JPH09120584A - Optical disk, optical disk recording and reproducing device and method, and optical disk forming device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record or reproduce data with high density by forming a track in alternately disposing a pregroove and a land on an optical disk. SOLUTION: On the disk 1, the pregroove 2 and the land 3 are alternately disposed on the track during every rotation, and they are continued to each other to constitute a spiral. A wall surface on the inner circumferential side (or outer circumferential side) of the pregroove 2 is wobbled in accordance with address information. This address wobbling pattern of the pregroove 2 is the same as the land 3 on the outer circumferential side (or inner circumferential side). Consequently, when a data is to be recorded or reprotuced in the pregroove 2, reference is made to the address information recorded on the inner circumferential side of the pregroove 2, and moreover, detection of the pregroove 2 not the land 3 is performed. Then, when the land 3 is to be accessed, reference is made to the address information on the outer circumferential side of the land 3, and moreover, detection of the land 3 not the pregroove 2 is performed.

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, an optical disk recording / reproducing method, an optical disk forming apparatus, and an optical disk forming method, and in particular, tracks are formed by alternately arranging pregrooves and lands. The present invention relates to an optical disc, an optical disc recording / reproducing device, an optical disc recording / reproducing method, an optical disc forming device, and an optical disc forming method.

[0002]

2. Description of the Related Art FIG. 15 shows an example of the structure of a disc having pregrooves and lands. A pregroove 2 is spirally formed in advance on the disc 1 from the inner circumference to the outer circumference. As shown in an enlarged view of a part of FIG. It is wobbled and meanders (wobbles) at a predetermined cycle. In this example, the data is recorded in the pre-groove 2 (or the land 3).

Recently, in order to further increase the density of a disc, it has been considered to record data on both the groove and the land of the track. FIG. 16 shows an example of this case. In this example, the recording data is not only recorded on both the pre-groove 2 and the land 3, but also wobbling is formed only on one side wall of the pre-groove 2 in order to further increase the density by the narrow track pitch. ing. Further, in this example, the land 3 and the pre-groove 2 are
As shown in FIG. 17, the discs 1 are alternately arranged from the inner circumference to the outer circumference. That is, the pre-groove 2
Is formed as one spiral, and land 3
Is also formed as another spiral.

[0004]

However, in the method of recording data on the pre-groove 2 (or the land 3), there is a problem that it is difficult to increase the recording capacity of the disc.

Further, in the method of recording data on both the pre-groove 2 and the land 3 and wobbling one wall surface, data is recorded in two spirals. Therefore, when recording or reproducing information, these two spirals must be appropriately selected, and there is a problem that control becomes complicated.

The present invention has been made in view of such a situation, and realizes high-density recording on an optical disk by simple control.

[0007]

An optical disk according to a first aspect of the invention is characterized in that tracks are formed by alternately arranging pregrooves and lands.

An optical disk recording / reproducing apparatus according to a fifth aspect of the present invention includes a reading means for reading address information recorded by wobbling a track, a recording / reproducing means for recording or reproducing data on a pre-groove and a land, and a reading means. Control means for controlling recording or reproduction of the recording / reproducing means based on the address information read by the means.

According to a seventh aspect of the present invention, there is provided an optical disk recording / reproducing method for reading recorded address information by wobbling a track and controlling the recording / reproducing position of data with respect to the pre-groove and the land based on the address information. Characterize.

The optical disk forming apparatus according to the eighth aspect is
The present invention is characterized by comprising forming means for forming tracks in which pregrooves and lands are alternately arranged, and wobbling means for wobbling one wall surface of the pregroove according to address information.

According to a ninth aspect of the optical disc forming method,
It is characterized in that a track in which pregrooves and lands are alternately arranged is formed, and one wall surface of the pregroove is wobbled according to address information.

In the optical disc according to claim 1,
Pregrooves and lands are alternately arranged to form a track.

In the optical disk recording / reproducing apparatus according to the fifth aspect, the reading means reads the address information recorded by wobbling the track, and the recording / reproducing means records or reproduces the data in the pre-groove and the land. The control means controls recording or reproduction of the recording / reproducing means based on the address information read by the reading means.

In the optical disc recording / reproducing method according to the seventh aspect, the address information recorded by wobbling the track is read, and the recording / reproducing position of the data with respect to the pre-groove and the land is controlled based on the address information.

In the optical disk forming apparatus according to the present invention, the forming means forms the track in which the pregrooves and the lands are alternately arranged, and one wall surface of the pregroove is formed by the wobbling means according to the address information. Wobble.

In the optical disc forming method according to the ninth aspect, a track in which pregrooves and lands are alternately arranged is formed, and one wall surface of the pregroove is wobbled according to address information.

[0017]

FIG. 1 shows an example of the configuration of an optical disk according to the present invention. As shown in FIG.
In the above, the pre-grooves 2 and the lands 3 are alternately formed (arranged) on the track every one revolution (one rotation), and these are continuously configured to form one spiral.

The wall surface of the pre-groove 2 on the inner peripheral side (or the outer peripheral side) may be wobbled according to the address information. This address is the same for the pregroove 2 and the land 3 on the inner peripheral side (or the outer peripheral side may be used). Therefore, when recording or reproducing data on the pre-groove 2, the address information recorded on the inner peripheral side of the pre-groove 2 is referred to, and further the land 3
It is not pregroove 2 but it is detected. Also,
When accessing the land 3, the address information on the outer peripheral side of the land 3 is referred to and it is detected that the land 3 is not the pre-groove 2.

The disk shown in this figure is a CAV (Constan
t Angular Velocity) disk, and the wobbling fundamental frequency is constant.

The depth of the pre-groove 2 is set to about ⅛ of the wavelength of the reproduction light so that a push-pull signal for detecting a tracking error can be obtained.

Further, the address information is recorded by wobbling the wall surface of only one of the pregrooves 2. In other words, the wobbling side wall is displaced by one track pitch (width of the land 3) for each track circumference.

According to the above configuration, not only can address information that can be referred to from either the pre-groove 2 or the land 3 be formed, but also one continuous spiral can be formed by the pre-groove 2 and the land 3. Therefore, not only the recording density can be increased, but also the data can be recorded or reproduced accurately and with simple control.

Next, details of the address information recorded by wobbling will be described.

FIG. 3 shows the structure of a wobbling address frame. As shown in the figure, the wobbling address frame is composed of 60 bits, and the first 4 bits are a synchronization signal (Sync) indicating the start of the wobbling address frame. The next 4 bits are a layer (Laye
r). The next 20 bits are used as a track address. Further, the next 4 bits are designed to represent a frame number. 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. Last 2 bits (Rese
rved) is reserved as a reserve for the future.

In a CAV disc having a constant rotational angular velocity, the wobbling address frame is composed of, for example, 8 frames per track.

FIG. 4 shows a clock synchronization mark area and a clock synchronization mark (Fine Clock Mark). Data of 60 bits is recorded in each frame, and 1 bit is 7 out of signals of a predetermined frequency as shown in FIG.
If it is represented by waves (carriers), there will be 420 waves in one frame. Assuming that the disk is rotated at 1200 rpm, the frequency of this carrier is 67.2 kHz.

As shown in FIG. 4, in the wobbling address frame shown in FIG. 3, each clock synchronization mark area is arranged by one bit for every four bits of address information. That is, data is recorded with a cycle of 5 bits. Of the 5 bits, the first 1 bit is a carrier of 7 waves including a clock synchronization mark (Fine Clock Mark), and the remaining 4 bits are a section modulated by substantial address data that does not include a fine clock mark. To be done. Therefore, 12 bits (pieces) and 48 bits (pieces) are included in one frame.
Data will be recorded, and 96 (= 12 × 8) fine clock marks will be recorded in one rotation (one track).

The address information is biphase-modulated and further frequency-modulated. Then, according to the signal, wobbling is formed on one wall surface of the pre-groove 2. In the clock synchronization mark area, the wobbling frequency of the pregroove 2 is set to the center frequency of the modulation frequency of the address information. Alternatively, it is set to a frequency higher than the modulation frequency of the address information.

The clock synchronization mark is used to modulate the recording / reproducing data by EFM (Eight To Fourteen Modulatio) of a CD or the like.
In the case of n: (8-14) modulation, one wavelength wobbling is performed with a mark length of 6 to 8T as shown in FIG.

FIG. 5 shows an example of the construction of a wobbling address generation circuit for generating a wobbling signal for wobbling the pregroove 2. Generation circuit 11
Are designed to generate a signal with a frequency of 44.1 kHz. The frequency of 44.1 kHz is the same frequency as the sampling clock of audio data of Mini Disc (trademark).

The signal generated by the generating circuit 11 is supplied to the dividing circuit 12, is divided by the value "7", and then the frequency 63 is generated.
It is supplied to the biphase modulation circuit 13 as a biphase clock signal of 00 Hz. Bi-phase modulation circuit 1
3 is also supplied with ADIP (ADress In Pre-groove) data.

The ADIP data is sector data, and the format of each sector is defined as follows. That is, the first 4 bits are the synchronization signal, the next 8 bits are the upper 8 bits representing the cluster number, and the next 8 bits are the lower 8 bits representing the cluster number. The next 8 bits represent the sector number and the remaining 1
4 bits are used as a CRC signal for error detection and correction.

The bi-phase modulation circuit 13 includes a divider 12
The supplied bi-phase clock is bi-phase modulated with ADIP data supplied from a circuit (not shown), and the bi-phase signal is output to the FM modulation circuit 15. The FM modulator circuit 15 also applies a value of “2” to the 44.1 kHz signal generated by the generation circuit 11 by the divider 14.
A carrier having a frequency of 22.05 kHz obtained by dividing by is input. The FM modulation circuit 15 uses the divider 1
The carrier input from 4 is supplied to the biphase modulation circuit 1
Frequency modulation is performed with the bi-phase signal input from the signal No. 3, and the resulting FM signal is output. One side wall of the pre-groove 2 of the disc is formed (wobbled) in response to this FM signal.

FIG. 6 and FIG. 7 show the biphase modulation circuit 13
2 shows an example of a bi-phase signal output from. In this example, when the leading bit is a 0,
As shown in, the synchronization pattern is “111010.
00 "is used and the preceding bit is 1, the synchronization pattern is" 00010 "as shown in FIG.
111 ″ is used.

The data bits (Data Bits) are bi-phase modulated and converted into channel bits (Channel Bits). SYNC is an irregular pattern that does not appear in modulation. "Wave Form" is a pattern in which channel bits are converted into a pattern of "1" and "0".

FIG. 8 shows an example of the structure of a recording apparatus (disk forming apparatus) for manufacturing a disk having a pre-groove. The wobbling signal generation circuit 21 has the configuration shown in FIG. 5 described above and outputs the FM signal to the synthesis circuit 22. The mark signal generation circuit 23 generates a mark signal at the timing of forming a synchronization mark and outputs it to the synthesis circuit 22. The synthesizing circuit 22 synthesizes the FM signal output by the wobbling signal generating circuit 21 and the mark signal output by the mark signal generating circuit 23, and outputs the synthesized signal 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.
(Forming means, wobbling means) is controlled to generate laser light for forming the pre-groove 2 and the synchronization mark on the master 26. 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 the master 26 rotated by the spindle motor 27 at a predetermined speed. The recording circuit 24 shifts the position where the pre-groove 2 is formed by one track pitch (for the width of the land 3) each time the master 26 makes one rotation,
The pregrooves 2 and the lands 3 are controlled so as to be alternately arranged for each track (one rotation).

The master 26 is developed, a stamper is created from the master 26, and a large number of replica disks are formed from the stamper. As a result, it is possible to obtain a disk in which the pregroove 2 having the spiral in which the pregroove 2 and the land 3 described above are alternately arranged and the clock synchronization mark are formed.

FIG. 9 shows an example of the structure of an optical disc recording / reproducing apparatus for recording or reproducing data on the disc thus obtained. Spindle motor 31
Is configured to rotate the disk 1 at a predetermined speed. The optical head 32 irradiates the disk 1 with laser light, records data on the disk 1, and reproduces data from the reflected light. The recording / reproducing circuit 33 (recording / reproducing means) temporarily records the recording data input from a device (not shown) in the memory 34, and when one cluster of data as a recording unit is stored in the memory 34, the recording data of one cluster is recorded. Data of the optical head 32 and is modulated by a predetermined method.
It is designed to output to. In addition, the recording / reproducing circuit 3
Reference numeral 3 appropriately demodulates the data input from the optical head 32 and outputs the demodulated data to a device (not shown).

The address generating / reading circuit 35 (reading means) generates an address to be recorded in the track (pregroove 2) in response to the control from the control circuit 38 (control means), and outputs it to the recording / reproducing circuit 33. ing. The recording / reproducing circuit 33 adds this address to recording data supplied from a device (not shown) and outputs it to the optical head 32. Further, when the reproduction data reproduced by the optical head 32 from the track of the disk 1 includes address data,
This is separated and output to the address generation / read circuit 35. The address generation / read circuit 35 outputs the read address to the control circuit 38.

Further, the mark detection circuit 36 includes 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 reads the address information contained in the wobbling signal from the RF signal output from the optical head 32, detects the frame address, and supplies it to the cluster counter 46.

That is, when recording or reproducing data on the pre-groove 2, the address information recorded as wobbling on the inner circumference of the pre-groove 2 is read. When recording or reproducing is performed on the land 3, the address information recorded by wobbling on the outer periphery of the land 3 (the inner periphery of the pre-groove 2 in contact with the outer periphery of the land 3) is read. It will be. Based on the read address information and the pre-groove / land discrimination signal described later, the current optical head 32
The address on the disk will be calculated.

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 is not locked to an incorrect phase when the detection pulse is not input at a constant cycle.

The PLL circuit 41 includes a phase comparator 42,
Low pass filter 43, voltage controlled oscillator (VCO) 4
4 and a frequency divider 45. Phase comparator 42
Is the input from the mark period detection circuit 40 and the frequency divider 45.
The phase with the input from is compared and the phase error is output. The low-pass filter 43 compensates 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 it to the frequency divider 45.
The frequency divider 45 frequency-divides 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 a control circuit 38 to move the optical head 32 to a predetermined track position on the disk 1. The tracking control circuit 47 controls so that the optical head 32 is always positioned above the track. Further, 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 during data recording will be described. Optical head 3
Reference numeral 2 irradiates the disc 1 with laser light and outputs an RF signal obtained from the reflected light. The frame address detection circuit 37 reads the wobbling information (address information) from this RF signal and outputs the read result to the control circuit 3.
8 and also supplies to the cluster counter 46. The wobbling information is also input to a mark detection circuit 36, where a clock synchronization mark is detected and supplied to a mark cycle detection circuit 40.

The mark period detection circuit 40 determines the periodicity of the clock synchronization mark, generates a predetermined pulse corresponding to it, and outputs it to the PLL circuit 41. PLL circuit 41
Is supplied to the cluster counter 46.

The control circuit 38 uses the frame address supplied from the frame address detection circuit 37, the structure of the wobbling address frame, and the pre-groove / land discrimination signal, which will be described later, to determine the reference clock synchronization mark in one round of the track. The position can be detected.
Based on this, it becomes possible not only to access the pre-groove 2 and the land 3 at arbitrary positions on the disk 1 but also to access arbitrary positions on the track from the recording clock.

FIG. 10 is a block diagram showing an example of the configuration of a circuit for generating a pregroove / land discrimination signal.
This circuit corresponds to the frame address detection circuit 37 shown in FIG.
It is built in. In this circuit, the light receiver 61 is
The reflected light from the optical disk 1 is received by four independent parts A to D and converted into electric signals corresponding to the respective parts. The adder 62 is configured to add the signals output from the four parts A to D of the light receiver 61 and output the result. The comparator 63 compares the output signal of the adder 62 with the reference voltage V _Rf of the reference power supply 64. If the output signal of the adder 62 exceeds the reference voltage V _Rf , a predetermined voltage (“H”) is output. When it is lower than the above value, "L" is output.

Regardless of the presence or absence of pits (hollows of the optical disc 1 formed for recording data), the land 3
The intensity of the reflected light from is always higher than the intensity of the reflected light from the pre-groove 2. Therefore, in the example shown in FIG.
The output signals from the four parts A to D of the light receiver 61 are added by the adder 62, and this output value and the reference voltage V _Rf are compared by the comparator 63. As a result, the adder 6
When the output signal from 2 is larger than the reference voltage V _Rf ,
The output signal (pre-groove / land discrimination signal) is set to "H" to indicate that the laser spot is located on the land 3. On the contrary, when the output signal from the adder 62 is lower than the reference voltage V _Rf , the pre-groove / land signal is set to the “L” state, indicating that the laser spot is located on the pre-groove 2.

By referring to the state of the pre-groove / land discrimination signal, it is possible to detect whether the laser spot is located on the pre-groove 2 or the land 3.

According to the above embodiment, data can be recorded or reproduced on the disk 1 having the spiral in which the pregrooves 2 and the lands 3 are alternately arranged. Further, not only is the wobbling of one wall surface of the pre-groove 2 according to the address information,
Since the clock sync mark is also recorded at the same time,
It becomes possible to record or reproduce data at an accurate position.

Next, another embodiment of the present invention will be described.

FIG. 11 is a diagram showing another embodiment of the CAV optical disk according to the present invention. In this embodiment, the pre-grooves 2 and the lands 3 are alternately arranged for every predetermined data block (for example, 2 kbyte block) shorter than one round. In addition, the wobbling side walls of the block are formed so as to be alternately opposite sides.
That is, if the inner circumference side of the pre-groove 2 is wobbled in a predetermined block, the outer circumference side of the pre-groove 2 is wobbled in the blocks adjacent in the track direction. Therefore, in the case of this embodiment, the same side (right or left side) is always wobbled during one round of the track.

According to the above configuration, the connection position (switching position) between the pre-groove 2 and the land 3 is detected,
Data recording and reproduction can be performed more accurately based on this position.

FIG. 12 is a diagram showing still another embodiment of the optical disk according to the present invention. In this embodiment, as in the embodiment of FIG. 11, the pregrooves 2 and the lands 3 are alternately arranged for each predetermined data block to form one spiral. However, in this embodiment, the inner circumference side or the outer circumference side of the pre-groove 2 is alternately wobbled in any data block.

In this embodiment, when the wobbling is formed on the wall surface of the pre-groove 2, the wobbling may be formed on only one of the inner peripheral surface and the outer peripheral surface (in the example of FIG. 12, it is formed only on the inner peripheral surface). Exist).

FIG. 13 is a block diagram showing an example of the configuration of a circuit for canceling the tracking offset by utilizing the wobbling of the disc of FIG. This circuit is incorporated in the tracking control circuit 37 shown in FIG. In this circuit, the light receiver 61 is configured to convert the reflected light from the optical disc 1 into corresponding electric signals by the four independent portions A to D. In addition,
As for the reflected light input to the light receiver 61, as shown in FIG. 14, the portions A and D of the light receiver 61 receive the reflected light from both ends of the track, and the portions B and C. Is designed to receive the reflected light from the central portion of the track.

Among the detection signals converted into electric signals by the photodetector 61, the output signal from the A part and the output signal from the D part of the photodetector 61 are the wobbling fundamental frequency and the center frequency of the pass band. Band pass filter (BP
F) 71 and 72 respectively. The peak detection circuits (Peak det.) 73 and 74 detect the peak values of the signals supplied from the bandpass filters 71 and 72. Delay device (DL; Delay Line)
75 delays the output signal from the peak detection circuit 73 by a 2 kbyte block length and outputs it. Differential amplifier 76
Is the output signal from the delay device 75 and the peak detection circuit 74.
It is designed to output the difference from the output signal from.
The multiplier (× K) 77 multiplies the output signal from the differential amplifier 76 by a predetermined value “K” and outputs the result. The sample / hold circuit (S / H) 78 samples the output of the multiplier 77 and holds it for a predetermined period.

The differential amplifier 79 having four input terminals is
A push-pull signal is generated from the output signal of the light receiver 61. That is, A to D of the light receiver 61
If the values of the output signals of a are a to b, respectively, ((a +
b)-(c + d)) is calculated. The differential amplifier 80 outputs the difference between the output signal from the differential amplifier 79 and the output signal from the sample / hold circuit 78. Tracking Actuato
r) 81 (tracking control means) is a differential amplifier 80
The lens (not shown) of the optical head 32 is controlled according to the output signal from the optical head 32.

Next, the operation of the above embodiment will be described.

The reflected light from the optical disk 1 is normally incident on the center of the light receiver 61. When tracking is done normally, the light intensity of the upper half of the input light (corresponding to a + b)
And the lower half light amount (corresponding to c + d) is the same. However, when the tracking is deviated, a light amount difference occurs between them. That is, when the tracking is normally performed, the push-pull signal ((a + b)-
(C + d)) (output signal of the differential amplifier 79) is “0”
When the tracking shifts, the push-pull signal takes a voltage value corresponding to this shift width. Therefore, if a lens (not shown) of the optical head 32 is controlled according to the push-pull signal, accurate tracking can be performed.

However, for example, when a lens (not shown) is moved by the tracking actuator 81 in order to correct tracking, the reflected light is reflected by the light receiver 61.
May deviate from the center of. At this time, even if the tracking is returned to the normal state (the state where the upper and lower light amounts of the input light are equal) due to the movement of the lens, the push-pull signal becomes “0” because the reflected light is deviated from the center of the light receiver 61. However, an offset may occur.

In order to cancel this offset, the circuit shown in FIG. 13 obtains the difference (a value proportional to the offset value) between the wobbling signal before the 2 kbyte block length and the current wobbling signal. Then, the offset is canceled by subtracting a value (offset value) obtained by multiplying this difference by a predetermined value from the value of the push-pull signal.

That is, the wobbling signal components are extracted from the signals detected by A and D of the photodetector 61 by the bandpass filters 71 and 72. Then, the peak detection circuits 73 and 74 detect the peak values of these signals. Since only the signal detected by A of the light receiver 61 passes through the delay device 75 having a block length of 2 kbytes, the signals input to the plus and minus terminals of the differential amplifier 76 are 2 kbytes before the track. It becomes the peak value of the wobbling signal detected from the current wobbling signal.

Now, it is assumed that the reflected light is deviated above the light receiver 61 (direction from D to A of the light receiver 61).
At this time, the signal output from the peak detection circuit 74 is
The output decreases in accordance with this deviation. On the other hand, the delay device 75
Since the output signal from is a signal of 2 kbytes before, the output value hardly changes depending on the speed at which the deviation occurs. As a result, the value of the signal output from the delay device 75 becomes larger than the value of the signal output from the peak detection circuit 74. The differential amplifier 76 outputs a signal corresponding to these differences, and a multiplier 77 multiplies the signal by a predetermined value. The output signal of the multiplier 77 is sampled by the sample / hold circuit 78 and then held for a certain period. The differential amplifier 80 subtracts the output value (offset value) of the sample / hold circuit 78 from the value of the push-pull signal output from the differential amplifier 79, and the offset value obtained as a result is canceled in push-pull. The signal controls the tracking actuator 81.

According to the above-described embodiment, since the offset included in the push-pull signal can be canceled by using the wobbling signal, the data can be recorded or reproduced at a more accurate position. .

In the above embodiments, the embodiments relating to the CAV disc have been described. However, CL
It goes without saying that the present invention can be applied to a V (Constant Linear Velocity) disk.

In the above embodiment, the pregroove 2
And lands 3 were alternately arranged so as to form a spiral. However, it goes without saying that these may be arranged alternately to form concentric tracks.

[0071]

According to the optical disc of the first aspect,
Since the pregrooves and the lands are alternately arranged to form the tracks, it is possible to record or reproduce the data with high density.

According to the optical disk recording / reproducing apparatus of the fifth aspect and the optical disk recording / reproducing method of the seventh aspect, the address information recorded by wobbling the track is read, and the pre-groove is read based on the address information. Since the recording / reproducing position of the data with respect to the land is controlled, the data can be recorded or reproduced at a high density and the optical head can be accurately controlled based on the address information.

According to the optical disk forming apparatus of the eighth aspect and the optical disk forming method of the ninth aspect, a track in which pregrooves and lands are alternately arranged is formed, and one wall surface of the pregroove is formed. Since wobbling is performed according to the address information, a high density optical disc can be easily formed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a configuration of an optical disc according to the present invention.

FIG. 2 is a diagram showing a positional relationship between lands and pregrooves of the optical disc shown in FIG.

FIG. 3 is a diagram showing an example of the structure of a wobbling address frame.

FIG. 4 is a diagram showing a clock synchronization mark area and a clock synchronization mark.

FIG. 5 is a diagram showing an example of a configuration of a wobbling address generation circuit.

6 is a diagram showing an example of a bi-phase signal output from the bi-phase modulation circuit 13 of FIG.

FIG. 7 is a diagram showing another example of a biphase signal output from the biphase modulation circuit 13 of FIG.

FIG. 8 is a diagram showing an example of a configuration of a recording device for manufacturing a disc 1 having a pre-groove.

FIG. 9 is a diagram showing an example of a configuration of an optical disc recording / reproducing apparatus according to the present invention.

FIG. 10 is a diagram showing an example of a configuration of a circuit that generates a pregroove / land discrimination signal.

FIG. 11 is a diagram showing an example of another configuration of the optical disc according to the present invention.

FIG. 12 is a diagram showing an example of still another configuration of the optical disc according to the present invention.

13 is a block diagram showing an example of a configuration of a circuit that cancels an offset of a push-pull signal obtained from the optical disc shown in FIG.

14 is a diagram showing a correspondence relationship between a track and a laser spot on a light receiver 61. FIG.

FIG. 15 is a diagram showing a state in which an optical disc is pre-wobbled.

FIG. 16 is a diagram showing an example of a configuration of a conventional optical disc.

17 is a diagram showing an arrangement relationship between pregrooves and lands of the optical disc shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 optical disk 2 pre-groove 3 land 11 generation circuit 12,14 divider 13 bi-phase modulation circuit 15 FM modulation circuit 21 wobbling signal generation circuit 22 synthesis circuit 23 mark signal generation circuit 24 recording circuit 25 optical head (forming means, wobbling means) ) 26 master 27, 31 spindle motor 32 optical head 33 recording / reproducing circuit (recording / reproducing means) 34 memory 35 address generating / reading circuit (reading means) 36 mark detecting circuit 37 frame address detecting circuit 38 control circuit (controlling means) 39 thread motor 40 mark cycle detection circuit 41 PLL circuit 42 phase comparator 43 LPF 44 VCO 45 frequency divider 46 cluster counter 61 light receiver 62 adder 63 comparator 64 reference power supply 71, 72 bandpass filter 73, 74 Over click detecting circuit 75 delayer 76,79,80 differential amplifier 77 the multiplier 78 sample / hold circuit 81 tracking actuator (tracking control means)

Claims (9)

[Claims] 1. In an optical disc in which a track for recording data is formed in advance and one wall surface of the track is wobbled according to address information, pregrooves and lands are alternately arranged, and the track is formed. An optical disc, characterized in that 2. The pregrooves and the lands are alternately arranged for each turn.
An optical disk according to claim 1. 3. The optical disk according to claim 1, wherein the pre-grooves and the lands are alternately arranged for each predetermined data block. 4. The optical disk according to claim 3, wherein the data blocks whose outer peripheral wall surfaces are wobbled and the data blocks whose inner peripheral wall surfaces are wobbled are alternately arranged. . 5. An optical disk recording / reproducing apparatus for recording / reproducing data on / from an optical disk having a track in which pregrooves and lands are alternately arranged, and reading address information recorded by wobbling the track. Reading means, recording / reproducing means for recording or reproducing the data in the pre-groove and the land, and control means for controlling recording or reproducing of the recording / reproducing means based on the address information read by the reading means. An optical disc recording / reproducing apparatus comprising: 6. The optical disk recording according to claim 5, further comprising tracking control means for performing tracking control based on a difference signal between the wobbling signal and the wobbling signal delayed by a predetermined data amount. Playback device. 7. An optical disk recording / reproducing method for recording or reproducing data on an optical disk having a track in which pregrooves and lands are alternately arranged, wherein address information recorded by reading the track is read. An optical disk recording / reproducing method characterized by controlling a recording / reproducing position of data with respect to the pre-groove and the land based on the address information. 8. An optical disk forming apparatus for forming an optical disk having a pre-groove, wherein forming means for forming tracks in which the pre-grooves and lands are alternately arranged and one wall surface of the pre-groove are used as address information. An optical disc forming apparatus, comprising: a wobbling unit that performs wobbling according to the present invention. 9. An optical disk forming method for forming an optical disk having a pre-groove, wherein tracks in which the pre-grooves and lands are alternately arranged are formed, and one wall surface of the pre-groove is wobbled according to address information. A method for forming an optical disk, comprising: