JP5081092B2 - Optical recording medium drive device and additional recording method - Google Patents

Description

  The present invention relates to an optical recording medium drive apparatus and an additional recording method for driving an optical recording medium having multiple recording layers.

  As an optical disk having a large number of recording layers, as shown in FIG. 1A, a guide layer-integrated disk in which a recording layer and a guide layer are formed in the same layer for each recording layer, and FIG. As shown in FIG. 2), a guide layer separation type disc in which each recording layer and guide layer are separately formed is known. The guide layer is a layer in which servo signals including position (address) information are recorded as guide tracks. In the case of a guide layer-integrated disc, tracking control is possible using a guide track integrated with the recording layer even in an unrecorded portion where information on the recording layer is not recorded. Information can be recorded on a track. In addition, there is an advantage that information can be recorded and reproduced with a single laser beam.

On the other hand, in the case of a guide layer separation type disc, a servo laser beam for reading a guide track from the guide layer and a recording / reproducing laser beam for writing information to the recording layer or reading the recorded information When recording information on one recording layer, the focal position of the servo laser beam is moved on the guide track of the guide layer by tracking control, and the recording / reproducing laser beam is applied to one recording layer. Information is written by condensing the light (see Patent Documents 1 and 2). This guide layer separation type disk can be easily manufactured because it has a structure in which recording layers having a simple structure are stacked. Further, since the recording layer can be easily multilayered as compared with the guide layer-integrated disc, there is an advantage that the recording density can be increased.
JP 2004-241088 A JP 2001-52374 A

  However, in the case of a guide layer separation type disc, if the optical disc has an inclination such as warp, the positional relationship between the guide track and the recording track of the recording layer changes. For example, after recording while following the guide track as shown in FIG. 2 (a), the tilt state of the disc with respect to the optical axis of the irradiated beam has changed due to warpage due to aging of the disc or attachment to the apparatus. In this case, if additional recording is performed while following the guide track, a deviation occurs between the recorded recording track and the recording track during additional recording, as shown in FIG. Such a recording track shift causes uneven track pitch and not only deteriorates the reproduction performance, but also records information on the recorded information in the recorded area and destroys the recorded information in the recorded area. There was a problem that it might be.

  Therefore, the problem to be solved by the present invention includes the above-mentioned drawbacks as an example, and the tilt state of the optical recording medium with respect to the optical axis of the irradiation beam has been previously observed when additional recording is performed on the guide layer separation type optical recording medium. It is an object of the present invention to provide an optical recording medium drive device and an additional recording method capable of appropriately performing additional recording without destroying the recorded information even if the recording has changed since the time of recording.

An optical recording medium drive apparatus according to a first aspect of the present invention is provided on the recording layer of a guide layer separation type optical recording medium in which a guide layer on which a guide track including position information is formed and a recording layer are separated from each other. An optical recording medium drive apparatus for optically recording or reproducing information in accordance with the guide track, and detecting the reflected light by irradiating the guide layer with a first laser beam for servo through an objective lens A recording / reproducing optical system for irradiating the recording layer with a second laser beam for recording or reproducing through the objective lens and detecting the reflected light, and reflected light by the servo optical system Based on the detected level, a guide layer tracking error signal indicating an error from the center of the guide track of the irradiation spot position of the first laser beam on the guide layer is generated. Id layer tracking error generating means, tracking drive means for performing tracking driving for moving the objective lens in a direction perpendicular to the tangential direction of the guide track so as to reduce the guide layer tracking error signal, and recording in the recording layer When there is a recorded area, an additional recording start position detecting means for detecting the additional recording start position following the recorded area, and when the additional recording starts, the tracking drive means is controlled to move away from the additional recording start position to the unrecorded area side. and a track shifting means for the irradiation spot follow the movement to the recording layer of the second laser beam by the position moving the irradiation spot of the first laser beam at a position on the guide track opposite to the, The irradiation spot of the second laser beam moved by the track shift means Add the bets position on the recording layer recording is started, the track shifting means includes a tilt sensor for detecting a tilt of the optical recording medium, from the inclination of the optical recording medium during recording of the recorded area The irradiation spot of the first laser beam and the irradiation spot of the second laser beam are moved from the additional recording start position by the number of tracks corresponding to the amount of change in the tilt of the optical recording medium at the start of additional recording, and the optical recording medium The inclination of the optical recording medium is recorded on the optical recording medium at the end of recording, and is used for the next additional recording as the inclination of the optical recording medium at the time of recording in the recorded area .

According to a seventh aspect of the present invention, there is provided an additional recording method according to a seventh aspect of the present invention, wherein the guide layer of the guide layer separation type optical recording medium in which the guide layer on which the guide track including the position information is formed and the recording layer are separated and stacked is used for the servo A servo optical system that irradiates the first laser beam through the objective lens and detects the reflected light, and irradiates the recording layer with a second laser beam for recording or reproduction through the objective lens. A recording / reproducing optical system that detects reflected light, and a guide that indicates an error from the center of the guide track of the irradiation spot position of the first laser beam on the guide layer based on a detection level of reflected light by the servo optical system Guide layer tracking error generating means for generating a layer tracking error signal; and the objective lens is moved to reduce the guide layer tracking error signal. And an optical recording medium drive device for optically recording or reproducing information on the recording layer in accordance with the guide track. A recording method comprising: a first step of detecting a postscript start position following a recorded area in the recording layer; and controlling the tracking drive means at the start of additional recording to move away from the postrecording start position toward the unrecorded area side. a second step of Ru to follow moving the irradiation spot on the recording layer of the second laser beam by moving the irradiation spot of the first laser beam at a position on the guide track opposite the positions, the first starts additional recording from the irradiation spot position of the second laser beam after follow-up movement by two steps to the recording layer In the second step, the tilt of the optical recording medium is detected by a tilt sensor, and the optical recording medium at the start of additional recording from the tilt of the optical recording medium at the time of recording in the recorded area is recorded. The irradiation spot of the first laser beam and the irradiation spot of the second laser beam are moved from the additional recording start position by the number of tracks corresponding to the change amount of the inclination, and the inclination of the optical recording medium is completed at the end of recording of the optical recording medium. Is recorded on the optical recording medium and used as the inclination of the optical recording medium at the time of recording in the recorded area at the next additional recording .

According to the optical recording medium drive apparatus of the invention according to claim 1 and the additional recording method of the invention according to claim 7 , the additional recording start position following the recorded area in the recording layer of the guide layer separation type optical recording medium is detected. When the additional recording is started, the second laser laser for recording or reproduction is moved by moving the irradiation spot of the first laser beam for servo to a position on the guide track facing the position away from the additional recording start position to the unrecorded area side. Since the irradiation spot on the recording layer of the beam is moved following, and additional recording on the recording layer is started from the irradiation spot position of the second laser beam after the movement, recording of the recorded area of the recording layer of the optical recording medium is performed. Information can be appropriately additionally recorded in an unrecorded area without destroying the information.

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

  FIG. 3 shows the configuration of an optical disc drive apparatus according to the present invention. This optical disk drive apparatus includes a disk drive system, an optical system, and a signal processing system, and optically records / reproduces information on / from an optical disk 1 on which a large number of recording layers are laminated. In this embodiment, it is assumed that a plurality of (for example, 16) recording layers and one guide layer are separately formed on the optical disc 1. Guide tracks are formed in the guide layer.

  The disk drive system has a structure in which the optical disk 1 is held by a clamp mechanism 2 and is rotated by a motor 3.

  The optical system is further divided into a recording / reproducing optical system and a servo optical system.

  The recording / reproducing optical system includes a light source 11, a collimator lens 12, beam splitters 13 and 14, a spherical aberration correction element 15, an objective lens 16, a condenser lens 17, and a light receiving element 18.

  The light source 11 is a semiconductor laser element that emits a recording or reproducing laser beam (second laser beam). The collimator lens 12 converts the laser beam emitted from the light source 11 into parallel light and supplies it to the beam splitter 13. The beam splitter 13 supplies the parallel laser beam supplied from the collimator lens 12 to the beam splitter 14 as it is.

  The beam splitter 14 reflects the laser beam incident from the beam splitter 13 at an angle of approximately 90 degrees with respect to the incident beam, and supplies the laser beam to the objective lens 16 via the spherical aberration correction element 15. The spherical aberration correction element 15 is composed of an expander lens or a liquid crystal element, and is capable of correcting spherical aberration for each recording layer of the optical disc 1. The objective lens 16 converges the parallel laser beam from the spherical aberration correction element 15. The objective lens 16 is provided with an actuator 16a. The actuator 16a includes a focusing portion that moves the objective lens 16 in the optical axis direction, and a tracking portion that moves the objective lens 16 in a disk radial direction perpendicular to the optical axis (a direction perpendicular to the tangential direction of the guide track).

  The laser beam reflected by one of the recording layers of the optical disk 1 returns to the beam splitter 14 as a parallel laser beam through the objective lens 16 and the spherical aberration correction element 15. The beam splitter 14 reflects the reflected laser beam at an angle of approximately 90 degrees with respect to the incident and supplies the reflected laser beam to the beam splitter 13. Similarly, the beam splitter 13 reflects the laser beam from the beam splitter 14 at an angle of approximately 90 degrees with respect to the incident beam and supplies the reflected light to the condenser lens 17. The condensing lens 17 condenses the reflected laser beam on the light receiving surface of the light receiving element 18 to form a spot there. For example, the light receiving element 18 has four light receiving surfaces, and generates a voltage signal of a level corresponding to the light reception intensity for each divided surface.

  The output voltage signal of the light receiving element 18 is supplied to a reproduction processing circuit (not shown). In the reproduction processing circuit, a reproduction signal of recorded information is generated according to the read signal obtained from the output voltage signal of the light receiving element 18.

  The servo optical system shares the beam splitter 14, the spherical aberration correction element 15, and the objective lens 16 provided in the recording / reproducing optical system, and further, a light source 21, a collimator lens 22, a beam splitter 23, a condenser lens 24, and a light receiving unit. An element 25 is provided.

  The light source 21 is a semiconductor laser element that emits a servo laser beam (first laser beam). The collimator lens 22 converts the servo laser beam emitted from the light source 21 into parallel light and supplies it to the beam splitter 23. The beam splitter 23 supplies the parallel laser beam supplied from the collimator lens 22 to the beam splitter 14 as it is. The beam splitter 14 supplies the servo laser beam incident from the beam splitter 23 to the objective lens 16 through the spherical aberration correction element 15 as it is.

  The objective lens 16 can focus the servo laser beam on the guide layer of the optical disc 1 by the focusing portion of the actuator 16a, and simultaneously focus the recording or reproducing laser beam on any one of the plurality of recording layers. Can be burnt. In addition, the tracking portion can position the light spot of the servo laser beam on the guide track of the guide layer, and at the same time, the recording or reproducing laser beam can be positioned at the position corresponding to the guide track in the one recording layer. A light spot can be irradiated.

  The servo laser beam reflected by the guide layer of the optical disc 1 returns to the beam splitter 14 as a parallel laser beam through the objective lens 16 and the spherical aberration correction element 15. The beam splitter 14 supplies the reflected servo laser beam to the beam splitter 23 as it is. The beam splitter 23 reflects the laser beam from the beam splitter 14 at an angle of approximately 90 degrees with respect to the incident beam, and supplies it to the condenser lens 24. The condensing lens 24 condenses the reflected servo laser beam on the light receiving surface of the light receiving element 25 to form a spot there. The light receiving element 25 has, for example, a four-part light receiving surface, and generates a voltage signal having a level corresponding to the light reception intensity for each divided surface.

  The above optical system is movable in the radial direction of the optical disc 1 by a transfer driving unit (not shown).

  The signal processing system includes a disk drive unit 31, a recording / reproduction light source drive unit 32, a mode switching unit 33, a servo light source drive unit 34, a guide layer tracking error generation unit 35, a tracking control unit 36, an additional recording start position detection unit 37, and a track shift unit. 38, an objective lens driving unit 39, a focus error generating unit 40, a focus control unit 41, a recording layer tracking error generating unit 42, and a main controller 43.

  The disk drive unit 31 rotates the optical disk 1 by rotating the motor 3 in response to a command from the main controller 43. The disk drive unit 31 performs spindle servo control to rotate the optical disk 1 at a constant linear velocity.

  The mode switching unit 33 switches the driving power of the recording / reproducing light source driving unit 32 in accordance with a command from the main controller 43. The operation modes include a recording mode and a reproduction mode, and the driving power (recording power) in the recording mode is made larger than the reproduction power in the reproduction mode. The recording / reproducing light source driving unit 32 drives the light source 11 to emit light in accordance with a command supplied from the main controller 43 via the mode switching unit 33. The laser beam emitted from the light source 11 when driven by the reproduction power is a reproduction laser beam, the laser beam emitted from the light source 11 when driven by the recording power is a recording laser beam, and the recording data Is modulated according to.

  The servo light source drive unit 34 drives the light source 21 to emit light in accordance with a command supplied from the main controller 43.

  The guide layer tracking error generator 35 generates a guide layer tracking error signal according to the output voltage signal of the light receiving element 25. The guide layer tracking error signal is a signal indicating an error from the center of the guide track of the position of the spot irradiated to the guide layer of the servo laser beam. The recording layer tracking error generation unit 42 generates a recording layer tracking error signal according to the output voltage signal of the light receiving element 18. The recording layer tracking error signal is a signal indicating an error from the recording track center of the irradiation spot position on the recording layer of the reproducing laser beam. In order to generate these tracking error signals, for example, a known signal generation method such as a push-pull method can be used. The outputs of the guide layer tracking error generator 35 and the recording layer tracking error generator 42 are connected to a tracking controller 36.

  The additional recording start position detection unit 37 determines whether or not there is a recorded area on the optical disc 1, and when there is a recorded area, the additional recording (additional recording) start position following the final recording position of the recorded area is determined. To detect. For example, the first recording layer of the optical disc 1 is provided with a recording area for detecting the additional recording start position, and each time the recording operation is completed, the additional recording start position (address) is recorded in the additional recording start position detecting recording area. The additional recording start position is detected by reproducing the recording area for detecting the additional recording start position immediately before the start of recording. The recorded area, that is, the additional recording start position may be detected by checking the presence or absence of a signal recorded by the recording / reproducing beam while searching for the servo beam on the guide layer of the optical disc 1.

  The track shift unit 38 instructs a shift (track jump) from the guide track corresponding to the additional recording start position obtained by the additional recording start position detecting unit 37 to the guide track on the unrecorded area side when additional recording is started. The shift amount is at least one track.

  The tracking controller 36 receives the guide layer tracking error signal generated by the guide layer tracking error generator 35 or the recording layer tracking error signal generated by the recording layer tracking error generator 42, and controls the tracking by the objective lens 16. For this purpose, a tracking control signal is supplied to the objective lens driving unit 39. Normally, the tracking control signal is generated so that the tracking error signal becomes zero level. In addition, the tracking control unit 36 generates a tracking control signal for moving the servo laser beam spot to the track jump destination in response to the track shift command.

  The focus error generation unit 40 generates a focus error signal according to the output voltage signal of the light receiving element 25. For the generation of the focus error signal, for example, a known signal generation method such as an astigmatism method can be used. The focus control unit 41 supplies a focusing control signal to the objective lens driving unit 39 in order to control focusing by the objective lens 16. The focusing control signal is generated so that the focus error signal becomes zero level.

  The objective lens drive unit 39 drives the tracking portion of the actuator 16a according to the tracking control signal to move the objective lens 16 in the disc radial direction perpendicular to the optical axis, and drives the focusing portion of the actuator 16a according to the focusing control signal. Then, the objective lens 16 is moved in the optical axis direction.

  The main controller 43 controls on / off of tracking servo control by the tracking control unit 36 and on / off of focusing servo control by the focus control unit 41.

  In the optical disk drive having such a configuration, when information is recorded on the optical disk 1, a recording command from an operation unit (not shown) is supplied to the main controller 43. As shown in FIG. 4, the main controller 43 starts a recording operation in response to the recording command, first generates a disk driving command to the disk driving unit 31 (step S1), and further, the recording / reproducing light source driving unit 32 and the servo. A light emission drive command in the reproduction mode is generated for the light source drive unit 34 (step S2). The disk drive unit 31 drives the motor 3 to rotate the optical disk 1, the recording / reproduction light source drive unit 32 drives the light source 11 with reproduction power to emit a reproduction laser beam, and the servo light source drive unit 34 The light source 25 is driven to emit a servo laser beam. Further, the main controller 43 instructs the focus control unit 41 to turn on the focusing servo control (step S3). When the focusing servo control is turned on, a focus servo loop including the servo optical system, the focus error generation unit 40, the focus control unit 41, and the objective lens driving unit 39 is formed. Therefore, the focus control unit 41 sets the focus error signal to zero level. Since the focusing control signal is generated so that the position of the objective lens 16 in the optical axis direction is controlled, the focal point of the spot light by the servo laser beam is positioned on the guide layer of the optical disc 1, and at the same time the reproducing laser The focal point of the spot light by the beam is located in the recording layer (for example, the first recording layer) of the optical disc 1.

  When the focus of each spot light is determined by the focusing servo control, whether or not there is a recorded area on the optical disc 1 by the additional recording start position detector 37 according to the output signals of the light receiving elements 18 and 25 is detected as described above. If there is a recorded area, the additional recording start position following the final recording position of the recorded area is detected as the recording start position (step S4). The spot light generated by each laser beam for reproduction is moved by the transfer driving unit (step S5). In the case of an unrecorded disc having no recorded area, the initial address of the first recording layer is set as the recording start position and moved to the initial address. The movement of the spot light to the recording start position is performed by the tracking control operation of the tracking control unit 36 according to the command of the track shift unit 38 based on the detection result of the additional recording start position detection unit 37.

  When the spot light of the reproduction laser beam moves to the track at the recording start position, the additional recording start position detector 37 determines whether or not there is a recorded area on the track after the movement (step S6). When the additional recording start position detection unit 37 determines that there is a recorded area on the track according to the output signal of the light receiving element 18, it issues a track shift command to the tracking control unit 36 via the track shift unit 38 (step). S7). The tracking control unit 36 generates a tracking control signal so as to shift the track toward the unrecorded area by a predetermined number of tracks. In response to the track shift tracking control signal, spot light generated by the servo laser beam is moved by the objective lens driving unit 39 along the guide track of the guide layer of the optical disc 1 by a predetermined number of tracks. At the same time, spot light by the reproducing laser beam moves to the unrecorded area side by a predetermined number of tracks in the recording layer of the optical disc 1. For example, when recording is performed spirally from the inside of the recording layer of the optical disc 1 to the outside, the spot light of each of the servo and reproducing laser beams moves outward by a predetermined number of tracks in the radial direction.

  When the track shift of the spot light is completed by the execution of step S7 and the completion is notified to the main controller 43 from the additional recording start position detection unit 37, for example, the main controller 43 turns on the tracking servo control to the tracking control unit 36. Command (step S8). If it is determined in step S6 that there is no recorded area on the track, step S8 is immediately executed. When the tracking servo control is turned on, a tracking servo loop including the servo optical system, the guide layer tracking error generation unit 35, the tracking control unit 36, and the objective lens driving unit 39 is formed. Therefore, the tracking control unit 36 has zero tracking error signal. Since the tracking control signal is generated so as to be level and the position of the objective lens 16 in the radial direction is controlled, the spot light by the servo laser beam is positioned on the guide track of the guide layer of the optical disc 1 and follows it. As a result, the spot light by the reproducing laser beam moves to a position to be recorded on the recording layer.

  When the tracking servo control is started, the main controller 43 determines whether or not the recording is actually started (step S9). If the recording is started, the switching to the recording mode is performed via the mode switching unit 33. The recording / reproducing light source driving unit 32 is instructed (step S10). Then, after the recording is started, it is determined whether or not the recording is finished (step S11). In the recording mode, the driving power for the light source 11 of the recording / reproducing light source driving unit 32 is set to a recording power greater than the reproducing power, and the light source 11 is driven according to the information to be recorded and the spot light of the recording laser beam is emitted. It is formed in an unrecorded area of the recording layer.

  In the case of an optical disk having a recorded area, when the additional recording start position is detected by the additional recording start position detector 37, the spot light of the servo laser beam and the reproduction laser are detected at the recording start position. The beam spot light is moved. When it is detected from the output signal of the light receiving element 18 that there is a recorded area at the destination position, a track shift (jump) is performed to the unrecorded area side of the recording layer by a predetermined number of tracks. That is, the spot light of the laser beam for servo moves by a predetermined number of tracks on the guide track of the guide layer, so that the spot light of the laser beam for reproduction on the recording layer is the same as shown by arrow A in FIG. The number of tracks moves to the unrecorded area side. Then, the recording is switched to the recording laser beam, and additional recording of information is started in the unrecorded area. Therefore, additional recording is started with a gap from the final recording position of the recorded area. Therefore, as shown in FIG. 6 with respect to the optical axis of each laser beam as shown in FIG. Thus, even if there is a tilt (tilt) on the optical disc, it is possible to prevent additional recording from being recorded in the recorded area. That is, information can be additionally recorded in an unrecorded area without destroying recorded information in the recorded area.

  As shown in FIG. 7, considering the amount of deviation between the recording position when recording is performed in a state where the optical axis of each optical beam and each laser beam is not tilted, and the recording position when recording is performed in a tilted state. The amount of deviation in the disc radial direction is larger than the disc thickness direction. For example, when the layer distance d between one recording layer and the guide layer is 300 μm and the angle difference θ due to the tilt of the disk is 1 °, the recording track shift amount is 5 μm or more (the focus position shift is 0 at this time). .05 μm or less) and the track pitch Tp is 0.32 μm, the number of tracks to be shifted, that is, the predetermined number of tracks is 16 or more.

  As described above, the tracking operation in the case of reproducing the optical disc 1 after the information is additionally recorded by performing track shift on the optical disc 1 having the recorded area can be executed as shown in FIG. .

  The tracking operation of FIG. 8 is an operation of performing reproduction in the order in which information is recorded on the recording layer in focus, and is executed by the main controller 43, for example. First, tracking servo control by the recording track of the recording layer of the optical disc 1 is executed (step S21). The recording track of the recording layer is a track formed by optical writing of information to the recording layer. The tracking servo control by the servo optical system is turned off, the tracking servo control by the recording / reproducing optical system is turned on, and includes a recording / reproducing optical system, a recording layer tracking error generating unit 42, a tracking control unit 36, and an objective lens driving unit 39. Since the tracking servo loop is formed, the tracking control unit 36 generates a tracking control signal so that the tracking error signal generated from the recording layer tracking error generating unit 42 becomes zero level, and the position of the objective lens 16 in the radial direction is determined. Therefore, the spot light by the reproducing laser beam is positioned on the recording track recorded on the recording layer of the optical disc 1.

  After execution of step S21, it is determined whether or not there is a reproduction signal obtained from the recording layer (step S22). As described above, the reproduction processing circuit generates a reproduction signal of recorded information according to the read signal obtained from the output voltage signal of the light receiving element 18. Tracking servo control by the recording track of the recording layer is executed as long as a reproduction signal exists. The absence of the playback signal means that there is no recording track in the recording layer, but there is a portion where the recording track does not exist due to the track shift between the recorded area and the additionally recorded area as described above. When spot light from the reproduction laser beam enters the portion, there is no reproduction signal. Thus, when there is no reproduction signal, tracking servo control is performed by the guide track of the guide layer (step S23). The tracking servo control by the recording / reproducing optical system is turned off, and the tracking servo control by the servo optical system is turned on as in step S8. The servo optical system, the guide layer tracking error generating unit 35, the tracking control unit 36, and the objective lens Since a tracking servo loop including the drive unit 39 is formed, the tracking control unit 36 generates a tracking control signal so that the tracking error signal becomes zero level, and the position of the objective lens 16 in the radial direction is controlled. Spot light generated by the servo laser beam is positioned on the guide track of the guide layer of the optical disc 1, and the spot light generated by the reproducing laser beam moves on the recording layer.

  After execution of step S23, it is determined whether or not there is a reproduction signal obtained from the recording layer (step S24). When the reproduction signal does not exist, the spot light by the reproduction laser beam is located in the portion where the recording track does not exist due to the track shift between the recorded area and the additionally recorded area of the recording layer. On the other hand, since the reproduction signal is generated in the reproduction processing circuit when the spot light by the reproduction laser beam moves to the additionally recorded area, the tracking servo control by the recording track of the recording layer of the optical disc 1 is executed (step S25). As in step S21, the tracking servo control by the servo optical system is turned off, and the tracking servo control by the recording / reproducing optical system is turned on. In the reproduction processing circuit, a reproduction signal of the recorded information of the additionally recorded area is generated according to the read signal obtained from the output voltage signal of the light receiving element 18.

  By performing the tracking operation in this manner, the additional recording portion can be continuously reproduced from the recorded portion even in the case of the optical disc having the track shift portion.

  In steps S21 and S24, it may be determined whether the read signal is obtained from the output voltage signal of the light receiving element 18 instead of the reproduction signal.

  FIG. 9 shows the configuration of an optical disk drive apparatus as another embodiment of the present invention. This optical disc drive apparatus includes a tilt sensor 44 and a track shift amount calculation unit 45 in addition to the configuration of the optical disc drive apparatus of FIG. The tilt sensor 44 detects the tilt amount of the optical disc 1. The track shift amount calculation unit 45 is connected to the light receiving elements 18 and 25 and the tilt sensor 44 and calculates the track shift amount based on the tilt amount detected by the tilt sensor 44. The other configuration is the same as that of the apparatus shown in FIG. 3, but the recording layer tracking error generator 42 is not shown in FIG.

  In the optical disk drive device having the configuration shown in FIG. 9, when information is recorded on the optical disk 1, when a recording command from an operation unit (not shown) is supplied to the main controller 43, as shown in FIG. Done. That is, the main controller 43 generates a disk drive command to the disk drive unit 31 in response to the recording command (step S31), and generates a light emission drive command in the playback mode for the recording / playback light source drive unit 32 and the servo light source drive unit 34. Then, the focusing control unit 41 is instructed to turn on the focusing servo control (step S33). In addition, the additional recording start position detector 37 detects the additional recording start position as the recording start position (step S34). Steps S31 to S34 are the same as steps S1 to S4 shown in FIG.

  After execution of step S34, the track shift amount calculation unit 45 takes in the disc tilt amount recorded on the disc 1 as a (step S35). As will be described later, when information is recorded on the disc 1, the disc tilt amount detected at that time is written at a specific initial reading position such as TOC, and thus the already written disc tilt amount is read out in step S35. .

  Then, the spot light generated by the servo laser beam and the reproduction laser beam is moved to the recording start position by the transfer driving unit (step S36), and the additional recording start position detection unit 37 is a recorded area on the track after the movement. It is determined whether or not there is (step S37). Steps S36 and S37 are the same as steps S5 and S6 shown in FIG. If there is a recorded area, the track shift amount calculation unit 45 takes in the disc tilt amount at that position as b from the tilt sensor 44 (step S38), and calculates the track shift amount (step S39). In step S39, the amount of change between the disc tilt amounts a and b is calculated as the tilt angle θ = b−a, and the distance d between the guide layer of the disc 1 and the recording layer on which information is to be recorded is d · tan θ. Is a disc radius shift amount in the recording layer. When the pitch of the guide track formed on the guide layer is Tp and m is an integer such as 0, 1, 2,..., The minimum value of m · Tp that satisfies d · tan θ ≦ m · Tp is track shifted. Calculate as a quantity. The calculated track shift amount m · Tp is supplied to the track shift unit 38.

  The track shift unit 38 issues a track shift command including the track shift amount m · Tp to the tracking control unit 36 (step S40). The tracking control unit 36 generates a tracking control signal so as to shift the track to the unrecorded area side by the track shift amount m · Tp. In response to this track shift tracking control signal, the spot light from the servo laser beam is moved by the objective lens driving section 39 along the guide track of the guide layer of the optical disc 1 by the number of tracks m as shown in FIG. At the same time, spot light by the reproducing laser beam moves to the unrecorded area side by a predetermined number of tracks in the recording layer of the optical disc 1. For example, in the case of recording from the inside of the recording layer of the optical disc 1 to the outside in a spiral shape, the spot light of each laser beam for servo and reproduction moves outward in the radial direction by the number of tracks m.

  When the track shift of the spot light is completed by executing step S40, the main controller 43 instructs the tracking control unit 36 to turn on tracking servo control (step S41), and determines whether or not recording is actually started (step S41). If the recording is started, the recording / reproducing light source driving unit 32 is instructed to switch to the recording mode via the mode switching unit 33 (step S43). And it is discriminate | determined whether recording was complete | finished (step S44). Steps S41 to S44 are the same as steps S8 to S11 shown in FIG.

  After the end of recording, the track shift amount calculation unit 45 fetches the disc tilt amount at the recording end position as c from the tilt sensor 44 (step S45), and the main controller 43 obtains the disc tilt amount c from the track shift amount calculation unit 45, The recording / reproducing light source driving unit 32 is instructed via the mode switching unit 33 to record the disc tilt amount c together with the address of the recording end position at the specific initial reading position of the disc 1 (step S46). In step S46, the disk tilt amount at that position is written in the specific initial reading position of the disk 1 together with the address of the recording end position at the previous recording time. Therefore, at the time of the next recording, the disc tilt amount c is read as the disc tilt amount a in step S35.

  Therefore, according to the optical disk drive apparatus of FIG. 9, the minimum number of tracks is determined as the track shift amount according to the amount of change in the tilt of the disk, and the recorded area and the actual recording start position are spaced by the number of tracks. Therefore, it is possible to perform additional recording without destroying the recorded information in the recorded area, and it is possible to minimize a decrease in recording density.

  The track shift amount is not determined according to the disc tilt change amount as in the embodiment shown in FIG. 9, but the track shift at the start of additional recording becomes longer as the distance between the recording layer where the additional recording start position exists and the guide layer is longer. You may make it increase quantity. As described above, since the displacement amount in the radial direction of the focal recording layer due to the tilt of the disk is d · tan θ, the displacement amount increases in proportion to the distance d between the guide layer and the recording layer. Therefore, the necessary track shift amount can be determined so as to increase in proportion to the distance d.

  In this way, by changing the track shift amount according to the distance between the guide layer and the recording layer where the additional recording start position exists, it is possible to perform additional recording without destroying the recorded information in the recorded area, and to increase the recording density. Degradation can be minimized.

  FIG. 12 shows a flowchart of the recording operation as another embodiment of the present invention. This recording operation is executed in the optical disk drive apparatus of FIG. 3 or FIG. First, after the spot lights by the servo and reproduction laser beams are moved to the additional recording start position by the operations of steps S51 to S55 (same as S1 to S5 described above), the main controller 43 uses the guide track of the guide layer. The tracking control unit 36 is commanded to turn on tracking servo control (step S56), and one-track reproduction is performed (step S57). Then, the additional recording start position detector 37 determines whether or not a read signal is obtained from the output signal of the light receiving element 18 (step S58). If there is a read signal, since the spot light is located in the recorded area, a track shift to the unrecorded area side is commanded to the tracking control section 36 via the track shift section 38 (step S59). The tracking control unit 36 generates a tracking control signal so as to shift the track to the unrecorded area side. In response to the track shift tracking control signal, the objective lens drive unit 39 causes the spot light by the servo laser beam to move, for example, one guide track on the guide layer of the optical disc 1. At the same time, the spot light generated by the reproducing laser beam moves to the unrecorded area side by one track in the recording layer of the optical disc 1, for example. After this track shift, steps S57 to S58 are executed again. Therefore, the spot light can be positioned in an unrecorded area of the recording layer where a read signal cannot be obtained by executing steps S57 to S59. The track shift amount in step S59 is at least one track.

  The additional recording start position detection unit 37 commands the tracking control unit 36 to shift only one track toward the recorded area side via the track shift unit 38 (step S60). That is, a tracking control signal is supplied to the objective lens driving unit 39 so as to return to the recorded area side by one track. Then, it is determined whether or not recording is actually started (step S61). If recording is started, switching to the recording mode is commanded to the recording / reproducing light source driving unit 32 via the mode switching unit 33. (Step S62). Thereafter, it is determined whether or not the recording is finished (step S63). In the recording mode, the driving power for the light source 11 of the recording / reproducing light source driving unit 32 is set to a recording power greater than the reproducing power, and the light source 11 is driven according to the information to be recorded, and the spot light of the recording laser beam is emitted. It is formed in an unrecorded area of the recording layer.

  In this embodiment, the necessary track shift amount can be determined without particularly providing a complicated configuration for detecting the tilt of the disk. As a result, a decrease in recording density can be minimized. Further, it is possible to cope with recording on an unrecorded recording layer that does not require track shift.

  FIG. 13 shows a flowchart of a recording operation as another embodiment of the present invention. This recording operation is executed in the optical disk drive apparatus of FIG. 3 or FIG. First, after the spot lights by the servo and reproduction laser beams are moved to the additional recording start position by the operations of steps S65 to S69 (same as S1 to S5 described above), the main controller 43 uses the guide track of the guide layer. The tracking controller 36 is commanded to turn on the tracking servo control (step S70), and one track reproduction is performed (step S71). Then, the additional recording start position detector 37 determines whether or not a tracking error signal is obtained from the output signal of the light receiving element 18 (step S72). If there is a tracking error signal, the number of tracks that overlap with the recorded area is estimated by counting the number of zero-crossing points, and the track shift amount (track number) is calculated (step S73). The calculated track shift amount is supplied to the track shift unit 38 and commands the tracking control unit 36 to shift the track to the unrecorded area side (step S74). The tracking control unit 36 generates a tracking control signal so as to shift the track to the unrecorded area side. In response to the track shift tracking control signal, the spot light by the servo laser beam is moved by the objective lens driving unit 39 by the number of tracks calculated for the guide track of the guide layer of the optical disc 1. At the same time, the spot light from the reproducing laser beam moves to the unrecorded area side by the calculated number of tracks in the recording layer of the optical disc 1. After this track shift, steps S71 and S72 are executed again. Therefore, the spot light can be positioned in an unrecorded area of the recording layer where a read signal cannot be obtained by executing steps S71 to S74. The track shift amount in step S74 is at least one track.

  The additional recording start position detection unit 37 instructs the tracking control unit 36 to shift only one track to the recorded area side via the track shift unit 38 (step S75). That is, a tracking control signal is supplied to the objective lens driving unit 39 so as to return to the recorded area side by one track. Then, it is determined whether or not recording is actually started (step S76). If recording is started, switching to the recording mode is instructed to the recording / reproducing light source driving unit 32 via the mode switching unit 33. (Step S77). Thereafter, it is determined whether or not the recording is finished (step S78). In the recording mode, the driving power is modulated by the recording / reproducing light source driving unit 32, and the light source 11 is driven according to the information to be recorded, and the spot light of the recording laser beam is formed in the unrecorded area of the recording layer.

  In the embodiment of FIG. 13 as well, as in the embodiment of FIG. 12, the required track shift amount can be determined without particularly providing a complicated configuration for detecting the tilt of the disk. As a result, a decrease in recording density can be minimized. Further, it is possible to cope with recording on an unrecorded recording layer that does not require track shift.

  In each of the above embodiments, the optical disk is provided with a plurality of recording layers together with a single guide layer. However, any optical disk in which at least one recording layer is stacked apart from the guide layer may be used. Further, the optical recording medium may be an optical memory in which a recording layer and a guide layer are laminated instead of a disk having a disk shape as in the embodiment.

  The present invention can be applied not only to the optical disk drive device but also to other devices such as a hard disk recording / reproducing device including the optical disk drive device.

It is a figure which shows the structure of each of a guide layer integrated disc and a guide layer separation type disc. It is a figure which shows a recording state when a disk inclines in the normal recording state and the subsequent additional recording. It is a figure which shows the structure of the optical disk drive device as an Example of this invention. 4 is a flowchart showing a recording operation in the apparatus of FIG. 3. It is a figure which shows the track shift in the case of additional recording. It is a figure which shows the recording state when a disc inclines in the case of additional recording. It is a figure which shows the difference angle of the recording track position in the case where there is no inclination of a disk in the case of additional recording, and the case where there is inclination. It is a flowchart which shows the tracking operation | movement at the time of reproduction | regeneration. It is a figure which shows the structure of the optical disk drive device as another Example of this invention. 10 is a flowchart showing a recording operation in the apparatus of FIG. It is a figure which shows the guide track shift of m * Tp. It is a flowchart which shows recording operation | movement as another Example of this invention. It is a flowchart which shows recording operation | movement as another Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 3 Motor 11, 21 Light source 15 Spherical aberration correction element 16 Objective lens 18, 25 Light receiving element 37 Additional write start position detection part 38 Track shift part 43 Main controller 44 Tilt sensor

Claims (7)

Optical recording or reproduction of information in accordance with the guide track with respect to the recording layer of the guide layer separation type optical recording medium in which the guide layer including the position information formed thereon and the recording layer are separated from each other. An optical recording medium drive device for performing
A servo optical system for irradiating the guide layer with a servo first laser beam through an objective lens and detecting the reflected light;
A recording / reproducing optical system for detecting the reflected light by irradiating the recording layer with a second laser beam for recording or reproducing through the objective lens;
Guide layer tracking error generation for generating a guide layer tracking error signal indicating an error from the center of the guide track of the irradiation spot position of the first laser beam on the guide layer based on a detection level of reflected light by the servo optical system Means,
Tracking drive means for performing tracking drive for moving the objective lens in a direction perpendicular to the tangential direction of the guide track so that the guide layer tracking error signal is reduced;
If there is a recorded area in the recording layer, additional recording start position detection means for detecting the additional recording start position following the recorded area;
Wherein by moving the irradiation spot of the first laser beam at a position on the guide track in which the controlling the tracking driving unit when adding the recording start facing the position apart in the unrecorded area side from the recordable starting position first Track shift means for following and moving the irradiation spot of the two laser beams on the recording layer,
Additional recording on the recording layer is started from the irradiation spot position of the second laser beam moved by the track shift means ,
The track shift means has a tilt sensor for detecting the tilt of the optical recording medium,
The irradiation spot of the first laser beam from the additional recording start position and the number of tracks corresponding to the amount of change in the inclination of the optical recording medium at the start of additional recording from the inclination of the optical recording medium at the time of recording in the recorded area and the Move the irradiation spot of the second laser beam,
The optical recording medium is recorded on the optical recording medium at the end of recording of the optical recording medium, and used for the next additional recording as the inclination of the optical recording medium at the time of recording in the recorded area. Recording medium drive device. The number of tracks, the optical recording medium of the guide layer and the recording layer and the optical recording medium drive apparatus according to claim 1, wherein the determined according to the distance. Wherein the change in slope theta, the distance d between the guide layer and the recording layer of the optical recording medium, the track pitch of the guide layer and the guide track of Tp of the optical recording medium, and the number of the track is m,
d · tanθ ≦ m · Tp
3. The optical recording medium drive apparatus according to claim 2, wherein the number of tracks is determined from a minimum value of m · Tp that satisfies the following conditions.   The track shift means reads a predetermined number of tracks when a read signal is detected by reading the recording layer from the additional recording start position in the tracking drive state according to the guide layer tracking error signal. 2. The optical recording medium drive apparatus according to claim 1, wherein an operation of shifting the track to the unrecorded area side is performed, and the operation of the track shift is repeated until the read signal is not detected. Recording layer tracking error generation for generating a recording layer tracking error signal indicating an error from the recording track center of the irradiation spot position of the second laser beam on the recording layer based on a detection level of reflected light by the recording / reproducing optical system Including means,
The track shift means reads one recording layer from the additional recording start position in the tracking driving state according to the guide layer tracking error signal, and zero-crosses the recording layer tracking error signal within the reading period. The number of track shift tracks is calculated according to the number of tracks, the track shift operation is performed to the unrecorded area by the calculated track count, and the track shift operation is repeated until the recording layer tracking error signal is no longer detected. 2. The optical recording medium drive device according to claim 1, wherein Recording layer tracking error generation for generating a recording layer tracking error signal indicating an error from the recording track center of the irradiation spot position of the second laser beam on the recording layer based on a detection level of reflected light by the recording / reproducing optical system Including means,
The tracking drive means performs the tracking drive according to the recording layer tracking error signal when a detection output is obtained by the recording / reproducing optical system at the time of reproducing the additionally recorded optical disc, and the recording / reproducing optical system 2. The optical recording medium drive device according to claim 1, wherein when no detection output is obtained, the tracking drive is performed in accordance with the guide layer tracking error signal. A first laser beam for servo is irradiated through an objective lens to the guide layer of the guide layer separation type optical recording medium in which the guide layer including the guide information on which the position information is formed and the recording layer are separated from each other. Servo optical system that detects the reflected light,
A recording / reproducing optical system for detecting the reflected light by irradiating the recording layer with a second laser beam for recording or reproducing through the objective lens;
Guide layer tracking error generation for generating a guide layer tracking error signal indicating an error from the center of the guide track of the irradiation spot position of the first laser beam on the guide layer based on a detection level of reflected light by the servo optical system Means,
Tracking drive means for performing tracking drive for moving the objective lens in a direction perpendicular to the tangential direction of the guide track so that the guide layer tracking error signal is reduced, and according to the guide track with respect to the recording layer An additional recording method of an optical recording medium drive device for optically recording or reproducing information,
A first step of detecting a postscript start position following a recorded area in the recording layer;
Wherein by moving the irradiation spot of the first laser beam at a position on the guide track in which the controlling the tracking driving unit when adding the recording start facing the position apart in the unrecorded area side from the recordable starting position first 2 and the laser beam of the second step of the irradiation spot Ru to follow movement to the recording layer,
A third step of starting additional recording on the recording layer from the irradiation spot position of the second laser beam after the follow-up movement in the second step ;
In the second step, the tilt of the optical recording medium is detected by a tilt sensor,
The irradiation spot of the first laser beam from the additional recording start position and the number of tracks corresponding to the amount of change in the inclination of the optical recording medium at the start of additional recording from the inclination of the optical recording medium at the time of recording in the recorded area and the Move the irradiation spot of the second laser beam,
The optical recording medium tilt is recorded on the optical recording medium at the end of recording of the optical recording medium, and used as the tilt of the optical recording medium at the time of recording in the recorded area for the next additional recording. Recording method.

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