as (e) Data reading (PbA) is performed. On the other hand, the period in which the switching pulse SWP is at the "H" level is the processing period for the reproduced data from the reproducing head 16B, and the track TK _B is scanned by the reproducing head 16B in this period, and the track is reproduced as shown in FIG. Data reading (PbB) from TK _B is performed.

In the timing ATF processing section 61, the falling timing of the switching pulse SWP is tracked by the track TK.
Timing regarding _A The reference phase position of the rotating drum is used as the reference for the ATF operation. This corresponds to the timing TR _A in FIG. Then, as shown in FIG. 4, the tracking detection period M _TTP (A) from the timing TR _A until the timing detection pulse TTP is input is measured. That is, from the reference phase position of the rotary drum, the head detects a predetermined signal (timing detection pulse TT
The time until P) is detected will be measured.

The free running counter 63 is used for the measurement operation of the tracking detection period M _TTP (A). For example, the falling timing TR _A of the switching pulse SWP
Latches the count value of the free running counter 63, and latches the count value of the free running counter 63 at the input timing of the timing detection pulse TTP. Then, the tracking detection period M _TTP (A) can be measured by subtracting the two count values, and the measurement value as the tracking detection period can be obtained. Then, the measured value of the tracking detection period M _TTP (A) thus obtained is set to a preset reference value (track TK
(Reference value for _A ), and compare the error amount with track TK
Let _{A be the} tracking error SV.

Regarding the track TK _B , the rising timing of the switching pulse SWP is set to the timing ATF.
The timing TR _B is the reference phase position of the rotary drum which is the reference of the operation. Then, the tracking detection period M _TTP (B) from the timing TR _B until the timing detection pulse TTP is input is similarly set in the free running counter 6
3 is used for measurement. Then, the measured value of the tracking detection period M _TTP (B) thus obtained is compared with a preset reference value (reference value for the track TK _B ) and the error is tracked with respect to the track TK _B. The error is SV.

The tracking error SV for the A azimuth track TK _A and the B azimuth track TK _B thus obtained is input to the subtractor 66 and is reflected in the target speed signal CV to control the rotation speed of the capstan 28. By doing so, the relative speed between the drum rotation speed and the tape running speed is adjusted so that a good tracking state is obtained.

4. Recording Operation The recording operation timing is shown in FIG. As described above, at the time of recording, the switching pulse SWP changes the recording operation period of A azimuth track TK _A and B azimuth track TK _B.
The switching pulse SWP is a signal that defines the recording operation period of the reference timing R _SWP of FIG.
From FIG. 5 (b), a pulse as shown in FIG. 5 (c) falls at the timing when the delay time value set in the delay amount register 69 is given.

The period in which the switching pulse SWP is at the "L" level is the A channel recording period, recording of the A azimuth track TK _A is performed by the recording head 14A as shown in FIG. 5D, and the switching pulse SWP is also used. The "H" level period is the B channel recording period, and recording on the B azimuth track TK _B is performed by the recording head 14B. This recording operation is performed by azimuth solid recording as described with reference to FIG.

By the way, in the case of this example, the reproducing operation is carried out simultaneously with the recording operation to check whether or not the data to be recorded is accurately recorded on the magnetic tape 90. This is called a read-after-write operation, and the track recorded by the recording head 14A is reproduced by the reproducing head 16A immediately after that, and the track recorded by the recording head 14B is reproduced by the reproducing head 16B immediately thereafter. Then, it is confirmed whether or not the data to be recorded is actually recorded. For example, if there is a recording error, a recording retry is performed to improve the reliability of the recording operation. The read-after-write operation itself is not directly related to the present invention, so a detailed description thereof will be omitted. However, this operation enables the timing detection signal TTP to be detected from the data reproduced during recording.

The reproduction operation as the read-after-write operation is performed at the timing shown in FIG. 5 (e). The recording head 14A and the reproducing head 16A are arranged 90 ° apart as shown in FIG.
The height position on the rotary head drum 50 is set so that the reproducing head traces the tracks with a delay of two tracks after ¼ rotation when the recording is performed.

Therefore, a certain track recorded by the recording head 14A is reproduced by the reproducing head 16A in the A channel period in which the switching pulse SWP is next at the "L" level. Similarly, a certain track recorded by the recording head 14B is reproduced by the reproducing head 16B in the B channel period in which the switching pulse SWP subsequently becomes the "H" level. This state is indicated by an arrow in the figure. Then, for such a reproducing operation, the timing detection signal TTP is obtained as shown in FIG.

5. Timing Error Value Storage Operation This example has a feature in the running-back playback operation at the time of append recording, but in order to execute the running-back playback operation in this example, the timing error value is measured in advance and EE
It is necessary to store it in the P-ROM 68.

The timing error value is a value corresponding to the center deviation in the tracking direction caused by the mounting position error between the recording head 15 and the reproducing head 16. For example, in the ideal position state of the recording head 15 and the reproducing head 16, the width W _RP is set between the head centers of the recording head 15 and the reproducing head 16 as shown in FIG. 19A. However, due to mounting error,
As in (b) and (c), the width becomes W _RP 1 or the width W _RP 2. The error between the width W _RP 1 (or the width W _RP 2) and the width W _RP in the ideal state causes a fluctuation in the track width during append recording. The timing error value is the off-track amount corresponding to the error between the width W _RP 1 (or the width W _RP 2) and the width W _RP and is the timing value in the timing ATF tracking servo.

The timing error value is a value corresponding to the mounting position error between the recording head 15 and the reproducing head 16.
The value is unique to each recording / reproducing device. Therefore, at the final adjustment of the manufacturing process, the timing error value is measured for each recording / reproducing apparatus and stored in the EEP-ROM 68. The operation for this storage is performed by the procedure shown in FIG. 6 as the operation of the system controller 31 and the servo circuit 30.

When the storage process of the timing error value is started during the adjustment, the recording operation by the recording head 15 is started at step F101. At this time, a simultaneous reproducing operation by the reproducing head 16 is also executed as a read-after-write operation. Then, the timing detection pulse TTP is detected from the data reproduced by the reproducing head 16, that is, the data immediately after recording, and the timing ATF processing unit 61 is detected.
Then, the tracking detection period M _TTP is measured.
When a certain number of measurement value samples of the tracking detection period M _TTP are collected, the recording operation is ended in step F102, and the measurement value samples are averaged to obtain the value TW.

This value TW is the value of the tracking detection period M _TTP observed by the reproducing head 16 when recording is performed by the recording head 15 of the recording / reproducing apparatus. Since the recording operation is being performed, the timing AT is the same as that of the reproducing operation.
F tracking servo is not applied, so the value T
W has a value corresponding to the tracking phase state of the reproducing head 16 when the recording head 15 is appropriately performing recording scanning.

Then, in step F103, the portion recorded in step F101 is reproduced. Then, from the timing detection pulse TTP detected during reproduction, the timing A
The TF processing unit 61 measures the tracking detection period M _TTP , and measures the reference value for timing ATF tracking, that is, the tracking detection period M _TTP in the just tracking state. Therefore, a certain number of measurement value samples of the tracking detection period M _TTP are collected in various tracking phase states in the recorded area, after which the reproduction operation is ended in step F104 and the measurement value samples are averaged. The value TM, that is, the reference value for the ATF tracking servo is obtained.

This value TM is just the tracking detection period M in the just tracking state of the reproducing head 16.
It is the value of _TTP . Then, in step F105, the value TW is subtracted from the value TM to obtain the timing error value TA, and
This timing error value TA is stored in the EEP-ROM 68 by F106.
And the process ends.

6. Operation during append recording Next, the operation during append recording will be described. FIG. 7 shows processing at the time of append recording, and FIGS. 8 and 9 show operation images. When there is a track previously recorded as the file F1 as shown by the solid line track TK in FIG. 9A, the file F2 is followed by the file F2.
Is to be recorded.

As for the operation at the time of append recording, as shown in the lower part of FIG. 9A, first, the reproducing operation is performed for the area of the file F1 (rewind reproduction), and the timing AT
A reference value for F tracking will be measured.
Then, when the reference value is measured, the timing ATF tracking operation is turned on to perform the running reproduction, and the file F1
The recording operation is switched at the end of the area of, and the track TK indicated by the broken line as the file F2 is recorded.
However, as the timing ATF tracking servo during the approach reproduction, the reference value measured immediately before is not used as it is, but the reference value is corrected by the timing error value TA stored in the EEP-ROM 68.

The processing for such an operation will be described with reference to FIG. At the time of append recording, first, at step F201, the timing AT is set in the already recorded area (area of the file F1).
A reference value measuring operation for the F tracking servo is performed, which performs scanning in various tracking phase states on the track as described with reference to FIG. Then, when a predetermined number or more of samples as the measurement value of the tracking detection period M _TTP are collected, the average thereof is taken as the reference value TR.

Next, in step F202, the reference value TR is set to E.
The timing error value TA stored in the EP-ROM 68 is added, and this is used as the reference value TR that is actually used. Then, in step F203, the running reproduction is performed while applying the timing ATF tracking servo using the reference value TR, and when the area of the file F1 ends, the recording operation is switched to in step F204. In other words, in this example, during the running recovery, the measured reference value is corrected by the timing error value TA to be the reference value TR actually used, and the timing AT
By performing F tracking, the track pitch is made constant at the append portion.

As described above, the timing error value TA is calculated from the value TM and the value TW. The value TW as the tracking detection period measured by the recording operation and the simultaneous reproduction is
It is a value corresponding to the tracking state of the reproducing head 16 when the recording operation of the recording head 15 is used as a reference. Therefore, as shown in FIG. 8, the reproducing head 16 is in the tracking state when the edge of the recording head 15 coincides with the edge of the track TK. In FIG. 8, the center of the reproducing head 16 corresponds to the one-dot chain line TPC. This is the tracking detection period in the tracking state. On the other hand, the value TM is a tracking detection period when the reproducing head 16 is set to just tracking, that is, a tracking detection period when the track center TC of FIG. 8 and the center TPC of the reproducing head 16 match each other.

In the ideal state as shown in FIG. 19A, when the reproducing head 16 is just tracking, the recording head 15 is also in the ideal state.
If the arrangement of the recording head 15 and the reproducing head 16 is in the ideal state, the value TW and the value TM are the same value, that is, the timing error TA is zero.

However, the recording head 15 and the reproducing head 16
If the arrangement is not in the ideal state, a value corresponding to the error from the ideal state will be obtained as the timing error TA. In FIG. 8, when the recording head 15 is in the ideal tracking state for the recording operation, the head center of the reproducing head 16 is at the position of the alternate long and short dash line TPC, that is, it is off-tracked by the amount indicated by the offset OF from just tracking. Shows. The offset OF has a width in the tracking direction that corresponds to an error in the mounting position with respect to the ideal state, and has a width that corresponds to the timing value held as the timing error TA.

Therefore, when the timing ATF tracking is performed as usual during the run-back reproduction as in the prior art, the track pitch fluctuates by the offset OF when the recording is performed, but in the case of this example, the run-out playback is performed. In the timing ATF tracking at that time, since the timing error TA is added to the measured reference value, the on-tracking state as the timing ATF tracking servo is obtained at the position of the one-dot chain line TPC in FIG. That is, during the run-up reproduction, the servo control is performed to the position where the offset OF is applied from the original just tracking position, and thus the run-out reproduction is performed with the recording head 15 maintained in the ideal position state for the recording operation as shown in FIG. . Therefore, when the running reproduction is finished and the recording operation is switched to, the recording scanning is performed in the ideal state by the recording head 15, and the track width (track pitch) changes in the append portion as shown in FIG. 9B. All tracks are kept at the track width TP1.

By eliminating the track width variation at the time of append recording by the above-mentioned operation, the timing ATF tracking operation is adversely affected by the track width variation at the time of reproduction, and the reproduction error is eliminated. Then, even when the reproduction retry is performed, it is minimized, and the reproduction operation time and the error are reduced. Therefore, the reliability of the recording / reproducing apparatus is greatly improved.

It should be noted that, for simplification of description, the description is made in common for the A / B azimuth, but actually, as the ATF tracking operation, the reference value for A azimuth and the reference value for B azimuth are set. , These may be used individually for tracking servo for each azimuth track, or may be averaged and used in common. In any case, since the reference value is set for each azimuth track, it is preferable that the correction of the reference value at the time of running recovery in this example is performed on the reference value for each A / B azimuth. Of course, as the timing error value, the timing error value for A azimuth corresponding to the mounting error of the A azimuth recording head 15A and the A azimuth reproducing head 16A, the B azimuth recording head 15B, and the B azimuth reproducing head 16B.
The timing error value for B azimuth corresponding to the mounting error of No. 1 is measured individually and stored in the EEP-ROM 68.

7.2 Example of application with a two-head system Although the above example describes a four-head system recording / reproducing apparatus in which a recording head and a reproducing head are separately provided, the present invention is a two-head system recording provided with a recording / reproducing head. It can also be applied to a playback device.

As described above, in the case of the two-head system, the recording / playback head HRP is used. Therefore, the head for running playback and the head for recording are the same, and there is no possibility of center deviation due to mechanical error. However, since the ideal tracking state is different between during reproduction and during recording, if the just tracking state during reproduction during the running reproduction is used, the track width will change when the recording operation is switched to. Therefore, when the present invention is applied to the two-head system, the timing value is measured and stored in advance, and the reference value of the timing ATF tracking servo at the time of running reproduction is corrected and used with the stored timing value. To

The timing value storing operation in the adjusting step is as shown in FIG. When the timing value storage process is started during the adjustment, the recording operation by the recording / reproducing head is first started as step F301. Needless to say, the read-after-write operation is not possible in the case of the 2-head system.

Next, in step F302, the portion recorded in step F301 is reproduced. In this case, the reproduction scanning tracking state is the same as the recording scanning tracking state in step F301. Then, the tracking detection period M _TTP is measured from the timing detection pulse TTP detected during reproduction.

The value of the tracking detection period M _TTP obtained at the time of reproduction differs from the value of the tracking detection period M _{TTP in} the just tracking state because the ideal tracking state at the time of recording differs from that at the time of reproduction. Don't On the other hand, the value of the tracking detection period M _{TTP in} the just tracking state is known as the time value when the fragment header data that becomes the TTP detection timing at the time of recording is recorded. Therefore, the difference T between the time value and the value of the detected tracking detection period M _TTP
N is a value according to the tracking state that should be changed during reproduction and recording. Therefore, the difference value TN is calculated in step F3.
The timing value TA is set at 03, and EEP-R is set at step F304.
It is stored in the storage unit such as the OM and the process ends.

The process for actually performing the append recording is the same as that for the four-head system shown in FIG. 7, that is, the reference value for the timing ATF operation during the running reproduction is the measured reference value. The value is corrected by the value TA. Then, the tracking state during run-up playback is shown in Fig. 1.
As shown in 1, the track center T only by the offset OF
It will be converged from C to an off-track state.
In such a tracking state, the edge of the recording / reproducing head HRP coincides with the edge of the track TK, so that it becomes a proper tracking state during recording. Thus, the recording / reproducing head HRP can perform recording scanning in an ideal tracking state, and the track width does not change at the append portion. Therefore, the same effect as in the case of the above-described four-head system can be obtained also in the two-head system recording apparatus.

In the present specification, since an example in which azimuth recording is adopted as the DDS recording / reproducing apparatus is taken, for convenience, the 4-head system is assumed to have two recording heads and two reproducing heads, and the 2-head system. Is provided with two recording / playback heads, but there are actually various head configuration examples. For example, one print head and one
Two playback heads, two heads, 1
One recording head, one reproducing head, and one recording / reproducing / combining head are provided to form three heads, and four recording / reproducing / combining heads are provided to form four heads. In any case, the above-described four-head system embodiment can be applied to a pair of heads having separate recording and reproducing heads, and the above-described two-head system embodiment can be applied to a recording / reproducing head. Become.

[0107]

As described above, in the recording / reproducing apparatus of the present invention, when the recording head and the reproducing head are separate, the timing error value due to the mounting position error affecting the tracking direction of the recording head and the reproducing head is stored. In the case of performing append recording, a reference value for tracking operation is set using the measurement reference value measured in the data recorded area and the timing error value stored in the storage means. In the data recorded area, the timing ATF tracking servo is executed by using the reference value to perform the running reproduction operation, and when the area to be recorded is reached, the recording operation is switched to. That is, the tracking state of the reproducing head during the run-up reproduction is set to the off-track state by an amount corresponding to the timing error value due to the mounting position error that affects the tracking direction of the recording head and the reproducing head. Since the position is ideal in the track width direction, the track width can be kept constant in the append area. Therefore, during playback, playback errors due to track pitch fluctuations are almost eliminated, and playback retries are minimized, which has the effect of shortening playback operation time and reducing errors. Reliability is greatly improved.

Further, in the recording / reproducing apparatus of the present invention in which the recording / reproducing head is used, the storage means for storing the timing value according to the fluctuation amount of the tracking state which should be changed when the operation of the recording / reproducing head is switched from reproducing to recording. When performing append recording, the reference value for the tracking operation is set using the measurement reference value measured in the data recorded area and the timing value stored in the storage means, and the reference value is set in the data recorded area. The recording / reproducing head performs the run-back reproducing operation while executing the tracking servo by using, and the recording / reproducing head starts the recording operation when the area to be recorded is reached. In other words, the tracking state of the recording / reproducing head during the run-up reproduction is set to the off-track state by the fluctuation amount that should be the ideal state when switching to the recording operation.
At the start of recording, the recording / reproducing head is in an ideal position in the track width direction for recording operation, and the track width can be kept constant in the append area. Therefore, at the time of reproduction, the reproduction error due to the track pitch variation is almost eliminated, and the reproduction retry is minimized, so that the reliability of the recording / reproducing apparatus is greatly improved.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram of a rotary head drum of the recording / reproducing apparatus of the embodiment.

FIG. 3 is a block diagram of a capstan servo system of the recording / reproducing apparatus of the embodiment.

FIG. 4 is an explanatory diagram of an operation of a capstan servo system of the recording / reproducing apparatus of the embodiment.

FIG. 5 is an explanatory diagram of a recording operation of the recording / reproducing apparatus of the embodiment.

FIG. 6 is a flowchart of a timing error value storage process according to the embodiment.

FIG. 7 is a flowchart of processing during append recording according to the embodiment.

FIG. 8 is an explanatory diagram of a tracking state during running-back reproduction according to the embodiment.

FIG. 9 is an explanatory diagram of an operation during append recording according to the embodiment.

FIG. 10 is a flowchart of a timing value storage process according to the embodiment.

FIG. 11 is an explanatory diagram of a tracking state during running-back reproduction according to the embodiment.

FIG. 12 is an explanatory diagram of tracks formed on a DDS3 type tape.

FIG. 13 is an explanatory diagram of a track format in the DDS3 system.

FIG. 14 is an explanatory diagram of a track of a helical scan system.

FIG. 15 is an explanatory diagram of azimuth solid recording on a track.

FIG. 16 is an explanatory diagram of a 4-head system and a 2-head system.

FIG. 17 is an explanatory diagram of a timing ATF operation.

FIG. 18 is an explanatory diagram of a reference value setting operation for timing ATF.

FIG. 19 is an explanatory diagram of an influence of a mounting position error between the reproducing head and the recording head.

FIG. 20 is an explanatory diagram of the influence of a mounting position error between the reproducing head and the recording head on the track pitch.

FIG. 21 is an explanatory diagram of a tracking state at the time of recording and reproducing by the recording / reproducing head.

FIG. 22 is an explanatory diagram of the influence on the track pitch by the tracking state during recording and reproduction by the recording / reproducing head.

[Explanation of symbols]

1 interface section, 2 index addition circuit,
3 C3 encoder, 4 C2 encoder, 5 C1 encoder, 6 memory, 7 subcode addition circuit, 8
Subcode generator, 9 Header parity addition circuit, 10
8/10 modulation circuit, 11 sync signal addition circuit, 12
Margin adding circuit, 13 recording amplifier, 14, 17 rotary transformer, 15, 15A, 15B recording head, 16, 16A, 16B reproducing head, 18 reproducing amplifier, 19 sync signal detecting circuit, 20 10/8 demodulating circuit, 21 header parity Check circuit, 22 subcode separation circuit, 23 C1 decoder, 24 C2 decoder, 25 C3 decoder, 26 index separation circuit, 27 timing detection pulse generation circuit, 28 capstan, 29 pinch roller, 30 servo circuit, 3
1 system controller, 32 drum motor driver, 33 drum motor, 34 capstan motor driver, 35 capstan motor, 36 drum P
G, 37 drum FG, 38, 39, 41 amplifier, 4
0 capstan FG, 42 oscillator, 50 rotating head drum, 61 timing ATF processing part, 62 switching pulse generating part, 63 free running counter, 64 servo switch, 65 capstan reference speed generating part, 66 subtractor, 67 speed servo signal Generator, 68EEP-ROM, 69 Delay amount register

Claims (2)

[Claims] 1. A recording head disposed on a rotary drum records data on a tape-shaped recording medium as an inclined track, and when a reproducing head reproduces data recorded as an inclined track. The tracking detection period from the time when the rotary drum reaches the reference phase position within one rotation cycle to the time when the reproduction head obtains the timing detection signal corresponding to the predetermined position on the track is measured. By comparing the measured value of 2 with the reference value of the set tracking detection period, error information is generated for the relative speed between the running speed of the tape-shaped recording medium and the rotating speed of the rotating drum, and tracking servo is performed. In the device, due to a mounting position error that affects the tracking direction of the recording head and the reproducing head. A storage means for storing the imming error value, and a measurement reference value measured in the data recorded area when the new data recording is performed following the data recorded area of the tape-shaped recording medium and the storage means. The reference value for the tracking operation is set using the timing error value that is set, and the run-back reproduction operation is performed by the reproduction head while performing the tracking servo using the reference value in the data recorded area, and the data should be recorded. A recording / reproducing apparatus, comprising: recording control means for controlling the recording operation by the recording head when the recording area is reached. 2. A recording / reproducing head disposed on a rotating drum records data on a tape-shaped recording medium as an inclined track, and when reproducing data recorded on the inclined track, a rotation is performed. The tracking detection period from the time when the drum reaches the reference phase position within one rotation cycle to the time when the recording / reproducing head obtains the timing detection signal corresponding to the predetermined position on the track is measured. By comparing the measured value with the reference value of the set tracking detection period,
In a recording / reproducing apparatus that performs tracking servo by generating error information with respect to the relative speed between the running speed of a tape-shaped recording medium and the rotating speed of a rotating drum, the operation of the recording / reproducing head should be changed when switching from reproducing to recording. A storage unit that stores a timing value according to the fluctuation amount of the tracking state, and a measurement reference value measured in the data recorded area when new data is recorded continuously in the data recorded area of the tape-shaped recording medium. And a timing value stored in the storage means is used to set a reference value for the tracking operation, and in the data recorded area, the tracking reproduction is performed using the reference value, and the run-back reproduction operation by the recording / reproduction head is performed. And when the area to be recorded is reached, recording by the recording / reproducing head is performed. Recording reproducing apparatus characterized by recording control means for performing control so as to start the work, is provided.