JP2008090985A - Optical disk drive device and tilt correcting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve tilt correction in which an optical axis of a laser beam is tilted at an appropriate angle by setting a tilt correction value when recording of an outer peripheral side of a boundary position of the zone is started accurately even when disk deformation caused by abrupt variation of rotation speed in a boundary part of a zone affects to tilt, in the optical disk drive device and the tilt correcting method. <P>SOLUTION: The prescribed tilt variation quantity is added to a tilt correction value upon interruption of recording in an inner peripheral side zone of the prescribed boundary part, the tilt correction value at the time of re-start of recording in the outer peripheral side zone of the prescribed boundary part is calculated, this value is set to the control means as the prescribed tilt correction value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical disc drive apparatus and tilt correction method for controlling a data recording layer of an optical disc and an optical axis of laser light applied to the optical disc to be perpendicular to each other.

  If the optical axis of the laser beam emitted from the optical pickup and the data recording layer of the optical disc are always in a vertical relationship, the laser beam formed for recording / reproducing on the track of the optical disc is the data recording Since the focal point is correctly formed on the surface, no coma aberration occurs, and the beam spot diameter of the laser beam is the smallest in the data recording layer, so that sufficient read / write quality can be obtained.

  However, the optical disk may be distorted or warped depending on various process conditions such as temperature, pressure, cooling time, etc. and its management state during resin molding. Even if the optical axis of the optical pickup mounted on the optical disc drive apparatus is in an allowable tilt range, the optical axis of the laser beam and the data recording layer of the optical disc are not perpendicular to each other. There is a case where recording / reproduction quality deteriorates due to inability to read / write properly, or a recording / reproduction operation becomes impossible due to a servo control error.

  In addition, in order to increase the storage capacity of the optical disk, when performing rotation control by the CLV method (Constant Linear Velocity) or the ZLCV method (Zoned Constant Linear Velocity), the rotation speed of the optical disk is set to a radius to make the linear velocity constant. In order to vary according to the recording / reproducing position in the direction, the rotational speed is controlled to gradually decrease as recording / reproducing proceeds from the inner circumference side to the outer circumference side.

  In particular, in the ZCLV method, the optical disk is divided into a plurality of zones in the radial direction, and the rotational speed is controlled to gradually decrease from the inner peripheral side to the outer peripheral side for each zone. When recording proceeds from the inner circumference side to the outer circumference side as in the first layer of the two-layer disc, the rotation speed of the optical disc changes rapidly from the low rotation to the high rotation at the zone boundary, and the two layers of the two-layer disc. When recording proceeds from the outer circumference side to the inner circumference side as in the eye, the rotation speed of the optical disk changes rapidly from the high rotation to the low rotation at the zone boundary.

  Therefore, when the optical disk suddenly turns to high speed, the air in the closed space on the upper surface side is sent out in the centrifugal direction, and the air pressure in the space on the upper surface side becomes a negative pressure state more rapidly than the air pressure in the space on the lower surface side. As a result, the pressure difference between the space on the upper surface side and the space on the lower surface side may cause more noticeable disk deformation on the peripheral side, resulting in poor read / write quality and / or servo control. An error may occur and recording / playback may become inoperable.

  In order to deal with such a problem, the tilt value of a predetermined area of the optical disc is detected at the start-up before starting the recording operation, and the laser beam is detected based on the predetermined tilt correction value corresponding to the tilt value. Control means for tilt correction by tilting the optical axis is used.

  For example, as shown in the schematic diagram showing the correspondence between the tilt zone and the tilt correction in the prior art in FIG. 8, a tilt correction method is proposed in which the boundary of the tilt zone coincides with the boundary of the zone of the ZCLV method. ing.

  In this case, the tilt is switched only at the zone boundary of the ZCLV system, and the tilt correction can be performed without affecting the random access performance in the zone of the ZCLV system.

  The graph of FIG. 8 represents the correspondence relationship between the movement amount of the optical disk in the radial direction, the deflection amount of the optical disk, and the tilt control output.

  Since the optical disk is bent, the amount of disk deflection changes in the radial direction of the optical disk. For this reason, the inclination of the optical disk also changes in the radial direction of the optical disk.

  In order to cope with the change in the tilt of the optical disk, a tilt zone is provided. The tilt zone coincides with the boundary of the ZCLV system zone, and the tilt correction amount is constant within the zone. It is an area to do.

  In FIG. 8, the optical disk is divided into eight tilt zones 0 to 7, and each of the tilt zones 0 to 7 corresponds to the tilt correction values T0 to T7. This tilt correction value can be appropriately determined based on the tilt correction signal Tc near the tilt zone boundary. It is also possible to set a tilt correction amount in advance using a table or the like (Patent Document 1).

  Further, as another conventional technique, although not shown, for example, a step of detecting a tilt correction value at an arbitrary position of an optical disk rotating at a predetermined rotational speed, and when the rotational speed of the optical disk is a predetermined rotational speed, The step of performing tilt correction based on the detected tilt correction value, and when the rotation speed changes, the tilt correction value is re-corrected based on the amount of change in the tilt correction value due to the change in the rotation speed set in advance. A tilt correction method including a step of performing is proposed (Patent Document 2).

Further, as another conventional technique, although not shown, for example, the optical pickup is moved in the radial direction with respect to the entire surface of the optical disk, and the tilt value is measured at a plurality of arbitrary points. Based on the tilt value, the entire surface of the optical disk is measured. There has been proposed a tilt correction method based on whole surface tilt learning to obtain an approximate curve of tilt values over a range (Patent Document 3).
Japanese Patent Laying-Open No. 2005-317146 (page 9, FIG. 2) Japanese Patent Laying-Open No. 2006-179037 (page 11, FIG. 2) Japanese Patent Laying-Open No. 2003-281761 (page 35, FIG. 15)

  However, in the conventional technique described in the above (Patent Document 1), since the boundary position of the tilt zone coincides with the boundary position of the ZCLV system zone in advance, the random access performance in the ZCLV system zone Although the tilt correction can be performed without affecting the rotation speed, if the rotation speed changes greatly in the ZCLV zone, the disk is deformed due to the change in the rotation speed and is set in the tilt zone. It becomes difficult to perform tilt correction based on the tilt correction value, and proper read / write cannot be performed, and recording / playback quality deteriorates, or a servo control error occurs and recording / playback cannot be performed. There is.

  In addition, the conventional technique described in (Patent Document 2) can cope with a case where the rotation speed largely changes in the zone of the ZCLV method, but the tilt detected at a predetermined rotation speed at the time of startup in advance. This is a method for re-correcting the tilt correction value when the rotation speed changes based on the value and the amount of change in the tilt value when the rotation speed is changed. During the process, tilt changes caused by heat generated by the spindle motor, actuator drive, etc. are also added, making it difficult to perform tilt correction with high accuracy, resulting in inadequate reading / writing, and poor recording / reproduction quality, or servo control. A control error may occur and recording / reproduction may become inoperable.

  Further, in the conventional technique as described in (Patent Document 3), in the middle of continuous recording operation, thermal disk deformation due to heat generation of the spindle motor or the control circuit board or rotation at the boundary of the zone When disk deformation due to abrupt changes in speed affects the tilt, it becomes difficult to perform tilt correction based on the tilt correction value obtained from the entire surface tilt learning, and recording cannot be performed properly. • Playback quality may be degraded, or servo control errors may occur, making recording / playback operation impossible.

  The present invention solves the above-described conventional problems, and during the continuous recording operation, the rotational speed rapidly increases at the boundary of the zone due to thermal disk deformation due to heat generation of the spindle motor or the control circuit board. Even when disc deformation due to changes affects the tilt, it is possible to improve the recording and playback quality by accurately setting the tilt correction value at the start of recording on the outer peripheral side of the zone boundary to the control means. realizable.

  In order to solve the above-described conventional problems, the optical disc drive apparatus of the present invention adds a predetermined amount of tilt change to the tilt correction value at the time of recording interruption in the inner peripheral zone of a predetermined boundary portion, and Computation processing means for computing a tilt correction value at the time of resuming recording in the outer peripheral zone and setting this as a predetermined tilt correction value in the control means is provided.

  With this configuration, thermal deformation of the disk due to heat generated by the spindle motor, control circuit board, etc. during the continuous recording operation, or disk deformation due to a sudden change in the rotational speed at the zone boundary, affects the tilt. Even in this case, it is possible to accurately set a predetermined tilt correction value at the time of resuming recording on the outer peripheral side of the zone boundary in the control means.

  Further, the tilt correction method of the present invention adds a predetermined tilt change amount to the tilt correction value at the time of recording interruption in the inner peripheral zone of the predetermined boundary portion, and resumes recording in the outer peripheral zone of the predetermined boundary portion. A tilt correction value is calculated and set as a predetermined tilt correction value.

  According to the optical disc drive apparatus and tilt correction method of the present invention, it is possible to accurately set a predetermined tilt correction value at the time of resumption of recording on the outer peripheral side of the zone boundary portion in the control means. Can be improved.

  According to the first aspect of the present invention, the rotation speed of the optical disk is controlled so that the optical disk is divided into a plurality of zones and the linear velocity of each zone is kept constant, and tilt correction is performed based on a predetermined tilt correction value. And a control means for performing the detection, and before starting the recording operation, the tilt value is detected at two different rotational speeds at the boundary portion of each zone, and the reference tilt change amount is calculated for each zone boundary portion based on the two tilt values. And calculating a reference rotation speed change amount indicating a difference between the two rotation speeds, calculating a reference tilt change rate indicating a ratio of the reference rotation speed change amount to the reference tilt change amount for each zone boundary portion, Corresponding to a predetermined boundary portion, a predetermined rotational speed change amount which is a difference between the rotational speed at the time of recording interruption in the inner peripheral zone of the boundary portion and the rotational speed at the time of resuming recording in the outer peripheral zone of the predetermined boundary portion. Multiply the quasi-tilt change rate to calculate the predetermined tilt change amount, add the predetermined tilt change amount to the tilt correction value at the time of recording interruption in the inner peripheral side zone of the predetermined boundary portion, and the outer peripheral side of the predetermined boundary portion Calculation processing means for calculating a tilt correction value at the time of resuming recording in the zone and setting this as a predetermined tilt correction value in the control means, so that a spindle motor or Even if the disk deformation due to thermal disk deformation due to heat generation of the control circuit board or the like or the rotation speed suddenly changes at the boundary of the zone affects the tilt, the outer peripheral side of the boundary of the zone is accurately detected. Since it is possible to set a predetermined tilt correction value at the time of resuming recording in the control means, it is possible to improve recording / reproduction quality.

  According to the second aspect of the present invention, the two tilt values detected at two different rotational speeds at the boundary portions of the zones are the tilt values obtained by the entire surface tilt learning before the start of the recording operation. As a result, efficient tilt correction can be performed in a short time.

  According to the invention described in claim 3 of the present invention, the arithmetic processing means corresponds to the position at the additional recording position before starting the recording operation when the additional recording is performed on the optical disk recorded halfway through the zone. The tilt value is detected at the rotational speed controlled in this way, and the tilt correction value according to the rotational speed is set even at the time of additional recording by setting the control means as the tilt correction value at the time of additional recording based on the tilt value. Therefore, the recording / reproduction quality can be improved.

  According to the fourth aspect of the present invention, the two different types of rotation speeds are the maximum rotation speed and the minimum rotation speed of the optical disk controlled during the recording operation by the control means. Since it is possible to obtain the reference tilt change rate in the entire range of the rotational speed that is varied by the control, the control means sets the tilt correction value as a predetermined tilt correction value at the time of resuming recording on the outer peripheral side of the zone boundary. Therefore, the recording / reproduction quality can be improved.

  According to the fifth aspect of the present invention, the calculation by the calculation processing means is sequentially performed for each zone boundary portion in the direction from the outer peripheral side to the inner peripheral side of the optical disc, and recording in the outer peripheral side zone of the boundary portion is performed. If the rotation speed at the start is set at the maximum rotation speed by the control means and the predetermined tilt change amount obtained by the calculation is equal to or less than the predetermined threshold value, the calculation processing means at the boundary of the zone on the inner circumference side By canceling the calculation according to, the processing on the inner peripheral side of the optical disk that has a small tilt correction value and falls within the allowable tilt range of the optical pickup mounted on the optical disk drive device is omitted. More efficient tilt correction can be realized.

  According to the sixth aspect of the present invention, based on the predetermined tilt correction value in the optical disc drive apparatus whose rotational speed is controlled so as to make the linear velocity of each zone of the optical disc divided into a plurality of zones constant. The tilt correction method performs tilt correction, and detects the tilt value at two different rotation speeds at the boundary between the zones and starts the reference tilt change amount based on the two tilt values before starting the recording operation. Is calculated for each boundary portion, a reference rotational speed change amount indicating a difference between two types of rotational speeds is calculated, and a reference tilt change rate indicating a ratio of the reference rotational speed change amount to the reference tilt change amount is calculated for each zone boundary portion. And a predetermined rotational speed change that is the difference between the rotational speed at the time of recording interruption in the inner peripheral zone of the predetermined boundary and the rotational speed at the time of resuming recording in the outer peripheral zone of the predetermined boundary. Is multiplied by the reference tilt change rate corresponding to the predetermined boundary portion to calculate a predetermined tilt change amount, and the predetermined tilt change amount is added to the tilt correction value at the time of recording interruption in the inner peripheral zone of the predetermined boundary portion. By calculating the tilt correction value at the time of resuming recording in the outer peripheral zone of the predetermined boundary, and setting this as the predetermined tilt correction value, the spindle motor and the control circuit are in the middle of continuous recording operation. Even if thermal deformation of the disk due to heat generated by the substrate, etc. or disk deformation due to a sudden change in the rotation speed at the boundary of the zone affects the tilt, the recording on the outer peripheral side of the boundary of the zone is accurately resumed. Since the predetermined tilt correction value at the time can be set in the control means, the recording / reproduction quality can be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
1 to 4, FIG. 1 is a block diagram of an optical disc drive apparatus according to Embodiment 1 of the present invention, and FIG. 2 shows a procedure for performing tilt correction of the optical disc drive apparatus according to Embodiment 1 of the present invention. FIG. 3 is a schematic diagram for explaining a processing procedure for each zone boundary, and FIG. 4 is a diagram showing a calculation result for each step performed by the calculation processing means.

  First, as shown in FIG. 1, a pickup module 2 is disposed below an optical disc 1 that has a recording layer and can be recorded or reproduced, and the optical disc 1 is variably rotated in the pickup module 2. Alternatively, a spindle motor 3 that provides a rotational driving force that rotates at a constant speed is mounted.

  Further, the optical pickup 4 constituting the optical pickup module 2 and having an objective lens writes (records) information in a predetermined area of the optical disk 1 by irradiating the optical disk 1 with laser light, or irradiates the laser light. In order to read (reproduce) information based on the reflected light, the carriage 5 is driven by the feed unit 6 and reciprocates in the radial direction of the optical disc 1.

  The feed unit 6 is provided with a feed motor 7 for driving the carriage 5, a gear (not shown), a screw shaft (not shown), and the like, and the carriage is rotated by rotating the feed motor 7. 5 is configured to be able to reciprocate from the inner circumference side to the outer circumference side, which is the radial direction of the optical disc 1.

  That is, the pickup module 2 of the small / thin optical disk drive apparatus is configured by the main components as described above.

  The analog signal processing unit 8 outputs a focus error signal and a tracking error signal based on an output signal from a photosensor (not shown) inside the optical pickup 4 mounted on the carriage 5 inside the pickup module 2. Generated and output to the servo processing unit 9 that drives the triaxial actuator of the optical pickup 4.

  The servo processor 9 also temporarily stores an A / D converter that converts the analog signal sent from the analog signal processor 8 into a digital signal, and a digital signal converted by the A / D converter. Memory, an arithmetic circuit for calculating a digital signal stored in the memory or a digital signal sent from the A / D converter by a predetermined method, and a D / D for converting the digital signal calculated by the arithmetic circuit into an analog signal It is composed of an A converter or the like, and filter signal processing and various arithmetic processing are performed by digital arithmetic so that the beam spot of the laser beam formed on the data recording layer of the optical disc 1 accurately follows the information track of the optical disc 1. Is going.

  Then, the servo processing unit 9 controls the objective lens (not shown) mounted on the optical pickup 4 via the actuator driving unit 10 to move in the focus direction or the tracking direction, or to tilt the tilt lens in the tilt direction. In addition to the above, the transfer control of the feed unit 6 and the rotation control of the spindle motor 3 are performed.

  Further, in the servo processing unit 9, various parameter settings and sequence control are flexibly performed according to commands related to control from the controller 13.

  At the time of reproducing operation, the optical disk 1 is irradiated with laser light from the optical pickup 4 and the reflected light from the optical disk 1 is received by a photosensor (not shown), and an analog signal is generated as a reproduction signal according to the received reflected light. Via the processing unit 8, it is sent to the digital signal processing unit 11 composed of a data slicer, data PLL circuit, jitter measurement circuit, error correction unit, modulation / demodulation unit / buffer memory / laser control unit, etc. The signal output from the signal processing unit 11 is transferred to the host (HOST in FIG. 1) as effective reproduction data.

  On the other hand, at the time of recording operation, data sent from the host is modulated by the digital signal processing unit 11, and a predetermined light source such as a laser (not shown) mounted in the optical pickup 4 via the laser driving unit 12 is specified. A drive current is supplied, and the light source emits light in a pulse form, for example, and recording is performed on the information track of the optical disc 1.

  Further, the temperature sensor 14 mounted on the carriage 5 is for detecting the temperature in the optical disc drive, and before recording or reproducing information on the optical disc 1 after the optical disc 1 is inserted into the optical disc drive apparatus. That is, the temperature at the start-up or the temperature at the recording / reproducing operation is detected.

  The analog output from the temperature sensor 14 is A / D converted by the A / D conversion circuit unit 15 and output to the controller 13. The controller 13 detects tilt detection or the like described later according to the output. Tilt correction is performed.

  As described above, the controller 13 controls the rotation speed of the optical disk 1 by controlling the rotation of the spindle motor 3 so that the optical disk 1 is divided into a plurality of ZCLV zones and the linear velocity of each zone is constant, and a predetermined tilt correction is performed. Control means for performing tilt correction based on the value is provided.

  The controller 13 also has arithmetic processing means that will be described in detail next, and a tilt correction procedure performed by the arithmetic processing means will be described with reference to FIG.

  First, when the optical disc 1 is loaded in the optical disc drive device and the optical disc drive device is turned on, the optical disc drive device is activated immediately (S1). The type of disc recorded in the lead-in area, how many layers the disc is, etc. The information is acquired, and then the tilt value is detected at two different rotational speeds, and the reference tilt change amount is calculated for each zone boundary based on the two tilt values (S2).

  Here, the two different rotational speeds are preferably the maximum rotational speed and the minimum rotational speed controlled by the control means described above, and the entire range of rotational speeds that can be varied by controlling the rotational speed of the optical disc 1. The reference tilt change rate can be obtained and can be set in the control means as a predetermined tilt correction value when resuming recording on the outer periphery of the zone boundary, thus improving recording and playback quality. it can.

  Then, a reference rotation speed change amount indicating a difference between the two different rotation speeds is calculated (S3), and a reference tilt change rate indicating a ratio of the reference rotation speed change amount to the reference tilt change amount is calculated for each zone boundary. Calculate (S4).

  Next, the recording operation of the optical disc 1 is started (S5), and the recording operation is continuously continued from the inner peripheral side to the outer peripheral side in the radial direction of the optical disc 1, but the disc type acquired from the lead-in area Based on the information, it is always determined whether or not the zone boundary is reached under the control of the controller 13 (S6). If the determination result is no, the recording operation is continued.

  Then, the recording operation is interrupted when reaching the boundary portion of the zone where the determination result is “yes” (S7), and the rotational speed and the boundary portion at the time of recording interruption in the inner peripheral zone of the boundary portion where the recording operation is interrupted The predetermined amount of change in tilt is calculated by multiplying the predetermined amount of change in rotational speed, which is the difference from the rotational speed at the time of resuming recording in the outer peripheral zone, by the reference tilt change rate corresponding to the boundary portion (S8).

  Then, the tilt change amount is added to the tilt correction value at the time of recording interruption in the inner peripheral zone of the boundary portion to calculate the tilt correction value at the time of resuming recording in the outer peripheral zone of the boundary portion (S9). Is set in the control means described above as a predetermined tilt correction value (S10).

  Thereafter, the recording operation is resumed based on the tilt correction value set in the control means (S11).

  Further, for the sake of easy understanding, a supplementary explanation will be given with reference to FIG.

  First, as shown in the ZLCV optical disk zone division diagram, for example, when the optical disk 1 is a DVD ± R, DVD ± RW, DVD ± R DL, etc., the data recording area is a double speed zone from the inner circumference side, 4 The zone is divided into a plurality of zones by boundary portions P0, P1, P2, P3, and P4 so that the linear velocity is sequentially doubled with the double speed zone, the 8 × speed zone, and the 16 × speed zone, so that the linear velocity is constant in each zone. It is controlled.

  The rotation speed diagram of the optical disk shows that the rotation speed of the optical disk 1 varies according to the recording / reproducing position in the radial direction of the optical disk 1 during the recording operation or the reproducing operation. The rotation speed is controlled to gradually decrease as recording / reproduction proceeds from the outer circumference to the outer circumference side.

  In other words, when recording proceeds from the inner circumference side to the outer circumference side as in the first layer of a single-layer disc or a double-layer disc, the rotational speed of the optical disc 1 at each of the zone boundaries P0, P1, P2, P3, and P4. Changes rapidly from low rotation to high rotation, and when recording proceeds from the outer peripheral side to the inner peripheral side as in the second layer of the dual-layer disc, each of the zone boundaries P0, P1, P2, P3, and P4 As a result, the rotational speed of the optical disk 1 changes rapidly from high to low.

  As is clear from this figure, at any of the zone boundaries P0, P1, P2, P3, and P4, the rotation is rapidly changed from a predetermined minimum rotation speed to a predetermined maximum rotation speed by the rotation control by the ZLCV method. It shows that you are doing.

  Next, the contents described with reference to FIG. 2 will be further supplemented with reference to disk deformation diagrams at two different rotational speeds.

  Before the recording operation, when the optical disk 1 is rotated at two different rotational speeds, for example, a predetermined minimum rotational speed and a predetermined maximum rotational speed set by rotational control by the ZLCV method, the disk is at the minimum rotational speed. It changes from the state indicated by the solid line with small deformation to the state indicated by the broken line with large disk deformation at the maximum rotational speed.

  That is, when the optical disk 1 is rotated at a high speed, the air in the closed space on the upper surface side is sent out in the centrifugal direction, and the air pressure in the space on the upper surface side becomes a negative pressure state than the air pressure in the space on the lower surface side. It shows that the disk deformation occurs due to the pressure difference between the space on the upper surface side and the space on the lower surface side.

  In the figure showing the detected tilt values, the tilt values detected at the respective rotational speeds at the boundaries of the zones are shown, and the solid line plot shows the state in which the optical disc 1 is rotated at the minimum rotational speed. The broken line plot shows the tilt value when the optical disc 1 is rotated at the maximum rotation speed.

  As is apparent from this figure, when the optical disc 1 is rotated at the maximum rotation speed, the tilt value on the outer peripheral side is larger than that on the inner peripheral side, and the deformation of the disc on the outer peripheral side is larger. Indicates that it will grow.

  Next, in the figure showing the reference tilt change rate, a reference tilt change amount is calculated based on two tilt values for each boundary portion, and a reference rotation speed change amount indicating a difference between two types of rotation speeds is calculated. A reference tilt change rate indicating a ratio of the reference rotation speed change amount to the reference tilt change amount is calculated for each zone boundary portion and indicated by a solid line plot.

  Then, a predetermined rotational speed change amount (maximum) that is a difference between the rotational speed at the time of recording interruption in the inner peripheral zone of the boundary portion where the recording operation is interrupted and the rotational speed at the time of resuming recording in the outer peripheral zone of the boundary portion. Is multiplied by the reference tilt change rate corresponding to the boundary portion to calculate a predetermined tilt change amount.

  In the figure showing the tilt correction value, the tilt correction value when resuming recording in the outer peripheral zone of the boundary by adding the amount of tilt change to the tilt correction value at the time of recording interruption in the inner peripheral zone of the boundary. The tilt correction value obtained by calculating is shown by a solid line plot.

  Then, the tilt correction value is set as the predetermined tilt correction value in the control means described above. At the start of recording, tilt correction is performed using the tilt correction value. However, in the zone, the tilt correction value is servo-controlled by the tilt servo, so that the rotational speed decreases as it goes to the outer circumference side, so it is indicated by a solid line. As shown, the tilt correction value gradually decreases.

  Further, FIG. 4 shows a calculation result for each step performed by the calculation processing means shown in FIG. As is apparent from this figure, the calculation corresponding to each step described above is performed for each zone boundary, and finally the tilt correction value at the time of recording interruption in the inner peripheral zone of each boundary is set to a predetermined value. The tilt correction value at the time of resuming recording in the outer peripheral zone of the boundary portion is calculated by adding the amount of tilt change.

  Next, a modification of the first embodiment of the present invention will be described with reference to FIGS.

  FIG. 5 is a flowchart in which a part of the procedure for performing tilt correction in the modified example is omitted, and FIG. 6 is a diagram illustrating a calculation result for each step performed by the arithmetic processing unit in the modified example.

  First, when the optical disc 1 is loaded in the optical disc drive device and the optical disc drive device is turned on, the optical disc drive device is activated immediately (S21). The type of disc recorded in the lead-in area, the number of layers of the disc, etc. Information is acquired, and then a predetermined boundary is set as the outermost boundary (S22).

  Then, tilt values are detected at two different rotational speeds, and a reference tilt change amount is calculated for a predetermined boundary portion based on the two tilt values (S23).

  Further, a reference rotational speed change amount indicating a difference between two different rotational speeds is calculated (S24), and a reference tilt change rate indicating a ratio of the reference rotational speed change amount to the reference tilt change amount is calculated for the boundary portion ( S25).

  Then, a predetermined rotational speed change amount that is a difference between the rotational speed at the time of recording interruption in the inner peripheral zone of the predetermined boundary and the rotational speed at the time of resuming recording in the outer peripheral zone of the boundary is set to the boundary A predetermined tilt change amount is calculated by multiplying by a reference tilt change rate corresponding to (S26).

  Next, it is determined whether or not the rotational speed at the start of recording in the outer peripheral zone of the boundary is set at the maximum rotational speed by the control means described above (S27). If not (no), the predetermined boundary is determined. Is set as one inner boundary (S28), and the reference tilt change amount is calculated based on the two tilt values for the boundary (S23), and the process returns.

  If the determination in S27 is true (yes), it is further determined whether or not the predetermined tilt change amount is equal to or less than a predetermined threshold (S29). If the determination is not true (no), one predetermined boundary is provided. The inner boundary is set (S28), and the reference tilt change amount is calculated based on the two tilt values for the boundary (S23).

  If the determination in S29 is true (yes), the recording operation of the optical disc 1 is started (S30), and thereafter, the same processing as the flowchart shown in FIG.

  Further, as shown in FIG. 6, the calculation in this case is sequentially performed as P4, P3, and P2 for each zone boundary portion in the direction from the outer peripheral side to the inner peripheral side of the optical disc 1, but by the calculation at the boundary portion P2 Since the obtained predetermined amount of tilt change is equal to or less than a predetermined threshold value (for example, 0.7), the calculation is stopped for the boundary portions P1, P0 of the inner peripheral zone.

  Therefore, a predetermined tilt change amount is not added to the tilt correction value at the time of recording interruption in the inner peripheral zone of each of the boundary portions P1 and P0, and the tilt correction value is not changed in the outer peripheral zone of each boundary portion. The tilt correction value when recording is resumed is set in the control means.

  Here, although the predetermined tilt change amount at the boundary portion P3 is equal to or less than a predetermined threshold value (for example, 0.7), the calculation is not stopped at the start of recording in the outer peripheral zone of the boundary portion. Is not set at the maximum rotation speed by the control means, so that it is not applicable in the determination of S27 (no), and a predetermined boundary is set as one inner boundary by the processing of S28, and the processing of S23 This is to return to the processing.

  As described above, the calculation by the calculation processing means is sequentially performed for each zone boundary portion in the direction from the outer peripheral side to the inner peripheral side of the optical disc 1, and the rotation speed at the start of recording in the outer peripheral side zone of the boundary portion is as described above. If the predetermined tilt change amount set by the control means at the maximum rotation speed and obtained by the calculation is equal to or less than the predetermined threshold value, the calculation by the calculation processing means at the boundary of the inner zone is stopped. As a result, for the zone on the inner circumference side of the optical disk 1 that has a small tilt correction value and falls within the allowable tilt range of the optical pickup 4 mounted in the optical disk drive device, the processing related to the arithmetic processing means is omitted, so that the efficiency is improved. Tilt correction can be realized.

  Note that the two tilt values detected at two different rotational speeds at the boundary of each zone may be the tilt values obtained by full-face tilt learning before the start of the recording operation. The optical pickup 4 is moved in the radial direction with respect to the entire surface of the optical disc 1 at a rotational speed, and the tilt value is measured at a plurality of arbitrary points, and the tilt value over the entire surface of the optical disc 1 is approximated based on the tilt value. By obtaining a curve and obtaining a tilt value corresponding to the boundary portion of each zone from the approximate curve, an efficient tilt correction can be performed in a shorter time.

  The two different rotation speeds are preferably the maximum rotation speed and the minimum rotation speed controlled during the recording operation by the control means described above. However, in order to obtain more accuracy, the rotation speed of the optical disc 1 is controlled. A rotational speed exceeding the entire range of rotational speeds that can be varied during recording may be set, or the range may be narrower than the entire range of rotational speeds that may be varied during recording by controlling the rotational speed of the optical disc 1 to reduce time. It doesn't matter.

(Embodiment 2)
Next, FIG. 7 is a flowchart showing a procedure for performing tilt correction of the optical disc drive apparatus according to the second embodiment of the present invention. The block diagram of the optical disc drive apparatus is shown in FIG. 1 described in the first embodiment. The explanation is omitted because it is the same as.

  Hereinafter, a case where recording is additionally recorded on the optical disk 1 recorded halfway through the zone will be described with reference to FIG.

  First, when the optical disk 1 recorded in the middle of the zone is loaded in the optical disk drive device and the optical disk drive device is turned on, the optical disk drive device starts immediately (S41), the type of disk recorded in the lead-in area, and how many layers Get information such as whether the disk is

  Next, a tilt value is detected at a rotational speed controlled corresponding to the position at the additional recording position (S42), and is set in the control means as a tilt correction value at the time of additional recording based on the tilt value (S43). .

  Then, the tilt value is detected at two different rotational speeds, and the reference tilt change amount is calculated for each zone boundary based on the two tilt values (S44).

  Here, the two different rotational speeds are preferably the maximum rotational speed and the minimum rotational speed controlled by the control means described above, and the entire range of rotational speeds that can be varied by controlling the rotational speed of the optical disc 1. Since the reference tilt change rate can be obtained, it can be set to the control means as a predetermined tilt correction value at the time of resuming recording on the outer peripheral side of the boundary of the zone with higher accuracy, thus realizing improved recording and playback quality it can.

  Then, a reference rotational speed change amount indicating a difference between two different rotational speeds is calculated (S45), and a reference tilt change rate indicating a ratio of the reference rotational speed change amount to the reference tilt change amount is calculated for each zone boundary. (S46).

  Next, the write-once recording operation of the optical disc 1 is started (S47), and the recording operation is continuously continued from the inner peripheral side to the outer peripheral side in the radial direction of the optical disc 1, but the disc type acquired from the lead-in area On the basis of this information, it is always determined whether or not the zone boundary is reached under the control of the controller (S48), and if the determination result is no, the recording operation is continued.

  Then, the recording operation is interrupted when reaching the boundary portion of the zone where the determination result is “yes” (S49), and the rotational speed and the boundary portion at the time of recording interruption in the inner peripheral zone of the boundary portion where the recording operation is interrupted. The predetermined amount of change in tilt is calculated by multiplying the predetermined amount of change in rotational speed, which is the difference from the rotational speed at the time of resuming recording in the outer peripheral zone, by the reference tilt change rate corresponding to the boundary portion (S50).

  Then, the tilt change value is added to the tilt correction value at the time of recording interruption in the inner peripheral zone of the boundary portion to calculate the tilt correction value at the time of resuming recording in the outer peripheral zone of the boundary portion (S51). Is set in the control means described above as a predetermined tilt correction value (S52).

  Thereafter, the recording operation is resumed based on the tilt correction value set in the control means (S53).

  By performing the tilt correction according to such a procedure, it becomes possible to set a tilt correction value according to the rotational speed even at the time of additional recording, so that it is possible to improve the recording / reproduction quality.

  Note that the tilt value detected at the rotational speed controlled in accordance with the position at the additional recording position may be a tilt value obtained by full-scale tilt learning before the start of the additional recording operation. The tilt value is measured at a plurality of arbitrary points on the optical disc 1 at a rotational speed controlled in accordance with the recording position, an approximate curve of the tilt value over the entire surface of the optical disc 1 is obtained, and it corresponds to the additional recording position from the approximate curve. By obtaining the tilt value to be performed, it is possible to perform efficient tilt correction in a shorter time.

  In the above description of the embodiment, the case of recording (writing) information on the optical disc 1 has been described. However, the same procedure can be applied to the case of reproducing (reading) information from the optical disc 1. Needless to say.

  The optical disc drive apparatus and tilt correction method according to the present invention is capable of accurately resuming the recording on the outer peripheral side of the boundary portion of the zone in the ZLCV rotation control that divides the zone into a plurality of zones and keeps the linear velocity of each zone constant. A predetermined tilt correction value can be set in the control means, and recording / reproduction quality can be improved, so that the data recording layer of the optical disc and the optical axis of the laser beam irradiated to the optical disc are perpendicular to each other. It is useful as an optical disk drive device and tilt correction method that are controlled in the same manner.

1 is a block diagram of an optical disc drive apparatus according to Embodiment 1 of the present invention. 6 is a flowchart showing a procedure for performing tilt correction of the optical disc drive apparatus according to the first embodiment of the present invention. Schematic diagram explaining the processing procedure for each zone boundary The figure which shows the calculation result for every step performed by a calculation processing means The flowchart which abbreviate | omitted and showed the procedure which performs the tilt correction in a modification The figure which shows the calculation result for every step performed by the arithmetic processing means in a modification. 7 is a flowchart showing a procedure for performing tilt correction of the optical disc drive apparatus according to the second embodiment of the present invention. Schematic diagram showing the correspondence between tilt zones and tilt correction in the prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 2 Pickup module 3 Spindle motor 4 Optical pick-up 5 Carriage 6 Feed part 7 Feed motor 8 Analog signal processing part 9 Servo processing part 10 Actuator drive part 11 Digital signal processing part 12 Laser drive part 13 Controller 14 Temperature sensor 15 A / D Conversion circuit section

Claims (6)

Control means for controlling the rotational speed of the optical disk so as to divide the optical disk into a plurality of zones and making the linear velocity of each zone constant and performing tilt correction based on a predetermined tilt correction value;
Before starting the recording operation, a tilt value is detected at two different rotation speeds at the boundary between the zones, and a reference tilt change amount is calculated for each zone boundary based on the two tilt values.
Calculating a reference rotational speed change amount indicating a difference between the two rotational speeds;
A reference tilt change rate indicating a ratio of the reference rotational speed change amount to the reference tilt change amount is calculated for each zone boundary,
The predetermined boundary is set to a predetermined rotational speed change amount that is a difference between the rotational speed at the time of recording interruption in the inner peripheral zone of the predetermined boundary and the rotational speed at the time of resuming recording in the outer peripheral zone of the predetermined boundary. Multiply the reference tilt change rate corresponding to the part to calculate a predetermined tilt change amount,
Calculating the tilt correction value at the time of resuming recording in the outer peripheral side zone of the predetermined boundary in the previous period by adding the predetermined tilt change amount to the tilt correction value at the time of recording interruption in the inner peripheral side zone of the predetermined boundary, And an arithmetic processing means for setting the predetermined tilt correction value in the control means. 2. The optical disc according to claim 1, wherein the two tilt values detected at two different rotation speeds at the boundary between the zones are tilt values obtained by full-face tilt learning before the start of a recording operation. Drive device. The arithmetic processing means detects a tilt value at a rotational speed controlled in accordance with the position of the additional recording position before starting the recording operation when recording additional recording on the optical disk recorded halfway through the zone. 2. The optical disc drive apparatus according to claim 1, wherein the control means sets the tilt correction value at the time of additional recording based on the tilt value. 2. The optical disk drive device according to claim 1, wherein the two different types of rotation speeds are a maximum rotation speed and a minimum rotation speed of the optical disk controlled by the control means during a recording operation. The calculation by the calculation processing means is sequentially performed for each boundary portion of the zone in the direction from the outer periphery side to the inner periphery side of the optical disc, and the rotation speed at the start of recording in the outer periphery side zone of the boundary portion is If the predetermined tilt change amount set at the maximum rotation speed and obtained by the calculation is equal to or less than a predetermined threshold, the calculation by the calculation processing means at the boundary of the zone on the inner circumference side is stopped. The optical disc drive apparatus according to claim 4. A tilt correction method for performing tilt correction based on a predetermined tilt correction value in an optical disk drive device whose rotational speed is controlled so as to make the linear velocity of each zone of an optical disk divided into a plurality of zones constant,
Before starting the recording operation, a tilt value is detected at two different rotation speeds at the boundary between the zones, and a reference tilt change amount is calculated for each zone boundary based on the two tilt values.
Calculating a reference rotational speed change amount indicating a difference between the two rotational speeds;
A reference tilt change rate indicating a ratio of the reference rotational speed change amount to the reference tilt change amount is calculated for each zone boundary,
The predetermined boundary is set to a predetermined rotational speed change amount that is a difference between the rotational speed at the time of recording interruption in the inner peripheral zone of the predetermined boundary and the rotational speed at the time of resuming recording in the outer peripheral zone of the predetermined boundary. Multiply the reference tilt change rate corresponding to the part to calculate a predetermined tilt change amount,
Calculating the tilt correction value at the time of resuming recording in the outer peripheral side zone of the predetermined boundary in the previous period by adding the predetermined tilt change amount to the tilt correction value at the time of recording interruption in the inner peripheral zone of the predetermined boundary, A tilt correction method characterized by setting this as the predetermined tilt correction value.

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