JP3077185B2 - Disk recording and playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk recording / reproducing apparatus, and in particular, a recording area for servo information such as a clock and a tracking is preliminarily formed intermittently along a recording track direction. The present invention relates to a disk recording / reproducing apparatus for recording or reproducing data on a disk having a so-called sample servo format.

B. Summary of the Invention In the disk recording / reproducing apparatus according to the present invention, the servo areas and the data recording areas are alternately arranged along the recording track direction, and the servo areas are arranged radially from the disk rotation center. A disk recording / reproducing apparatus for recording / reproducing data while rotating a pre-formed disk recording medium at a constant angular velocity, comprising: a clock generator for forming a data recording / reproducing clock based on clock information recorded in a servo area. Means and controlling the clock forming means to change the frequency of the data recording / reproducing clock from the clock forming means in accordance with the track position of the disk recording medium, and when changing the frequency of the data recording / reproducing clock, Control means for stopping data recording for a predetermined time, The circuit that forms the raw clock can be configured with a simple circuit, and the reduction in recording capacity can be reduced, making it suitable for recording or reproducing data that requires continuity such as video and audio. It is made possible.

C. Prior Art Servo areas (for example, about 1000 to 2000 pieces per track) are discretely formed in advance on recording tracks of a disk, and servo information is obtained using servo information obtained from these discrete servo areas. Such as recording or reproducing data while performing clocking and tracking between areas,
2. Description of the Related Art A disk recording medium of a so-called sample servo format and a disk recording / reproducing apparatus for recording or reproducing data using such a disk recording medium are conventionally known.

In the disk recording medium of this sample servo format, the servo area is generally formed so as to be at the same position between adjacent tracks, that is, radially from the center of rotation of the disk.
The recording or reproduction of data is performed while rotating in V).

In this case, since the data recording capacity per unit track length of the disk, that is, the linear recording density is the highest at the innermost track and the lowest at the outermost track, the maximum data recording capacity of the disk is equal to the innermost track. It is determined by the upper limit of the recordable linear recording density, and recording is performed on the outer peripheral side at a linear recording density lower than the upper limit. Accordingly, only a recording capacity lower than the original recording capacity of the entire medium can be realized, and there is a problem that the use efficiency of the medium is poor.

Therefore, for example, as in the recording method of a small optical disk disclosed in Japanese Patent Application Laid-Open No. 1-204272, the recording track of the optical disk is divided into a plurality of areas in the radial direction (so-called zoning), and a data recording / reproduction clock is used. By increasing the frequency of a certain so-called channel clock toward the outer peripheral region, data is recorded or reproduced at substantially uniform linear density on the inner and outer tracks, thereby increasing the recording capacity.

D. Problems to be Solved by the Invention By the way, in the recording method for a small optical disc described above, the PL
After the basic clock is reproduced from the clock information in the servo area by the L circuit, this clock is frequency-divided by the frequency divider to obtain the channel clock. The degree of increase was small.

Therefore, for example, in the optical disk recording / reproducing apparatus proposed by the present applicant in Japanese Patent Application No. 63-318159, a channel clock having an arbitrary frequency is obtained by using a PLL circuit instead of the frequency divider. The recording capacity has been increased.

Specifically, first, to reproduce the basic clock phi ₁ of frequency f ₁ from the clock information of the servo area by the first PLL circuit. Next, the basic clock phi ₁ to form a clock phi ₂ of frequency f ₂ by M / N times by the second PLL circuit. By this clock phi ₂ and channel clock, is changed according to the frequency conversion ratio M / N to the track position, any frequency corresponding to the track position
it is possible to obtain a channel clock of f _2.

By using the channel clock whose frequency is changed according to the track position obtained in this way, that is, the track number, the recording density can be increased in the optical disc rotated by CAV, but the frequency of the channel clock is changed. In this case, it takes time until the second PLL circuit locks to the new frequency. However, it is almost impossible to lock the PLL circuit while the optical head is passing through the area where the channel clock is not used, that is, the servo area. For a while, the channel clock of the new frequency is not supplied.

In particular, when seeking a new recording track by a so-called track jump operation, a channel clock suitable for the target track cannot be obtained for a while immediately after accessing the target track, and as a result, the access time is long. There was a problem of becoming.

Furthermore, since the continuity of data is impaired until the second PLL circuit is locked, there is a problem in recording and reproducing data requiring continuity such as video and audio.

In view of the above, the applicant of the present application has disclosed in the specification and drawings of Japanese Patent Application No. 2-52802 that the second PLL circuit is constituted by two PLL circuits connected in parallel with each other, and the channel clocks are set in different domain units. Has proposed an optical disk recording / reproducing apparatus that alternately uses the channel clock output from each PLL circuit.

According to such prior art, the recording capacity of the optical disk recording medium can be increased, and the recording and reproduction of video data and audio data that require continuity can be adapted. There is a problem that the circuit becomes complicated, for example, two PLL circuits are required.

The present invention has been made in view of such circumstances, and is a disk recording and reproducing apparatus that uses a disk recording medium of a sample servo format and changes the frequency of a data recording and reproducing clock according to a track position,
The present invention is intended to provide a disk recording / reproducing apparatus in which a decrease in recording capacity is small, suitable for recording or reproducing data requiring continuity of video and audio, and a circuit for changing a frequency of a data recording / reproducing clock is simple. I do.

E. Means for Solving the Problems In the present invention, in order to solve the above problems, servo areas and data areas are alternately arranged along the recording track direction, and the servo areas are radially A disk recording and reproducing apparatus for recording and reproducing data in sector units while rotating a disk recording medium formed in advance so as to be arranged at a constant angular velocity, based on clock information recorded in the servo area. Clock forming means for forming a data recording / reproducing clock;
When controlling the clock forming means so as to change the frequency of the data recording / reproducing clock from the clock forming means in accordance with the track position of the disk recording medium, and changing the frequency of the data recording / reproducing clock. If the remaining area obtained by dividing the recording capacity per track by the capacity of one sector is larger than the area corresponding to the pull-in time required for the frequency pull-in by the clock forming means, the above-mentioned time is equal to the remaining area. When the control for stopping data recording is performed and the surplus area is smaller than the area corresponding to the pull-in time, the data recording is performed for a time corresponding to an area obtained by adding an area for one sector to the surplus area. And control means for performing control to stop.

F. Function In the disk recording / reproducing apparatus according to the present invention, when the recording / reproducing head shifts to a region where the frequency of the data recording / reproducing clock is different, the recording capacity per track is divided by the capacity of one sector. When the surplus area is larger than the area corresponding to the pull-in time required for the frequency pull-in by the clock forming means, the data recording is stopped for a time corresponding to the surplus area, and the surplus area corresponds to the pull-in time. When the area is smaller than the corresponding area, the data recording is stopped for a time corresponding to the area obtained by adding the area for one sector to the surplus area, and a stable next data recording / reproducing clock is formed during that time. .

G. Embodiment Hereinafter, an embodiment of a disk recording / reproducing apparatus according to the present invention will be described with reference to the drawings.

In this embodiment, the present invention is applied to an optical disk recording / reproducing apparatus using an optical disk as a disk recording medium. FIG. 1 is a block circuit diagram of the optical disk recording / reproducing apparatus, and FIG. 2 shows a schematic configuration of the optical disk. It is a top view.

Here, the optical disk shown in FIG. 2 will be described first.

As shown in FIG. 2, in the optical disc 10, servo areas As and data areas Ad are alternately arranged along a recording track direction which is a disc rotation direction, and a data area Ad continuous with one servo area As is provided. And one segment SG
Is composed. Each servo area As is a disk rotation center R. Are formed in advance (so-called pre-format) so as to be radially arranged from. Then, the servo area As
Using a predetermined channel clock obtained based on the above clock information, addresses such as so-called sector marks and track addresses (hereinafter referred to as reference ref) and a predetermined number of data DA are continuously recorded. That is, the optical disk 10 has a sample servo format.

Here, the predetermined channel clock is a frequency f ₂ (f ₁ × M / N) obtained by converting the frequency f ₁ of the servo clock obtained by reproducing the block information of the servo area As into M / N times.
The frequency conversion ratio M / N changes according to the recording track number of the optical disc, that is, the position in the radial direction. By setting this frequency conversion ratio M / N small on the inner circumference side and larger on the outer circumference side, the channel clock is set lower on the inner circumference side and higher on the outer circumference side, so that the line of each recording track on the inner circumference and outer circumference is The recording density is made substantially uniform. That is, the reference ref and the data AD are recorded or reproduced in each data area Ad of the recording track using the frequency-converted channel clock. Therefore, as shown in FIG.
A sector SC having a fixed number of bytes consisting of f and data AD is
The number of segments to be used differs between the inner sector SC and the outer sector SC.
The problem can be solved by performing management using the reference ref recorded immediately after.

Specifically, for example, in a 3.5-inch magneto-optical disk, each radius of the outermost track and the innermost track is 4
0.0mm, 20.0mm, between which 11024 tracks are 1.
They are provided at a 45 μm pitch. Also, each track has
There are 1344 segments. Further, the servo area As of each segment has a capacity of, for example, 5 bytes. In the servo area As, for example, as shown in FIG. 2, so-called wobble pits P _A for tracking servo,
P _B, so-called clock pit P _C for clock recovery, two pits P _E for the so-called Gray code to perform a track jump or the like, P _F, etc. is formed in advance (pre-formatted). The data area Ad following the servo area As
Has a capacity of, for example, 20 bytes of the channel clock in the innermost track, and in this data area Ad,
For example, a 15-byte reference such as a sector mark and a track address and 600-byte data (total of 512-byte user data and a redundant code) have a substantially uniform linear density regardless of the track position using a predetermined channel clock. So that they are recorded continuously.

That is, the wobble pits P _A and P _B in the reproduced RF signal
The tracking servo is applied so that the difference between the detected intensities becomes zero. Between the clock pit P _C of the servo area As, since will be 25 bytes of channel bits at the inner periphery of the track top is present, 200 detection period of the clock pit P _C (= 8 × 25 ) signals of predetermined frequency f ₁ for dividing the basic clock phi _1, the basic clock phi ₁ of frequency f ₂ to the frequency f ₁ is converted to M / N times (= f ₁ × M
/ N) of the recording or reproduction of the reference and data using the clock phi ₂ as the channel clock is executed. At this time, the frequency conversion ratio M / N is determined according to the disk radial direction.

As described above, by changing the channel clock in accordance with the track position, the recording density of the optical disk can be made substantially uniform between the inner and outer tracks, and the storage capacity of the medium can be increased. I have.

As shown in FIG. 1, an optical disk recording / reproducing apparatus using an optical disk having the sample servo format as described above scans a recording track of the optical disk 10 with a sample servo format with a laser beam and reads data. an optical head 21 for recording and reproducing, a clock reproducing circuit 30 for reproducing a basic clock phi ₁ of frequency f ₁ for data recording and reproduction based on the clock information of the servo area of the optical disk 10, from the clock recovery circuit 30 the basic clock phi ₁ the frequency converting circuit 50 for forming a clock phi ₂ of frequency f ₂ is converted to M / N times, equalizes the reproduction signal by using the clock phi ₂ from the frequency converting circuit 50 as a channel clock a digital equalizer 25, end to encode record data by using also the clock phi ₂ as channel clock And over da 42 comprises a system controller 41 for controlling the frequency conversion circuit 50 and the encoder 42 and the like.

The optical disk 10 is rotationally driven at a constant angular velocity (CAV) by a spindle motor 20, and an optical head 21 scans the optical disk 10 with a laser beam along with the rotation of the disk, thereby optically (or magneto-optically) transferring data. It is designed to record or play back.

In the optical head 21, a laser light source that is driven by a laser driving circuit 22 and outputs a laser beam for data recording and reproduction,
A photodetector or the like for detecting the reflected light of the laser light from the laser light source by the optical disc 10 is provided. The reproduced RF signal from the optical head 21 is supplied from an A / D (analog / digital) converter 24 to a first preamplifier 23 of a data reproduction processing system.
Is supplied to a digital equalizer 25 through which the digital signal is subjected to an equalizing process, and the decoder 26 decodes and outputs the reproduced digital data _DOUT . The reproduction RF signal is supplied from the second preamplifier 27 of the servo information reproduction processing system to the head servo circuit 28 and the spindle servo circuit 29, and is also supplied to the clock reproduction circuit 30.

The head servo circuit 28 drives and controls a so-called two-axis actuator in the optical head 21 to perform tracking servo and focus servo. That is, the head servo circuit 28 performs tracking servo control by detecting a tracking error based on the reproduction output of the wobble pits P _A and P _B for tracking, and also removes the pit-free reflection surface portion of the servo area As. The focus servo control is performed using this. The spindle servo circuit 29 on the basis of the reproduction output of the clock pit P _C described above, and controls the motor drive circuit 40 detects the rotation angle error of the spindle motor 20, by rotating the drive control of the spindle motor 20 Then, the spindle servo control is performed so that the optical disk 10 rotates at a constant angular velocity (CAV).

The clock recovery circuit 30 includes a preamplifier 27 from the optical head 21.
The clock pit P _C during playback RF signal obtained through the
Synchronization with the detection pulse is taken and 200 times the frequency and a PLL circuit for outputting a basic clock phi ₁ of (the frequency f _1). Basic clock phi ₁ from the clock reproducing circuit 30 is sent to a frequency conversion circuit 50 formed by using a PLL circuit or the like. The basic clock φ ₁ is sent to the head servo circuit 28 and the spindle servo circuit 29, respectively.

Frequency converting circuit 50, the frequency f ₁ of the fundamental clock phi ₁ from the clock recovery circuit 30, which converts the M / N times the frequency f _2, the frequency conversion ratio M / N, the optical head 21 is It is controlled by the system controller 41 so as to change according to the track address of the track being scanned. That is, the frequency conversion circuit 50, a first programmable divider for dividing the basic clock phi _1, which is input to the 1 / N, VCO oscillation output of the PLL circuit system (frequency f ₂ = f ₁
× M / N) is divided into 1 / M, and a second programmable divider is provided. By performing PLL control so that the phase difference between the output signals from these two programmable dividers becomes 0, to obtain the clock φ ₂ of frequency f _2. The division ratio of each of these programmable dividers
The 1 / N and 1 / M, the control data D _N from the system controller 41 variably controls the D _M. Then, when the scanning track of the optical head 21 is inside suppressing the frequency f ₂ by reducing the conversion ratio M / N, as the scanning track on the outside M /
By increasing the frequency f ₂ by increasing the N, linear recording density on the optical disk 10 is not controlled to be substantially uniform at any track.

Thus, the clock phi ₂ from the frequency conversion circuit 50 which is a frequency f ₂ corresponding to the radial position of the recording track (track address) is sent to the phase control circuit 60 as a channel clock. From this phase control circuit 60,
A clock for operating the A / D converter 24, the equalizer 25, and the like is output. The clock phi ₂ from the frequency conversion circuit 50 is sent as a channel clock to the encoder 42 of the data recording system. The encoder 42, when the recording mode, so as to supply the reference and the recording data D _IN, such as the input sector mark and track address is converted to a recording timing pulse synchronized with the clock phi ₂ to the laser drive circuit 22 I have.

Meanwhile, in order to obtain a clock phi ₂ of frequency f ₂ in accordance with the track position has to lock PLL circuit of the frequency converter circuit 50, the lock of the PLL circuit, some pull-in time, as described above Is required. Therefore,
In the present invention, the system controller 41 when changing the frequency f ₂ of the clock phi ₂ as described above, for example 3
As shown in the figure, when the optical head 21 shifts to the zones Z ₁ , Z _2, ... Having different frequencies of the channel clocks divided (zoned) in the radial direction, the optical head 21 scans a new area. At the start time, the encoder 42 is controlled so that the data recording is stopped for a predetermined time so that the PLL circuit of the frequency conversion circuit 50 is locked to the new frequency.

Specifically, the system controller 41
When migrating but for example from the region Z ₁ in the region Z _2, the time required for retraction of the PLL circuit of the frequency converter 50, the region Z ₁
(In the Figure 3 the following areas of the sector S ₁₀₎ last region of the last track of controlling the encoder 42 to stop the data record for. As a result, no data is recorded in the last area of the last track of each area Z ₁ , Z ₂ ,... (Hereinafter, an area where this data is not recorded is referred to as a gap GAP). That is, during data recording, the optical head 21 scans the gap GAP, while the PLL circuit of the frequency converter circuit 50 is a pull-in operation is not performed to record the data, area optical head 21, for example, from the region Z ₁ Z at the time of the transition to _2, PLL circuit of the frequency converter circuit 50 is locked to the new frequency, the data recording is possible by using the channel clock of the new frequency from the head of the sector S ₁₁ region Z _2. During data reproduction, the optical head 21 scans the gap GAP, and data is not reproduced while the PLL circuit of the frequency conversion circuit 50 is performing the pull-in operation.
At the time but a transition example from the region Z ₁ in the region Z _2, PLL circuit of the frequency converter circuit 50 is locked to the new frequency, by using the channel clock of the new frequency from the head of the sector S ₁₁ region Z ₂ Data reproduction becomes possible. In other words, when changing the frequency f ₂ of the clock phi _2, by providing the gap GAP which data is not recorded by stopping the data recording predetermined time, ensuring the pull-in time of the PLL circuit of the frequency converter 50 Can be. In this case, in the present invention, the frequency conversion circuit 50 that forms the channel clock for data recording and reproduction can be configured by one PLL circuit as described above.

By the way, the channel clock, that is, the clock φ
Varying the _second frequency f _2, the recording capacity per track is changed, the recording capacity per track 1
It does not become an integral multiple of the capacity of the sector (the number of bytes), but a fraction (too much) occurs. Therefore, the predetermined time for stopping data recording, that is, the size of the gap, that this fractional area is larger than the area corresponding to the pull-in time of the PLL circuit of the frequency conversion circuit 50 is regarded as this fractional area as it is,
If the fractional area is smaller than the area corresponding to the pull-in time, the fractional area is added to the area for one sector. By providing a gap in which data is not recorded in this manner, the storage capacity of the entire medium is reduced. For example, in a 200 MB optical disk in which the channel clock is divided (zoned) into ten areas different from each other, For example, if the capacity of one sector is 512 bytes, it is 4608 (= 512 × 9) bytes. Therefore, the degree of the decrease is about 2 × 10 ^-3 (≒ 4608 ÷ 200MB)
And has almost no effect.

When recording or reproducing data requiring continuity, such as video and music, when recording data, the data is continuously input to a buffer memory provided inside the encoder 42 for absorbing the gap, for example. The data to be read out is temporarily stored, the data is read out from the buffer memory and recorded, and at the time of data reproduction, the reproduced data is temporarily stored in a buffer memory provided inside the decoder, for example, to absorb the gap. It accumulates and outputs the accumulated data continuously. That is, by recording data once in the buffer memory that absorbs the gap and recording or reproducing the data, continuity of data can be ensured.

As described above, in the optical disc recording / reproducing apparatus to which the present invention is applied, when recording / reproducing data while rotating the optical disc 10 having the sample servo format at a constant angular velocity, the data recorded in the servo area from the clock reproducing circuit 30 is recorded. and frequency conversion to form a data recording and reproducing clock phi _{2 (channel} clock) in the frequency converting circuit 50 of the clock phi _1, which is reproduced on the basis of it being a clock information, channel for data recording and reproduction from the frequency conversion circuit 50 The system controller 41 controls the frequency conversion circuit 50 to change the frequency of the clock in accordance with the track position of the disk recording medium, and stops the data recording for a predetermined time when changing the frequency of the channel clock. Changes the frequency of the channel clock for data recording and playback The frequency conversion circuit 50 to be performed can be configured by a simple circuit.

In addition, the decrease in the recording capacity due to the stoppage of data recording and the provision of the gap has a small gap capacity and hardly affects the recording capacity of the entire medium.

In addition, the gap capacity is small, and the discontinuity of data due to the gap can be easily absorbed by the buffer memory, and can be adapted to the recording or reproduction of data requiring continuity of video and audio. .

It should be noted that the present invention is not limited to only the above-described embodiment. For example, as the optical disk 10, various magneto-optical disks, write-once optical disks, and the like can be used. Further, it goes without saying that an apparatus for recording or reproducing data on or from an optical disk is not limited to the example shown in FIG.

H. Effects of the Invention As is clear from the above description, in the present invention, the servo areas and the data areas are alternately arranged along the recording track direction, and the servo areas are radially arranged from the disk rotation center. A disk recording / reproducing apparatus for recording / reproducing data in sector units while rotating a disk recording medium formed in advance at a constant angular velocity, wherein the data recording / reproducing is performed based on clock information recorded in the servo area. Clock forming means for forming a clock for use in recording, and controlling the clock forming means so as to change the frequency of the data recording / reproducing clock from the clock forming means in accordance with the track position of the disk recording medium; When changing the frequency of the reproduction clock, the recording capacity per track is reduced by the capacity of one sector. If the remaining area is larger than the area corresponding to the pull-in time required for frequency pull-in by the clock forming means, control is performed to stop the data recording for a time corresponding to the remaining area, and the remaining area is controlled. Is smaller than the area corresponding to the pull-in time, by providing control means for controlling to stop the data recording for a time corresponding to an area obtained by adding an area for one sector to the surplus area, The clock forming means for forming the data recording / reproducing clock can be constituted by a simple circuit.

In addition, the decrease in the recording capacity due to the stoppage of data recording and the provision of the gap has a small gap capacity and hardly affects the recording capacity of the entire medium.

In addition, the gap capacity is small, and the discontinuity of data due to the gap can be easily absorbed by the buffer memory, and can be adapted to the recording or reproduction of data requiring continuity of video and audio. .

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of an optical disk recording and reproducing apparatus to which the disk recording and reproducing apparatus according to the present invention is applied.
FIG. 3 is a plan view showing a schematic configuration of an optical disk used in the optical disk recording / reproducing apparatus. FIG. 3 is a plan view showing a schematic configuration of the optical disk for explaining a gap in which data is not recorded. 10 optical disk 30 clock reproduction circuit 50 frequency conversion circuit 41 system controller

Claims (1)

(57) [Claims] 1. A disk recording medium formed in advance so that servo areas and data areas are alternately arranged along the recording track direction and the servo areas are radially arranged from the center of rotation of the disk. A disk recording / reproducing apparatus for recording / reproducing data in sector units while rotating at a clock rate, comprising: clock forming means for forming a data recording / reproducing clock based on clock information recorded in the servo area; Controlling the clock forming means so as to change the frequency of the data recording / reproducing clock from the means in accordance with the track position of the disk recording medium, and changing the frequency of the data recording / reproducing clock by one track The remaining area obtained by dividing the recording capacity per unit by the capacity of one sector is used as the clock forming means. If it is larger than the area corresponding to the pull-in time required for the frequency pull-in, control is performed to stop the data recording for the time corresponding to the surplus area, and the surplus area is smaller than the area corresponding to the pull-in time. A disk recording / reproducing apparatus comprising: a control unit for performing a control to stop the data recording for a time corresponding to an area obtained by adding an area for one sector to the surplus area when the area is small.