JP2013186915A - Optical disk recording and playback device and recording and playback method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk recording and playback device capable of performing stable tracking servo control even in an OPC (Optimum Power Control) area, and an OPC method.SOLUTION: The optical disk recording and playback device for performing recording on an optical disk having at least one guide layer having tracks and at least one recording layer having no track structure includes a first optical system for focusing a first laser beam on the guide layer, a second optical system for focusing a second laser beam divided into a plurality of parts on the recording layer, tracking error signal generation means for generating a plurality of tracking error signals from a signal of the second laser beam, and tracking error signal selection means for selecting a signal to be controlled from the tracking error signals, and forms a recording mark in an unrecorded OPC area after performing OPC processing for performing recording on the recording layer with optimum recording power.

Description

The present invention relates to an optical disc recording / reproducing apparatus and a recording / reproducing method for reproducing or recording information using a laser.

  As a background art, for example, there is a technique described in Patent Document 1. The summary of Japanese Patent Laid-Open No. 2004-228561 has an object of “being able to improve the positional accuracy in the radial direction when a plurality of mark layers are formed in the recording layer of an optical disk”. Then, as a means for solving the problem, “the optical disk apparatus 10 appropriately adjusts the optical paths of the servo light beam LS, the information light beam LM, and the tracking light beam LK in the optical path forming unit 70 of the optical pickup 17, and then the objective lens 18. Then, the servo light beam LS, the information light beam LM, and the tracking light beam LK are condensed respectively, and the optical pickup 17 controls the focus of the objective lens 18 so that the servo light beam LS is focused on the reference layer 104, and By performing tracking control of the objective lens 18 so that the tracking light beam LK is focused on the reference track TE of the target mark layer YG, the focus FM of the information light beam LM condensed by the objective lens 18 is changed to the target mark layer YG. Can be matched to the target track TG " It has been described.

JP2009-151900

  In recent years, in the Blu-ray Disc (TM) standard optical disc, an optical disc having three or four recording layers in addition to the conventional one or two layers has been developed and standardized. In the future, it is expected that an optical disc having a further recording layer will be developed with the aim of further increasing the capacity, but it is difficult to manufacture a large number of layers having a physical groove structure in terms of manufacturing the disc. It was a thing. Therefore, in order to facilitate manufacturing even when a large number of recording layers are stacked, a layer having a physical groove structure including addresses for addressing and tracking servo control (hereinafter referred to as a guide layer) is provided, There has been proposed an optical disc (hereinafter referred to as a grooveless disc) composed of a layer (hereinafter referred to as a recording layer) that performs recording / reproduction without a physical groove structure such as a land / groove structure.

  In this grooveless disk, the relative position of the optical spot irradiated to the recording layer is shifted due to the relative angle in the radial direction between the optical disk and the pickup being shifted. Due to this relative positional deviation, for example, there is a problem that overwriting of a mark already recorded at the time of additional recording occurs and data is lost.

  The optical disk recording / reproducing apparatus copes with variations in recording film characteristics and the like for each disk by performing a process called OPC (Optimum Power Control) for obtaining the optimum light intensity for recording. In the OPC processing, recording is performed while changing the intensity of the laser beam in an OPC area provided on the disk, and a portion is recorded that deviates from the optimum light intensity.

  Therefore, when tracking control is performed in the OPC area with the optical disc recording / reproducing apparatus of Patent Document 1 described above, a tracking error signal is not normally generated in a portion recorded with a deviation from the optimum light intensity, and tracking servo control is not performed. There is a problem of becoming stable.

  Therefore, an object of the present invention is to provide an optical disc recording / reproducing apparatus and an OPC method capable of performing stable tracking servo control even in the OPC area.

  The above problem is solved by, for example, the invention described in the claims.

  According to the present invention, stable tracking servo control can be performed even in the OPC region.

Switching operation of tracking error signal generation mark row of light spot in embodiment 1 Schematic diagram of the configuration of the optical disc recording / reproducing apparatus of Example 1 Example 1 Optical Disc Structure (Cross Section) Processing flow of optical disc recording / reproducing apparatus when optical disc is inserted into optical disc recording / reproducing apparatus of embodiment 1 Structure of optical disc targeted by Example 1 (enlarged view) Example 1 of flowchart of OPC operation of embodiment 1 Example of mark recording pattern of Example 1 Example 2 of flowchart of OPC operation of embodiment 1 Example of flowchart of OPC operation of embodiment 2 Example of laser intensity for overwriting in Example 2 FIG. 3 is an internal configuration diagram of a tracking error signal generation unit according to the first embodiment. Operation flow when receiving a recording command according to the first embodiment

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

(Optical disc form)
FIG. 3 shows the structure (cross section) of the optical disc 102 targeted by this embodiment. The optical disk 102 shown in the figure is an optical disk 102 having one guide layer with grooves and one or more flat recording layers without grooves. The groove of the guide layer is a spiral groove centered on the disk rotation axis, like the groove found on a disk such as DVD or BD.
The groove has a undulation structure (wobble) having a substantially constant period in the length direction as seen in a disk such as a DVD or a BD.
Although not shown, information indicating the current position (address) is added to the guide layer so as to be seen on a disc such as a DVD or a BD.
For example, a method of adding an address includes adding a portion to be modulated to wobble and adding a pit to the groove structure.

Further, the objective lens 311 in the figure is an objective lens 311 of an optical disc recording / reproducing apparatus (not shown) for condensing a laser beam on the optical disc 102. In the figure, two different light beams pass through the objective lens 311, one light beam generates a laser spot LSg on the guide layer of the optical disk 102, and the other light beam is out of a plurality of recording layers of the optical disk 102. One shows that the laser spot LSW is generated. In this way, the optical disk 102 targeted by this embodiment performs recording or reproduction using two or two or more light beams.
(Configuration of optical disc recording / reproducing apparatus)
FIG. 2 is a block diagram showing an embodiment of the optical disc recording / reproducing apparatus 101 according to the present invention.

An optical disk recording / reproducing apparatus 101 records or reproduces information by irradiating an optical disk 102 mounted on the apparatus with laser light, and a host 103 such as a PC (Personal Computer) through an interface such as SATA (Serial Advanced Technology Attachment). Communicate.
The optical disc recording / reproducing 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, a slider driving unit 205 that drives the slider motor 204, Aberration correction driving means 206 for driving the spherical aberration correction element 309 provided in the optical pickup 203, a spindle motor 207 for rotating the optical disk 102, and a rotation signal for rotating the spindle motor 207 are generated. Spindle control means 208, spindle drive means 209 for driving the spindle motor 207 in accordance with the rotation signal generated by the spindle control means 208 and generating an FG signal having a frequency corresponding to the rotation speed of the spindle motor 207, and the optical disc 102 Recording layer focus error indicating the amount of deviation between the recording layer and the focal position of the laser spot LSW A focus error signal generating unit 211 for generating a signal, a focus control unit 212 for generating a focus drive signal in accordance with the recording layer focus error signal, and an actuator 312 provided in the optical pickup 203 in accordance with the focus drive signal Focus driving means 213 for performing recording, tracking error signal generating means 214 for generating a recording layer tracking error signal indicating the amount of displacement between the recording layer track and the light spot 500 or the light spot 501 or the light spot 502 on the recording layer, and an optical disc Tracking error signal generating means 210 for generating a guide layer tracking error signal indicating the amount of positional deviation between the 102 guide layer tracks and the laser spot LSg on the guide layer, and according to the recording layer tracking error signal or the guide layer tracking error signal Tracking to generate tracking drive signal A control unit 215, a tracking drive unit 216 that drives the actuator 312 in response to the tracking drive signal, and a focus error that generates a guide layer focus error signal indicating the amount of deviation between the guide layer of the optical disc 102 and the focal position of the laser spot LSg A signal generation unit 217, a relay lens control unit 218 that generates a relay lens drive signal according to the guide layer focus error signal, and a relay lens drive unit 219 that drives the relay lens 321 according to the tracking drive signal and the relay lens drive signal. It has.

  The optical pickup 203 performs servo control on the guide layer, and data on a guide layer optical system for reproducing an address and disc-specific information corresponding to the position on the disc, and a plurality of recording layers at different distances from the guide layer. Is composed of a recording layer optical system for recording / reproducing data.

  First, the operation of the recording layer 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 LBw having a wavelength of 405 nm, for example, 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 LBw focused 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 beam LBw that has passed through the beam splitter 304 is reflected by the polarization beam splitter 307, and the convergence / divergence is controlled by the spherical aberration correction element 309 driven by the aberration correction drive means 206, and passes 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. The laser beam LBw that has passed through the dichroic mirror 308 becomes circularly polarized light by the quarter-wave plate 310 and is focused as a laser spot LSW on the recording layer of the optical disk 102 by the objective lens 311. Here, the spherical aberration correction element 309 is controlled from the controller 201 via the aberration correction driving means 206 so as to be at a predetermined position corresponding to the recording layer of the grooveless disk. The intensity of the laser beam LBw reflected by the optical disc 102 is modulated according to information recorded on the optical disc 102. The light is linearly polarized by the quarter-wave plate 310, passes through the dichroic mirror 308, and passes through the polarization beam splitter 307 and the spherical aberration correction element 309. The transmitted laser light LSW is condensed on the detector 314 by the condenser lens 313. The detector 314 detects the intensity of the laser beam LBw and outputs a signal corresponding to the intensity to the signal processing means 202. The focus error signal generation unit 211 generates a recording layer 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 according to the focus drive signal to displace the position of the objective lens 311 in the direction perpendicular to the recording surface, and the recording layer focus servo so that the laser beam LBw is focused on the recording layer. Take control. The signal output from the detector 314 is also input to the tracking error signal generation unit 214 to generate a recording layer tracking error signal for the recording layer.

FIG. 11 shows an internal configuration of the tracking error signal generation unit 214.
The tracking error signal generation unit 214 performs tracking using the light spot 501 and the SUB tracking error signal generation unit 1101 that generates the tracking error signal from the light spot 502 and the main tracking error signal generation unit 1102 that generates the tracking error signal from the light spot 500. Subsequent to generating an error signal, a SUB tracking error signal generating unit 1103 and a tracking error signal selecting unit 1104 for selecting a tracking error signal to be output depending on a state such as recording, reproduction, and OPC are provided.

The tracking error signal selection unit 1104 outputs, for example, the tracking error signal generated by the Main tracking error signal generation unit 1102 when reproducing information, and the tracking error generated by the subsequent Sub tracking error signal generation unit 1103 during recording. It operates by switching the tracking error signal to be output as described later during OPC.
Here, in this embodiment, as shown in FIG. 1, there are three light spots 500 to 502 focused on the recording layer. For this reason, there are three tracking error signal generating means: the front SUB tracking error signal generating means 1101, the main tracking error signal generating means 1102, and the rear SUB tracking error signal generating means 1103. However, the tracking error signal generating means 214 can output the tracking error signal. This embodiment can be implemented if the error signal can be generated from one or more light spots in addition to the light spot 500 used for recording and reproduction.
The tracking control unit 215 outputs a tracking drive signal corresponding to the output of the tracking error signal generation unit 214 or the tracking error signal generation unit 210 to the tracking drive unit 216 according to a control signal from the controller 201.

  Next, the guide layer optical system will be described. Similar to the recording layer optical system, the laser driver 301 is controlled by the controller 201 and outputs a current for driving the laser diode 315. The laser diode 315 emits laser light LBg having a wavelength of 650 nm, for example. A part of the laser beam LBg is monitored by a power monitor 319 through a collimator lens 316, a beam splitter 317, and a condenser lens 318. By feeding back the monitored power to the controller 201, the intensity of the laser beam LBg focused on the guide layer of the optical disc 102 is maintained at a desired power such as 3 mW. The laser beam LBg 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, diverge, and change the optical axis. The laser beam LBg 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 as a laser spot LSg on the guide layer of the optical disk 102 by the objective lens 311. The laser beam LBg 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 detector 323 detects the intensity of the laser beam and outputs a signal corresponding to this to the signal processing means 202. The signal processing means 202 is a synchronization signal for controlling the rotation of the optical disk 102 by a signal corresponding to a track formed by wobbling the guide layer output from the detector 323, and a clock used as a reference for recording or reproduction. A signal is generated, and an address corresponding to the position on the optical disk 102 followed by the laser spot LSg is reproduced and output to the controller 201. The synchronization signal output from the signal processing unit 202 and the FG signal output from the spindle driving unit 209 are input to the spindle control unit 208. The spindle control means 208 outputs a spindle drive signal based on an FG signal having a frequency corresponding to the rotational speed of the spindle motor 207 when the optical disk 102 is rotated at a constant angular velocity by the control signal from the controller 201, and the optical disk 102 is When rotating at a constant linear velocity, a spindle drive signal based on the synchronization signal reproduced from the guide layer is output. The spindle driving means 209 performs spindle control so that the rotational speed of the optical disc 102 becomes a predetermined value by driving the spindle motor 207 in accordance with the spindle driving signal. The focus error signal generation means 217 generates a guide layer focus error signal corresponding to the deviation between the guide layer of the optical disc 102 and the in-focus position of the laser spot LSg from the signal output from the detector 323, and the relay lens control means 218 A relay lens driving signal corresponding to the layer focus error signal is generated. The relay lens driving means 219 performs guide layer focus servo control so that the laser spot LSg is focused on the guide layer by driving the relay lens 321 according to the relay lens drive signal. The relay lens driving means 219 changes the relative position in the radial direction between the laser spot LSg and the laser spot LSw by driving the relay lens 321 to change the optical axis according to the tracking drive signal. Further, the tracking error signal generation unit 210 generates a guide layer tracking error signal corresponding to the positional deviation between the track of the guide layer of the optical disc 102 and the laser spot LSg from the signal output from the detector 323, and the tracking control unit 215 Output to. The tracking control unit 215 outputs a tracking drive signal corresponding to the output of the tracking error signal generation unit 214 or the tracking error signal generation unit 210 to the tracking drive unit 216 according to a control signal from the controller 201.

  When recording on the recording layer, the laser spot LSW is recorded on the recording layer by driving the actuator 312 with the focus drive signal generated based on the recording layer focus error signal output from the focus error signal generating unit 211. The recording layer focus servo control is performed so as to focus on the layer, and the relay lens 321 is driven by the relay lens drive signal generated based on the guide layer focus error signal output from the focus error signal generation unit 217. Guide layer focus servo control is performed so that the laser spot LSg is focused on the guide layer in the recording layer.

  In addition, the tracking drive signal generated based on the tracking error signal output from the tracking error signal generating unit 214 or the tracking error signal generating unit 210 from the tracking control unit 215 by the control signal from the controller 201 is sent to the tracking driving unit 216. Is output. The tracking drive means 216 drives the actuator 312 and the relay lens 321 according to the tracking drive signal, so that the laser spot LSg follows the track of the guide layer, and the light spot 501 or the light spot 502 that does not perform recording is recorded on the recording layer. Tracking servo control is performed so as to follow the mark row. The slider control means 220 that receives the control signal from the controller 201 outputs a slider drive signal for driving the slider motor 204 based on the average value of the tracking drive signal. In accordance with this slider drive signal, the slider motor 204 is driven by the slider drive means 205, and the optical pickup 203 is moved in the disk radial direction so that the actuator 312 operates in the vicinity of the center position of the movable range in the disk radial direction. Data to be recorded on the recording layer input from the host 103 and address information corresponding to the position on the optical disc 102 where the data is recorded are output from the controller 201 to the signal processing means 202. The signal processing means 202 modulates the input data and address information by a predetermined method based on the reference clock signal reproduced from the guide layer, and outputs it to the laser driver 301. The laser driver 301 outputs a drive current corresponding to the output of the signal processing means 202 to the laser diode 302, and the laser diode 302 emits the laser beam LBw with a corresponding intensity so that recording is performed on the recording layer of the optical disc 102. Thus, recording can be performed on the recording layer at the focal distance between the light spot 500 for recording and the light spot 501 or the light spot 502 for servo control. By recording the light spot 500 and the light spot 501 or servo spot 502 for which servo control is performed at the same focal distance as the track spacing of the guide layer, information is recorded on the recording layer in the same locus as the spiral of the guide layer track. Can be done. If the light spot used for tracking servo control is used as the light spot 501 when the guide layer track is spirally formed from the inner periphery to the outer periphery, the guide layer track is changed from the outer periphery to the inner periphery. When the light spot 502 is used for tracking servo control of the recording layer, a recording mark can be formed in a spiral shape from the outer periphery to the inner periphery.

  When reproducing the information recorded on the recording layer, the actuator 312 is driven by the focus drive signal generated based on the recording layer focus error signal output from the focus error signal generating means 211, thereby causing the recording layer to laser. Recording layer focus servo control is performed so that the spot LSW is focused on the recording layer. Further, by driving the relay lens 321 with the relay lens driving signal generated based on the guide layer focus error signal output from the focus error signal generating means 217, the laser spot LSg is focused on the guide layer at the guide layer. The guide layer focus servo control is performed. The tracking error detection unit 214 outputs a tracking error signal corresponding to the deviation between the track formed by the locus of information recorded on the recording layer and the light spot 500 irradiated on the recording layer. A tracking drive signal generated based on the recording layer tracking error signal output from the tracking error signal generation unit 214 is output from the tracking control unit 215 to the tracking drive unit 216 by the control signal from the controller 201. The tracking drive means 216 drives the actuator 312 according to the tracking drive signal, and tracking servo control is performed so that the light spot 500 follows the track formed by the locus of information recorded on the recording layer, and recording is performed from the detector 314. A reproduction signal from the layer is output. The slider control means 220 that receives the control signal from the controller 201 outputs a slider drive signal for driving the slider motor 204 based on the average value of the tracking drive signal. In accordance with this slider drive signal, the slider motor 204 is driven by the slider drive means 205, and the optical pickup 203 is moved in the disk radial direction so that the actuator 312 operates in the vicinity of the center position of the movable range in the disk radial direction. The signal processing unit 202 generates a synchronization signal for controlling the rotation of the optical disc 102 and a clock signal serving as a reference when performing reproduction from the input reproduction signal. The signal processing unit 202 performs processing such as amplification, equalization, and decoding on the reproduction signal, and outputs the decoded data and address information corresponding to the position of the data on the optical disk 102 to the controller 201. The controller 201 outputs the reproduced data to the host 103.

  Here, the same laser driver 301 is used to drive the laser diode 302 and the laser diode 315, but each laser diode may be provided with a unique laser driver. 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 recording / reproducing apparatus 101 when the optical disc 102 is inserted into the optical disc recording / reproducing apparatus 101.

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

  Next, in S403, adjustment processing for making various parameters in the optical disc recording / reproducing apparatus 101 suitable for the inserted optical disc 102 is performed. 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 disc 102 is read in S404.

  When the processing proceeds to S405, the recording or reproduction is possible, and recording or reproduction can be performed in accordance with a command from the host 103.

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

FIG. 12 shows a processing flow in the case where a recording command is sent to the optical disc recording / reproducing apparatus 101 in the recordable / reproducible state.
When receiving the recording command (S1201), the optical disc recording / reproducing apparatus 101 determines whether an OPC process is necessary when recording is performed on the optical disc 102 currently inserted (S1202).
OPC processing is necessary, for example, when the optical disc 102 is inserted into the optical disc recording / reproducing apparatus 101 and the optimum recording laser light intensity for the inserted optical disc 102 is not found, such as when the first recording command is received. It is determined.
If it is determined that the OPC process is necessary, an OPC process to be described later is performed to obtain an optimum recording laser beam intensity (S1203).
Thereafter, a seek operation is performed to position the laser spot LSW and the laser spot LSg at the recording position (S1204).
Thereafter, a recording process (S1205) is performed.
Here, the recording process (S1204) will be described with reference to FIG.

  FIG. 5 is an enlarged view of a part of the optical disc 102 having the structure shown in FIG.

FIG. 5 shows a state in which the recording light spot 500 is focused on the recording layer and the mark is recorded while proceeding in the tangential direction of the optical disk 102. At the same time, the tracking servo control light spot 501 and the light are recorded. The spot 502 is placed at a certain distance in the radial direction from the light spot 500 and the optical disc 102, and is focused on the recorded mark and on the area where the mark is scheduled to be recorded (unrecorded area). It shows that the light spot 511 is condensed in the groove (track) of the guide layer substantially directly below the light spot 500. The light spots 500, 501, and 502 are originally separated from the same light flux and emitted from the same objective lens 311 (not shown), and are described as laser spots LSW in FIG.
The light spot 511 is a light flux different from the light spots 500, 501, and 502, but indicates that it is emitted from the same objective lens 311, and is described as a laser spot LSg in FIG.
When there is a recorded mark on the recording layer, the optical disc recording / reproducing apparatus 101 controls tracking so that the light spot 501 or the light spot 502 follows the recorded mark, and determines the position of the light spot 500 in the disc radial direction. Then, the mark is recorded by changing the intensity of the laser beam of the light spot 500.
The light spot 511 is controlled so as to be positioned on the track of the guide layer, and by reading the wobble of the track, the relative speed between the light spot 500 and the optical disk 102 is obtained, thereby determining the length of the mark to be recorded. .
When the recording operation (S1205) ends, the recording operation ends (S1206).
If it is determined that the OPC process is unnecessary, the seek operation (S1204) and the recording operation (S1295) are performed, and the recording operation ends (S1206).

(Explanation of OPC operation)
Next, the operation of OPC will be described. FIG. 6 shows an example of a flowchart of the OPC operation.
First, when the OPC operation is started in S601, first, it is checked in step S602 whether OPC has been performed for the designated layer of the inserted optical disk 102 for the first time.
For this check, for example, the laser spot LSW may be moved to the OPC region of the designated layer to identify whether the recording mark row is detected from the reflected light.
If it is the first OPC for the specified layer, the position is set at the position of the first OPC (S603).
At this time, the tracking control unit 215 outputs a signal for driving the tracking driving unit 216 based on the tracking error signal from the tracking error signal generating unit 210, and moves the objective lens 311.
At this time, the tracking control unit 215 does not output the driving signal to the relay lens driving unit 219 or outputs a constant signal.
Since the input to the relay lens driving means 219 is constant or not input, the radial direction of the relay lens 321 is not driven or is positioned at a fixed position.
Thereafter, the first OPC operation S604 is performed.
The operation of the OPC is, for example, by performing test recording while changing the intensity of the laser beam, and then reproducing the area where the test recording has been performed, and the optimum recording laser based on the change in the amplitude of the reproduction signal and the intensity of the laser beam during the test recording The optimum laser light intensity is obtained by calculating the light intensity.
After that, a mark row is recorded in the OPC area with the intensity of the laser beam obtained by the OPC (S605).
Here, as shown in FIG. 7, for example, the mark row to be recorded has a pattern in which the recording mark row and the unrecorded portion for OPC alternate in one round.
At this time, the tracking control unit 215 outputs a signal for driving the tracking driving unit 216 based on the tracking error signal from the tracking error signal generating unit 210, and moves the objective lens 311.
At this time, the tracking control unit 215 does not output the driving signal to the relay lens driving unit 219 or outputs a constant signal.
Since the input to the relay lens driving means 219 is constant or not input, the radial direction of the relay lens 321 is not driven or is positioned at a fixed position.
The current position at the time of recording is acquired from address information added to the guide layer.
Here, the pattern method for performing recording with the optimum laser light intensity in the OPC area may be recorded so that tracking servo control can be performed by switching the light spot that generates the tracking error signal, as will be described later.

  For example, in the case of the optical disc recording / reproducing apparatus 101 having the light spot 501 and the light spot 502 in the front and rear tracks with respect to the light spot 500 to be recorded, at least one of the three tracks at any of the three consecutive tracks is taken out. If there is a mark row recorded with the optimum laser light intensity for the track, the tracking servo control can be stably performed on the OPC area, and N light beams having different distances from the recording light spot 500 in the radial direction of the optical disk 102 are respectively obtained. In the case of the optical disk 102 having spots, stable tracking servo control is possible if there are mark rows recorded with an optimum laser beam intensity for at least one continuous N track.

  For example, in the case of the optical disc recording / reproducing apparatus 101 having three spots, a rotation synchronization signal from the spindle motor 207 is used to switch the light spot that generates a tracking error signal when a track sequence of one track and one round is recorded on three tracks. But you can take the timing.

For example, by setting the circumferential length of an unrecorded track that does not generate a mark row with the optimum laser light intensity to be an integral multiple of the length used in OPC, all areas that cannot be used in test recording for OPC It can be recorded as a record mark row for tracking servo control.
As a result, the light spot that generates the tracking error signal becomes longer since the tracking error signal generated from both the light spot before and after the switching is approximately the same in the vicinity of the switching timing. It is possible to increase the time width during which switching is possible.

  In addition, the mark row to be recorded is good because it is possible to detect the position of the light spot 500 that is currently recording / reproducing during tracking servo control of the OPC area by entering layer information and an address indicating the radial position. .

  In addition to the above, for each layer, it is possible to analyze before performing tracking servo control, for example, by recording a repetitive mark pattern of different length marks, the current light spot 500 is in focus before track control is performed. It is good because the layer can be detected.

In addition, the recorded mark row is recorded not for recording information at a high density but for generating a tracking error signal that enables stable tracking servo control of the light spot 500, so that actual information is recorded. Unlike the mark row of the portion to be processed, if the mark row has a stable quality of the tracking error signal, stable tracking servo control may be possible.
When the mark row recording is completed in the OPC area, the OPC operation ends (S608).
If the OPC for the specified layer of the inserted optical disk 102 is the second or later, the tracking servo is performed using the mark train recorded with the optimum recording laser light intensity already recorded in the OPC area. The control is performed, and an area usable for OPC is searched S606.

  Here, a method of generating a tracking error signal in tracking servo control of the OPC area in the second and subsequent OPC processes will be described with reference to FIG.

FIG. 1 is a diagram showing three times during which the light spot 500, the light spot 501, and the light spot 502 perform tracking servo control on the recording mark row in the OPC area.
Time advances in the order of (a), (b), and (c), and the light spot 500, the light spot 501, and the light spot 502 advance from left to right as viewed in the figure.
Here, in the case of (a), tracking servo control is performed using the tracking error signal generated from the light spot 500.
In the case of (b), the light spot that generates the tracking error signal is switched from the light spot 500 to the light spot 501 or the light spot 502, and tracking servo control is performed.
In the case of (C), the light spot for generating the tracking error signal is switched from the light spot 501 or the light spot 502 to the light spot 500 to perform tracking servo control.
In this way, the light spot that generates the tracking error signal is switched using the tracking error signal selection means 1104 and tracking servo control is performed, so that the mark row is not recorded or the laser light intensity is optimized. It is possible to scan the light spot 500 while performing stable tracking servo control even on a track where there is a non-existing region.
At this time, the switching operation of the tracking error signal selection means 1104 may be performed based on position information read from a recorded mark row, for example.
Alternatively, the light spot that generates the tracking error signal may be switched when the signal amplitude from the mark row obtained from the light spot to be switched next becomes a certain value or more.
In addition, when recording is performed in a fixed pattern as shown below, switching the light spot that generates the tracking error signal according to the pattern allows the switching timing to be grasped in advance. This is good because the process can be simplified.

Thereafter, as described above, the OPC operation is performed while performing the tracking servo control by performing the switching operation of the light spot that generates the tracking error signal (S606).
The OPC operation here is characterized in that the OPC operation is performed by performing tracking servo control while switching the light spot that generates the tracking error signal with respect to the initial OPC operation S604.
In this way, OPC processing is performed while performing stable tracking servo control by performing tracking servo control with a light spot different from the light spot 500 where recording is actually performed, and performing the second and subsequent OPC operations. I can do it.

Here, in the flowchart of FIG. 6, mark row recording S605 is performed in the OPC area immediately after OPC recording.
As a result, the mark row recording S605 can be performed in the OPC area in the state of the relative angle similar to the relative angle in the radial direction between the optical disc 102 and the optical pickup 203 at the time of the first OPC operation S604.
Further, if the optical disk 102 is not taken out, the mark row recording operation is performed before the optical disk 102 is taken out, as long as the relative angle in the radial direction between the optical disk 102 and the optical pickup 203 does not change. For example, if the OPC is performed as shown in the flowchart of FIG. 8 and the mark string recording operation in the OPC area is performed after the data recording operation, the time required until the data recording is performed. Can be shortened.
By performing the OPC operation as described above, the OPC operation can be performed while performing stable tracking servo control even in the optical disc 102 in which the recording layer and the guide layer are separated.

  Further, in the present embodiment, it is described that the relative position in the radial direction between the laser spot LSg and the laser spot LSW is changed by driving the relay lens 321 so as to change the optical axis, but for example, the dichroic mirror 308 is provided. By rotating, the relative position in the radial direction between the laser spot LSg and the laser spot LSw focused on the optical disk 102 may be changed. In other cases, the relative position between the laser spot LSg and the laser spot LSw may be changed to a radius. If the direction can be changed, this embodiment can be implemented.

(Optical disc form)
The form of the optical disk 102 of the present embodiment is the same as that of the first embodiment.

(Configuration of optical disc recording / reproducing apparatus)
The form of the optical disc recording / reproducing apparatus 101 of the present embodiment is the same as that of the first embodiment.
As an operation, the OPC process is different from the process described in the first embodiment.

(Explanation of OPC operation)
The operation of the OPC according to this embodiment will be described with reference to FIG.
FIG. 9 shows an example of a flowchart of the OPC operation.
First, the OPC operation is started (S901). Then, first, it is checked whether or not OPC is performed for the designated layer of the inserted optical disk 102 (S902).
For this check, for example, the laser spot LSW may be moved to the OPC region of the designated layer to identify whether the recording mark row is detected from the reflected light.
If it is the first OPC for the specified layer, it is positioned at the position of the first OPC (S903).
Thereafter, the first OPC operation is performed (S904).
The operation of OPC is shown in the first embodiment.
Thereafter, the area used for OPC is overwritten (S905).

At this time, the intensity of the laser beam for overwriting is shown in FIG.
The operation of the OPC is performed by performing test recording by changing the intensity of the laser beam, and then reproducing the recorded area, and the optimum laser beam from the change due to the intensity of the laser beam at the time of trial recording with the amplitude of the reproduction signal Learning the intensity of.
Therefore, there are marks recorded with a plurality of laser light intensities different from the optimum laser light intensity for trial recording in the area after OPC.
In the overwriting process S905, recording is performed with the intensity of the laser beam that can be recorded again on the area having the mark recorded by the trial recording.

  Here, the intensity of the laser beam when re-recording is the mark recorded with the laser beam intensity at which the tracking error signal generated from the record mark sequence after the overwrite process S905 is performed is in an optimum recording state. It is only necessary to be recorded so as to be equivalent to the tracking error signal generated from the column. For example, the laser beam that is the optimum recording for which the average intensity of a plurality of laser light intensities recorded by the OPC process is obtained. When recording is performed again with the intensity of the laser beam subtracted from the intensity, a mark row recorded with the laser beam intensity that is optimally recorded on average can be generated.

Also, for example, by changing the intensity of the laser beam at the time of recording according to the intensity of the laser beam at the time of test recording, the signal amplitude of the entire mark can be changed by changing the recorded mark to be reproduced as a constant signal amplitude. It is good because it can be made constant.
By doing so, it becomes possible to form a mark row recorded with a certain amplitude or more in the OPC area after recording, and to perform stable tracking servo control.
At this time, if the pattern of the mark row to be overwritten is the same as the mark row recorded at the time of OPC, the signal amplitude of the mark row recorded by OPC can be increased.

By performing recording as described above, a stable mark row can be formed even in an area used in OPC.
As a result, stable tracking servo control can be realized in the OPC region.
Further, in the method of the second embodiment, since the mark row for tracking servo control is not recorded in the OPC area unlike the method of the first embodiment, it is preferable that the area usable for the OPC is increased.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. 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. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  In addition, each of the above-described configurations may be configured such that some or all of them are configured by hardware, or are implemented 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, an optical disk having a plurality of recording layers is targeted. However, the optical disk does not necessarily have a structure having a plurality of recording layers. For example, it has a three-dimensional recording layer for volume recording. It may be an optical disk.

101 Optical disk recording / playback device
102 optical disc
500 light spots
501 Light spot
502 Light spot
511 Light spot
1101 Front SUB tracking error signal generation means
1102 Main tracking error signal generation means
1103 Post SUB tracking error signal generation means
1104 Tracking error signal selection means

Claims (17)

In an optical disc recording / reproducing apparatus for recording on an optical disc having at least one guide layer having a track and at least one recording layer not having a track structure,
A first optical system for focusing the first laser beam on the guide layer;
A second optical system for focusing the second laser beam divided into a plurality of parts on the recording layer;
Tracking error signal generating means for generating a plurality of tracking error signals from the second laser light signal;
Tracking error signal selection means for selecting a signal to be controlled from the tracking error signal;
With
An optical disc recording / reproducing apparatus, wherein a recording mark is formed in an unrecorded OPC area after performing an OPC (Optimum Power Control) process for performing recording with an optimum recording power on the recording layer.   2. The optical disc recording / reproducing apparatus according to claim 1, wherein the recording mark is recorded for each track equal to or less than the number of divisions of the second laser beam.   2. The optical disc recording / reproducing apparatus according to claim 1, wherein at least one recording mark is recorded between a plurality of continuous tracks divided by the second laser beam.   4. The optical disc recording / reproducing apparatus according to claim 1, wherein the recording mark has a mark length different from a mark length recorded in the data area.   5. The optical disc recording / reproducing apparatus according to claim 1, wherein the recording mark has a different pattern for each recording layer.   6. The optical disc recording / reproducing apparatus according to claim 1, wherein a width of an unrecorded area between the recording marks is an integral multiple of a width of an area used in the OPC process.   The optical disc recording / reproducing apparatus according to claim 1, wherein the recording timing is immediately after the OPC process. An optical disc recording / reproducing apparatus for performing recording on an optical disc having a recording mark already formed in the OPC area, wherein the optical disc has at least one guide layer having a track and at least one recording layer not having a track structure. ,
A first optical system for focusing the first laser beam on the guide layer of the optical disc;
A second optical system for focusing the second laser beam on the recording layer of the optical disc;
Tracking error signal generating means for generating a plurality of tracking error signals from the second laser light signal;
Tracking error signal selection means for selecting a signal to be controlled from the tracking error signal;
The second laser beam focused on the recording layer has at least two focal points: a recording / reproducing focal point and a track king focal point;
An optical disc recording / reproducing apparatus that performs OPC processing by performing track following with the recording mark. A recording / reproducing method for recording information on an optical disc having at least one guide layer having a track and at least one recording layer not having a track structure,
Performing an OPC (Optimum Power Control) process for recording at an optimum recording power on the recording layer;
Forming a recording mark in the OPC area of the optical disc after the OPC processing;
And a step of recording information in the data area with the optimum recording power obtained by the OPC process.   10. The recording / reproducing method according to claim 9, wherein the recording mark is formed in the OPC area every three tracks or less.   11. The recording / reproducing method according to claim 9, wherein at least one recording mark is formed between three consecutive tracks in the OPC area.   12. The recording / reproducing method according to claim 9, wherein a recording mark having a mark length different from that recorded in the data area is formed in the OPC area.   13. The recording / reproducing method according to claim 9, wherein the recording mark is formed in the OPC area with a different pattern for each recording layer.   14. The recording mark is formed so that a width of an unrecorded area between marks to be recorded in the OPC area is an integral multiple of a width used in an OPC process. Recording and playback method. A recording / reproducing method for performing recording and reproduction on an optical disc having at least one guide layer having a track and at least one recording layer not having a track structure,
Focusing the first laser beam on the guide layer;
Focusing a second laser beam on the recording layer;
Performing an OPC (Optimum Power Control) process for recording at an optimum recording power on the recording layer;
And a step of performing overwriting with the intensity of the laser beam for recording in the area subjected to the OPC process.   16. The recording / reproducing method according to claim 15, wherein the mark row for recording is the same as the mark row recorded by the OPC process.   The intensity of the laser beam for overwriting recording is changed so that the intensity of the laser beam for overwriting recording is inversely proportional to the intensity of the laser beam output during OPC processing. Recording and playback method.

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