JP2006277913A - Reproduction recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a period of time for tilt correction processing to a recording medium. <P>SOLUTION: Before recording information in an optical disk 10, a controller 8 rotates the optical disk 10 at the minimum speed and the maximum speed of rotational speed, within the rotational speed in multiple steps. At each of the rotational speed, multiple points from an inner circumference side through an outer circumference side of a recording surface of the optical disk 10 is irradiated with a laser beam L from multiple angles, based on each of reflected beams of each of the irradiation beams, a value of the tilt correction calculation at the multiple points of the optical disk 10 is obtained, and the tilt correction information for correcting the tilt of the laser beam L to the optical disk 10 is obtained by designated calculation processing from each of the obtained value for the tilt calculation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes an optical disc drive for recording and reproducing information on a recording medium including a CD, a CD-R disc, a CD-RW disc, a DVD + R disc, a DVD + RW disc, a DVD-R disc, and a DVD-RW disc. The present invention relates to a recording apparatus.

Currently, a reproducing and recording apparatus that records and reproduces information on a recording medium is widely used.
As such playback and recording devices, optical disc drives that perform recording and playback on optical discs including CDs, CD-R discs, CD-RW discs, DVD + R discs, DVD + RW discs, DVD-R discs, and DVD-RW discs are widely used. is doing. Many of these optical disk drives are capable of recording and reproducing on various optical disks that are commercially available.
The above-mentioned commercially available optical discs are roughly classified into two types, that is, a CD type and a DVD type. Currently, DVD type optical discs are remarkably improved in recording speed. For example, the maximum speed is 16 times faster. The performance related to the recording quality is affected by various adjustment items of the optical disk drive.

In particular, when warping of the optical disk occurs, even if information is recorded by irradiating such an optical disk with laser light, the recording surface may not be correctly irradiated with laser light, so that the recording quality may deteriorate.
Therefore, conventionally, a reproducing / recording apparatus that performs tilt correction processing for correcting the tilt of the optical system unit including the optical pickup with respect to the optical disc so as to reduce the tilt of the laser beam with respect to the recording surface of the recording medium (for example, Patent Document 1, Patent) Reference 2).
Japanese Patent Laid-Open No. 2001-05361 JP 2003-281863 A

However, in the conventional reproducing / recording apparatus, since the tilt correction processing is performed for all of a plurality of types of speeds at the time of recording before recording on the recording medium, the recording on the recording medium is performed, so it takes time to start recording. There was a problem.
The present invention has been made in view of the above points, and an object thereof is to shorten the time of tilt correction processing for a recording medium.

In order to achieve the above object, the present invention provides the following reproducing / recording apparatus.
(1) The recording medium can be rotated at a plurality of stages of rotation speed, the recording medium is rotated at any one of the above-described rotation speeds, and the recording medium is irradiated with light, and the recording medium is irradiated with light based on the irradiated light. In a reproducing / recording apparatus provided with means for reproducing and recording information on a recording medium, the recording medium is rotated at a low speed and a high speed among the plurality of stages before the information is recorded on the recording medium. Based on each reflected light of each of the irradiated light, each of which is rotated at a speed, and the light is irradiated at a plurality of angles at a plurality of positions from the inner peripheral side to the outer peripheral side of the recording surface of the recording medium for each rotational speed. Thus, the tilt correction calculation values at the plurality of locations of the recording medium are obtained, and the tilt correction information for correcting the light inclination with respect to the recording medium is calculated from the obtained inclination calculation values by a predetermined calculation process. The reproducing and recording device provided.

(2) The reproducing / recording apparatus according to (1), wherein the type of the predetermined calculation process is different between when rotated at the low speed and when rotated at the high speed.
(3) The reproducing / recording apparatus according to (1) or (2), wherein the number of the plurality of positions is different depending on whether the number of places is rotated at the low speed or the high speed.
(4) The reproducing / recording apparatus according to (1) or (2), wherein the positions of the plurality of locations are different depending on whether the position is rotated at the low speed or the high speed.
(5) In the reproducing / recording apparatus according to any one of (1) to (4), reproduction before information is recorded on the recording medium is performed before the optimum recording power determination process at the start of recording on the recording medium. Recording device.

(6) The recording medium can be rotated at a plurality of stages of rotation speeds, the recording medium is rotated at any one of the above-described rotation speeds, and the recording medium is irradiated with light, and the recording medium is irradiated with light based on the irradiated light. In a reproducing / recording apparatus having means for reproducing and recording information on a recording medium, the recording medium is designated in the optimum recording power determination process before the optimum recording power determination process at the start of recording on the recording medium. The recording medium of the recording medium is rotated at a rotational speed, and the light is irradiated to a plurality of positions from the inner peripheral side to the outer peripheral side of the recording medium at a plurality of types of angles, and based on each reflected light of the irradiated light, Reproduction recording provided with a means for obtaining inclination correction calculation values at the plurality of locations and obtaining inclination correction information for correcting the inclination of the light with respect to the recording medium by a predetermined calculation process from the obtained inclination calculation values. Apparatus.

  The reproducing / recording apparatus according to the present invention can shorten the time of tilt correction processing on the recording medium.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
[Example 1]
FIG. 1 is a block diagram showing the configuration of a DVD + RW drive apparatus according to Embodiment 1 of the present invention.
This DVD + RW drive device includes a motor 1 that rotates an optical disc 10 that is a recording medium including a CD, a CD-R disc, a CD-RW disc, a DVD + R disc, a DVD + RW disc, a DVD-R disc, and a DVD-RW disc. Motor / optical pickup control that performs various controls including a rotation control system unit 2 that controls the rotational drive of the optical disk, a coarse motion motor that moves the optical pickup 3 in the radial direction of the optical disk 10, and a light emission control of the laser light L of the optical pickup. A system part 4 is provided.

  In addition, the signal processing system unit 5 that controls the input / output of the reproduction signal from the optical pickup 3 and the recording signal to the optical pickup 3, the data written to the optical disk 10 received from the host computer, and the data reproduced from the optical disk 10 are temporarily stored. The invention is realized by a cache memory 6 to be stored, an external interface control system unit 7 including ATAPI, SCSI, USB, IEEE1394 for controlling data exchange with a host computer, and a microcomputer comprising a CPU, ROM, RAM, etc. The controller 8 which performs the process which concerns on is provided.

FIG. 2 is a block diagram showing a configuration of main parts inside the optical pickup 3 and the motor / optical pickup control system unit 4 shown in FIG.
The optical pickup 3 irradiates the optical disk 10 with laser light L generated from a semiconductor laser light source (LD), and tilts the irradiation angle of the laser light L applied to the optical disk 10 by the tilt coil 11. The photodetector 12 receives the reflected light of the laser beam L irradiated onto the optical disc 10, converts it into a track error signal (abbreviated as “TE signal”), and outputs it.
The motor / optical pickup control system unit 4 amplifies the TE signal output from the photodetector 12 by the RF amplifier 13, outputs the TE signal to the controller 8 via the servo control circuit 14, and based on an instruction from the controller 8, the servo control circuit The motor driver 15 is controlled by 14, and the tilt coil 11 is controlled by the motor driver 15.

  In this DVD + RW drive device, the rotation control system unit 2 controls the rotation of the motor 1 based on an instruction from the controller 8, whereby the optical disk 10 is rotated at a plurality of stages (for example, 4 × speed, 6 × speed, 8 × speed, 16 × speed). The optical disk 10 is rotated at any one of the rotation speeds, and the motor / optical pickup control system unit 4 and the signal processing system unit 5 are operated based on an instruction from the controller 8. When the optical disk 10 is reproduced, the optical pickup 3 irradiates the optical disk 10 with the laser light L, and the signal processing system unit 5 sends a reproduction signal to the controller 8 based on the reflected light of the irradiated light. The controller 8 temporarily stores the reproduction signal in the cache memory 6 and then sends it to the host computer via the external interface control system unit 7.

  When recording on the optical disk 10, the controller 8 temporarily stores information received via the external interface control system unit 7 in the cache memory 6, and the rotation control system unit 2 rotates the motor 1 based on an instruction from the controller 8. By controlling, the optical disk 10 is rotated at the rotational speed of any one of the plurality of stages, and the information stored in the cache memory 6 is converted into a recording signal by the signal processing unit 5 based on an instruction from the controller 8 Under the control of the motor / optical pickup control system 4, the optical pickup 3 irradiates the optical disc 10 with the laser light L corresponding to the recording signal, and records information on the optical disc 10.

Next, a description will be given of processing when the DVD + RW drive device is rotated at four stages of rotation speeds of 4 × speed, 6 × speed, 8 × speed, and 16 × speed, and inclination correction information is obtained for each rotation speed.
1) The optical disk 10 is rotated at a rotation speed of 4 times speed, 6 times speed, 8 times speed, and 16 times speed, respectively.
2) At each of the above rotational speeds, the optical pickup 3 is measured at a plurality of locations from the inner peripheral side to the outer peripheral side of the recording surface of the optical disc 10 under the control of the motor / optical pickup control system 4 based on the instruction of the controller 8. Move to each.

3) At each measurement position, the controller 8 controls the servo control circuit 14, the servo control circuit 14 controls the motor driver 15 based on the control, and the motor driver 15 drives and controls the tilt coil 11. The laser beam L irradiated from the optical pickup 3 is tilted at a plurality of preset angles, and the optical disc 10 is irradiated with the laser beam L according to each tilt.
4) The photodetector 12 receives each reflected light of the light irradiated at each angle, converts it into a track error signal (abbreviated as “TE signal”), and sends it to the RF amplifier 13. The RF amplifier 13 amplifies the TE signal and sends it to the controller 8 via the servo control circuit 14. The controller 8 measures the amplitude value of each TE signal.

FIG. 3 is a diagram showing the waveform value of the amplitude value of each TE signal when the tilt amount of the laser light L is changed in a plurality of stages at one measurement location of the optical disc 10.
As shown in (a) of the figure, by changing the tilt amount of the laser light L stepwise, the amplitude value of the TE signal changes as shown in the waveform shown in (b) of the figure.
5) The controller 8 adopts the maximum value of the amplitude value of each measured TE signal as a value for tilt correction calculation (referred to as “tilt correction calculation value”) at the measurement location (measurement position).
Then, tilt correction information for correcting the tilt of the laser beam L with respect to the optical disc 10 is obtained from the obtained tilt correction calculation values by a predetermined calculation process.

The tilt correction calculation value is obtained from the maximum value (maximum amplitude value) of the amplitude value of the TE signal obtained from the tilt amounts tilted at a plurality of angles at each predetermined measurement position in the radial direction of the optical disc 10. The tilt amount, which is referred to as a tilt acquisition value. The tilt acquisition value is a tilt control value corresponding to the tilt amount, and therefore has no specific unit.
In this embodiment, the tilt control value in the range of 00h to FFh (hexadecimal) is set so that the central 80h is a neutral position of the tilt control value, and 80h is 128 in decimal. is there.

FIG. 4 is a diagram showing tilt acquisition values at each measurement point of the optical disc 10 obtained when the optical disc 10 is rotated at rotation speeds of 4 ×, 6 ×, 8 ×, and 16 ×.
As shown in the figure, even when the same measurement location on the optical disc 10 is rotated at a low speed (4 × speed, 6 × speed) and obtained at a high tilt speed (8 × speed, 16 × speed). It can be seen that the obtained tilt acquisition value differs greatly.
In addition, the distribution of tilt acquisition values is not different for each rotation speed, and there is a difference between the low speed side and the high speed side.
Therefore, it is not necessary to perform tilt correction processing at all rotation speeds. The minimum requirement is to perform tilt correction processing at two types of rotation speeds, low speed and high speed, and to perform each tilt correction processing on the low speed side. It can be seen that it can be applied to the high speed side. Examples of the combination of the two types of rotational speeds include a low speed and a high speed, a low speed and a maximum speed, a minimum speed and a high speed, and an optimum speed and a maximum speed.

Therefore, this DVD + RW drive device rotates the optical disk 10 at two stages of rotation speeds of 4 times the minimum speed and 16 times the maximum speed, and controls the motor / optical pickup based on instructions from the controller 8 for each rotation speed. Under the control of the system unit 4, the optical pickup 3 is moved from the inner peripheral side of the recording surface of the optical disk 10 to a plurality of measurement positions on the outer peripheral side.
Further, at each measurement position, the controller 8 controls the servo control circuit 14, the servo control circuit 14 controls the motor driver 15 based on the control, and the motor driver 15 drives and controls the tilt coil 11. The laser beam L irradiated from the optical pickup 3 is tilted at a plurality of preset angles, and the optical disc 10 is irradiated with the laser beam L according to each tilt.

Further, the photodetector 12 receives each reflected light of the light irradiated at each angle, converts it into a TE signal, and sends it to the RF amplifier 13. The RF amplifier 13 amplifies the TE signal and sends it to the controller 8 via the servo control circuit 14. The controller 8 measures the amplitude value of each TE signal.
Then, tilt correction information for correcting the tilt of the laser beam L with respect to the optical disc 10 is obtained from the obtained tilt correction calculation values by a predetermined calculation process.
Referring to the distribution of each 4 × speed tilt acquisition value and the distribution of each 16 × speed tilt acquisition value in FIG. 4, the 16 × speed greatly changes between the inner and outer peripheral sides of the optical disc 10. Moreover, a sudden rise near the outer periphery can be confirmed.

FIG. 5 is a waveform diagram showing an approximate curve obtained from each of the 4 × speed and 16 × speed tilt acquisition values shown in FIG. 4.
In the figure, a quadratic approximation curve A obtained by subjecting each quadruple speed tilt acquisition value shown in FIG. 4 to a quadratic approximation process and a quadratic approximation to each 16 × speed tilt acquisition value shown in FIG. A quadratic approximate curve B obtained by performing the process, and a cubic approximate curve C obtained by performing the third approximate process on each 16 × speed tilt acquisition value shown in FIG. 4 are shown.
As described above, when the rotation with respect to the optical system at the rotation speed of the optical disk 10 is examined for the case of rotating at a low speed and the case of rotating at a high speed, the shape of the optical disk 10 changes as the speed increases. Unevenness occurs.

Therefore, the predetermined calculation process is different depending on whether the rotation is performed at a low speed or when the rotation is performed at a high speed. For example, it is possible to improve the accuracy by applying the quadratic approximation process to the minimum speed of 4 × speed and applying the cubic approximation process to the maximum speed of 16 × speed. The approximation process applied to each speed may be any one of the first to third approximation processes.
In the above description, the results of measuring each tilt (Tilt) when rotating at a low speed and when rotating at a high speed are different depending on the individual optical disks. Although the example using the cubic approximation process at the time of rotation at the speed is shown, depending on the result of measuring the tilt by the quadratic approximation process and the cubic approximation process, the secondary approximation curve and the cubic approximation curve show the same tendency from the beginning. There is a case.

FIG. 6 is a waveform diagram showing an example of an approximate curve obtained from each tilt acquisition value of 8 × speed and 12 × speed.
As shown in the figure, the second-order approximate curve D and the third-order approximate curve E for the tilt acquisition value during rotation at 8 × speed are the same.
Here, if the speed is close to the maximum speed, it can be determined that the third-order approximation process is effective. However, the calculation results equivalent to the second-order approximation process and the third-order approximation process can be obtained even in the non-maximum speed except for the low speed part. Then, even when the rotational speed does not reach the maximum speed, the tilt correction by the third-order approximation process is effective.

Next, in the above description, attention has been paid to the tendency of the optical disk to be greatly distorted at high speed as the tendency of the optical disk. However, some optical disks may be distorted even if the speed is not high.
FIG. 7 is a waveform diagram showing an example of an approximate curve obtained from each tilt acquisition value of 4 × speed, 6 × speed, 8 × speed, and 16 × speed.
As shown in the figure, in the case of an optical disc that is distorted even if it does not become high speed, not only the maximum speed but also the tendency by n (n is 1, 2, 3) order approximation processing from the low speed side is investigated, Optimal recording quality can be obtained by performing optimal tilt correction calculation.

FIG. 8 is a waveform diagram showing a second-order approximation curve and a third-order approximation curve for the tilt acquisition value at the quadruple speed shown in FIG.
As shown in the figure, as a tendency at a quadruple speed, the third-order approximation curve G resulting from the third-order approximation processing is more measured than the second-order approximation curve F resulting from the second-order approximation processing. It can be seen that there is little difference. In this way, there are cases where the third order approximation process is preferably performed at a low speed.

Next, an example of processing for determining the order of approximation processing will be described.
FIG. 9 is a flowchart illustrating an example of processing for determining the order of approximation processing.
This process is performed by the controller 8, and in step (indicated by “S” in the figure) 1, an error value between the tilt acquisition value of each measurement location and the approximate curve value is acquired by the primary approximation process. An error value between the obtained tilt value and the approximate curve value at each measurement location by the second order approximation process is acquired. In step 3, an error value between the obtained tilt value at each measurement location and the approximate curve value by the third order approximation process is obtained. Approximation of the order in which the error value obtained in step 4 is the minimum value among the error values between the tilt acquisition value of each measurement location and the approximate curve value obtained in the first to third order approximation processing in step 4 above. In step 5, the obtained n (n is 1, 2, 3) approximation process is set. In the subsequent processes, the set n-order approximation process is adopted, and this process is terminated.

In the process of step 4, a predetermined error value is applied instead of the minimum value, and each error value between the obtained tilt value and the approximate curve value obtained in the first to third order approximation process is obtained. Among them, an approximation process of the order in which an error value that is equal to or smaller than a predetermined error value is obtained may be obtained.
In the above-described processing, the case where all the first to third approximation processes are performed has been described. However, the approximation process applied at low speed and high speed may be different. For example, primary approximation processing and secondary approximation processing are performed at low speeds, and secondary approximation processing and tertiary approximation processing are performed at high speeds. Further, the secondary approximation process is performed at a low speed, and the secondary approximation process and the tertiary approximation process are performed at a high speed.
In this way, this DVD + RW drive device can improve the recording quality by increasing the accuracy of the tilt correction value.

Next, if the measurement location of the optical disk 10 is the same at the low rotation speed and the high rotation speed, an error occurs in the obtained tilt correction value.
Therefore, for example, in order to increase the approximation accuracy at the maximum speed of 16 × speed, the number of measurement locations at 16 × speed is increased from the measurement location at 4 × speed, and the measurement position at 16 × speed is measured at 4 × speed. Different from the positions, the intervals between the measurement positions may be made fine in order to increase the approximation accuracy near the outer periphery.

FIG. 10 is a waveform diagram showing an approximate curve obtained from each tilt acquisition value when the number of measurement points is increased by rotating the optical disc 10 at 16 × speed.
Thus, by increasing the number of measurement points near the outer periphery of the optical disc 10, the accuracy of the cubic approximation curve obtained by performing the cubic approximation process on each tilt acquisition value is improved.
Therefore, the accuracy of the tilt correction process at the maximum speed with respect to the entire surface of the optical disc 10 in the controller 8 is improved.

At the time of recording on the optical disc 10, the controller 8 calculates a tilt correction value from the tilt correction information obtained at a quadruple speed and the recording position of the optical disc 10 if the rotational speed of the optical disc 10 is a low-speed rotational speed, and performs servo control. The circuit 14 is controlled, the motor driver 15 is controlled by the servo control circuit 14, and the tilt coil 11 is moved by the motor driver 15 to correct the tilt amount of the laser light L. In this way, the tilt of the optical system unit with respect to the optical disc 10 is optimally maintained, and the recording quality is improved.
In this way, this DVD + RW drive apparatus does not need to perform tilt correction processing at any speed with respect to the optical disk, and therefore can shorten the time until recording starts.

Next, the execution timing of the tilt correction process will be described.
FIG. 11 is a diagram showing the relationship between the recording address and the recording speed in the case of CLV recording.
As shown in the figure, in the case of CLV recording, the recording speed changes from the inner circumference side to the outer circumference side.
Therefore, the tilt correction process is ideally performed for each recording speed of the optical disc 10, but it can be compensated even if it is not performed at all speeds in the above description.
However, before information is recorded on the optical disc 10, there is a process for optimizing the laser power at the time of recording by a laser power correction function called an optimum recording power determination process (optimum power control: OPC). By performing the control by the processing, it is possible to make the determination of the laser power at the time of recording, which is an important factor for the recording quality, more accurate.

Therefore, the controller 8 performs the tilt correction process described above before the optimum recording power determination process at the start of recording on the optical disc 10.
As described above, by performing the tilt correction process by the OPC process before the actual recording, the tilt correction operation necessary for the recording can be performed in advance, and the OPC process can be performed with high accuracy.

Next, by performing the tilt correction process described above at the rotational speed required for the OPC process, it is not necessary to perform a tilt correction at a new recording speed when recording actual information on the optical disc 10.
In this case, the controller 8 rotates the optical disc 10 at the rotation speed set during the OPC process, and the optical pickup 3 is moved to the recording surface of the optical disc 10 under the control of the motor / optical pickup control system 4 based on the instruction of the controller 8. The controller 8 controls the servo control circuit 14, and the servo control circuit 14 controls the motor driver 15 based on the control. The motor driver 15 Controls the tilt coil 11 to tilt the laser beam L emitted from the optical pickup 3 to a plurality of preset angles, and irradiates the optical disc 10 with the laser beam L according to each tilt.

Further, the photodetector 12 receives each reflected light of the light irradiated at each angle, converts it into a TE signal, and sends it to the RF amplifier 13. The RF amplifier 13 amplifies the TE signal and sends it to the controller 8 via the servo control circuit 14. The controller 8 measures the amplitude value of each TE signal.
Then, the controller 8 employs the maximum value of the amplitude value of each measured TE signal as a value for tilt correction calculation at the measurement location, and performs a predetermined calculation process on the optical disc 10 from the obtained tilt correction calculation values. The tilt correction information for correcting the tilt of the laser beam L with respect to is obtained.

FIG. 12 is a diagram showing the format of the recording area of the optical disc 10.
As shown in the figure, the area used in the OPC process is an inner disk test zone in an inner drive area located on the inner peripheral side of the optical disk 10.
Further, by performing tilt correction processing at a speed on the inner periphery side of the optical disc as in CLV recording, the tilt correction processing performed at the time of OPC processing can be performed at other speeds without performing tilt correction at other speeds. The part can be shared.

[Example 2]
FIG. 13 is a block diagram showing the internal configuration of the optical pickup and the motor / optical pickup control system section of the DVD + RW drive apparatus according to the second embodiment of the present invention. Components common to those in FIG. The description is omitted.

The DVD + RW drive apparatus according to the second embodiment includes a tilt sensor 16 that detects the tilt of the laser light L with respect to the optical disk 10 in the optical pickup 3, and a servo control circuit 14 according to the rotational speed of the optical disk 10 during tilt correction. Switches between the reproduction signal from the RF amplifier 13 and the tilt detection signal from the tilt sensor 16 and outputs them to the controller 8.
For example, at the time of tilt correction, when the optical disk 10 is rotated at the highest rotational speed, tilt correction information is obtained based on the tilt detection signal obtained from the tilt sensor 16, and in other cases, a reproduction signal obtained from the photodetector 12 is obtained. Is used to obtain tilt correction information.
In addition, the tilt correction information may be obtained based on the tilt detection signal obtained from the tilt sensor 16 for a portion where the fluctuation of the tilt acquisition value is large from the detection result of the tilt amount before the start of recording on the optical disc 10.

  As described above, when the tilt sensor is provided, the number of parts, the manufacturing cost, and the power consumption increase, but the tilt correction processing to the optical disk having complicated tilt fluctuation can be performed accurately, and the tilt detection before the start of recording is performed. There is an advantage that becomes unnecessary.

  The reproducing / recording apparatus according to the present invention can be applied to all optical disk drives.

1 is a block diagram showing a configuration of a DVD + RW drive apparatus according to Embodiment 1 of the present invention. FIG. FIG. 2 is a block diagram showing a configuration of main parts inside an optical pickup 3 and a motor / optical pickup control system unit 4 shown in FIG. 1. FIG. 2 is a diagram showing waveform values of amplitude values of TE signals when the tilt amount of laser light L is changed in a plurality of stages at one measurement location of the optical disc 10 shown in FIG. It is a figure which shows the tilt acquisition value in each measurement location of the optical disk 10 obtained when the optical disk 10 shown in FIG. 1 was rotated at the rotational speed of 4 times speed, 6 times speed, 8 times speed, and 16 times speed, respectively.

FIG. 5 is a waveform diagram showing an approximate curve obtained from each of the 4 × speed and 16 × speed tilt acquisition values shown in FIG. 4. It is a wave form diagram which shows an example of the approximate curve obtained from each tilt acquisition value of 8 times speed and 12 times speed. It is a wave form diagram which shows an example of the approximate curve obtained from each tilt acquisition value of 4 times speed, 6 times speed, 8 times speed, and 16 times speed. FIG. 8 is a waveform diagram showing a second-order approximation curve and a third-order approximation curve with respect to a tilt acquisition value at quadruple speed shown in FIG. 7.

It is a flowchart figure which shows an example of the process which determines the order of an approximation process. It is a wave form diagram which shows the approximate curve obtained from each tilt acquisition value when rotating the optical disk 10 shown in FIG. 1 at 16 time speed, and increasing a measurement location. It is a figure which shows the relationship between the recording address and recording speed in the case of CLV recording. It is a figure which shows the format of the recording area of the optical disk 10 shown in FIG. It is a block diagram which shows the internal structure of the optical pick-up of the DVD + RW drive apparatus of Example 2 of this invention, and a motor / optical pick-up control system part.

Explanation of symbols

1: Motor 2: Rotation Control System Unit 3: Optical Pickup 4: Motor / Optical Pickup Control System Unit 5: Signal Processing System Unit 6: Cache Memory 7: External Interface Control System Unit 8: Controller 10: Optical Disc 11: Tilt Coil 12 : Photo detector 13: RF amplifier 14: Servo control circuit 15: Motor driver

Claims (6)

The recording medium can be rotated at a plurality of rotation speeds, the recording medium is rotated at any one of the rotation speeds, and the recording medium is irradiated with light, and the recording medium is applied to the recording medium based on the irradiated light. In a playback / recording apparatus comprising means for playing back and recording information,
Before recording information on the recording medium, the recording medium is rotated at a low rotational speed and a high rotational speed among the plurality of stages of rotational speeds, and each rotational speed is within the recording surface of the recording medium. The light is irradiated from a peripheral side to a plurality of locations on the outer peripheral side at a plurality of angles, and values for calculating inclination correction at the plurality of locations on the recording medium are obtained based on reflected lights of the irradiated light, and the calculation is performed. A reproduction recording apparatus comprising means for obtaining inclination correction information for correcting the inclination of the light with respect to the recording medium by a predetermined calculation process from each inclination calculation value.   2. The reproducing / recording apparatus according to claim 1, wherein the type of the predetermined calculation process is different between when the rotation is performed at the low speed and when the rotation is performed at the high speed.   3. The reproducing / recording apparatus according to claim 1 or 2, wherein the number of the plurality of locations is made different between when the rotation is performed at the low speed and when the rotation is performed at the high speed.   3. The reproducing / recording apparatus according to claim 1, wherein the positions of the plurality of locations are different depending on whether the position is rotated at the low speed and when the position is rotated at the high speed.   5. The reproduction recording apparatus according to claim 1, wherein the information is recorded on the recording medium before the optimum recording power determination process at the start of recording on the recording medium. A playback / recording device. The recording medium can be rotated at a plurality of rotation speeds, the recording medium is rotated at any one of the rotation speeds, and the recording medium is irradiated with light, and the recording medium is applied to the recording medium based on the irradiated light. In a playback / recording apparatus comprising means for playing back and recording information,
Before the optimum recording power determination process at the start of recording on the recording medium, the recording medium is rotated at a rotation speed specified in the optimum recording power determination process, and the recording surface of the recording medium is changed from the inner peripheral side to the outer peripheral side. Irradiating the plurality of locations with the light at a plurality of angles, obtaining values for calculating the tilt correction at the plurality of locations of the recording medium based on the reflected lights of the irradiated light, and calculating the obtained tilts. A reproducing / recording apparatus comprising means for obtaining tilt correction information for correcting the tilt of the light with respect to the recording medium from a value by a predetermined calculation process.

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