JPH04155663A - Disc recording/reproducing device - Google Patents

Abstract

PURPOSE:To simplify the circuitry by varying the frequency of clock for recording/reproducing data according to the track position. CONSTITUTION:When data is recorded or reproduced while rotating an optical disc 10 having sample servo format at a constant angular speed, a clock phi1 reproduced based on clock information recorded in a servo area fed from a reproducing circuit 30 is subjected to frequency conversion through a converting circuit 50 thus forming a data recording/reproducing clock phi2. On the other hand, the converting circuit 50 is controlled to vary the frequency of the data recording/reproducing channel clock phi2 according to the track position of a disc recording medium. Furthermore, a system controller 41 interrupts data recording for a predetermined time when the clock phi2 is varied.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application The present invention relates to a disk recording/reproducing device, and in particular to a disk recording/reproducing device in which recording areas for servo information such as clocks and tracking are formed intermittently in advance along the recording track direction. The present invention relates to a disc recording and reproducing apparatus that records or reproduces data on a disc having a so-called sample servo format.

B1 Summary of the Invention In the disk recording and reproducing apparatus according to the present invention, servo areas and data recording areas are arranged alternately along the recording track direction, and the servo areas are arranged radially from the center of disk rotation. A disk recording and reproducing device that records and reproduces data while rotating a formed disk recording medium at a constant angular velocity, the clock forming means forming a data recording and reproducing clock based on clock information recorded in a servo area. and controlling the clock forming means to change the frequency of the data recording and 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 and reproducing clock, By including a control means that controls to stop data recording for a predetermined period of time, the circuit that forms the data recording and reproducing clock can be configured with a simple circuit, and the decrease in recording capacity can be minimized. It is also suitable for recording or reproducing data that requires continuity, such as video and audio.

C1 Conventional technology Servo areas (for example, about 1000 to 2000 per track) are formed discretely on the recording tracks of a disk, and servo information obtained from these discrete servo areas is used to create servo areas. A so-called sample servo format disk recording medium that records or reproduces data while performing clocking or tracking, and a conventional disk recording/reproducing device that records or reproduces data using such a disk recording medium. Are known.

In this sample servo format disk recording medium, the servo areas are formed radially from the center of disk rotation so that adjacent tracks are at the same position, and the disk is moved at a constant angular velocity (CA).
V) is used to record or reproduce data.

In this case, the data recording capacity per unit track length of the disc, that is, the linear recording density, is highest at the innermost track and lowest at the outermost trough, so the maximum data recording capacity of the disc is at the innermost track. This is determined by the upper limit of recordable linear recording density, and recording is performed at a linear recording density lower than the upper limit on the outer circumferential side.

Therefore, there is a problem that only a recording capacity lower than the original recording capacity of the entire medium can be achieved, resulting in poor utilization efficiency of the medium.

Therefore, for example, as in the recording method for 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/reproducing clock is used. By increasing the frequency of a certain so-called channel clock in the outer circumference side, data is recorded or reproduced at a substantially uniform linear density on the inner and outer tracks,
We are trying to increase the recording capacity.

D1 Problem to be solved by the invention By the way, in the above-mentioned recording method for a small optical disc, the PL
After the L circuit reproduces the basic tarokku from the clock information in the servo area, this clock is divided by the frequency divider to obtain the channel clock, so there are many restrictions on the frequency of the obtained channel clock (, recording The degree of increase in capacity was small.

Therefore, for example, the present applicant first applied for patent application No. 63-3181.
In the optical disk recording and reproducing apparatus proposed in No. 59, a PLL circuit is used instead of the above-mentioned splitter to obtain a channel clock of an arbitrary frequency, thereby increasing the recording capacity.

Specifically, first, the first PLL circuit reproduces the basic clock φ of frequency f1 from the clock information in the servo area. Next, the second PLL circuit multiplies the basic clock φ1 by M/N to form a clock φ having a frequency f. Then, by using this clock φ2 as a channel clock and changing the frequency conversion ratio M/N according to the track position, a channel clock having an arbitrary frequency f according to the track position can be obtained.

By using a channel clock whose frequency is changed according to the track position obtained in this way, that is, the track number, it is possible to increase the recording density on an optical disk rotated by CAV. When changing the frequency, it takes some time for the second PLL circuit to lock onto the new frequency.

However, it is almost impossible to achieve locking of the PLL circuit while the optical head is passing through the channel clock or an unused area, i.e. the servo area, so if the optical head reaches the data area However, a new frequency channel clock will not be supplied for a while.

In addition, especially 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, resulting in a long access time. There was a problem with that.

Furthermore, data continuity is disrupted until the second PLL circuit locks, which poses a problem when recording and reproducing data that requires continuity, such as video or audio.

Therefore, in the specification and drawings of Japanese Patent Application No. 2-52802, the applicant proposed that the second PLL circuit is configured by two PLL circuits connected in parallel, and that the channel clock is set in different area units. proposed an optical disk recording and reproducing apparatus that alternately uses channel clocks output from each PLL circuit.

With such prior application technology, it is possible to increase the recording capacity of the optical disk recording medium, and it is also suitable for recording or reproducing video data and audio data that require continuity. There is a problem that the circuit becomes complicated as two PLL circuits are required.

The present invention has been made in view of the above circumstances, and is a disk recording and reproducing apparatus that uses a sample servo format disk recording medium and changes the frequency of a data recording and reproducing clock according to the track position. The purpose of the present invention is to provide a simple disk recording and reproducing device that is suitable for recording or reproducing data that requires continuity of video, audio, etc. with a reduced recording capacity or a small amount, and that is a circuit that changes the frequency of a clock for data recording and reproducing. do.

89 Means for Solving the Problems In the present invention, in order to solve the above problems, servo areas and data recording areas are arranged alternately along the recording track direction, and the servo areas are arranged radially from the center of rotation of the disk. A disk recording and reproducing device that records and reproduces data while rotating a disk recording medium formed in advance so as to be arranged in a constant angular velocity, and records and reproduces data based on clock information recorded in the servo area. The clock forming means is controlled to change the frequency of the data recording/reproducing clock from the core clock forming means and the clock forming means for forming the clock for data recording according to the track position of the disk recording medium. The apparatus is characterized by comprising a control means for controlling data recording to be stopped for a predetermined period of time when changing the frequency of the reproduction clock.

F1 action In the disk recording and reproducing apparatus according to the present invention, when the recording and reproducing head moves between areas where the data recording and reproducing clock is different, data recording is stopped for a predetermined period of time, and during that time, the next data recording and reproducing is performed stably. form a clock for use.

G. Embodiment Hereinafter, an embodiment of a disc 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 and reproducing apparatus that uses an optical disk as a disk recording medium. FIG. 1 is a block circuit diagram of the optical disk recording and reproducing apparatus, and FIG. 2 is a schematic diagram of the optical disk. FIG. 3 is a plan view showing the configuration.

First, the optical disc shown in FIG. 2 will be explained.

As shown in FIG. 2, in the optical disc lO, the servo area As
and data areas Ad are arranged alternately, and one servo area As and a continuous data area Ad constitute one segment SG. Each servo area As is formed in advance (so-called preformat) so as to be arranged radially from the disk rotation center R0. Then, using a predetermined channel clock obtained based on the clock information of the servo area As, 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. It has become. That is, the optical disc 10 has a sample servo format.

Here, the above-mentioned predetermined channel clock is the frequency f of the servo clock obtained by reproducing the clock information of the servo area As, the frequency f converted to jE-M/N times,
(=f, XM/N), and the frequency conversion ratio M
/N changes depending on the recording track number of the optical disc, that is, the position in the radial direction. This frequency conversion ratio M/
By setting N smaller on the inner circumference side and larger on the outer circumference side,
By setting the channel clock low on the inner circumferential side and high on the outer circumferential side, the linear recording density of each recording track on the inner circumference and the outer circumference is made to be approximately uniform. That is, the reference ref and data DA are stored in each data area Ad of the recording track using the frequency-converted channel clock.
This means recording or playing back. Accordingly, as shown in FIG.
The number of segments used in sector SC and the sector SC on the outer circumferential side may be different. This can be solved by managing using the reference ref recorded immediately after the servo area As.

Specifically, for example, in a 3.5-inch magneto-optical disk, the radius of each of the outermost and innermost tracks is 40 mm.
．． 0mm, 20.0mm, and 11024 between them
The tracks are arranged at a pitch of 1.45 μm.

Furthermore, each track is provided with 1344 segments. Furthermore, the servo area As of each segment has a capacity of, for example, 5 bytes, and as shown in FIG. Two pits Pt, PF, etc. for so-called gray codes for performing rack jumps, etc., are formed in advance (preformatted). Further, following this servo area As (the data area Ad has a capacity of, for example, 20 bytes of the channel clock on the innermost track, this data area Ad contains, for example, 15 bytes of sector marks, track addresses, etc.). Byte reference and data of 600 bytes (total of 512 bytes of user data and redundant code) are recorded continuously using a predetermined channel clock so that the linear density is approximately uniform regardless of the track position. It looks like this.

That is, the above-mentioned wobble ping (PA) in the reproduced RF signal,
Tracking servo is applied so that the difference in detection strength of P becomes zero. Furthermore, since there are 25 bytes of channel pits on the innermost track between the clock pit PCs in the servo area As, the clock pit PC detection period is set to 200 (=8X2
5) The signal of the predetermined frequency f1 to be divided is divided into the basic clock φ,
Then, a clock φ2 with a frequency f, (=f, XM/N) obtained by converting the frequency f of this basic clock φ1 by M/N times.
Reference and data are recorded or reproduced using this as a channel clock. At this time, the frequency conversion ratio M/N is determined according to the disk radial direction.

In this way, by changing the channel clock according to the track position, it is possible to make the recording density of an optical disk approximately uniform between the inner and outer troughs, and to increase the storage capacity of the medium. There is.

As shown in FIG. 1, an optical disk recording and reproducing apparatus using an optical disk having a sample servo format as described above includes an optical disk 10 having a sample servo format and a recording track of the optical disk 10 scanned with a laser beam to record data. an optical head 21 for recording and reproducing;
Basic clock φ1 of frequency f1 for data recording and reproduction based on the clock information of the servo area of the optical disc 10.
a clock regeneration circuit 30 for regenerating the clock regeneration circuit 30, and a frequency conversion circuit 50 for converting the basic clock φ1 from the clock regeneration circuit 30 by M/N times to form a clock φ2 with a frequency f.
, a digital equalizer 25 that equalizes the reproduced signal using the clock φ from the frequency conversion circuit 50 as a channel clock, an encoder 42 that encodes recorded data using the clock φ as a channel clock, and Conversion circuit 50 and encoder 42
It has a system controller 41 etc. that controls the above.

The optical disk 10 is rotated by a spindle motor 20 at a constant angular velocity (CAV), and as the disk rotates, an optical head 21 or the optical disk 10 is scanned with a laser beam, thereby optically (or magneto-optically) reading data. It is designed to be recorded or played back.

Inside the optical head 21, there are provided a laser light source that is driven by a laser drive circuit 22 to output laser light for data recording and reproduction, and a photodetector that detects the reflected light of the laser light from the laser light source by the optical disk 10. ing.

The reproduced RF signal from the optical head 21 is supplied from the first preamplifier 23 of the data reproduction processing system to the digital equalizer 25 via the A/D (analog/digital) converter 24, subjected to equalization processing, and then sent to the decoder. Reproduction digital data D at 26. It is decoded into ol and output. The reproduced 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 as well as 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, this head servo circuit 28 detects a tracking error based on the reproduction output of the two optical pits PA, P for tracking and performs tracking servo control, and also utilizes the pit-free reflective surface portion of the servo area As. to perform focus servo control. Also,
The spindle servo circuit 29 detects the rotation angle error of the spindle motor 20 based on the reproduction output of the clock pit PC and controls the motor drive circuit 40.
By controlling the spindle motor 20 to rotate,
Spindle servo control is performed so that the optical disk IO rotates at a constant angular velocity (CAV).

The clock reproducing circuit 30 generates a basic clock φ, which is synchronized with the clock pit Pc detection pulse in the reproduced RF signal obtained from the optical head 21 via the preamplifier 27 and has a frequency 200 times higher (the frequency 1+). It consists of a PLL circuit that outputs . The basic clock φ1 from the clock regeneration circuit 30 is sent to a frequency conversion circuit 50 using a PLL circuit or the like. Further, the basic clock φ1 is sent to the head servo circuit 28 and the spindle servo circuit 29, respectively.

The frequency conversion circuit 50 converts the frequency f1 of the basic clock φ from the clock regeneration circuit 30 into a frequency f1 times M/N,
This frequency conversion ratio M/N is controlled by the system controller 41 so as to change depending on the track address of the track being scanned by the optical head 21. That is, the frequency conversion circuit 50 includes a first programmable divider that divides the input basic clock φ1 into 1/N, and a PLL circuit system (7).
VCO oscillation output (frequency f, = f, XM/N) by 1/M
A second programmable divider is provided, and a clock φ having a frequency f is obtained by performing PLL control so that the phase difference between the output signals from these two programmable dividers becomes 0. ing. The frequency division ratios of each of these programmable dividers, l/N and 1/M, are provided as control data D from the system controller 41. .

D, is variably controlled. When the scanning track of the optical head 21 is on the inside, the conversion ratio M/N is decreased to keep the frequency f low, and as the scanning track is on the outside, M/N is increased to keep the frequency f! By increasing the
The linear recording density on the optical disk 10 is controlled so as to be substantially uniform on all tracks.

In this way, the frequency conversion circuit 50 has a frequency f corresponding to the radial position (track address) of the recording track.
The tarock φ from the channel clock φ is sent to the phase control circuit 60 as a channel clock. This phase control circuit 60 outputs a clock for operating the A/D converter 24, equalizer 25, etc. Further, the clock φ from the frequency conversion circuit 50 is sent as a channel clock to the encoder 42 of the data recording system. In the recording mode, the encoder 42 converts input references such as sector marks and track addresses and recording data DIN into recording timing pulses synchronized with the clock φ, and supplies the pulses to the laser drive circuit 22. There is.

By the way, in order to obtain the clock φ with the frequency f2 corresponding to the track position, the PLL circuit of the frequency conversion circuit 50 must be locked, and for the PLL circuit to lock,
As mentioned above, a certain amount of lead-in time is required. Therefore, in the present invention, when changing the frequency f2 of the clock φ2 as described above, the system controller 41
For example, as shown in FIG.
, Z6, . The encoder 42 is controlled so as to stop for a predetermined period of time.

Specifically, the system controller 41 controls the optical head 2
1 or, for example, when moving from area Z to area Z2, the time required for the PLL circuit of the frequency conversion circuit 50 to pull in, the last area of the last track of area Z1 (in FIG. The encoder 42 is controlled to stop recording data to the area). As a result, no data is recorded in the last area of the final track of each area Z1, Z2, . . . (hereinafter, this area where no data is recorded is referred to as a gap GAP). That is, during data recording, data is not recorded while the optical head 21 scans the gap GAP and the PLL circuit of the frequency conversion circuit 50 performs a pull-in operation, and the optical head 21 moves from area Z1 to area Zt, for example. At the time of transition, the PLL circuit of the frequency conversion circuit 50 is locked to the new frequency, and data can be recorded from the first sector Sl+ of area Z using the channel clock of the new frequency. Also, when reproducing data, the optical head 21
While the AP is being scanned and the PLL circuit of the frequency conversion circuit 50 is performing a pull-in operation, data is not reproduced, and the optical head 21 is moving from, for example, area Z1 to area Z! At the time of transition, the PLL circuit of the frequency conversion circuit 50 is locked to the new frequency, and data can be reproduced from the first sector Sl+ of the area Z* using the channel clock of the new frequency. In other words, the frequency f of the clock φ.

By stopping data recording for a predetermined time to provide a gap GAP in which no data is recorded when changing the frequency, it is possible to secure the pull-in time of the PLL circuit of the frequency conversion circuit 50.

In this case, according to the present invention, the frequency conversion circuit 50 that forms the channel clock for data recording and reproduction can be configured with one PLL circuit as described above.

By the way, the channel clock, that is, the clock φ,
When the frequency f of is changed, the recording capacity per track changes, so the recording capacity per track becomes 1
It is not an integral multiple of the sector capacity (number of bytes), and a fraction is generated. Therefore, if the predetermined time for stopping data recording, that is, the size of the gap described above, is larger than this fractional region or the region corresponding to the pull-in time of the PLL circuit of the frequency conversion circuit 50, it is set as this fractional region as it is. If the fractional area is smaller than the area corresponding to the pull-in time, the area is the fractional area plus an area for one sector. Note that by providing a gap in which no data is recorded, the storage capacity of the entire medium is reduced, but this reduction is due to, for example, the channel clock being divided into 10 different areas (zoning).
For example, on a 00MB optical disc, the capacity of one sector is 5
If it is 12 bytes, it will be 4608 (=512×9) bytes. Therefore, the degree of decrease is approximately 2
IO-"(#4608÷200MB), which has almost no effect.

Furthermore, when recording or reproducing data that requires continuity, such as video or music, the data is continuously input to a buffer memory provided inside the encoder 42 that absorbs the gaps. Once the data is stored, the data is read out from this buffer memory and recorded. Also, when reproducing data, the reproduced data is first stored in a buffer memory provided inside the decoder that absorbs the gap. Accumulate and output the accumulated data continuously. That is, data continuity can be ensured by once recording data in a buffer memory that absorbs gaps in this way and then recording or reproducing the data.

As described above, in the optical disk recording and reproducing apparatus to which the present invention is applied, when recording and reproducing data while rotating the optical disk 10 having the sample servo format at a constant angular velocity, data is recorded in the servo area from the clock reproducing circuit 30. The frequency conversion circuit 50 converts the frequency of the clock φ, which is reproduced based on the clock information, to form the data recording/reproducing clock φ, (channel clock). The system controller 41 controls the frequency conversion circuit 50 to change the frequency of the channel clock according to the track position of the disk recording medium, and also controls to stop data recording for a predetermined time when changing the frequency of the channel clock. By doing so, the frequency conversion circuit 50 that changes the frequency of the channel clock for data recording and reproduction can be configured with a simple circuit.

Furthermore, the reduction in recording capacity caused by stopping data recording and creating a gap has little effect on the recording capacity of the entire medium because the capacity of the gap is small.

In addition, the capacity of the gap is small, and data discontinuity caused by the gap can be easily absorbed by a buffer memory, making it suitable for recording or reproducing data that requires continuity, such as video and audio. .

It should be noted that the present invention is not limited to the above-mentioned embodiments, and for example, various magneto-optical disks, write-once optical disks, etc. can be used as the optical disk IO. Furthermore, it goes without saying that the apparatus for recording or reproducing data on or from an optical disc is not limited to the example shown in FIG.

H1 Effects of the Invention As is clear from the above explanation, in the present invention, the servo areas and the data recording areas are arranged alternately along the recording track direction, and the servo areas are arranged radially from the center of rotation of the disk. A disk recording and reproducing device that records and reproduces data while rotating a preformed disk recording medium at a constant angular velocity, and forms a clock for data recording and reproduction based on clock information recorded in a servo area. A clock forming means, 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, and changing the frequency of the data recording/reproducing clock. Furthermore, by providing a control means for controlling the stopping of data recording for a predetermined period of time, the clock forming means for forming the data recording/reproducing clock can be constructed with a simple circuit.

Furthermore, the reduction in recording capacity caused by stopping data recording and creating a gap has little effect on the recording capacity of the entire medium because the gap capacity is small.

In addition, the capacity of the gap is small, and data discontinuity caused by the gap can be easily absorbed by a buffer memory, making it suitable for recording or reproducing data that requires continuity, such as video and audio. .

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram of an optical disc recording/reproducing apparatus to which the disc recording/reproducing apparatus according to the present invention is applied;
This figure is a plan view showing a schematic structure of an optical disk used in this optical disk recording/reproducing apparatus, and FIG. 3 is a plan view showing a schematic structure of an optical disk for explaining gaps in which no data is recorded. lO...Optical disk 30...Clock regeneration circuit 50...Frequency conversion circuit 41...System controller

Claims (1)

[Scope of Claims] A disk recording medium is provided in which servo areas and data recording areas are arranged alternately along the recording track direction, and the servo areas are arranged radially from the center of rotation of the disk. A disk recording and reproducing device that records and reproduces data while rotating at a constant angular velocity, comprising: a clock forming means that forms a data recording and reproducing clock based on clock information recorded in the servo area; and the clock forming means. The clock forming means is controlled to change the frequency of the data recording/reproducing clock from the disk according to the track position of the disk recording medium, and when changing the frequency of the data recording/reproducing clock, the data recording/reproducing clock is controlled to What is claimed is: 1. A disc recording/reproducing apparatus comprising: a control means for controlling a stop for a predetermined period of time.