JPH0554608A - Rotary head type recording and reproducing device - Google Patents

Abstract

PURPOSE:To always rerecord a correct signal in a correct area by controlling relation between a positioning signal and a switching signal to be fixed at the time of rerecording of a part of a recording track. CONSTITUTION:Error DELTAt between a time difference (t) between a switching signal SWP and a first sampling pulse ATFS1 and a format is detected to discriminate whether the error DELTAt is positive or negative. When it is positive, the extent of delay of the switching signal SWP is increased because the position of the sampling pulse ATFS1 is later than the format and the delay quantity is small. When it is negative, the delay quantity of the switching signal SWP is reduced since the position of the sampling pulse ATFS1 is eariler than the format and the extent of delay is large. Consequently, the switching signal SWP in fixed relation to the first sampling pulse ATFS1 is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is, for example, a rotary head type DA.
The present invention relates to a rotary head type recording / reproducing apparatus suitable for application to T (digital audio tape recorder).

[0002]

2. Description of the Related Art A rotary head type DAT as shown in FIGS. 5 to 11 has been proposed. In the figure, 1A and 1B are rotary heads, and 2 is a magnetic tape as a recording medium.
As shown in FIG. 6, the rotary heads 1A and 1B are arranged around the guide drum 3 at equal angular intervals, that is, at intervals of 180 degrees. On the other hand, the magnetic tape 2 is narrower than its 180 degree angular range around the tape guide drum 3, for example, 9
Wrapped over the 0 degree angle range. Then, the rotary heads 1A and 1B move at an arrow 4H at a rate of 30 revolutions per second.
7 and the tape 2 is run at a predetermined speed in the direction indicated by the arrow 4T, and the rotary heads 1A and 1B move the magnetic tape 2 on the magnetic tape 2 one by one as shown in FIG. 5A ₁ , 5B ₁ , 5A ₂ , 5B
₂ ... Is formed, for example, in a so-called overwritten state. That is, the width of the head gap (scanning width)
W is made larger than the track width. In this case, the width directions of the gaps of the rotary heads 1A and 1B are different from the direction orthogonal to the scanning direction. That is, the so-called azimuth angles are made different.

Then, there occurs a period in which the two rotary heads 1A and 1B are not in contact with the tape 2 together (this is a period corresponding to an angular range of 90 degrees in this example), and this period is used. The apparatus can be simplified by adding redundant data during recording and by performing correction processing during reproduction.

FIG. 5 shows the structure of this rotary head type DAT, and 6 shows two rotary heads 1A, 1 as shown in FIG.
B, a traveling system of the magnetic tape 2, and a mechanical system portion including the tape guide drum 3. The mechanical system portion 6 also includes an electromagnetic conversion system such as a high frequency amplifier.

Reference numeral 7 denotes a mechanical system control CPU that controls and servos the mechanical system unit 6 in accordance with an instruction from a main central control unit (main CPU) 8. The mechanical system control CPU 7 will be described later from the mechanical system unit 6. The position signals f ₂ and f ₃ , and the drum PG obtained in association with the rotation of the rotary heads 1A and 1B
The pulse and the drum FG pulse are supplied, and the equal positioning signals f ₂ , f ₃ and the drum PG pulse and the drum F are supplied.
A control signal obtained in response to the G pulse is supplied to the mechanical system unit 6 so that the mechanical system unit 6 can be variously controlled as well known.

Reference numeral 9 denotes a signal processing unit for processing a recording data signal and a reproduction data signal in accordance with a command from the main CPU 8. The recording data signal from this signal processing unit 9 is supplied to the rotary head of the mechanical system unit 6. The reproduction data signal obtained by the mechanical system unit 6 is transmitted to the signal processing unit 9
Supply to. Also, for example, 30H obtained by the signal processing unit 9
The z reference signal REF is supplied to the mechanical system control CPU 7.

Further, the CPU 7 for controlling the mechanical system obtains a switching signal SWP of, for example, 30 Hz as shown in FIG. 8A of the rotary heads 1A and 1B based on the drum PG pulse, and outputs the rotary head switching signal SWP to the mechanical system section 6 and the signal. It is supplied to the processing unit 9, respectively. FIG. 8B shows a period in which the rotary heads 1A and 1B are in contact with the magnetic tape 2.

A sampling pulse ATFS for detecting a pilot signal f ₁ for auto-tracking, which is obtained from the positioning signals f ₂ and f ₃ , is supplied to the signal processor 9. Recording tracks 5A ₁ , 5B ₁ , 5A on the magnetic tape 2
_When re-recording a part of ₂ , 5, B ₂ ... (After-recording mode), the signal processing section 9 obtains an after-record window signal W ₀ indicating a recording area with reference to the sampling pulse ATFS, and this after-record window signal W _0. Are supplied to the mechanical system section 6. In this case, when the positioning signals f ₂ and f ₃ are not reproduced well, the switching signal SW
An after-record window signal W ₀ is formed with P as a reference.

As shown in FIG. 7, the recording format of this DAT track is a margin section 5M of 11 blocks and a subcode section 5 of 11 blocks along the longitudinal direction of the track.
S, 11 blocks of ATF section 5T ₁ , 130 blocks of PCM signal section 5P, 11 blocks of ATF section 5T ₂ , 1
One block of sub-code portion 5S and 11 blocks of margin portion 5M are arranged in sequence. Where 1
The block has 360 channels and 38.3 μsec.

This ATF section 5T₁Is the first track 5B
₁At 3 blocks along the length of the track
Erase signal f_FourPart, 1 block second positioning signal f
₃Part, 2 blocks of erasing signal f_FourPart, 2 blocks
Ilot signal f₁Signal f for partial and three blocks_FourDepartment
Consisting of a second track 5A₁3 blocks in
Erasing signal f_FourPart, 2 blocks of pilot signal f₁
Part, 1 block erase signal f_FourPart, 1 block first
Positioning signal f of₂Signal for erasure of a part and 4 blocks_Four
Part 3 and a third track 5B₂In 3 blocks
Elimination signal f_FourPart, 0.5 block, 2nd position
Signal f₃, 2.5 block erase signal f_FourPart, 2
Block pilot signal f₁Parts and 3 blocks
Signal f _FourPart 4 and the fourth track 5A₂At
Is an erasing signal f of 3 blocks_FourPart, 2 block pyro
Signal f₁Part, 1 block erase signal f_FourPart, 0.
First positioning signal f of 5 blocks₂Part and 4.5 Bro
Clock erasing signal f_FourThis ATF part 5T₁
The above is arranged so as to be repeatedly and sequentially arranged. Also
ATF part 5T₂Is the ATF part 5T as shown in FIG.₁Is symmetric
It was placed in.

The frequency of the pilot signal f ₁ is set to, for example, 130.67 KHz, and is recorded at a relatively high level. The frequency of the pilot signal f ₁ is preferably a frequency with a relatively small azimuth loss as long as the linearity of the tracking phase shift and the pilot reproduction output can be guaranteed.

The first and second positioning signals f ₂ and f ₃ also serve as the erasing signal of the pilot signal f ₁ , and the previously recorded information is erased by superposing it on the previously recorded magnetic tape. However, when a new recording is performed, the recording track does not always coincide with the previous recording track. Therefore, it is also used when it is necessary to erase the pilot signal f ₁ previously recorded. The frequencies are practically different from the frequencies of the pilot signal f ₁ , for example, 5 each.
22.67 KHz and 784.00 KHz. Further, the recording level of the pilot signal f ₁ can be practically erased.

As for the erasing signal f ₄ , when the pilot signal f ₁ and the positioning signals f ₂ and f ₃ are overwritten by this, the erasing rate of these signals f ₁ , f ₂ and f ₃ is high. Preferably, the frequency is, for example, 1.568
MHz is used.

This AFT section 5T₁Using trackin
When controlling, it is done as follows. now
For example, the rotary head 1B has a track 5B.₂Scan width W including
When scanning the range of,
B₂5A on both sides of₁, 5A₂Run across
(See FIG. 9A), and at this time, the pilot signal detection times
On the output side of the road, as shown in FIG.₁
And 5A₂Relatively low level pilot signal f₁
And truck 5B₂Higher level pilot than
Signal f ₁Is obtained.

At this time, a first sampling pulse ATFS ₁ for sampling the pilot signal f ₁ of the first adjacent track 5A ₁ as shown in FIG. 9C is formed in synchronism with the rising edge of the positioning signal f ₃ , and the first sampling pulse ATFS ₁ is formed. A second sampling pulse ATFS ₂ for sampling the pilot signal f ₁ of the second adjacent track 5A ₂ as shown in FIG. 9D is formed by delaying the _first sampling pulse ATFS ₁ by a predetermined time, and the first and _second sampling pulses ATFS ₂ are formed. Sampling pulse ATFS ₁
And ATFS ₂ sample the pilot signal f ₁ as shown in FIG. 9B, and perform tracking control so that the levels of the pilot signal f ₁ sampled by the first and second sampling pulses ATFS ₁ and ATFS ₂ become equal. To do. The same applies when scanning other tracks by the rotary heads 1A and 1B.

In such a DAT, it is possible to perform recording and reproduction favorably by performing tracking control as described above.

Further, for example, the subcode portion 5 of the recording track
When re-recording S (subcode after recording), ATF
When the position finding signals f ₂ and f _{3 of the} section T ₁ are reproduced well, the first sampling pulse ATFS ₁ obtained from the position finding signals f ₂ and f ₃ is used as a reference in FIG.
Forming a dubbing window signal W ₀ as shown in F, subcode portion 5 in this post-recording window signal W ₀ region present example corresponding to the after-recording window signal W ₀
S can be rerecorded well. 10A is a reference signal REF of 30 Hz from the signal processing unit 9, FIG. 10B is an envelope of a high frequency signal of a reproduction signal of the rotary head 1A or 1B, FIG. 10C is a rotary head switching signal SWP, and FIG.
D shows the first sampling pulse ATFS ₁ , and FIG. 10E shows the recording data signal.

When the subcode portion 5S is rerecorded,
Kini ATF Department T₁Positioning signal f of ₂, F₃Is good again
When it is not generated, the rotary head switching signal SWP is used as a reference.
After-record window signal W₀Is formed. in this case
It is recorded on the magnetic tape 2 according to the format of the track.
If so, the edge of the switching signal SWP and the first sample
Ng pulse ATFS₁Time difference x is a fixed value x₀And
You can re-record in the correct area as above.
It

[0019]

However, the ATF part T
Positioning signal f ₂ of _1, f ₃ is not satisfactorily reproduced, and A of the magnetic tape 2 for example offset rather than format as the track 11 (FIG. 11, B, C, D, E, F are each 10 corresponds to A, B, C, D, E, and F in FIG. 10), the after-recording window signal W ₀ is formed on the basis of the rotary head switching signal SWP when the recording is performed while being shifted forward. At this time, the dubbing window signal W ₀ corresponds to a portion of the reproduction signal which is deviated from the sub-code portion 5S as shown by the hatched line in FIG. It was

This was the same not only when re-recording the sub-code portion 5S but also when re-recording other portions. The present invention has been made in view of the above problems, and an object thereof is to always be able to re-record a correct signal in a correct area.

[0021]

DISCLOSURE OF THE INVENTION Rotary head type recording according to the present invention
For example, the playback device may include a plurality of rotary heads as shown in FIGS.
Diagonal track 5A depending on drive 1A, 1B₁, 5B₁，
5A₂, 5B₂... is formed on the recording medium 2 and recorded,
This truck 5A₁, 5B₁, 5A₂, 5B₂...... each
In the longitudinal direction, the data signal and
Racking pilot signal f₁Record with position
Output signal f₂, F₃When recording and reproducing, the scanning width W is
Recording track 5A₁, 5B₁, 5A₂, 5B₂…… width
The wider rotary heads 1A and 1B make this recording track
5A₁, 5B₁, 5A₂, 5B ₂When scanning ...
And this positioning signal f₂, F₃Sample based on
Ng pulse ATFS₁, ATFS₂Forming this sun
Pulling pulse ATFS₁, ATFS₂During this period
The moving heads 1A and 1B move from the relevant track being scanned.
Pilot signal f₁Is detected and the detected output signal
Therefore, tracking control of the rotary heads 1A and 1B is performed.
And the rotation of the rotary heads 1A and 1B
The rotary position pulse obtained by
To obtain the switching signal SWP for the plurality of rotary heads 1A, 1B
In the rotary head type recording / reproducing device configured as described above,
When re-recording a part of the recording track, this position
Issue f₂, F₃And the relationship between this switching signal SWP and
This variable delay means is controlled so that
is there.

[0022]

According to the present invention, since the relationship between the position finding signals f ₂ and f ₃ and the switching signal SWP is made constant,
Even if the recording format of the track is deviated and the position finding signals f ₂ and f ₃ are not reproduced well, the dubbing window signal W ₀ corresponding to the correct area can be obtained with the switching signal SWP as a reference and always correct. The correct data signal can be re-recorded in the area.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the rotary head type recording / reproducing apparatus of the present invention will be described below with reference to FIGS. This Figure 1
In FIG. 5, parts corresponding to those in FIG. 5 are designated by the same reference numerals and detailed description thereof will be omitted.

In FIG. 1, the mechanical system unit 6 includes two rotary heads 1A and 1B, a running system for the magnetic tape 2, a tape guide drum 3 and an electromagnetic conversion system such as a high frequency amplifier as shown in FIG. This mechanical system unit 6 is a CPU for mechanical system control
7, the control such as auto-tracking and servo are applied in accordance with the command from the main CPU 8. For this reason, the mechanical system control CPU 7 sends a positioning signal f to the mechanical system control CPU 7.
₂ , f ₃ , and the drum PG pulse and the drum FG pulse related to the rotation of the rotary heads 1A and 1B are supplied. This drum PG pulse is generated by one rotation of the rotary heads 1A and 1B.
As shown in FIG. 3B, one drum FG pulse is obtained so that 24 pulses can be obtained as shown in FIG. 3C for one rotation of the rotary heads 1A and 1B. The 24 FG pulses are obtained. Are set to "1", "2", "3" ... "23" and "0" in the order of occurrence after the drum PG pulse.

In the signal processing unit 9, the main CPU 8
The recording data signal and the reproduction data signal are processed in accordance with the command. The recording data signal from the signal processing unit 9 is supplied to the rotary heads 1A and 1B of the mechanical system unit 6, and the reproduction data signal obtained by the mechanical system unit 6 is supplied to the signal processing unit 9. ..

Further, for example, 30H obtained by the signal processing unit 9
A reference signal REF of z as shown in FIGS. 2A and 3A is supplied to the mechanical system control CPU 7. In the mechanical system control CPU 7, the reference signal REF and the drum P
A control signal is supplied to the mechanical system unit 6 so as to apply the speed servo and the phase servo so that the phase of the G pulse is matched.

In the CPU 7 for controlling the mechanical system, the first sampling pulse ATFS ₁ and the second sampling pulse ATFS ₁ as shown in FIGS. 9C and 9D are obtained from the positioning signals f ₂ and f ₃ from the ATF sections T ₁ and T ₂ of the track. Sampling pulse A
In addition to forming TFS ₂ , the pilot signal f ₁ is sampled by the first and second sampling pulses ATFS ₁ and ATFS ₂ to form an auto-tracking signal and supply the auto-tracking signal to the mechanical system section 6. There is.

Further, it is obtained by the CPU 7 for controlling the mechanical system.
First sampling pulse ATFS ₁Signal processing unit 9 and
And the sub CPU 10. This sub CPU 10
In addition, as shown in FIG.
To supply the PG pulse and the drum FG pulse.
It

The sub CPU 10 is adapted to generate the switching signal SWP for the rotary heads 1A and 1B. The sub CPU 10 has a delay timer for generating the switching signal which operates as shown in FIG. 3D. The delay timer pulse is set at the rising edge of the 23rd pulse of the FG pulse (delay timer pulse rising edge), and the delay timer is reset (falling edge of the delay timer pulse) at the falling point of the delay timer pulse and the first sampling pulse ATFS ₁ The delay timer is reset, that is, the falling point of the delay timer pulse is controlled so that the time difference t from the rising point of the delay timer becomes the value x ₀ according to the format.
As shown in FIG. 3E, the switching signal SWP for the rotary head whose switching point is the falling point of the delay timer pulse is generated.

Specifically, the switching signal SW of the rotary head 1A
P switching point (edge) and first sampling pulse AT
FS₁Format ta of the time difference from the trailing edge of₀Is 1
148.0 μsec, switching signal of the rotary head 1B
SWP switching point (edge) and first sampling pulse
ATFS₁Format tb of the time difference from the rising point of ₀
Is 1033.2 μsec.

The time difference t between the switching signal SWP and the first sampling pulse ATFS ₁ is measured by a free running counter (built-in microcomputer).

In the sub CPU 10, as shown in FIG. 4, the switching signal SWP and the first sampling pulse ATF.
An error Δt between the time difference t from S ₁ and the format ta ₀ or tb ₀ is detected, and it is determined whether the error Δt is positive or negative.
When this error Δt is positive, this sampling pulse AT
The position of FS ₁ is slower than the format and the switching signal S
Since the delay amount of the WP is small, the delay amount of the switching signal SWP is controlled so as to be large, and when the error Δt is negative, the position of the sampling pulse ATFS ₁ is earlier than that in the format, and the delay amount of the switching signal SWP is faster. Because there are many
The delay amount of the switching signal SWP is controlled to be small. Therefore, the sub CPU 10 can obtain the switching signal SWP having a constant relationship with the _first sampling pulse ATFS ₁ .

In practice, the rotary head 1A and the rotary head 1
The format of the time difference between the switching signal SWP and the sampling pulse ATFS ₁ for each of B is ta ₀ and tb.
Since it is different from ₀ , the error Δta Δta = t−ta ₀ in the rotary head 1A and the error Δtb Δtb = t−tb ₀ in the rotary head 1B are measured, and the guide drum 3 rotates once (one cycle of the switching signal SWP). Let Δt be the error detected in step Δt = (Δta + Δtb) / 2, and the delay timer for the switching signal be controlled by this Δt.

The rotary head switching signal SWP obtained by the sub CPU 10 is supplied to the signal processing section 9 and the mechanical system section 6.

In the present example, when a part of the recording tracks 5A ₁ , 5B ₁ , 5A ₂ , 5B ₂ ... Of the magnetic tape 2 is re-recorded (after-recording mode), the signal processing unit 9 uses the first Sampling pulse ATFS
₁ rerecording region to form dubbing window signal W ₀ indicating as reference, also based on the switching signal SWP for the rotary head when the positioning signal f _2, f ₃ not well reproduced, showing the re-recording area The after-record window signal W ₀ is formed, and this after-record window signal W ₀ is supplied to the mechanical system section 6. The after-record window signal W _{0 for} the partial re-recording can be selectively made to correspond to the sub-code section 5S and the PCM signal section 5P according to the instruction of the main CPU 8. In this example, the sub-code section 5S is re-recorded. It shall be. Other configurations are similar to those of the conventional rotary head type DAT.

Since this example is constructed as described above, it operates similarly to the conventional rotary head type DAT, and good recording and reproduction can be performed.

In addition, the sub-code portion 5S of the recording track is reproduced again.
ATF part when recording (sub-code dubbing)
T₁Positioning signal f of₂, F₃Is playing well
Sometimes this positioning signal f₂, F₃Figure obtained
First sampling pulse ATFS as shown in 2D₁To
As a reference, an after-record window signal W as shown in FIG. 2F ₀
To form this dubbing window signal W₀By this
Dubbing window signal W₀Area corresponding to
2E shows the subcode portion 5S of the reproduced signal shown in FIG. 2B.
Re-record with sub-data of recording data signal as shown
You can

When the subcode portion 5S is rerecorded,
Kini ATF Department T₁Positioning signal f of ₂, F₃Is good again
If it is not generated, it is based on the rotary head switching signal SWP.
Dubbing window signal W as an associate₀To form. This place
In the present example, as shown in FIG. 2C, this switching signal SW
P is the switching point (edge) and the first sampling pulse.
ATFS₁So that the time difference t between
Format recording of tracks on the magnetic tape 2.
This first sample pudding whether or not
Gpulse ATFS₁In the correct area as well as
The correct signal can be rerecorded.

This is not only for re-recording the sub-code portion 5S, but also for re-recording a part of the PCM signal portion 5P, such as a part of the PCM signal portion 5P. Can be re-recorded.

In the above embodiment, the three CPUs of the main CPU 8, the mechanical system control CPU 7 and the sub CPU 10 are used, but the function of the CPU 10 may be added to the main CPU 8 or the other three CPUs. It goes without saying that the CPUs 8, 7 and 10 may be one multifunctional CPU. Further, in the above-described embodiment, the example in which the present invention is applied to the rotary head type DAT has been described, but it can be easily understood that the present invention can be applied to other rotary head type recording / reproducing devices. Further, the present invention is not limited to the above-described embodiments, and needless to say, various other configurations can be adopted without departing from the gist of the present invention.

[0041]

According to the present invention, there is an advantage that the correct signal can always be re-recorded in the correct area.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a rotary head type recording / reproducing apparatus of the present invention.

FIG. 2 is a diagram for explaining the present invention.

FIG. 3 is a diagram for explaining generation of a switching signal SWP according to the present invention.

FIG. 4 is a diagram for explaining a sub CPU 10.

FIG. 5 is a configuration diagram showing an example of a conventional rotary head type DAT.

FIG. 6 is a plan view showing an example of a DAT rotary head device.

FIG. 7 is a diagram showing an example of a DAT tape pattern.

FIG. 8 is a diagram for explaining switching of the rotary head.

FIG. 9 is a diagram for explaining auto-tracking.

FIG. 10 is a diagram for explaining re-recording of a part of a recording track.

FIG. 11 is a diagram for explaining re-recording of a part of a recording track.

[Explanation of symbols]

1A, 1B Rotating head 2 Magnetic tape 3 Guide drum 5A ₁ , 5B ₁ , 5A ₂ , 5B ₂ ... Magnetic track 6 Mechanical system unit 7 Mechanical system control CPU 8 Main CPU 9 Signal processing unit 10 Sub CPU

Claims (1)

[Claims] 1. An oblique track is formed and recorded on a recording medium by a plurality of rotary heads, and a tracking pilot signal is recorded on each of the tracks in the longitudinal direction independently of a data signal as a recording area and at the same time. An output signal is recorded, a sampling pulse is formed on the basis of the position output signal when the recording track is scanned by a rotary head whose scanning width during reproduction is wider than the width of the recording track, and the rotation is performed during the sampling pulse. The head detects the pilot signal from the associated track being scanned, and the detection output signal is used to perform tracking control of the rotary head, and the rotary position pulse obtained in association with the rotation of the rotary head is delayed by a variable delay. Rotary head type recording means for obtaining the switching signals of the plurality of rotary heads through means. In the recording / reproducing apparatus, the variable delay means is controlled so that the relationship between the positioning signal and the switching signal becomes constant when re-recording a part of the recording track. Rotating head type recording / reproducing device.