JPH1021555A - Optical disk, and device and method for recording and reproducing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to access an optical position based on wobbling information in a disk having groove and land tracks. SOLUTION: In the even number frame of a groove track N, its track number N is recorded, and the track number N-1 one track inside is recorded in an odd number frame. In the odd number frame of a groove track N+1, its track number N+1 is recorded, and the track number N one track inside is recorded in the even number frame. A larges one is selected from track numbers read during making accessing to the groove track. A track number correctly read without producing any errors during making access to a land track is selected as a track number for a track being accessed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk, an optical disk recording / reproducing apparatus and method, and more particularly to an optical disk for recording data on both a groove track and a land track, and wobbling both side walls of the groove track. The present invention relates to an optical disc, an optical disc recording / reproducing apparatus, and a method capable of recording address information.

[0002]

2. Description of the Related Art In order to record data on a disk, it is necessary to record address information so that data can be recorded at a predetermined position. Conventionally, as a method of recording address information on an optical disc for recording and reproduction,
2. Description of the Related Art There is known a method of wobbling a pre-groove formed in advance on a spiral on a disk in order to perform tracking in accordance with address information.

That is, a track for recording data is formed in advance as a pre-groove, and the side wall of the pre-groove wobbles (meanders) in accordance with the address information. In this way, an address can be read from the wobbling information, a desired position can be accessed, and data can be recorded.

By the way, in order to realize higher density, by forming a pre-groove (groove),
It has been proposed to record data also on relatively formed lands. That is, in this case, both the groove and the land are used as tracks, and data is recorded on both the groove track and the land track.

[0005]

However, when data is recorded on both the groove track and the land track as described above, there is a problem that it becomes difficult to record an address due to wobbling.

The present invention has been made in view of such a situation, and it is an object of the present invention to enable an address to be recorded by wobbling even on a disk on which data is recorded on both a groove track and a land track. .

[0007]

According to the optical disk of the present invention, a track on which address information is recorded by wobbling is divided into a plurality of frames, and the first frame among the frames has a groove track. Is recorded, and the address information of the land track is recorded in the second frame.

According to another aspect of the present invention, there is provided an optical disk recording / reproducing apparatus for reading address information recorded by wobbling, determining whether an access point is on a groove track or a land track, When the access point is located on one of the track and the land track, the address information read by the reading means is detected as the address information of the access point, and when the access point is located on the other of the groove track and the land track. Detecting means for comparing the size of the address information read from each frame and detecting the address of the access information point in accordance with the result of the comparison.

[0011] In the optical disk recording / reproducing method according to the eleventh aspect, the address information recorded by wobbling is read, and it is determined whether the access point is on the groove track or the land track. When the access point is located at one of the two positions, the read address information is detected as the address information of the access point. When the access point is located at the other of the groove track and the land track, the address information read from each frame is detected. The size is compared, and address information of an access point is detected according to the comparison result.

[0010] In the optical disk according to the first aspect,
The track on which the address information is recorded by wobbling is divided into a plurality of frames.
In a first frame, address information of a groove track is recorded, and in a second frame, address information of a land track is recorded.

In the optical disk recording / reproducing apparatus according to the present invention, when the access point is located on one of the groove track and the land track, the read address information is read. When the access point is detected as the address information of the access point and the access point is located on the other of the groove track and the land track, the size of the address information read from each frame is compared. Address information is detected.

[0012]

FIG. 1 shows an example of the configuration of an optical disk according to the present invention. As shown in FIG. 1, a groove track 2 is formed on a disk (optical disk) 1 in advance in a spiral manner from the inner circumference to the outer circumference. Of course, the groove track 2 can be formed concentrically. Also, like this, the groove track 2
Is formed in advance, a land track 3 is formed between the groove track 2 and the adjacent groove track 2. In the present invention, both the groove track 2 and the land track 3 are tracks.
Data is recorded and reproduced in each case.

As shown in FIG. 1, a part of the groove track 2 is enlarged in FIG. 1, and its left and right side walls are wobbled in accordance with the address information and meander at a predetermined cycle.

FIGS. 2 and 3 show how the groove track 2 and the land track 3 are formed in this way. In the embodiment of FIG. 2, the radius of the groove track 2 and that of the land track 3 are set so as to form independent spirals (for even one track, the track is equivalent to two even tracks (in this embodiment, two tracks)). (Displaced in the direction).

On the other hand, in the embodiment of FIG.
The groove track 2 and the land track 3 are alternately displaced in the radial direction on one spiral every turn (one turn of the track makes an odd number of tracks (one track in this embodiment)). ) Is formed.

In any case, in the present invention, address information is recorded by wobbling only in one of the groove track 2 and the land track 3 (in this embodiment, the groove track 2). The left and right side walls of the groove track 2 are wobbled in accordance with the same address information.

One track (one groove track 2) is divided into a plurality of wobbling address frames, and each wobbling address frame has a configuration as shown in FIG.

As shown in FIG. 4, the wobbling address frame is composed of 60 bits, and the first 4 bits are:
This is a synchronization signal (Sync) indicating the start of the wobbling address frame. The next 4 bits are a layer (Layer) indicating which of the plurality of recording layers it is. The next 20 bits are used as a track address. The next four bits indicate the frame number of the wobbling address frame. The remaining 14 bits are used as an error correction code (CRC), and an error detection code excluding a synchronization signal (Sync) and a clock synchronization mark area (Sync mark) described later is recorded.
The next 12 bits are used as a clock synchronization mark area (note that, as will be described later with reference to FIG. 6, this area is actually arranged in a distributed manner, one bit at a time). The last two bits (Reserved) are reserved for future use.

For example, eight wobbling address frames are formed for one track (one round), and a CAV (Constant Angular) in which the rotational angular velocity of the disk is constant.
Velocity) Recorded on a disk.

FIG. 5 shows an example of a conversion table for converting address information into gray code. Here, for the sake of simplicity, a unit of gray-coded information is represented by ch (channel) for convenience. As shown in the figure, in the Gray code, the upper 4 ch and the lower 4 ch are 1of4 codes respectively. That is, 4
One predetermined channel among the channels is “1”, and the other three channels are “0”. Therefore, the upper channel and the lower channel are “0001”, “0010”,
One of the four patterns “0100” and “1000”. Thus, the upper channel and the lower c
Since four patterns can be set for h, respectively, the upper channel and the lower channel are combined to form 8 channels.
Then, 16 values from 0 to F (hexadecimal) can be represented.

As shown in FIG. 4, the track address and the frame address in the address information of the wobbling address frame are gray-coded based on the conversion table shown in FIG. Since the track address is 20 bits, it is divided into five groups (groups Tr1 to Tr5) of 4 bits each. That is, each group has 4 bits. Next, each data of the group Tr1 to the group Tr5 is converted into 8-ch gray code according to the conversion table shown in FIG. On the other hand, the frame address is 4
Since it is a bit, it is directly converted into an 8-ch gray code according to the conversion table shown in FIG.

In this way, the 20-bit track address is converted to a 40-ch gray code, and the 4-bit frame address is converted to an 8-ch gray code. Other address information remains unchanged. As a result, the address frame is converted into a code of 84 channels in total.

As shown in FIG. 5, as the data associated with the gray code changes from the value 0 to the value F, “1” is set in the lower 4 ch of the corresponding gray code. Move to the adjacent channel one channel at a time. When the value changes from the value F to the value 0, only the upper channel “1” moves while the lower channel remains unchanged. If the number of changed channels or the number of bits is defined as “information change amount”, the information change amount in this case is 2 or less in the lower channel.

On the other hand, if the value 0 is represented by “0000” and the value F is represented by “1111”, the amount of change in information when the value F changes to 0 is 4. Further, the value 0 is changed to “0”.
If it is expressed as 000 ", all bits are 0, and it may be difficult to detect it as information. Therefore, it is preferable to perform gray coding as in the embodiment.

As described above, by performing the gray code, the amount of change in information can be reduced, and the detection of information can be facilitated. Further, the gray-coded information indicates that all of the upper channels or lower channels are 0.
This also makes it easier to detect information.

For example, when the optical head moves to an adjacent track at the time of seeking or the like and reproduces the track address recorded on that track, if the track address is gray-coded as described above, the track address is , The lower ch of the gray code corresponding to the channel changes sequentially by 1 ch. Therefore, by detecting only the lower channel, it is possible to recognize that the head has moved to the next track. In this way, it is possible to move (seek) to a predetermined track at a high speed.

As described above, since the track address and the frame address are gray-coded, the seek can be performed while detecting only the lower bits.
High-speed access to a desired frame of a desired track becomes possible.

FIG. 6 shows a clock synchronization mark area and a clock synchronization mark (Fine Clock Mark) by channels. As described above, each wobbling address frame is composed of data of 84 channels (ch). Assuming that one channel is represented by seven waves (carriers) of a signal of a predetermined frequency as shown in FIG.
There will be 588 (= 84 × 7) waves in the frame. Assuming that the optical disk 1 is rotated, for example, at 1200 revolutions per minute, the frequency of this carrier is 94.08 (=
(588 × 8 × 1200/60) / 1000) kHz.

As shown in FIG. 6, the 12-bit clock synchronization mark area of the wobbling address frame shown in FIG. 4 is arranged for every 7 channels.
That is, data is recorded with a period of 7 ch. 7
The first one of the channels is a clock synchronization mark (Fine
Clock Mark) and the remaining 6 carriers
The ch is a section modulated by substantial address data not including the fine clock mark. Therefore,
In one frame, 12 (= 84/7) ch (fine) clock marks and 72 (= 84 × 6/7) ch
Thus, (clock) data is recorded, and 96 (= 12 × 8) ch (number) fine clock marks are recorded in one rotation (one track).

The gray code corresponding to the address information is
After the bi-phase modulation, the groove track 2 is frequency-modulated (wobbled). In the clock synchronization mark area, the wobbling frequency of the groove is set to the center frequency of the gray code modulation frequency corresponding to the address information. Alternatively, the frequency is set to a predetermined frequency higher than the modulation frequency of the gray code.

The clock synchronization mark is used to change the modulation of recording / reproducing data by using EFM (Eight To Fourteen Modulatio
n: (8-14) modulation), the wavelength is 6 to 8T
Is recorded as a one-wavelength signal having a length of

FIG. 7 shows an example of the configuration of a wobbling signal generating circuit for generating a wobbling signal for wobbling the groove track 2. Generation circuit 11
Generates a signal having a frequency of 188.16 kHz, for example.

The signal generated by the generation circuit 11 is supplied to a division circuit 12, where the signal is divided by a value of 7, and the frequency is 26.8.
It is supplied to the bi-phase modulation circuit 13 as an 8-kHz bi-phase clock signal. The gray code conversion circuit 16 also controls the biphase modulation circuit 13 for AD conversion.
IP (Address In Pre-groove)
Data obtained by converting data into Gray code is supplied.

The ADIP data is, for example, data corresponding to a wobbling address frame as shown in FIG.

The biphase modulation circuit 13 includes a divider 12
The bi-phase clock supplied thereto is bi-phase modulated by the gray code supplied from the gray code conversion circuit 16, and a bi-phase signal is output to the FM modulation circuit 15. A carrier having a frequency of 94.08 kHz obtained by dividing the signal of 188.16 kHz generated by the generation circuit 11 by a value of 2 by the divider 14 is also input to the FM modulation circuit 15. The FM modulation circuit 15 frequency-modulates the carrier input from the divider 14 with the bi-phase signal input from the bi-phase modulation circuit 13 and outputs a resulting FM signal. Disc 1
The left and right side walls of the groove track 2 are formed (wobbled) in accordance with the FM signal.

FIGS. 8 and 9 show the bi-phase modulation circuit 13.
2 shows an example of a bi-phase signal output from. Data bits (Data Bits) are bi-phase modulated and converted into channel bits (Channel Bits). SYNC
Is an “outof rule” pattern that does not appear in modulation. "Wave Form"
Is a pattern in which channel bits "1" are converted into an H pattern and "0" is converted into an L pattern.

In this embodiment, when the preceding bit is 0, as shown in FIG. 8, "11101000" is used as the synchronization pattern, and when the preceding bit is 1, the synchronization pattern is As shown in FIG. 9, "00010111" is used.

FIG. 10 schematically shows track numbers recorded by wobbling on each groove track as described above.

As shown in the figure, in the groove track N, its own track number N is recorded in the even-numbered frames (frame 0, frame 2, frame 4, frame 6). On the other hand, in odd-numbered frames (frame 1, frame 3, frame 5, frame 7), the track number N-1 of the inner circumference of one track is recorded.

In the groove track N + 1 on the outer periphery of one track, its own track number N + 1 is recorded in an odd frame, and the inner track number N of one track is recorded in an even frame.

Further, in the groove track N + 2 on the outer circumference of one track, a track number is recorded according to the same rule as that of the groove track N, and the groove track N + 3 on the outer circumference (groove track N- on the inner circumference of one track from the groove track N). 1), the track number is recorded according to the same rule as that for the groove track N + 1.

That is, when the groove track N is being accessed, its own track number N is read from the even-numbered frame, and the track number N-1 of the inner circumference of one track is read from the odd-numbered frame. On the other hand, in the groove track N + 1, its own track number N + 1 is read from the odd-numbered frame, and the track number N of the inner circumference of one track is read from the even-numbered frame.

In other words, in the groove track, the larger of the two track numbers read for each frame is the track number of the own track.

On the other hand, when the land track N is being accessed, its own track number N is read in an even frame, but in an odd frame, an inner track and an outer track are read. ,
Since a different track number is recorded, the read track number becomes an error (substantially cannot be read). When the land track N + 1 is reproduced, the track number N corresponding to its own track number is shifted from the left and right groove tracks in the odd frame.
While +1 can be read, in an even frame, different track numbers are read from the left and right groove tracks, and a substantially correct track number cannot be read.

Therefore, when a land track is reproduced, the track number that can be read correctly is its own track number.

Whether the light spot (access point) formed on the optical disk 1 is located on the groove track or on the land track depends on the polarity of the tracking error signal when the access point exists on the groove track. Since the polarity is reversed between the case where it exists on the land track and the case where it exists on the land track, it can be determined from the polarity.

FIG. 11 shows the data bits and the channel bits in the groove track N and the land track N on the outer periphery thereof, the groove track N + 1 on the outer periphery thereof, and the biphase signal corresponding to the channel bit.

In this embodiment, the data bit "0" is converted to a channel bit "00" or "11", and the data bit "1" is converted to a channel bit "01" or "10". Which channel bit is selected depends on the preceding channel bit, and the preceding channel bit is "0".
In the case of, the one with "1" at the beginning is selected, and when the preceding channel bit is "1", the one with "0" at the beginning is selected.

The channel bit "0" is represented by 3.5 waves, and the channel bit "1" is represented by four waves. Whether each wave starts with a positive or negative half-wave depends on the previous wave,
The phase of the leading wave is determined so as to be continuous with the immediately preceding wave.

As described with reference to FIG. 10, the track number N is recorded in the even frame of the groove track N, and the track number N-1 is recorded in the odd frame.
Is recorded. On the other hand, the groove track N + 1
In, the track number N is recorded in the even-numbered frame, and the track number N + 1 is recorded in the odd-numbered frame. Accordingly, the track numbers in the even-numbered frames are the same in the groove track N and the groove track N + 1, and differ by 2 bits in the odd-numbered frames. Therefore, the bi-phase modulated channel bits are also different from each other by two channels.

FIG. 11 shows that the lower 5 bits “01000” of the gray code “00101000” corresponding to the data 7 in FIG.
-1 and the groove track N + 1
The gray code “0100” corresponding to the data 9 in FIG.
The lower 5 bits “00100” of “0100” represent a state where the track number N + 1 is recorded.

FIG. 12 shows an example of the configuration of a recording apparatus for manufacturing a disk 1 having a groove track 2 and a land track 3. Wobbling signal generation circuit 21
Is configured as shown in FIG. 7, and outputs an FM signal to the synthesis circuit 22. The mark signal generating circuit 23 generates a mark signal at the timing of forming a synchronization mark, and outputs the signal to the synthesizing circuit 22. The synthesis circuit 22
An FM signal output from the wobbling signal generation circuit 21;
The signal and the mark signal output from the mark signal generation circuit 23 are combined and output to the recording circuit 24. The recording circuit 24 is provided with an optical head 25 corresponding to the signal supplied from the synthesizing circuit 22.
Is generated, and a laser beam for forming a synchronization mark with the groove track 2 (land track 3) on the master 26 is generated. The spindle motor 27 rotates the master 26 at a predetermined speed.

That is, the wobbling signal generation circuit 21
Is generated in the synthesizing circuit 22 with the mark signal output from the mark signal generating circuit 23,
The data is input to the recording circuit 24. The recording circuit 24 controls the optical head 25 according to the signal input from the synthesizing circuit 22 to generate a laser beam. The laser light generated by the optical head 25 is applied to a master 26 rotated at a predetermined speed by a spindle motor 27.

The master 26 is developed, a stamper is created from the master 26, and a number of replica disks 1 are formed from the stamper. Thus, the disk 1 on which the groove track 2 having the above-described clock synchronization mark is formed can be obtained. The land tracks 3 are relatively formed by forming the groove tracks 2.

FIG. 13 shows an example of the configuration of an optical disk recording / reproducing apparatus for recording or reproducing data on the disk 1 thus obtained. The spindle motor 31 rotates the disk 1 at a predetermined speed. The optical head 32 (reading means) irradiates the disk 1 with a laser beam, records data on the disk 1, and reproduces data from the reflected light.

The tracking and focusing servo circuit 47 generates a tracking error signal based on the principle of the push-pull method, and performs tracking servo of the optical head 32 in accordance with the tracking error signal. Further, a focusing error signal is generated based on the astigmatism method, and a focusing servo is executed in accordance with the focusing error signal. The tracking and focusing servo circuit 47 also determines the polarity of the tracking error signal, and outputs the result of the determination to the frame address detection circuit 37.

The recording / reproducing circuit 33 temporarily records the recording data input from a device (not shown) in the memory 34. When the data of, for example, one cluster as a recording unit is stored in the memory 34, Is read out, modulated by a predetermined method, and output to the optical head 32. Here, for example, one cluster can be composed of eight sectors, and one sector can be composed of 28 frames. Further, the recording / reproducing circuit 33
Demodulates the data input from the optical head 32 as appropriate,
The data is output to a device (not shown).

The address generating / reading circuit 35 includes the control circuit 3
8 generates an address to be recorded in a track (groove track or land track) in response to the control from
It is output to the recording / reproducing circuit 33. Recording / reproducing circuit 33
Add this address to recording data supplied from a device (not shown) and output it to the optical head 32. Also,
When the address data is included in the reproduction data reproduced from the track of the disk 1 by the optical head 32, the address data is separated and output to the address generation / read circuit 35. The address generating / reading circuit 35 outputs the read address to the control circuit 38.

The mark detection circuit 36 is provided with the optical head 3
2 detects a component corresponding to the clock synchronization mark from the RF signal reproduced and output. The frame address detection circuit 37 (detection means) reads gray-coded information corresponding to the address information included in the wobbling signal from the RF signal output from the optical head 32, detects the frame address, and supplies the frame address to the cluster counter 46. It has been made to be.

The mark cycle detection circuit 40 determines the periodicity of a detection pulse output when the mark detection circuit 36 detects a clock synchronization mark. That is, since the clock synchronization mark is generated at a constant cycle, the mark detection circuit 3
It is determined whether or not the detection pulse input from 6 is a detection pulse generated at a fixed cycle, and if the detection pulse is generated at a fixed cycle, a pulse synchronized with the detection pulse is generated. Phase comparator 4 of the subsequent PLL circuit 41
Output to 2. Further, the mark cycle detection circuit 40 generates a pseudo pulse at a predetermined timing so that the PLL circuit 41 at the subsequent stage does not lock to an erroneous phase when a detection pulse is not input at a fixed cycle. It has been done.

The PLL circuit 41 includes a phase comparator 42,
Low-pass filter (LPF) 43, voltage-controlled oscillator (V
CO) 44 and a frequency divider 45. The phase comparator 42 compares the phase of the input from the mark period detection circuit 40 with the phase of the input from the frequency divider 45, and outputs the phase error. The low-pass filter 43 compensates for the phase of the phase error signal output from the phase comparator 42 and outputs it to the VCO 44. The VCO 44 generates a clock having a phase corresponding to the output of the low-pass filter 43 and outputs the clock to the frequency divider 45. The frequency divider 45 divides the frequency of the clock input from the VCO 44 by a predetermined value, and outputs the frequency-divided result to the phase comparator 42.

The clock output from the VCO 44 is supplied to each circuit and also to the cluster counter 46. The cluster counter 46 counts the number of clocks output from the VCO 44 based on the frame address supplied from the frame address detection circuit 37, and counts the counted value to a predetermined value (corresponding to the length of one cluster). When the threshold value is reached, a cluster start pulse is generated and output to the control circuit 38.

The thread motor 39 is controlled by the control circuit 38 to move the optical head 32 to a predetermined track position on the disk 1. The control circuit 38
Controls the spindle motor 31 to rotate the disk 1 at a predetermined speed.

Next, the operation will be described. Here, the operation at the time of data recording will be described. Optical head 3
Reference numeral 2 irradiates the optical disk 1 with laser light and outputs an RF signal obtained from the reflected light. The tracking and focusing servo circuit 47 generates a tracking error signal based on the push-pull method and generates a focusing error signal based on the astigmatism method. Then, a tracking servo and a focusing servo are executed in accordance with the tracking error signal and the focusing error signal.

The frame address detection circuit 37 reads gray-coded information corresponding to wobbling information (address information) from the RF signal output from the optical head 32, and outputs the detected track address and frame address to the control circuit 38. At the same time, it is also supplied to the cluster counter 46.

Here, a method of detecting the track address and the frame address will be described as follows. That is, the tracking and focusing servo circuit 47 determines the polarity of the tracking error signal from the optical head 3.
It is determined whether the light spot (access point) generated on the optical disc 1 by the laser light emitted from the optical disc 1 is located on the groove track 2 or the land track 3. Then, the determination result is output to the frame address detection circuit 37.

That is, as shown in FIG. 14, the tracking and focusing servo circuit 47 has a built-in circuit for switching the polarity of the tracking error signal when tracking the groove track 2 and when tracking the land track 3. ing.

The light receiving element 61 for receiving the reflected light from the optical disk 1 is divided into an area 61A and an area 61B in the direction parallel to the tracks. And the differential amplifier 6
2 generates a tracking error signal by subtracting the output of the area 61B from the output of the area 61A,
Generates a tracking error signal by subtracting the output of the area 61A from the output of the area 61B.
The switch circuit 64 selects either the tracking error signal output from the differential amplifier 62 or the tracking error signal output from the differential amplifier 63 in accordance with the switching signal supplied from the control circuit 38. The switch circuit 64 is switched upward in the figure when tracking control of the groove track 2 is performed by a switching signal, and is switched downward in the figure when tracking the land track 3.

For example, as shown in FIG. 15, when the access point is tracking on the groove track 2, the switching signal is set to low level, and the switching circuit 64
Selects the tracking error signal output from the differential amplifier 62. On the other hand, when the access point tracks on the land track 3, the switching signal is switched to a high level, and the switch circuit 64 selects the tracking error signal output from the differential amplifier 63. By switching the polarity of the tracking error signal in this manner, both the groove track 2 and the land track 3 can be tracked correctly.

As described with reference to FIG. 10, when the access point is located on the groove track 2, the track number of the frame address detected by the frame address detection circuit 37 is different between the even frame and the odd frame. Number. Therefore, the frame address detection circuit 37 compares the track number detected in the even-numbered frame with the track number detected in the odd-numbered frame, and determines the larger one as the track number of the groove track 2.

For example, as shown in FIG. 10, when the groove track N is being accessed, the track number N is read in the even frame, and the frame number N-1 is read in the odd frame. At this time, since N is larger than N-1, N is selected as the track number of the groove track N. Similarly, for example, when accessing the groove track N + 1, the track number N is read in an even frame, and the track number N + 1 is read in an odd frame. Since N + 1 is larger than N, in this case, N + 1 is selected as the track number of the groove track N + 1.

On the other hand, for example, when the access point is accessing the land track N, in an even frame,
Since the track numbers recorded on the right and left adjacent groove tracks are all N, this track number N
Can be read. On the other hand, in the odd-numbered frames, the track number recorded on the inner groove track N is N-1, and the track number recorded on the outer groove track N + 1 is N + 1. When reading simultaneously, an error occurs, and as a result, the track number cannot be read correctly. Therefore, the track number N that can be read correctly is
The track number of the currently accessed land track N is selected.

Similarly, for example, when accessing the land track N + 1, the track number N is obtained from the adjacent groove tracks N + 1 and N + 2 in the odd frame.
Although +1 is read, in the even-numbered frame, the track number N is reproduced from the inner groove track, and the track number N + 2 is reproduced from the outer groove track N + 2. Therefore, in an even frame, an error occurs and the track number cannot be read correctly. Therefore, the frame address detection circuit 37
Selects the track number that could be read correctly as the track number of the land track 3 currently being accessed.

When the switching circuit 64 of the tracking and focusing servo circuit 47 is switched to the polarity for tracking the groove track 2 (in FIG. 14, when it is switched upward), when the groove track 2 is being accessed, Correct tracking servo is performed, but when the land track 3 is accessed, the polarity of the tracking error signal is reversed. As a result, the access point jumps from the land track 3 to the groove track 2 as a result of the tracking servo. And a stable servo state is obtained.

Conversely, if the switch circuit 64 is switched to the polarity of the land track 3 (in FIG. 14,
If the track is tracked down, a correct servo is realized when tracking the land track 3, but the servo is not stable when tracking the groove track 2.
The result is that the access point jumps up. Therefore, it can be determined from the switching state of the switch circuit 64 whether the access point is located on the groove track 2 or the land track 3.

The RF signal output from the optical head 32 in FIG. 13 is also input to a mark detection circuit 36, where a clock synchronization mark is detected and supplied to a mark period detection circuit 40. The mark cycle detection circuit 40 determines the periodicity of the clock synchronization mark supplied from the mark detection circuit 36, generates a predetermined pulse corresponding thereto, and outputs the pulse to the PLL circuit 41. The output from the PLL circuit 41 is supplied to the cluster counter 46.

In the cluster counter 46, the PLL
The signal corresponding to the clock synchronization mark supplied from the circuit 41 is counted based on the signal corresponding to the track address or the frame address supplied from the frame address detection circuit 37, and when the count reaches a predetermined count value, the cluster start is started. A pulse is output.

The control circuit 38 can detect the position of the reference clock synchronization mark in one round of the track from the frame address supplied from the frame address detection circuit 37 and the structure of the wobbling address frame. For example, the first clock synchronization mark of frame 0 can be used as a reference clock synchronization mark for one rotation (one round). Based on this, an arbitrary position on the track can be accessed from the count value of the clock.

The PLL circuit 41 can generate a clock based on the clock synchronization mark in both the odd frame and the even frame shown in FIG.

As described above, in this embodiment, the track address is detected from the wobbling address information that has been converted into the gray code. As described above, when the gray code corresponding to the track address moves to the adjacent track, the position of the channel 1 of the lower address sequentially moves to the adjacent channel, and all the channels of the lower address become 0. Since there is no track, only the lower address can be detected to seek a desired track.
Therefore, unlike the related art, it is not necessary to detect both the upper address and the lower address at the time of seeking, so that high-speed access is possible.

The structure of the wobbling address frame in the above embodiment is an example, and other structures are possible.

The specific numerical values used in the above embodiment are examples, and the present invention is not limited to these numerical values.

Further, the conversion table in the above embodiment is an example, and the present invention is not limited to this. It is also possible to define another conversion table and convert address information into gray code.

Further, in the above embodiment, the case of the optical disk recording / reproducing apparatus has been described. However, the present invention can be applied to an apparatus which performs only reproducing or recording of the optical disk.

Further, the present invention relates to a CD-ROM (Compac
It can also be applied to Disc Read Only Memory) and minidiscs.

[0086]

As described above, according to the optical disk of the first aspect, the address information of the groove track is recorded in the first frame of the plurality of frames, and the land track is recorded in the second frame. Since an address information is recorded on an optical disc on which both a groove track and a land track are formed, it is possible to realize an optical disc capable of accessing an arbitrary position corresponding to the address information by wobbling. Can be.

According to the optical disk recording / reproducing apparatus of the eighth aspect and the optical disk recording / reproducing method of the eleventh aspect, when the access point is located on one of the groove track and the land track, the read address information is read. If the address is detected as the address of the access point and the access point is located on the other side, the address information of the access point is detected according to the comparison result of the size of the address information read from each frame. It is possible to reliably access an arbitrary position on the optical disc on which both the track and the land track are formed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a state where an optical disk of the present invention is wobbled.

FIG. 2 is a diagram showing a configuration of a groove track and a land track of the optical disc of the present invention.

FIG. 3 is a diagram showing another configuration of a groove track and a land track of the optical disc of the present invention.

FIG. 4 is a diagram illustrating a configuration example of a wobbling address frame that is gray-coded;

FIG. 5 is a diagram for explaining a gray coding method.

FIG. 6 is a diagram showing a clock synchronization mark area and a clock synchronization mark.

FIG. 7 is a diagram illustrating a configuration example of a wobbling signal generation circuit.

8 is a diagram illustrating an example of a bi-phase signal output by the bi-phase modulation circuit 13 in FIG.

9 is a diagram illustrating another example of the bi-phase signal output from the bi-phase modulation circuit 13 in FIG.

FIG. 10 is a diagram illustrating track numbers of respective frames in a groove track and a land track.

FIG. 11 is a diagram illustrating addresses on two adjacent groove tracks.

FIG. 12 is a diagram showing a configuration example of a recording device for manufacturing a disk 1 having a groove track and a land track.

FIG. 13 is a diagram showing a configuration example of an optical disc recording / reproducing apparatus of the present invention.

14 is a block diagram showing a configuration of a part of a tracking servo circuit of the tracking and focusing servo circuit 47 of FIG.

FIG. 15 is a diagram for explaining the operation of the embodiment in FIG. 14;

[Description of Signs] 1 optical disk, 2 groove tracks, 3 land tracks, 11 generation circuits, 12, 14 divider,
13 bi-phase modulation circuit, 15 FM modulation circuit, 16 Gray code conversion circuit, 21 wobbling signal generation circuit, 22 synthesis circuit, 23 mark signal generation circuit, 24 recording circuit, 25 optical head,
26 master, 27 spindle motor, 31 spindle motor, 32 optical head, 33 recording / reproducing circuit, 34 memory, 35 address generating / reading circuit,
36 mark detection circuit, 37 frame address detection circuit, 38 control circuit, 39 thread motor,
40 mark cycle detection circuit, 41 PLL circuit,
46 cluster counter, 47 tracking servo and focusing servo circuit, 61 light receiving element,
64 switch circuit

Claims (11)

[Claims] 1. A track for recording data is formed in advance as a groove track and a land track, and one of the groove track and the land track is
In an optical disc in which both side walls are wobbled corresponding to the same address information, the track on which the address information is recorded by wobbling is divided into a plurality of frames. An optical disc, wherein address information of the groove track is recorded in a frame, and address information of the land track is recorded in a second frame. 2. The optical disc according to claim 1, wherein the first frame is one of an odd frame and an even frame, and the second frame is the other. 3. An odd-numbered track or an even-numbered track among the tracks on which the address information is recorded by wobbling, an odd-numbered frame is the first frame, and the other is an odd-numbered track. 2. The optical disc according to claim 1, wherein an even frame is the first frame. 4. When the groove track makes one round,
2. The optical disk according to claim 1, wherein the optical disk is formed so as to be displaced in a radial direction by an odd number of tracks. 5. When the groove track makes one round,
2. The optical disc according to claim 1, wherein the optical disc is formed so as to be displaced in a radial direction by an even number of tracks. 6. The address information includes at least data corresponding to a synchronization signal, data corresponding to a track address, data corresponding to a frame address, and data corresponding to a code for error detection. The optical disk according to claim 1, wherein: 7. The optical disk according to claim 1, wherein the address information is converted into a gray code. 8. Data is recorded on both a groove track and a land track formed in advance, and
One of the groove track and the land track has both side walls wobbled corresponding to the same address information, and the track on which the address information is recorded by wobbling is divided into a plurality of frames. An optical disc recording / reproducing apparatus for recording or reproducing data on / from an optical disc, wherein: a reading means for reading the address information recorded by the wobbling; and whether an access point is on the groove track or the land track. Determining the address information read by the reading means as the address information of the access point when the access point is located on one of the groove track and the land track; And Landto Detecting means for comparing the size of the address information read from each of the frames when the access point is located at the other of the access points, and detecting the address information of the access point in accordance with the comparison result; An optical disk recording / reproducing device comprising: 9. The optical disk recording / reproducing apparatus according to claim 8, wherein said determining means determines which of said groove track and land track the access point is based on the polarity of a tracking error signal. 10. The detecting means, when the access point is located on the other of the groove track and the land track, uses the larger of the address information read from each of the frames as address information of the access point. The optical disk recording / reproducing apparatus according to claim 8, wherein the detection is performed as: 11. Data is recorded on both a groove track and a land track formed in advance, and one of the groove track and the land track is
Both of the side walls are wobbled in correspondence with the same address information, and the track on which the address information is recorded by wobbling is used to transfer data to an optical disc divided into a plurality of frames. In the optical disk recording / reproducing method for recording or reproducing, the address information recorded by the wobbling is read, and it is determined whether the access point is on the groove track or the land track. When the access point is located on one side, the read address information is detected as the address information of the access point, and when the access point is located on the other of the groove track and the land track, each of the frames is read. The address information to be read Of comparing the size, corresponding to the comparison result, the optical disc recording and reproducing method characterized by detecting the address information of the access point.