WO2013001679A1

WO2013001679A1 - Optical disk medium, recording method therefor, and recording device

Info

Publication number: WO2013001679A1
Application number: PCT/JP2012/001485
Authority: WO
Inventors: 純也飯塚
Original assignee: 日立コンシューマエレクトロニクス株式会社
Priority date: 2011-06-29
Filing date: 2012-03-05
Publication date: 2013-01-03
Also published as: JP2013012266A

Abstract

The purpose of the present invention is to provide an optical disk medium, an optical disk device, and an optical disk recording method capable of improving the accuracy of a recording position and increasing the recording density when recording and reproducing information to and from a grooveless disk. A pit structure representing address information is provided on either a land or a groove in a guide layer and the pit structure is detected when recording information so that the recording start position is determined.

Description

Optical disc medium, recording method thereof, and recording apparatus

The present invention relates to an optical disc apparatus, an optical disc recording method, or an optical disc medium for recording information on an optical disc using a laser.

Recently, in order to increase the recording capacity of the Blu-ray Disc (TM) standard optical disc, an optical disc having three or four recording layers has been developed and standardized. In the future, it is expected that an optical disc having a larger number of recording layers will be developed for the purpose of further increasing the capacity. For example, in Non-Patent Document 1, a layer having a physical groove structure (hereinafter referred to as a guide layer) for performing tracking servo control is provided, and a layer for recording / reproduction (recording layer) does not have a land / groove structure. An optical disc (grooveless disc) is shown, which is easy to manufacture even when a large number of recording layers are stacked. On the other hand, as described in Patent Document 1, for example, in a conventional optical disc having a land / groove structure, address information and information serving as a reference for a recording clock are superimposed on the land / groove structure. Controls the recording position and recording clock.

Japanese Patent Application Laid-Open No. H10-260260, which deals with grooveless discs, states that “the reproduction signal processing circuit 2 is based on the output signal (a plurality of photoelectric conversion signals) of the light receiver PD1 and addresses information, synchronization information, focus error signal and track error. Signal, etc. "(paragraph 0068). Here, “PD1” is indicated as “a photodetector that receives light reflected from the guide layer” (paragraph 0123). Further, “The guide track layer S has been described as having a groove for guiding, but the present invention is not limited thereto, and for example, a guide pit (pre-pit) may be formed. Both grooves and prepits may be formed "(paragraph 0118).

JP 2006-236574 A JP 2007-200427

As one of the problems when recording and reproducing such a grooveless disk as described above, since there is no land / groove structure in the recording layer of the disk, in the conventional optical disk method, the recording layer and the reference of the recording clock are used. It is mentioned that the signal which becomes is not obtained.

Patent Document 2 describes that address information, synchronization information, and the like are acquired based on an output signal of reflected light from a guide layer as described above.

However, in Patent Document 2, there is no specific description of what address information is arranged on the optical disc and how the address information is detected.

By the way, a laser for the recording layer is used with a wavelength as small as possible so that the recording density can be increased by reducing the light spot diameter, but the laser for the guide layer mainly for the purpose of servo processing is used for recording. A laser having a long wavelength and a large spot diameter is used as compared with the layer laser. For this reason, with respect to the track structure of the guide layer, as with many conventional optical disc media, either the land (the side that is concave when viewed from the laser beam incident direction) or the groove (the side that is convex when viewed from the laser beam incident direction) If only the tracking method is used, the track pitch on the recording layer becomes larger than that of a conventional optical disk having a guide groove on the recording layer, and the recording data amount per layer decreases.

On the other hand, when such a guide groove structure is applied, the track pitch becomes smaller than the light spot diameter for the guide layer, so that crosstalk from the guide groove adjacent to the guide groove at the radial position being tracked occurs. growing.

Therefore, an object of the present invention is to provide an optical disc medium, an optical disc apparatus, and an optical disc recording method capable of realizing improvement in recording position accuracy and recording density when recording / reproducing a grooveless disc.

The above-mentioned problem is solved, for example, by having an area in which an optical disk medium is provided with a pit structure representing address information in either a land or a groove of a guide layer.

According to the present invention, it is possible to provide an optical disc medium, an optical disc apparatus, and an optical disc recording method capable of realizing improvement in recording position accuracy and recording density when recording / reproducing a grooveless disc.

Configuration of controller 201 Block configuration showing one embodiment of an optical disc apparatus according to the present invention Structure of optical disk 102 Processing flow of optical disc device 101 when optical disc 102 is inserted Track placement on the guide layer Outline of track structure of guide layer Schematic diagram of a track extracted from only one wobble cycle Sequence of recording processing method An example of wobble detection means 616 Example of PLL617 configuration An example of pit detection means 606 An example of data detection means Outline of operation of sum signal data detection means 1104 Outline of operation of difference signal data detecting means 1103 Another example of the pit detection means 606

Hereinafter, details of embodiments of the present invention will be described with reference to the drawings.

(Details of the embodiment of the present invention)
FIG. 2 is a block diagram showing an embodiment of the optical disc apparatus according to the present invention.

The optical disc device 101 records or reproduces information by irradiating an optical disc 102 mounted on the device with laser light, and communicates with a host 103 such as a PC (Personal Computer) via an interface such as SATA (Serial Advanced Technology Attachment). Do.

The structure of the optical disk 102 is illustrated in FIG. The optical disk 102 has a guide layer having a track (guide groove) structure and N recording layers (N ≧ 1, N is a natural number) not having a track structure. The optical disc apparatus 101 can generate laser spots on the recording layer and the guide layer by the objective lens 311.

The optical disc apparatus 101 includes a controller 201, a signal processing unit 202, an optical pickup 203, a slider motor 204 that moves the optical pickup 203 in the radial direction of the optical disc 102, slider driving means 205 that drives the slider motor 204, Aberration correction driving means 206 for driving the spherical aberration correction element 309 provided in the pickup 203, a spindle motor 207 for rotating the optical disk 102, and a rotation signal for generating a signal synchronized with the rotation of the spindle motor 207 A generating unit 208; a spindle control unit 209 that generates a rotation signal for rotating the spindle motor 207; a spindle driving unit 210 that drives the spindle motor 207 in accordance with the rotation signal generated by the spindle control unit 209; Focus error indicating the amount of laser spot misalignment focused on the recording layer A focus error signal generating means 211 for generating a signal, a focus control means 212 for generating a focus drive signal in accordance with the focus error signal, and a focus for driving an actuator 312 provided in the optical pickup 203 in accordance with the focus drive signal Driving means 213, tracking error signal generating means 214 for generating a tracking error signal indicating the amount of positional deviation between the track on the guide layer of the optical disc 102 and the laser spot, and tracking for generating a tracking drive signal in accordance with the tracking error signal Control unit 215, tracking drive unit 216 that drives the actuator 312 in response to the tracking drive signal, and a relay lens error signal indicating the amount of displacement of the laser spot focused on the guide layer and the guide layer of the optical disc 102 Relay lens error signal generating means 21 7, a relay lens control unit 218 that generates a relay lens driving signal according to the relay lens error signal, and a relay lens driving unit 219 that drives the relay lens 321 according to the relay lens driving signal.

The optical pickup 203 includes two optical systems having different wavelengths such as 405 nm and 650 nm. First, the operation during reproduction of the 405 nm optical system will be described. The laser driver 301 is controlled by the controller 201 and outputs a current for driving the laser diode 302. This drive current is applied with high frequency superposition of several hundred MHz in order to suppress laser noise. The laser diode 302 emits a laser beam having a wavelength of 405 nm with a waveform corresponding to the drive current. The emitted laser light becomes parallel light by the collimator lens 303, a part of the light is reflected by the beam splitter 304, and is condensed on the power monitor 306 by the condenser lens 305. The power monitor 306 feeds back a current or voltage corresponding to the intensity of the laser light to the controller 201. As a result, the intensity of the laser beam condensed on the recording layer of the optical disc 102 is maintained at a desired value such as 2 mW. On the other hand, the laser light transmitted through the beam splitter 304 is reflected by the polarization beam splitter 307 and transmitted through the dichroic mirror 308. The dichroic mirror 308 is an optical element that reflects light of a specific wavelength and transmits light of other wavelengths. Here, it is assumed that light having a wavelength of 405 nm is transmitted and light having a wavelength of 650 nm is reflected. Convergence / divergence of the laser light transmitted through the dichroic mirror 308 is controlled by the spherical aberration correction element 309 driven by the aberration correction drive means 206, becomes circularly polarized by the quarter wavelength plate 310, and is optical disc by the objective lens 311. Concentrate on 102 recording layers. The position of the objective lens 311 is controlled by the actuator 312. The intensity of the laser light reflected by the optical disk 102 is modulated according to the information recorded on the optical disk 102. The light is linearly polarized by the quarter-wave plate 310, passes through the dichroic mirror 308 and the spherical aberration correction element 309, and passes through the polarization beam splitter 307. The transmitted laser light is condensed on the detector 314 by the condenser lens 313. The detector 314 detects the intensity of the laser beam and outputs a signal corresponding to the intensity to the signal processing unit 202. The signal processing unit 202 performs processing such as amplification, equalization, and decoding on the reproduction signal output from the detector 314, and outputs the decoded data to the controller 201. The controller 201 outputs data to the host 103.

Also, the focus error signal generation unit 211 generates a focus error signal for the recording layer from the signal output from the detector 314. The focus control unit 212 outputs a focus drive signal corresponding to the focus error signal to the focus drive unit 213 in response to a command signal from the controller 201. The focus drive unit 213 drives the actuator 312 in a direction perpendicular to the disk surface in accordance with the focus drive signal. As described above, the focus control unit 212 and the focus drive unit 213 operate, so that the focus control is performed so that the laser spot irradiated on the recording layer of the optical disc 102 is always focused on the recording layer.

When recording, recording data is input from the host 103 to the controller 201. The controller 201 outputs a recording waveform corresponding to the input data to the laser driver 301. The laser driver 301 outputs a drive current corresponding to the recording waveform to the laser diode 302, and the laser diode 302 emits laser light with a waveform corresponding to the recording, whereby recording is performed on the recording layer of the optical disc 102.

Next, the 650 nm optical system will be described. In this optical system, there is no difference in operation between recording and reproduction. Similar to the 405 nm optical system, the laser driver 301 drives the laser diode 315, and the laser diode 315 emits laser light having a wavelength of 650 nm. A part of the laser light passes through a collimator lens 316, a beam splitter 317, and a condenser lens 318, and the power is monitored by a power monitor 319. By feeding back the monitored power to the controller 201, the intensity of the laser light focused on the guide layer of the optical disc 102 is maintained at a desired power, such as 3 mW. The laser light that has passed through the beam splitter 317 passes through the polarization beam splitter 320 and is controlled by the relay lens 321 to converge and diverge. The laser light that has passed through the relay lens 321 is reflected by the dichroic mirror 308, passes through the quarter-wave plate 310, and is condensed on the guide layer of the optical disk 102 by the objective lens 311. The laser beam reflected by the optical disk 102 is reflected by the polarization beam splitter 320 and condensed on the detector 323 by the condenser lens 322.

The tracking error signal generation unit 214 generates a tracking error signal for the guide layer of the optical disc 102 from the signal output from the detector 323. The tracking control means 215 generates a tracking drive signal corresponding to the tracking error signal in response to a command signal from the controller 201. The tracking drive means 216 drives the actuator 312 in the radial direction of the disk according to the tracking drive signal. As described above, the tracking control unit 215 and the tracking driving unit 216 operate, so that the tracking control is performed so that the laser spot irradiated on the guide layer of the optical disc 102 always follows the track on the guide layer.

Also, the relay lens error signal generation means 217 generates a relay lens error signal that is an error signal in the focus direction with respect to the guide layer of the optical disc 102 from the signal output from the detector 323. The relay lens control means 218 generates a relay lens driving signal corresponding to the relay lens error signal in response to a command signal from the controller 201. The relay lens driving means 219 drives the relay lens 321 according to the relay lens driving signal. By driving the relay lens 321, the focus position of the laser spot focused on the guide layer changes, and the difference in position between the recording layer and the guide layer can be compensated. As described above, the relay lens control unit 218 and the relay lens driving unit 219 operate, so that the relay lens control is performed so that the laser spot irradiated on the guide layer of the optical disc 102 is always focused on the guide layer.

Also, the slider driving means 205, the aberration correction driving means 206, and the spindle control means 209 are also operated by a command signal from the controller 201.

Although the same laser driver 301 is used here to drive the laser diode 302 and the laser diode 315, each laser diode may be provided with a laser driver specific to it. Further, the spherical aberration correction element 309 may be disposed at a position that affects both the 405 nm optical system and the 650 nm optical system, and may be disposed between the quarter wavelength plate 310 and the dichroic mirror 308, for example. .

FIG. 4 shows a processing flow of the optical disc apparatus 101 when the optical disc 102 is inserted into the optical disc apparatus 101.

When the optical disk 102 is inserted into the optical disk apparatus 101 in S401, the optical disk apparatus 101 confirms the presence / absence of a disk and the disk type in S402. At this time, for example, the optical disc apparatus 101 can irradiate the optical disc 102 with laser light and perform recognition by reflected light.

Next, in S403, adjustment processing is performed on the inserted optical disc 102 to make various parameters in the optical disc apparatus 101 suitable. Examples of the various parameters include adjusting the amplification factor of the amplifier included in the focus control unit 212 and the tracking control unit 215 in accordance with the reflectance of the optical disc 102.

After performing various adjustments, the management information of the optical disk 102 is read in S404. When the process proceeds to S405, recording or playback is possible, and recording or playback can be performed in response to a command from the host 103.

The timing of the adjustment process S403 is not limited to this, and part of the adjustment process may be performed after the management information read S404.

Next, the structure of the guide layer in the optical disc 102 of the present embodiment will be described with reference to FIGS.
(Outline of the guide layer of the optical disk 102 of this embodiment)
FIG. 5 shows an outline of the track arrangement on the guide layer of the optical disc 102 of the present embodiment. The track is spirally formed with respect to the center of the disk, and is composed of lands (concave portions as viewed from the laser beam incident side) and grooves (convex portions as viewed from the laser beam incident side). At the corner position, the land and the groove are interchanged. In this embodiment, the optical disk 102 is a medium having a guide groove structure for tracking land and groove. The land and the groove have substantially the same width in the radial direction. Thus, at the time of recording / reproducing on the optical disc apparatus 101, the tracking position is switched between the land and the groove every rotation of the disc. In addition, this invention is not restricted to this, It is good also as the arrangement | positioning which a land and a groove interchange in the position of several rotation angles. If recording is performed on the recording layer while tracking such a guide layer, the mark row on the recording layer has a track pitch substantially the same as the distance between the land center and the groove center of the guide layer. A spiral track similar to that of the optical disc product can be obtained.

FIG. 6 shows an outline of an example of the track structure of the guide layer of the optical disc 102 in this embodiment. The tracks meander slightly in the radial direction. Hereinafter, this meander structure is referred to as wobble. The wobble period is constant with respect to the rotation angle of the disk, and all adjacent grooves and lands meander in the same phase. On the other hand, since the track width is extremely small, the wobble period can be regarded as approximately constant with respect to the tangential direction in the adjacent tracks. Further, the wobble cycle is set to a short length that the tracking servo process cannot follow at the rotational speed during the recording / reproducing process of the disk. In this embodiment, the recording clock is generated with reference to the wobble period of the track of the guide layer. The wobble component can be detected as a push-pull signal (difference signal) during tracking. The push-pull signal is a signal that is also used as an error signal in tracking servo, and is used with the amplitude polarity inverted between when tracking on the land side and when tracking on the groove side. For this reason, the polarity control of the tracking error signal and the switching control of the pit detection method are performed in conjunction with each other depending on whether the polarity of the guide groove at the tracking position is a land or a groove.

Also, pits are placed on either the groove or land. FIG. 6 shows an example of arrangement on a land. In the following, a case where pits are arranged on the land side will be described as an example, but it may be provided in the groove. Here, since the guide layer uses a guide layer laser having a long wavelength and a large spot diameter to scan a narrow track having a substantially same interval as the recording layer, a larger crosstalk occurs than the recording layer or the conventional optical disc. In order to reduce the influence, pits are arranged only in one of the groove and the land.

The pit is a microstructure whose height is changed by a certain minute amount compared to the position before and after the track. In this embodiment, address information is detected by determining the presence or absence of this pit string. That is, when tracking to the land, the address information is determined from the pit of the track, and when tracking to the groove, the address information is determined from the pit of the track adjacent to the inner periphery or the outer periphery.

Also, in addition to the address information, distance information to the next track polarity switching position may be added so that it can be referred to when controlling the timing of switching each process according to the tracking polarity. Hereinafter, it is collectively referred to as address information.

Changes in the return light due to the presence or absence of pits can be detected by changes in the intensity distribution of the light spot on the detector, but there are pits on the track being tracked and pits on adjacent tracks. Apply different detection methods.

When tracking to the land, it can be detected by the change in the total light quantity on the detector. The direction of change of the light intensity mainly depends on the wavelength of the guide laser beam and the groove depth, the pit height, the optical constant of the medium, etc., but if matched to the groove height, the diffracted light from the adjacent groove Since the phases of the reflected light from the position are aligned, the return light intensity is increased. In the following, it is assumed that the intensity of the return light is larger at the pit position than before and after.

Further, when tracking is performed on the groove, the light spot intensity distribution on the detector corresponding to the radial direction of the disk 102 becomes asymmetric at the place where the pit exists in the adjacent land. For this reason, it can be detected as a push-pull signal.

That is, when tracking is performed on the side where the pit is arranged, address information is detected from the pit of the track detected from the sum signal, and when tracking is performed on the side where the pit is arranged, a push-pull signal ( Address information can be obtained from the pits of adjacent tracks detected from the difference signal.

However, if pits exist simultaneously on both lands across the groove, the light spot intensity distribution on the detector does not become asymmetric, so this method cannot be applied. For this reason, the pits in both lands sandwiching the groove are arranged so as not to be in the same position with respect to the circumferential direction of the track.

If the wobble period is constant with respect to the rotation angle on the entire circumference of the optical disk 102, the circumferential length per period on the inner circumference side and the outer circumference side is greatly different in proportion to the radial position, and the outer circumference The recording density at lowers. For this reason, it is good to divide into several areas in the radial direction, and to make the meander cycle constant in the area with respect to the rotation angle. At this time, the track polarity on the side where the pits are arranged may be changed depending on each region. In this way, at the timing when the tracking position passes the boundary of the region, the amplitudes of the pit detection signals of both the difference signal and the sum signal are in the opposite directions without being linked with the polarity of the tracking error signal. Since the change greatly occurs, the change of the recording area can be determined by detecting this change even if the address information cannot be detected.

Fig. 7 is a schematic diagram of a track extracted from one wobble cycle.

* The length of the pits to be arranged should be sufficiently smaller than the meandering cycle. Moreover, the pit arrangement | positioning phase arrange | positioned within a meandering period is predetermined. This is to prevent a signal generated due to a defect or noise at another timing from being erroneously determined as a pit by prescribing the timing for determining whether or not there is a pit. Also, for example, if the pit arrangement phase within the same lap is kept constant and the pit arrangement phase is different between the odd-numbered lands and the even-numbered lands in the radial direction as shown in FIG. It is possible to arrange so that the pits in both lands sandwiching the track are not at the same position in the circumferential direction of the track.

Also, the ratio between the circumferential length of one wobble period and the circumferential length per bit of the recording mark on the recording layer needs to be determined in advance. Below, this ratio is set to Nch (integer). That is, an Nch bit mark is recorded during the track length of one cycle of wobble.

As described above, according to the optical disk of the present embodiment, land and groove address information can be detected by arranging pits on either the groove or the land of the guide layer. Thereby, it is possible to improve the recording density while reducing the influence of the crosstalk. Furthermore, by arranging the pits in both lands (or grooves) sandwiching the groove (or land) so as not to be in the same position with respect to the circumferential direction of the track, the influence of crosstalk can be further reduced. it can.

Next, the configuration of the controller 201 used in the optical disc apparatus 101 of this embodiment will be described with reference to FIG.
(One embodiment of controller 201)
FIG. 1 shows an example of a controller 201 that enables recording / reproduction of the optical disc 102 described above.

The controller 201 includes host interface means 601, buffer memory control means 602, buffer memory 603, microprocessor 604, tracking polarity signal generation means 605, pit detection means 606, address discrimination means 607, recording timing signal generation means 608, reproduction data demodulation Means 613, recording data modulation means 614, emission signal generation means 615, wobble detection means 616, and PLL617 are provided.

611 is a recording layer output light, 612 is a return light from the recording layer, 609 is a guide layer output light, 610 is a return light from the guide layer, 618 is a tracking polarity control signal, 619 is a pit detection processing control signal ing.

The host interface unit 601 receives a write command from the host 103, stores the recording data in the buffer memory 603 via the buffer memory control unit 602, and outputs a signal indicating that the write command has been issued to the microprocessor 604. introduce.

The recording data modulation means 614 adds the error correction code and the modulation processing to the recording data stored in the buffer memory 603, and generates recording data converted into a format for recording on the optical disc 102. .

The microprocessor 604 controls the entire optical disc device 101 based on a sequence stored in a program memory (not shown). During the recording process, the slider drive means 205 is set so that the light spot on the disk moves to the vicinity of the recording position where writing is performed upon receipt of the write command. Set to start. On the other hand, the recording timing signal generating means 608 is given address information for starting recording.

The tracking polarity signal generation means 605 gives an instruction signal indicating the polarity of the tracking position (either land or groove) to the pit detection means 606 and the tracking control means 215. This is because the tracking error signal using a push-pull signal, which is generally used in tracking servo processing of an optical disk device, needs to reverse the polarity of the signal when tracking to a land or tracking to a groove. is there. If tracking is successful and the address information can be detected, an instruction signal is generated with reference to the address information. Immediately after the start of tracking, the polarity is unknown until the address information is detected. During this period, a signal representing the same polarity is given to the pit detection means 606 and the tracking control means 215 as an initial value. As a result, tracking can be started from a position having the polarity given as the initial value among the tracks at the tracking start position or adjacent tracks, and then the address information can be detected.

The wobble detection means 616 detects the wobble signal from the output of the detector 323 that detects the return light 610 from the guide layer. The PLL 617 generates a multiplied clock that is phase-synchronized with the wobble signal and outputs it as a recording clock.

The pit detection means 606 detects pits arranged on the land of the guide layer from the output of the detector 323 that detects the return light 610 from the guide layer. As described above, the method used for detecting the pit differs depending on the polarity of the tracking position. For this reason, upon receiving an instruction signal indicating the polarity (either land or groove) of the tracking position from the tracking polarity signal generation means 605, a detection method suitable for the polarity of the tracking position is selected and applied.

The address discriminating means 607 discriminates the address information of the tracking position based on the pit detected by the pit detecting means 606.

The recording timing signal generation means 608 receives the address information for starting recording from the microprocessor 604 and the address information from the address determination means 607, and the light spot on the guide layer passes the recording start position and the recording start timing. The signal is output to the light emission signal generating means 615.

The light emission signal generating means 615 transmits a recording waveform corresponding to the data pattern recorded on the optical disc 102 to the LDD 301. A recording waveform corresponding to the data pattern to be recorded is generated from the recording data generated by the recording data modulation unit 614, and transmission to the LDD 301 is started at the timing when the recording start timing signal is obtained from the recording timing signal generation unit 608. To do. The transmission rate to be transmitted follows the frequency of the recording clock from the PLL 617.

Next, an outline of the sequence of the recording processing method used in the optical disc apparatus 101 of the present embodiment will be described with reference to FIG.
(Example of recording processing sequence of optical disc apparatus 101)
FIG. 8 is a flowchart of an example of a recording processing sequence of the optical disc apparatus 101 that enables recording and reproduction of the optical disc 102 described above.

S801 is a step of focusing the light spot from the laser for the guide layer on the guide layer.

S802 is a step of focusing the recording layer laser to the target layer.

S803 is a step of initializing tracking polarity information given to the tracking control means 215 and the pit detection means 606.

S804 is a step of driving the sled so that the light spot is positioned in the vicinity of the radial position where recording on the optical disk 102 is performed.

S805 is a step of starting tracking in the guide groove on the guide layer.

S816 is a step of starting the tracking to the guide groove on the guide layer and starting the wobble detection of the guide layer and the generation of the recording clock from the wobble detection signal.

S806 is a step of detecting the address of the guide layer.

S807 is a step of starting automatic switching of tracking polarity based on address information obtained from the guide layer.

S808 is a step of determining from the address information obtained in S806 whether or not it has moved within the radius position range as the movement target. If it is determined that the target radial position has not been reached, the process returns to the previous stage of step S803 to move the radial position again.

S809 is a step of giving a recording start address to the recording timing signal generating means 608.
Although illustration is omitted, it is necessary that the recording data modulation process be completed after the reception of the write command until S809 starts. If not, insert an appropriate amount of wait processing.

S810 is a step of detecting address information from the guide layer in order to determine the recording start position. S811 is a step of determining whether or not the recording start position is based on the address information obtained in step S810. The process returns to step S810 until the recording start position is reached, and the process proceeds to step S812 while reaching the recording start position. Although not shown, when it is determined that the position is after the recording start position, the process proceeds to step S803.

S812 is a step of controlling the recording layer laser so as to start the light emission with the light emission waveform / output according to the recording data while reaching the recording start position.

S813 is a step of detecting address information of the guide layer in order to confirm that it is being tracked at a desired position during recording.

S814 is a step of determining whether or not the desired position is tracked based on the continuity of the address information obtained in step S813. If it is determined that the continuity has been lost, it is considered that the recording has been unexpectedly moved to another track for some reason. Therefore, the recording process is stopped, and the amount of light emitted from the recording layer laser is changed to that for reproduction. Switch to things.

S815 is a step to confirm that all data to be recorded is completed. If it is determined that the process has not been completed, the process returns to step S813. When it is determined that the recording is completed, the amount of light emitted from the recording layer laser is switched to that for reproduction, and the recording process is terminated.

As described above, according to the optical disc apparatus and the optical disc recording method of the present embodiment, it is possible to detect the address information even when tracking is performed on both the land and the groove of the guide layer. Thereby, it is possible to improve the accuracy of the recording position and the recording density.

Next, the components of the controller 102 of the optical disk recording apparatus and the operation thereof will be described in more detail.
(Example of wobble detection means 616)
FIG. 9 shows an example of the wobble detection means 616.

Reference numeral 901 denotes a light spot on the detector 323. Reference numeral 902 denotes a difference signal calculation circuit.

Reference numerals

903, 904, and 907 are multipliers. 911 is an original wobble signal. Reference numeral 912 denotes a wobble phase synchronization signal. Reference numeral 913 denotes an inverted wobble phase synchronization signal. Reference numeral 914 denotes a comparator. 915 is a selector. 916 is a wobble carrier signal.

The detector 323 is for detecting the return light from the guide layer, and is used that is divided at least in the direction corresponding to the radial direction of the optical disk 102. In the figure, a four-divided configuration is also obtained, which is also divided into two in the tangential direction. In addition, this invention is not restricted to this, For example, it is good also as a 16 division structure. The difference signal calculation circuit 902 performs a calculation for obtaining a push-pull signal from the detection signal of each element of the detector 323. Specifically, the (A + D)-(B + C) calculation is performed on the detection signals of the elements A, B, C, and D of the quadrant detector in the figure, and the result is output. . Since the frequency component of the wobble signal to be detected is limited to a single frequency or a frequency in the vicinity thereof, a band pass filter or the like may be provided at the output of the difference signal calculation circuit 902.

The original wobble signal 911 is a signal having a variation similar to the wobble meandering amount on the guide layer. However, generally, since the amount of meandering of the track is very small, the quality cannot often be obtained sufficiently, and further carrier extraction processing is added.

Each element of each multiplier (903, 904, 907), each low-pass filter (905, 906), loop filter 908, VCO909, π / 2 phase shifter 910 forms a carrier demodulation circuit called a so-called Costas loop. . The output wobble phase synchronization signal 912 has the same frequency as the wobble original signal 911.

The outputs of the

multipliers

903 and 904 are signal outputs obtained by adding a cosine component cosθ of the phase error amount θ of the wobble phase synchronization signal 912 relative to the wobble original signal 911 and a component having a frequency twice the wobble frequency to the sine component sinθ, respectively. Is done.

The low-pass filter (905, 906) has a cut-off characteristic that can sufficiently suppress a component having a frequency twice the wobble frequency. From the output of the multiplier 907, a sine component (sin (2θ) / 2) having a phase amount twice the phase error amount is detected and used as a phase error signal. The loop filter 908 is a compensator for stabilizing the loop characteristics. The VCO 909 is a voltage controlled oscillator and outputs a signal having a frequency based on the magnitude of the input signal. From the VCO 909, a signal having the same frequency as the wobble original signal 911 is obtained as the wobble phase synchronization signal 912. However, if the sensitivity characteristic of the phase error signal (sin (2θ) / 2) has a period of π with respect to the phase error amount, a signal having the same phase as the wobble original signal 911 can be obtained as the wobble phase synchronization signal 912. In addition, there is a case where an inverted phase signal is obtained.

The comparator 914 and the selector 915 are for selecting signals having the same frequency and the same phase as the wobble original signal 911. The selector 915 receives a wobble phase synchronization signal 912 and an inverted wobble phase synchronization signal 913 which is an inverted signal thereof, and selects and outputs one of them. A signal for controlling the selection is supplied from the comparator 914.

The comparator 914 is for determining the phase relationship between the wobble phase synchronization signal 912 and the wobble original signal 911. For example, the output signal cos θ of the low-pass filter 905 has a positive value 1 when the phase error θ = 0 and a negative value −1 when θ = π. When this is compared with a reference potential (usually 0V) and the result of determining the polarity is output and supplied to the selector 915, the wobble carrier signal 916 can be obtained as a signal having the same frequency and the same phase as the wobble original signal 911.
(Example of the configuration of PLL617)
FIG. 10 shows an example of the configuration of the PLL 617, which internally includes a phase error detection means 1001, a loop filter 1002, a VCO (voltage controlled oscillator) 1003, and a frequency divider 1004. Also, 916 is a wobble carrier signal, 1005 is a wobble synchronization clock, and 1005 is a wobble multiplication clock.

The main input signal of the PLL 617 is a wobble carrier signal 916, which is a signal that is phase-synchronized with the wobble of the guide layer of the optical disc 102. The main output is a wobble multiplication clock 1005 output from the VCO 1003.

The phase error detection means 1001 compares the phase of the wobble synchronization clock 1005 obtained by dividing the wobble multiplication clock 1005 by the frequency divider 1004 with the wobble carrier signal 916, and has a magnitude corresponding to the amount of the phase difference. The phase error signal is output to the loop filter 1002. The loop filter 1002 is a frequency characteristic compensation unit provided for the purpose of stabilizing the feedback loop formed by the PLL 617, and provides a control signal to the VCO 1003 so that the phase error between the wobble synchronization clock 1005 and the wobble carrier signal 916 becomes small. As a result, the wobble carrier signal 916 matches the frequency and phase of the wobble synchronization clock 1005 that is the output of the frequency dividing means 1004. At this time, the frequency of the wobble multiplication clock 1005 that is input to the frequency divider 1004 is multiplied by the reciprocal of the frequency division ratio of the frequency divider 1004 with respect to the wobble synchronization clock 1005. Specifically, when the frequency dividing ratio of the frequency divider 1004 is 1 / N, a clock having a frequency N times that of the wobble synchronous clock 1005 is obtained as the wobble multiplied clock 1005. If N = Nch, a clock equivalent to one clock can be generated while passing the 1-bit recording mark length, so the divider ratio of the divider 1004 is 1 / Nch or 1 / nNch (n is a natural number) , Just an integer number of clocks are generated within the passing time of 1-bit recording mark length.

The wobble multiplication clock 1005 obtained in this way is supplied to the light emission signal generating means 615 as a recording clock.
(Example of pit detection means 606)
FIG. 11 shows an embodiment of the pit detection means 606.

1101 is a difference signal calculation circuit, 1102 is a sum signal calculation circuit, 1103 is a difference signal data detection means, 1104 is a sum signal data detection means, 1105 is a switching means, 1106 is an address data signal, and a pit detection means 606 is Have these inside. Reference numeral 323 denotes a detector for detecting return light from the guide layer, and reference numeral 901 denotes a light spot formed on the detector 323.

The difference signal calculation circuit 1101 obtains a signal for detecting a pit existing in the adjacent land when tracking to the groove, and performs an operation for obtaining a push-pull signal from the detection signal of each element of the detector 323. I do. It may be shared with the difference signal arithmetic circuit 902.

The sum signal calculation circuit 1102 obtains a signal for detecting a pit existing on the track when tracking to the land, and obtains a sum signal of detection signals of each element of the detector 323.

The difference signal data detection means 1103 detects a pit existing in the adjacent track from the signal obtained by the difference signal calculation circuit 1101 and outputs a data signal according to the detected pit to the switching means 1105. On the other hand, the sum signal data detection means 1104 detects pits existing in the adjacent track from the signal obtained by the sum signal calculation circuit 1102, and outputs a data signal according to the detected pit to the switching means 1105. .

The switching means 1105 selects the data from the difference signal data detection means 1103 while tracking to the groove in accordance with the pit detection processing control signal 619 from the tracking polarity signal generation means 605, and the subsequent stage as the address data signal 1106 During the tracking to the land, the data from the sum signal data detection means 1104 is selected and output as the address data signal 1106 to the subsequent stage.
(One example of sum signal data detecting means 1104 and difference signal data detecting means 1103)
An example of the sum signal data detection means 1104 and the difference signal data detection means 1103 will be described with reference to FIG. 12, FIG. 13, and FIG.

Both the sum signal data detection means 1104 and the difference signal data detection means 1103 can be realized by the configuration shown in FIG.

FIG. 13 shows an outline of the operation of the sum signal data detection means 1104. FIG. 14 shows an outline of the operation of the difference signal data detection means 1103.

1201 is an arithmetic output signal processed by the sum signal data detection means 1104 or the difference signal data detection means 1103.

1204 is a comparator. 1205 is a threshold signal generation means. Reference numeral 1206 denotes a threshold signal. Reference numeral 1207 denotes a pit detection gate signal. 1208 is an AND gate. Reference numeral 1209 denotes a pit detection signal. Reference numeral 1213 denotes a base level signal. 1214 is a peak level signal. 1215 is a count value. Reference numeral 1216 denotes a wobble reference phase signal.

First, the operation of the sum signal data detection means 1102 will be described with reference to FIGS.

The sum signal calculation circuit 1102 includes a low-pass filter 1202, a peak level detection circuit 1214, a comparator 1204, a threshold signal generation unit 1205, an AND gate 1208, a reference phase timing signal generation unit 1210, a counter circuit 1211, Pit detection gate signal generation means 1212.

Broadly divided, it is divided into a processing unit for obtaining a pulse signal corresponding to a pit from the sum signal 1201 and a processing unit for generating a gate signal for preventing erroneous detection at a position where there is no pit due to noise or the like.

The low-pass filter 1202, the peak level detection circuit 1214, the comparator 1204, and the threshold signal generation means 1205 form a processing unit that obtains a pulse signal corresponding to the pit from the sum signal 1201. In addition, each element of the reference phase timing signal generation means 1210, the counter circuit 1211, the pit detection gate signal generation means 1211, and the AND gate 1208 has a gate signal for preventing erroneous detection at a position where there is no pit due to noise or the like. A processing unit for generation is formed.

When the sum signal 1201 passes through the pit position while tracking to the land, it returns to a pulse shape and the light intensity increases. The low-pass filter 1202 smoothes a pulse-like intensity change component with respect to the signal from the sum signal data detection means 1104, thereby having a base level signal having a signal level substantially equivalent to a signal at a portion having no pit. 1213 is generated and supplied to the threshold signal generation means 1205. The peak level detection circuit 1214 performs peak hold processing on the sum signal, and supplies the peak level signal 1214 corresponding to the pulse height to the threshold signal generation means 1205. The threshold signal generation unit 1205 supplies the comparator 1204 with a threshold signal 1206 having a substantially intermediate level between the base level signal 1213 from the low-pass filter 1202 and the peak level signal 1214 from the peak level detection circuit 1203. The comparator 1204 compares the sum signal 1201 and the threshold signal 1206, and outputs to the AND gate 1208 a rectangular wave pulse signal that has a higher signal level when the sum signal 1201 is larger.

The reference phase timing signal generation means 1210 generates a wobble reference phase signal 1216 indicating a specific phase in the meandering cycle of the wobble carrier signal 916. For example, a pulse signal having a constant width is generated at the zero cross timing when the negative level changes to the positive level, and is supplied to the counter circuit 1211. The counter circuit 1211 is a counter that increments the value at the timing of the wobble multiplication clock 1006 and resets the value at the timing of the pulse signal representing the reference phase. Thus, the phase of the wobble carrier signal 916 is represented by the count value 1215. The pit detection gate signal generation means 1212 receives the count value 1215 of the counter circuit 1211 and generates a pit detection gate signal 1207 that is active before and after the phase where the pits are arranged. The AND gate 1208 generates an AND signal of the rectangular wave pulse from the comparator 1204 and the pit detection gate signal 1207. In this way, a pulse signal corresponding to the pit is obtained using the sum signal data detection means 1104.

The operation of one of the difference signal data detection means 1103 is the same except that the direction of the pulse component appearing in the input arithmetic output signal appears on both the large amplitude side and the small amplitude side. The direction of the pulse component is determined by the adjacent direction (inner side or outer side) of the land where the pit exists with respect to the tracking groove, so either one (the amplitude increases in FIG. 14). Pits existing in adjacent lands can be detected. In this way, a pulse signal corresponding to the pit is obtained from the difference signal data detection means 1103.

According to the optical disk medium, the optical disk apparatus, and the optical disk recording method of the first embodiment described above, the recording density can be improved while alleviating the influence of crosstalk.

Further, it is possible to obtain a recording clock by further multiplying the detected signal according to the amount of meandering from the meandering track of the guide layer at a substantially constant period. In addition, by recording address information representing the position on the guide layer by pits arranged on the track, the recording position on the recording layer is determined with reference to the address information on the guide layer during the recording process. It becomes possible.

Example 2 shows another example of the pit detection means 606. Since parts other than the pit detection means 606 are the same as those in the first embodiment, the description thereof is omitted.

FIG. 15 is a configuration example different from that of FIG. 11 of the pit detection means 606.

In the configuration of FIG. 15, sum signal data detection means 1104 and difference signal data detection means 1103 provided separately in the configuration of FIG. 11 are integrated into the data detection means 1501.

That is, instead of the switching means 1105 provided in the subsequent stage of the sum signal data detection means 1104 and the difference signal data detection means 1103 in the configuration of FIG. 11, the sum signal calculation circuit 1102, the difference signal calculation circuit 1101, and the data detection means The switching means 1506 is provided between the tracking position signal 1501 and the output corresponding to the tracking position is selected according to the pit detection processing control signal 619 from the tracking polarity signal generation means 605 and is output to the data detection means 1501 and the address data signal 1106 is generated.

Incidentally, in the data detection means 1501, processing parameters such as appropriate signal levels of the peak level signal 1214, the base level signal 1213, and the threshold signal 1206 differ depending on whether the input signal is switched depending on whether the tracking position is a land or a groove. Therefore, a sum signal parameter storage unit 1502 and a difference signal parameter storage unit 1503 are provided, and a processing parameter to be given to the data detection unit 1501 is switched by a switching unit 1504 controlled by a pit detection processing control signal 619. The sum signal parameter storage means 1502 and the difference signal parameter storage means 1503 may be formed of a register or a memory.

According to the optical disk medium, the optical disk device, and the optical disk recording method of the second embodiment described above, the same effects as those of the first embodiment can be obtained.

Further, in order to combine the data detection means 1104 for sum signal and the data detection means 1103 for difference signal into the data detection means 1501, processing equivalent to the configuration of FIG. 11 can be performed with a smaller apparatus than the first embodiment. Is possible.

In Examples 1 and 2 described above, an example in which a method of tracking both the land and the groove on the guide layer is applied as a method capable of realizing a higher recording density has been described. Needless to say, the optical disk recording apparatus and optical disk recording method described in (1) can be applied to the case of tracking only one of a land and a groove, which is simpler.

Further, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

Furthermore, each of the above-described configurations may be configured such that some or all of them are configured by hardware, or are realized by executing a program by a processor. Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

In the above embodiment, the optical disk recording apparatus has been described as an example. However, an optical disk recording / reproducing apparatus may be used, and the present invention can be applied to recording processing of a data recording / reproducing apparatus such as an optical disk drive apparatus. it can.

101 Optical disk device
102 optical disc
103 hosts
201 controller
202 Signal processor
203 Optical pickup
204 Slider motor
205 Slider drive means
206 Aberration correction drive means
207 Spindle motor
208 Rotation signal generation means
209 Spindle control means
210 Spindle drive means
211 Focus error signal generator
212 Focus control means
213 Focus drive means
214 Tracking error signal generation means
215 Tracking control means
216 Tracking drive means
217 Relay lens error signal generation means
218 Relay lens control means
219 Relay lens drive means
301 Laser driver
302 Laser diode
303 collimator lens
304 Beam splitter
305 condenser lens
306 Power monitor
307 Polarizing beam splitter
308 Dichroic Mirror
309 Spherical aberration correction element
310 1/4 wave plate
311 Objective lens
312 Actuator
313 condenser lens
314 Detector
315 laser diode
316 collimator lens
317 beam splitter
318 condenser lens
319 Power monitor
320 Polarizing beam splitter
321 Relay lens
322 Condensing lens
323 detector
601 Host interface means
602 Buffer memory control means
603 buffer memory
604 microprocessor
605 Tracking polarity signal generation means
606 Pit detection means
607 Address discrimination means
608 Recording timing signal generation means
609 Output light for guide layer
610 Return light from the guide layer
611 Emission light for recording layer
612 Return light from the recording layer
613 Reproduction data demodulation means
614 Recording data modulation means
615 Light emission signal generation means
616 Wobble detection means
617 PLL
618 Tracking polarity control signal
619 Pit detection processing control signal
901 Light spot
902 Difference signal calculation circuit
903 multiplier
904 multiplier
905 Low-pass filter
906 Low-pass filter
907 multiplier
908 Loop filter
909 VCO
910 π / 2 phase shifter
911 Wobble source signal
912 Wobble phase synchronization signal
913 Inverted wobble phase synchronization signal
914 Comparator
915 selector
916 wobble carrier signal
1001 Phase error detection means
1002 Loop filter
1003 VCO
1004 divider
1005 wobble sync clock
1005 Wobble multiplication clock
1101 Difference signal calculation circuit
1102 Sum signal arithmetic circuit
1103 Data detection means for difference signal
1104 Sum signal data detection means
1105 Switching means
1106 Address data signal
1201 Computation output signal
1202 Base level detection circuit
1203 Peak level detection circuit
1204 Comparator
1205 Threshold signal generation means
1206 Threshold signal
1207 Gate signal for pit detection
1208 AND gate
1209 Pit detection signal
1210 Reference phase timing signal generation means
1211 Counter circuit
1212 Gate signal generation means for pit detection
1213 Base level signal
1214 Peak level signal
1215 Count value
1216 Wobble reference phase signal
1501 Data detection means
1502 Sum signal parameter storage means
1503 Difference signal parameter storage means
1504 Switching means
1505 Switching means

Claims

An optical disc medium capable of recording information,
A recording layer having a recording area;
A guide layer,
The guide layer has a region composed of a plurality of lands and grooves arranged alternately,
In the area, pits are provided in one of the land and the groove, and address information indicating a position on the guide layer is recorded by arrangement of the pits.
The optical disk medium according to claim 1,
The optical disk medium, wherein the pits arranged in the land or the groove are arranged so as not to be in the same position with respect to a circumferential direction of a track.
An optical disc medium according to claim 2, wherein
An optical disc medium characterized in that arrangement phases of the pits arranged in the plurality of lands or the plurality of grooves are different from each other.
An optical disc medium according to claim 3,
The land and the groove have the same radial width,
The recording mark formed on the recording layer is recorded along both the land and the groove.
An optical disc medium according to claim 4, wherein
An optical disc medium, wherein the land and the groove are switched every round.
An optical disc apparatus for recording information on an optical disc medium having a recording layer having a recording area and a guide layer,
A first laser for irradiating the recording layer with a light spot;
A first detector for detecting return light from the recording layer;
A second laser for irradiating the guide layer with a light spot;
A second detector for detecting return light from the guide layer;
A tracking control unit that controls the tracking direction of the light spot of the guide layer based on the signal detected by the second detector;
A pit detector that detects pits of the optical disc medium based on a signal detected by the second detector;
An address information detection unit for obtaining address information based on a signal output from the pit detection unit,
Signals output by the pit detection unit when tracking control is performed on a land or groove where the pit is disposed and when tracking control is performed on a land or groove where the pit is not disposed An optical disc apparatus characterized by being made different.
The optical disc apparatus according to claim 6, wherein
The second detector is divided into a plurality of regions;
When tracking control is performed on a land or groove in which the pit is not disposed, the signal output from the pit detection unit outputs a signal corresponding to a difference in intensity between the plurality of regions. apparatus.
The optical disc apparatus according to claim 7, wherein
An optical disc apparatus that outputs a signal corresponding to a sum of intensities of the plurality of areas when tracking control is performed on a land or a groove in which the pit is arranged.
The optical disc apparatus according to claim 8, wherein
A wobble detection unit for detecting a signal corresponding to the meandering amount of the land or the groove;
A recording clock generation unit that generates a recording clock based on the signal detected by the wobble detection unit;
An issuance waveform generation unit that generates an emission waveform of the first laser based on the recording clock,
An optical disc apparatus, wherein information is recorded using a light emission waveform of the generated first laser at a position on a first recording layer based on an address obtained by the address information detection unit.
The optical disk device according to claim 9, wherein
An optical disc apparatus comprising a tracking polarity signal generation unit that generates and outputs a signal indicating whether a tracking position is a land or a groove.
The optical disc apparatus according to claim 10, wherein
The guide layer has a structure in which lands and grooves are switched every other turn,
The address information further includes distance information until the land and the groove are switched,
The optical disc apparatus, wherein the tracking polarity signal generation unit controls a polarity control signal based on address information detected by the address detection unit.
An optical disc recording method for recording information on an optical disc medium having a recording layer having a recording area and a guide layer,
Irradiating the recording layer with a light spot;
Detecting return light from the recording layer;
Irradiating the guide layer with a light spot;
Detecting return light from the guide layer;
Controlling the tracking direction of the light spot of the guide layer based on the signal detected by the step of detecting return light from the guide layer;
Detecting a pit of the optical disk medium based on a signal detected by the step of detecting return light from the guide layer;
Obtaining address information based on a signal output in the step of detecting the pit;
Recording information at a position of the recording layer based on the address information,
When the tracking control is performed on the land or groove where the pit is arranged and when the tracking control is performed on the land or groove where the pit is not arranged, the output is performed in the step of detecting the pit. An optical disc recording method, wherein different signals are used.
An optical disc recording method according to claim 12, comprising:
In the step of detecting the return light from the guide layer, the detection is performed using a detector divided into a plurality of regions,
When tracking control is performed on a land or groove in which the pit is not disposed, the signal output from the pit detection unit outputs a signal corresponding to a difference in intensity between the plurality of regions. Recording method.
An optical disk recording method according to claim 13, wherein
An optical disk recording method comprising: outputting a signal corresponding to a sum of intensities of the plurality of areas when tracking control is performed on a land or a groove in which the pit is arranged.
15. The optical disc recording method according to claim 14, wherein
Detecting a signal corresponding to the meandering amount of the land or the groove;
Generating a recording clock based on the signal detected by the wobble detection unit;
Generating an emission waveform of the first laser based on the recording clock,
An optical disk recording method, wherein information is recorded using a light emission waveform of the generated first laser at a position on the first recording layer based on the address information.
The optical disk recording method according to claim 15, wherein
An optical disc recording method comprising: generating and outputting a signal indicating whether a tracking position is a land or a groove.
The optical disk recording method according to claim 16, wherein
The servo layer has a structure in which lands and grooves are switched every other turn,
The address information further includes distance information until the land and the groove are switched,
An optical disk recording method, wherein a polarity control signal is controlled based on the address information.