JP2010040120A - Optical disk device and tilt control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device with which the driving value of an objective lens driving means corresponding to warpage of the optical disk, which varies depending on rotational frequency of the optical disk, is determined within a short period of time; and to provide the tilt control method thereof. <P>SOLUTION: The control means makes the optical disk rotate with a first rotational frequency b1 corresponding to a first predetermined position a1 and determines the first driving value c1 of the objective lens driving means corresponding to the first predetermined position a1, makes the optical disk rotate with a second rotational frequency b2 corresponding to a second predetermined position a2 and determines the second driving value c2 of the objective lens driving means corresponding to the second predetermined position a2, and determines the driving value of a tilt actuator in a region interposed between the first predetermined position a1 and the second predetermined position a2 based on the first driving value c1, the second driving value c2 and the rotational frequency of the optical disk corresponding to the recording or reproducing position of the optical disk. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical disc apparatus that performs at least one of recording and reproduction of information on an optical disc and a tilt control method.

  Currently, efforts are being made to improve the portability of PCs by reducing the thickness of optical disk apparatuses mounted on laptop PCs (Personal Computers). To reduce the thickness of the optical disk device, it is necessary to shorten the distance from the rotating optical disk to the cover that covers the optical disk device. Therefore, when the optical disk is rotated at a high speed, the rotating optical disk is greatly affected by wind pressure or negative pressure when the optical disk itself rotates. When the rotating optical disk is greatly affected by wind pressure or negative pressure, the optical disk warps in a direction away from the objective lens that focuses the laser light. This warpage increases as the rotational speed of the optical disk increases.

Since the optical disk has a different number of rotations at the time of recording or reproducing depending on the recording or reproducing position, that is, for each radial position, the rotating optical disk has a different amount of warpage depending on the recording or reproducing position. For this reason, the optical disk apparatus must determine the drive value of the tilt actuator that drives the objective lens in consideration of the influence of the warp of the optical disk in accordance with the rotational speed.
JP 2006-268691 A

  However, in order to set the drive value of the tilt actuator to a drive value corresponding to the rotational speed of the optical disk, it is necessary to actually rotate the optical disk at high speed and measure the drive value of the tilt actuator for each radial position of the optical disk. Therefore, there is a problem that it takes a lot of time to determine the drive value of the tilt actuator.

  FIG. 9 is a diagram showing the relationship between the radial position of the disk, the rotational speed of the optical disk, and the drive value of the tilt actuator, and FIG. 9A shows the relationship between the radial position of the disk and the rotational speed of the optical disk. FIG. 9B is a diagram showing the relationship between the radial position of the disk and the drive value of the tilt actuator. The horizontal axis in FIG. 9A is the radial position of the optical disk, the vertical axis is the rotational speed of the optical disk, the horizontal axis in FIG. 9B is the radial position of the optical disk, and the vertical axis is the drive value of the tilt actuator.

  For example, as shown in FIG. 9 (a), the optical disc apparatus has optical discs at respective rotational speeds corresponding to nine positions A, B, C, D, E, F, G, H, and I. Actually rotate. Then, the drive value of the tilt actuator corresponding to each position and the rotation number corresponding to each position is measured. At this time, the optical disk apparatus needs to rotate the optical disk at the respective rotational speeds corresponding to the radial positions of the optical disks A, B, C, D, E, F, G, H, and I. It takes a lot of time to reach the determined rotational speed. Then, as shown in FIG. 9B, for example, the optical disc apparatus tilts the objective lens at the radial positions A, B, C, D, E, F, G, H, and I to tilt the optical disc. It takes a lot of time to calculate the optimum drive value of the actuator.

  Therefore, there is a problem that it takes a lot of time to determine the drive value of the tilt actuator.

  The present invention has been made to solve the above problems, and an optical disc apparatus and a tilt control method thereof for determining a driving value of an objective lens driving means corresponding to warping of an optical disc that differs depending on the number of revolutions of the optical disc in a short time. The purpose is to provide.

  The present invention has been made to solve the above-described problems, and includes a rotation driving unit that rotates an optical disc, a light source that emits laser light, an objective lens that collects laser light, and an objective lens that has a radius of the optical disc. An objective lens driving unit that tilts in a direction, a light receiving unit that receives reflected light from the optical disc via the objective lens, a signal generating unit that generates an RF signal based on the reflected light received by the light receiving unit, and an amplitude of the RF signal Signal amplitude measuring means for measuring the amount, storage means for storing the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc and a predetermined position of the optical disc, and the amplitude amount of the RF signal at the predetermined position of the optical disc is maximized The driving value of the objective lens driving means corresponding to the warp amount of the optical disk according to the rotational speed of the optical disk is determined from the driving value of the objective lens driving means. And a predetermined position is two positions, a first predetermined position and a second predetermined position, and the control means rotates the optical disc at a first rotational speed corresponding to the first predetermined position to thereby form a first predetermined position. The first driving value of the objective lens driving means corresponding to the position is determined, and the optical disk is rotated at the second rotational speed corresponding to the second predetermined position, so that the second driving of the objective lens driving means corresponding to the second predetermined position is performed. An object in a region sandwiched between the first predetermined position and the second predetermined position from the first driving value, the second driving value, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. The driving value of the lens driving means is determined.

  The present invention also provides a rotation driving means for rotating an optical disk, a light source for emitting laser light, an objective lens for condensing the laser light, an objective lens driving means for tilting the objective lens in the radial direction of the optical disk, and an objective lens. A light receiving means for receiving reflected light from the optical disc, a signal generating means for generating an RF signal based on the reflected light received by the light receiving means, a jitter detection circuit for detecting and digitizing a jitter component from the RF signal, From the driving value of the storage means for storing the rotational speed of the optical disk corresponding to the recording or reproducing position of the optical disk and the predetermined position of the optical disk, and the objective lens driving means for minimizing the jitter component at the predetermined position of the optical disk to the rotational speed of the optical disk And a control means for determining a drive value of the objective lens drive means corresponding to the warp amount of the corresponding optical disk, and the predetermined position is the first position. The first driving of the objective lens driving means corresponding to the first predetermined position by rotating the optical disc at the first rotational speed corresponding to the first predetermined position by the control means, which is a fixed position and a second predetermined position. A second driving value of the objective lens driving means corresponding to the second predetermined position is determined by rotating the optical disc at a second rotational speed corresponding to the second predetermined position, and the first driving value and the second driving value are determined. The driving value of the objective lens driving means in the region sandwiched between the first predetermined position and the second predetermined position is determined from the driving value and the rotational speed of the optical disk corresponding to the recording or reproducing position of the optical disk. It is what.

  According to the above configuration, the present invention has the first driving value corresponding to the first predetermined position, the second driving value corresponding to the second predetermined position, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. Since the driving value of the objective lens driving means in the region sandwiched between the first predetermined position and the second predetermined position is determined, the number of times the driving value is measured by actually rotating the optical disk can be suppressed. As a result, it is possible to realize an optical disc apparatus and a tilt control method thereof that determine a driving value of an objective lens driving unit that varies depending on the rotational speed of the optical disc in a short time.

  The invention according to claim 1 is a rotation driving means for rotating an optical disk, a light source for emitting laser light, an objective lens for condensing the laser light, an objective lens driving means for tilting the objective lens in the radial direction of the optical disk, Light receiving means for receiving reflected light from the optical disc via the objective lens, signal generating means for generating an RF signal based on the reflected light received by the light receiving means, and signal amplitude amount measuring means for measuring the amplitude amount of the RF signal And a storage means for storing the rotation speed of the optical disk corresponding to the recording or reproducing position of the optical disk and a predetermined position of the optical disk, and a driving value of the objective lens driving means that maximizes the amplitude of the RF signal at the predetermined position of the optical disk. Control means for determining a driving value of the objective lens driving means corresponding to the warp amount of the optical disk in accordance with the rotational speed of the optical disk, and the predetermined position is The first predetermined position and the second predetermined position, and the control means rotates the optical disc at a first rotational speed corresponding to the first predetermined position, and the first objective lens driving means corresponding to the first predetermined position A driving value is determined, and the optical disk is rotated at a second rotational speed corresponding to the second predetermined position to determine a second driving value of the objective lens driving means corresponding to the second predetermined position, and the first driving value, The driving value of the objective lens driving means in the region sandwiched between the first predetermined position and the second predetermined position is determined from the two driving values and the rotational speed of the optical disk corresponding to the recording or reproducing position of the optical disk. It is a thing. Thus, the first predetermined position is obtained from the first drive value corresponding to the first predetermined position, the second drive value corresponding to the second predetermined position, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. Since the driving value of the objective lens driving means in the region sandwiched between and the second predetermined position is determined, the number of times the driving value is measured by actually rotating the optical disk can be suppressed. As a result, it is possible to realize an optical disc apparatus that determines the driving value of different objective lens driving means in a short time according to the rotational speed of the optical disc.

  According to the second aspect of the present invention, the number of rotations of the optical disk corresponding to the recording or reproducing position of the optical disk is represented by two functions of the first function and the second function, and the first function records or reproduces the optical disk. This corresponds to the case where the position is on the inner circumference side, the rotation speed of the optical disc is constant regardless of the recording or reproduction position of the optical disc, and the second function corresponds to the case where the recording or reproduction position of the optical disc is on the outer circumference side. However, the number of rotations becomes smaller as the recording or reproducing position of the optical disk becomes the outer peripheral side. As a result, the difference between the rotation speed on the inner circumference side and the rotation speed on the outer circumference side of the optical disk is reduced, so the time required for changing from the rotation speed on the inner circumference side to the rotation speed on the outer circumference side, or It is possible to reduce the time for changing to the rotation speed on the side. As a result, it is possible to determine the driving value of the objective lens driving means that varies depending on the rotational speed of the optical disc in a shorter time. Also, since the difference between the rotational speed on the inner peripheral side and the rotational speed on the outer peripheral side of the optical disk is reduced, the power to change from the rotational speed on the inner peripheral side to the rotational speed on the outer peripheral side, The power to be changed to the number of rotations can be reduced.

  The invention according to claim 3 is characterized in that the threshold value for discriminating between the inner and outer peripheral sides of the optical disc is a recording or reproducing position of the optical disc at which the rotational speed of the optical disc is the maximum rotational speed of the rotation driving means. It is. This increases the frequency with which the rotation driving means rotates the optical disk at the maximum number of rotations, so that the drive value of the objective lens driving means that differs depending on the number of rotations of the optical disk can be determined in a shorter time, and recording or reproduction of the optical disk can be performed. This time can be reduced.

  According to a fourth aspect of the present invention, the storage means stores a first constant that is multiplied by the first drive value, and the control means multiplies the first drive value by the first constant to obtain a third drive value, which is at the first predetermined position. The driving value of the objective lens driving means corresponding to the outer peripheral side of the optical disk is calculated from the corresponding third driving value and the second driving value corresponding to the second predetermined position. As a result, the recording area of the optical disc is divided into the inner circumference side and the outer circumference side, and the driving value of the outer circumference side area of the optical disc is calculated from the third driving value and the second driving value. Thus, the number of times the drive value is measured can be suppressed.

  According to a fifth aspect of the present invention, the storage means stores a second constant that is multiplied by the second drive value, and the control means multiplies the second drive value by the second constant to obtain a fourth drive value, which is at the first predetermined position. The driving value of the objective lens driving unit corresponding to the inner peripheral side of the optical disc is calculated from the corresponding first driving value and the fourth driving value corresponding to the second predetermined position. As a result, the recording area of the optical disc is divided into the inner circumference side and the outer circumference side, and the drive value of the inner circumference side area of the optical disc is calculated from the first drive value and the fourth drive value. It is possible to suppress the number of times of rotating and measuring the drive value.

  The invention according to claim 6 is a rotation driving means for rotating the optical disk, a light source for emitting laser light, an objective lens for condensing the laser light, and objective lens driving means for tilting the objective lens in the radial direction of the optical disk; Light receiving means for receiving the reflected light from the optical disc through the objective lens, signal generating means for generating an RF signal based on the reflected light received by the light receiving means, and jitter detection for detecting and digitizing the jitter component from the RF signal A circuit, a storage means for storing the rotational speed of the optical disk corresponding to the recording or reproducing position of the optical disk and a predetermined position of the optical disk, and a driving value of the objective lens driving means that minimizes the jitter component at the predetermined position of the optical disk. Control means for determining a driving value of the objective lens driving means corresponding to the amount of warp of the optical disc according to the rotational speed, and a predetermined position The first predetermined position and the second predetermined position, and the control means rotates the optical disc at a first rotational speed corresponding to the first predetermined position, and the objective lens driving means corresponding to the first predetermined position 1 driving value is determined, the optical disk is rotated at a second rotational speed corresponding to the second predetermined position, the second driving value of the objective lens driving means corresponding to the second predetermined position is determined, and the first driving value; Determining the driving value of the objective lens driving means in the region sandwiched between the first predetermined position and the second predetermined position from the second driving value and the rotational speed of the optical disk corresponding to the recording or reproducing position of the optical disk. It is a feature. Thus, the first predetermined position is obtained from the first drive value corresponding to the first predetermined position, the second drive value corresponding to the second predetermined position, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. Since the driving value of the objective lens driving means in the region sandwiched between and the second predetermined position is determined, the number of times the driving value is measured by actually rotating the optical disk can be suppressed. As a result, it is possible to realize an optical disc apparatus that determines the driving value of different objective lens driving means in a short time according to the rotational speed of the optical disc.

  According to the seventh aspect of the invention, the drive value of the objective lens corresponding to the amount of warp of the optical disk according to the rotation speed of the optical disk is determined from the inclination of the objective lens at which the amplitude of the RF signal is maximized at a predetermined position of the optical disk. A tilt control method for an optical disk device, wherein the predetermined position is two positions, a first predetermined position and a second predetermined position, and the optical disk is rotated at a first rotational speed corresponding to the first predetermined position to thereby obtain a first predetermined position. The first driving value for correcting the tilt of the objective lens corresponding to the second is determined, and the optical disc is rotated at the second rotational speed corresponding to the second predetermined position to correct the tilt of the objective lens corresponding to the second predetermined position. An area sandwiched between the first predetermined position and the second predetermined position based on the first driving value, the second driving value, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. In It is characterized in determining a drive value of the objective lens driving means. Thus, the first predetermined position is obtained from the first drive value corresponding to the first predetermined position, the second drive value corresponding to the second predetermined position, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. Since the driving value of the objective lens driving means in the region sandwiched between and the second predetermined position is determined, the number of times the driving value is measured by actually rotating the optical disk can be suppressed. As a result, it is possible to realize a tilt control method for the optical disc apparatus that determines the drive value of the objective lens drive means that varies depending on the rotational speed of the optical disc in a short time.

  According to an eighth aspect of the present invention, an optical disc that determines a drive value for driving an objective lens corresponding to the amount of warpage of the optical disc according to the number of revolutions of the optical disc is determined from the inclination of the objective lens at which a jitter component is minimized at a predetermined position of the optical disc. A tilt control method for an apparatus, wherein the predetermined position is two positions, a first predetermined position and a second predetermined position, and the optical disk is rotated at a first rotational speed corresponding to the first predetermined position to be set to the first predetermined position. A first drive value for correcting the tilt of the corresponding objective lens is determined, and the optical disk is rotated at a second rotational speed corresponding to the second predetermined position to correct the tilt of the objective lens corresponding to the second predetermined position. A drive value is determined, and an area between the first predetermined position and the second predetermined position is determined based on the first drive value, the second drive value, and the rotational speed of the optical disk corresponding to the recording or reproducing position of the optical disk. Oh It is characterized in determining a drive value of the objective lens driving unit that. Thus, the first predetermined position is obtained from the first drive value corresponding to the first predetermined position, the second drive value corresponding to the second predetermined position, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. Since the driving value of the objective lens driving means in the region sandwiched between and the second predetermined position is determined, the number of times the driving value is measured by actually rotating the optical disk can be suppressed. As a result, it is possible to realize a tilt control method for the optical disc apparatus that determines the drive value of the objective lens drive means that varies depending on the rotational speed of the optical disc in a short time.

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram of an optical disc apparatus according to Embodiment 1 of the present invention. In FIG. 1, 1 is a light source, 2 is an objective lens, 3 is a lens holder, 4a is a focus actuator, 4b is a tilt actuator, 4c is a tracking actuator, 5 is a photodetector, 6 is a spindle motor, 7 is a feed motor, 8 Is a focus error signal generation circuit, 9 is a tracking error signal generation circuit, 10 is a focus servo circuit, 11 is a signal amplitude measurement circuit, 12 is a memory, 13 is a CPU, 14 is a laser control unit, 15 is a driver, 16 is tracking A servo circuit, 17 is an RF signal generation circuit, 18 is a jitter detection circuit, 50 is an optical disk, 100 is an optical head unit, and 200 is a pickup module. In the first embodiment, the rotation driving means is the spindle motor 6, the light source is the light source 1, the objective lens is the objective lens 2, the objective lens driving means is the tilt actuator 4b, the light receiving means is the photodetector 5, and the signal generating means is RF. The signal generation circuit 17, the signal amplitude amount measurement means correspond to the signal amplitude amount measurement circuit 11, the storage means corresponds to the memory 12, and the control means corresponds to the CPU 13.

  The pickup module 200 includes a spindle motor 6 that rotates the optical disc 50, an optical head unit 100 that irradiates the optical disc 50 with light and receives reflected light from the optical disc 50, and moves the optical head unit 100 in the radial direction of the optical disc 50. And a feed section provided with a feed motor 7.

  The optical head unit 100 includes a light source 1 that emits laser light, an objective lens 2 that condenses the laser light emitted from the light source 1, a lens holder 3 that holds the objective lens 2 so as to be movable, and an objective lens. A photodetector 5 that receives reflected light from the optical disc 50 via 2, a focus actuator 4 a that drives the objective lens 2 in the focus direction, a tilt actuator 4 b that tilts the objective lens 2 in the radial direction of the optical disc 50, and an objective And a tracking actuator 4c for moving the lens 2 in the radial direction of the optical disk 50.

  The focus actuator 4a is provided with a focus adjustment coil, a magnet, and the like, and adjusts the focus of the objective lens 2 by driving the lens holder 3 in the focus direction by passing a current through the focus adjustment coil.

  The tilt actuator 4b is provided with a tilt adjustment coil, a magnet, and the like, and tilts the lens holder 3 in the radial direction of the optical disc 50 to adjust the tilt of the objective lens 2 by passing a current through the tilt adjustment coil.

  The tracking actuator 4c is provided with a tracking adjustment coil, a magnet, and the like, and moves the lens holder 3 in the radial direction of the optical disc 50 by passing an electric current through the tracking adjustment coil to perform tracking adjustment of the objective lens 2.

  The photodetector 5 receives the reflected light from the optical disc 50, generates an electrical signal corresponding to the received light quantity, and uses the generated electrical signal as the focus error signal generation circuit 8, the tracking error signal generation circuit 9, and the RF. The signal is output to the signal generation circuit 17.

  The focus error signal generation circuit 8 generates a focus error signal from the electrical signal input from the photodetector 5 and outputs the focus error signal to the focus servo circuit 10. The tracking error signal generation circuit 9 generates a tracking error signal from the electrical signal input from the photodetector 5 and outputs the tracking error signal to the tracking servo circuit 16 and the CPU 13. Further, the RF signal generation circuit 17 generates an RF signal from the electrical signal input from the photodetector 5 and outputs the RF signal to the signal amplitude measurement circuit 11 and the jitter detection circuit 18.

  The focus servo circuit 10 determines a current to flow through the focus adjustment coil provided in the focus actuator 4 a based on the focus error signal input from the focus error signal generation circuit 8 and outputs the current to the CPU 13. The tracking servo circuit 16 determines a current necessary for causing the objective lens 2 to follow the track on the optical disc 50 based on the tracking error signal input from the tracking error signal generation circuit 9 and outputs the current to the CPU 13. .

  The signal amplitude measurement circuit 11 measures the amplitude amount of the RF signal input from the RF signal generation circuit 17 and outputs the measured amplitude amount to the CPU 13.

  The jitter detection circuit 18 detects a jitter component of the RF signal input from the RF signal generation circuit 17, digitizes the jitter component, and outputs it to the CPU 13.

  The memory 12 stores the number of rotations of the optical disc 50 corresponding to the recording or reproducing position of the optical disc 50, a predetermined position for measuring the drive value of the tilt actuator 4b, a constant for multiplying the measured drive value of the tilt actuator 4b, Information on the boundary position dividing the inner peripheral side and the outer peripheral side is stored.

  Here, the characteristic part of this invention is demonstrated.

  When the CPU 13 determines the drive value of the tilt actuator 4b corresponding to the warp amount of the optical disk 50 according to the rotational speed of the optical disk 50, the CPU 13 reads information on a predetermined position of the optical disk 50 that determines the drive value from the memory 12. The information on the predetermined position of the optical disc 50 is two pieces of information on the first predetermined position and the second predetermined position. In the first embodiment, the first predetermined position is a position away from the center of the optical disk 50 by a radius of about 25 mm, and the second predetermined position is a position away from the center of the optical disk 50 by a radius of about 58 mm.

  Then, the CPU 13 moves the objective lens 2 to the first predetermined position via the driver 15, rotates the optical disc 50 at a rotation speed corresponding to the first predetermined position, and drives the tilt actuator 4b to move the objective lens 2 to the optical disc. Tilt to 50 radial directions. The direction in which the objective lens 2 is tilted is such that the light exit surface of the objective lens 2 is directed from the neutral position of the objective lens 2 toward the inner peripheral side of the optical disc 50 and the light exit surface of the objective lens 2 is from the neutral position of the objective lens 2 to the optical disc. The direction is toward the outer peripheral side of 50. At this time, the CPU 13 monitors the amplitude amount of the RF signal output from the signal amplitude amount measurement circuit 11, searches for the drive value of the tilt actuator 4b that maximizes the amplitude amount of the RF signal, and performs the first predetermined operation. A first drive value of the tilt actuator 4b corresponding to the position is determined.

  Next, the CPU 13 moves the objective lens 2 to the second predetermined position via the driver 15, rotates the optical disc 50 at a rotation speed corresponding to the second predetermined position, and drives the tilt actuator 4 b to move the objective lens 2. The optical disc 50 is tilted in the radial direction. The direction in which the objective lens 2 is tilted is such that the light exit surface of the objective lens 2 is directed from the neutral position of the objective lens 2 toward the inner peripheral side of the optical disc 50 and the light exit surface of the objective lens 2 is from the neutral position of the objective lens 2 to the optical disc. The direction is toward the outer peripheral side of 50. At this time, the CPU 13 monitors the amplitude amount of the RF signal output from the signal amplitude amount measuring circuit 11, searches for the drive value of the tilt actuator 4b that maximizes the amplitude amount of the RF signal, and performs a second predetermined operation. A second drive value of the tilt actuator 4b corresponding to the position is determined.

  Here, since the warp corresponding to the rotational speed of the optical disk 50 occurs in a direction in which the optical disk 50 moves away from the objective lens 2, the direction in which the objective lens 2 is tilted by driving the tilt actuator 4b is changed from the neutral position of the objective lens 2 to the objective. By setting the surface of the lens 2 toward the inner peripheral side of the optical disc 50, the time can be shortened.

  Thereafter, the CPU 13 is an area sandwiched between the first predetermined position and the second predetermined position from the first driving value, the second driving value, and the rotational speed of the optical disc 50 corresponding to the recording or reproducing position of the optical disc 50. The drive value of the tilt actuator 4b is determined.

  In the first embodiment, the CPU 13 monitors the amplitude amount of the RF signal output from the signal amplitude amount measuring circuit 11, and searches for the drive value of the tilt actuator 4b that maximizes the amplitude amount of the RF signal. Thus, although the first drive value and the second drive value of the tilt actuator 4b are determined, the method for determining the first drive value and the second drive value is not limited to this. For example, the jitter detection circuit 18 detects and digitizes a jitter component from the input RF signal, monitors the digitized jitter component, and sets the drive value of the tilt actuator 4b that minimizes the jitter component. The first drive value and the second drive value of the tilt actuator 4b may be determined by searching. In this case, an effect similar to that in the case of searching for the drive value of the tilt actuator 4b that maximizes the amplitude of the RF signal can be obtained.

  Next, a method for determining the driving value of the objective lens driving means in a region sandwiched between the first predetermined position and the second predetermined position will be specifically described with reference to FIGS.

  FIG. 2 is a diagram showing the relationship among the radial position of the optical disc, the rotational speed of the optical disc, and the drive value of the tilt actuator in Embodiment 1 of the present invention. FIG. 2A is a diagram showing the relationship between the radial position of the optical disk and the rotational speed of the optical disk. The horizontal axis represents the radial position of the optical disk, and the vertical axis represents the rotational speed of the optical disk. FIG. 2B is a diagram showing the relationship between the radial position of the optical disc and the drive value of the tilt actuator. The horizontal axis is the radial position of the optical disc, and the vertical axis is the drive value of the tilt actuator.

  The CPU 13 reads the information on the first predetermined position a1 and the information on the second predetermined position a2 from the memory 12. In the first embodiment, the first predetermined position a1 is a position with a radius of about 25 mm from the center of the optical disk 50, and the second predetermined position a2 is a position with a radius of about 58 mm from the center of the optical disk 50. Here, the first predetermined position in FIG. 2 corresponds to the first predetermined position a1, and the second predetermined position corresponds to the second predetermined position a2.

  The CPU 13 moves the objective lens 2 to the first predetermined position a1, rotates the optical disc 50 at the rotational speed b1 of the optical disc 50 corresponding to the first predetermined position a1 shown in FIG. 2A, and drives the tilt actuator 4b. Then, the objective lens 2 is tilted in the radial direction of the optical disc 50. At this time, the amplitude amount of the RF signal output from the signal amplitude amount measurement circuit 11 is monitored, and the drive value of the tilt actuator 4b that maximizes the amplitude amount of the RF signal is searched. As a result of this search, the drive value of the tilt actuator 4b that maximizes the amplitude of the RF signal is set as the first drive value c1 of the tilt actuator 4b. The relationship between the first drive value c1 and the first predetermined position a1 is as shown in FIG.

  Then, the CPU 13 moves the objective lens 2 to the second predetermined position a2, rotates the optical disc 50 at the rotational speed b2 of the optical disc 50 corresponding to the second predetermined position a2 shown in FIG. 2A, and moves the tilt actuator 4b. By driving, the objective lens 2 is tilted in the radial direction of the optical disk 50. At this time, the amplitude amount of the RF signal output from the signal amplitude amount measurement circuit 11 is monitored, and the drive value of the tilt actuator 4b that maximizes the amplitude amount of the RF signal is searched. As a result of this search, the drive value of the tilt actuator 4b that maximizes the amplitude of the RF signal is set as the second drive value c2 of the tilt actuator 4b. The relationship between the second drive value c2 and the second predetermined position a2 is as shown in FIG.

  FIG. 3 is a diagram showing the relationship among the radial position of the optical disc, the rotational speed of the optical disc, and the drive value of the tilt actuator in Embodiment 1 of the present invention, and is a continuation of FIG. The horizontal axis in FIG. 3A is the radial position of the optical disk, the vertical axis is the rotational speed of the optical disk, the horizontal axis in FIG. 3B is the radial position of the optical disk, and the vertical axis is the drive value of the tilt actuator.

  The CPU 13 reads from the memory 12 information on the boundary position that separates the inner and outer peripheral sides of the optical disc 50. In the first embodiment, the boundary position that divides the inner peripheral side and the outer peripheral side of the optical disc 50 is set to a radius of about 45 mm from the center of the optical disc 50. Here, the range from the first predetermined position a1 to the boundary position a3 is the inner peripheral side of the optical disc 50, and the range from the boundary position a3 to the second predetermined position a2 is the outer peripheral side of the optical disc 50. And In the first embodiment, the threshold for distinguishing the A zone and the B zone is the recording or reproducing position of the optical disc 50 at which the rotational speed of the optical disc 50 is the maximum rotational speed of the spindle motor 6. This increases the frequency with which the spindle motor 6 rotates the optical disk 50 at the maximum number of rotations. Therefore, the drive value of the tilt actuator that differs depending on the number of rotations of the optical disk 50 is determined in a shorter time, and recording or reproduction of the optical disk 50 is performed. Can reduce the time it takes.

  The CPU 13 reads from the memory 12 information on the number of revolutions of the optical disc 50 corresponding to the recording or reproducing position of the optical disc 50. In the first embodiment, the rotation speed of the optical disc 50 corresponding to the recording or reproducing position of the optical disc 50 is represented by two functions, a first function and a second function, and the first function is the A zone shown in FIG. The second function corresponds to the B zone shown in FIG. In the first function, the rotational speed of the optical disk 50 is constant regardless of the recording or reproducing position of the optical disk 50, and in the second function, the rotational speed decreases as the recording or reproducing position of the optical disk 50 becomes the outer peripheral side. As a result, the difference between the rotation speed on the inner circumference side and the rotation speed on the outer circumference side of the optical disk 50 is reduced, so that the time required for changing from the rotation speed on the inner circumference side to the rotation speed on the outer circumference side or the rotation speed on the outer circumference side is reduced. The time required for changing to the rotation speed on the circumferential side can be reduced. As a result, it is possible to determine the driving value of the objective lens driving means that varies depending on the rotational speed of the optical disc 30 in a shorter time. Also, since the difference between the rotational speed on the inner peripheral side and the rotational speed on the outer peripheral side of the optical disk is reduced, the power to change from the rotational speed on the inner peripheral side to the rotational speed on the outer peripheral side, or from the rotational speed on the outer peripheral side to the inner peripheral side It is possible to reduce the power to be changed to the number of rotations.

  FIG. 4 is a diagram showing the relationship among the radial position of the optical disc, the rotational speed of the optical disc, and the drive value of the tilt actuator in Embodiment 1 of the present invention, and is a continuation of FIG. The horizontal axis in FIG. 4A is the radial position of the optical disk, the vertical axis is the rotational speed of the optical disk, the horizontal axis in FIG. 4B is the radial position of the optical disk, and the vertical axis is the drive value of the tilt actuator.

  The CPU 13 reads the first constant k1 from the memory 12. Here, the first constant k1 is a constant in which the radial position of the optical disc 50 corresponds to the A zone, and is called a rotation speed correction coefficient, and is a change amount of the drive value of the tilt actuator 4b per one rotation of the optical disc. Further, the first constant k1 is priced to be one point on the second function by multiplying the first driving value c1 by the first constant k1.

  Then, the CPU 13 multiplies the first drive value c1 by the first constant k1 to calculate a third drive value c3 that is located on the extension line of the second function and that corresponds to the first predetermined position a1. In the first embodiment, since the second function is a linear function, the third drive value c3 corresponding to the first predetermined position a1 and the second drive value c2 corresponding to the second predetermined position a2 in FIG. The drive value of the tilt actuator 4b corresponding to the outer peripheral side of the optical disc 50 can be calculated from the straight line connecting In the case of the first embodiment, if the drive value of the tilt actuator 4b corresponding to the outer peripheral side of the optical disc 50 is cy and the radial position of the optical disc 50 is ax, the second function can be expressed by the following equation.

cy = (c2−c3) / (a2−a1) × ax + (a1 × c2−a2 × c3) / (a2−a1) (where a3 ≦ ax ≦ a2) (Formula 1)
Thus, the CPU 13 multiplies the first driving value c1 by the first constant k1 to obtain the third driving value c3, and the third driving value c3 corresponding to the first predetermined position a1 and the second driving position c2 corresponding to the second predetermined position a2. The drive value of the tilt actuator 4b corresponding to the outer peripheral side of the optical disc 50 is calculated from the two drive values c2. Thus, the recording area of the optical disc 50 is divided into the inner peripheral side and the outer peripheral side, and the drive value of the outer peripheral side region of the optical disc 50 is calculated from the third drive value and the second drive value. It is possible to reduce the number of times the drive value is measured by rotating it to the right.

  Next, the CPU 13 reads the second constant k2 from the memory 12. Here, the second constant k2 is a constant in which the radial position of the optical disc 50 corresponds to the B zone, and is called a rotation speed correction coefficient, and is a change amount of the drive value of the tilt actuator 4b per one rotation of the optical disc. Further, the second constant k2 is priced to be one point on the first function by multiplying the second driving value c2 by the second constant k2.

  Then, the CPU 13 multiplies the second drive value c2 by the second constant k2 to calculate a fourth drive value c4 that is located on the extension line of the first function and that corresponds to the second predetermined position a2. In the first embodiment, since the first function is a linear function, the first drive value c1 corresponding to the first predetermined position a1 and the fourth drive value c4 corresponding to the second predetermined position a2 in FIG. The drive value of the tilt actuator 4b corresponding to the inner peripheral side of the optical disc 50 can be calculated from the straight line connecting In the case of the first embodiment, if the drive value of the tilt actuator 4b corresponding to the inner peripheral side of the optical disc 50 is cy and the radial position of the optical disc 50 is ax, the first function can be expressed by the following equation. .

cy = (c4−c1) / (a2−a1) × ax + (a2 × c1−a1 × c4) / (a2−a1) (where a1 ≦ ax ≦ a3) (Formula 2)
Thus, the CPU 13 multiplies the second driving value c2 by the second constant k2 to obtain the fourth driving value c4, and the first driving value c1 corresponding to the first predetermined position a1 and the second driving value c2 corresponding to the second predetermined position a2. The drive value of the tilt actuator 4b corresponding to the inner peripheral side of the optical disc 50 is calculated from the four drive values c4. Thus, the recording area of the optical disc 50 is divided into the inner peripheral side and the outer peripheral side, and the drive value of the inner peripheral side region of the optical disc 50 is calculated from the third drive value and the second drive value. The number of times that the drive value of the drive value is measured by actually rotating can be suppressed.

  FIG. 5 is a diagram showing the relationship among the radial position of the optical disc, the drive value of the tilt actuator, and the position of the objective lens in Embodiment 1 of the present invention. FIG. 5A is a diagram showing the relationship between the radial position of the optical disc and the rotational speed of the optical disc, and FIGS. 5B to 5C are diagrams showing the relationship between the optical disc and the objective lens. The horizontal axis in FIG. 5A is the radial position of the optical disk, the vertical axis is the rotational speed of the optical disk, and FIG. 5B shows the case where the objective lens 2 is positioned closer to the inner side of the A zone shown in FIG. FIG. 5C shows a case where the objective lens 2 is located outside the A zone shown in FIG.

  As shown in FIG. 5A, when the objective lens 2 is positioned in the zone A of the optical disc 50, the rotational speed of the optical disc 50 is related to the recording or reproducing position of the optical disc 50, that is, the position of the objective lens 2. It is constant. However, the optical disk 50 has some warping even when it is not rotated, that is, when it is stationary.

  For this reason, when the objective lens 2 is positioned in the area of the A zone of the optical disc 50, as shown in FIGS. 5B to 5C, it corresponds to the warp amount of the optical disc 50 according to the rotational speed of the optical disc 50. The drive value of the tilt actuator 4b to be made variable is obtained from the drive value obtained in FIG. 4, that is, the first drive value c1 corresponding to the first predetermined position a1 and the fourth drive value c4 corresponding to the second predetermined position a2. Tilt control of the objective lens 2 is performed using the obtained drive value.

  FIG. 6 is a diagram showing the relationship among the radial position of the optical disc, the drive value of the tilt actuator, and the position of the objective lens in Embodiment 1 of the present invention. FIG. 6A is a diagram showing the relationship between the radial position of the optical disc and the rotational speed of the optical disc, and FIGS. 6B to 6D are diagrams showing the relationship between the optical disc and the objective lens. The horizontal axis of FIG. 6A is the radial position of the optical disk, the vertical axis is the rotational speed of the optical disk, and FIG. 6B shows the case where the objective lens 2 is located closer to the inner side of the B zone shown in FIG. 6C shows a case where the objective lens 2 is located in the middle of the B zone shown in FIG. 4, and FIG. 6D shows that the objective lens 2 is located outside the B zone shown in FIG. Shows the case.

  As shown in FIG. 6A, when the objective lens 2 is located in the B zone region of the optical disc 50, the rotational speed of the optical disc 50 is such that the recording or reproducing position of the optical disc 50 is closer to the outer peripheral side, ie, the objective lens. 2 becomes smaller as it is located on the outer peripheral side of the optical disk 50.

  For this reason, when the objective lens 2 is positioned in the inner region of the B zone of the optical disc 50, the warp amount of the optical disc 50 corresponding to the rotational speed of the optical disc 50 is obtained as shown in FIGS. 6 (b) to 6 (d). The drive value of the corresponding tilt actuator 4b is variable, and from the drive value obtained in FIG. 4, that is, the third drive value c3 corresponding to the first predetermined position a1 and the second drive value c2 corresponding to the second predetermined position a2. Tilt control of the objective lens 2 is performed using the obtained drive value.

  FIG. 7 is a flowchart for determining the drive value of the tilt actuator according to the first embodiment of the present invention. FIG. 7 shows a case where the drive value of the tilt actuator 4b that maximizes the amplitude of the RF signal is searched to determine the first drive value and the second drive value of the tilt actuator 4b.

  When the optical disk 50 is loaded in the optical disk apparatus, the CPU 13 rotates the spindle motor 6 via the driver 15 and causes the light source 1 to emit light via the driver 15 and the laser controller 14 (S101). Then, the CPU 13 reads from the memory 12 information relating to the first predetermined position a1, the information relating to the second predetermined position a2, and information relating to the rotational speed of the optical disc 50 corresponding to the recording or reproducing position of the optical disc 50 shown in FIG. (S102). Then, the CPU 13 moves the objective lens 2 to the first predetermined position a1 of the optical disk 50 via the driver 15, and rotates the optical disk 50 at the rotation speed b1 corresponding to the first predetermined position a1 (S103). Thereafter, the CPU 13 changes the tilt of the objective lens 2 by changing the drive value of the tilt actuator 4 b via the driver 15, and then passes through the photodetector 5, the RF signal generation circuit 17, and the signal amplitude measurement circuit 11. The amplitude of the RF signal is measured (S104). The CPU 13 detects the RF signal having the maximum amplitude from the measured RF signal, and the first drive value c1 when the drive value of the tilt actuator 4b corresponding to the amplitude amount is recorded or reproduced at the first predetermined position a1. (S105). The first drive value c1 is a drive value that can correct the influence of the warp that occurs at the first predetermined position a1 when the optical disk 50 is rotated at the rotation speed b1.

  Next, the CPU 13 moves the objective lens 2 to the second predetermined position a2 of the optical disk 50 via the driver 15, and rotates the optical disk 50 at the rotation speed b2 corresponding to the second predetermined position a2 (S106). Thereafter, the CPU 13 changes the tilt of the objective lens 2 by changing the drive value of the tilt actuator 4 b via the driver 15, and then passes through the photodetector 5, the RF signal generation circuit 17, and the signal amplitude measurement circuit 11. The amount of amplitude of the RF signal is measured (S107). The CPU 13 detects the maximum amplitude among the measured RF signals, and the second drive value c2 when the drive value of the tilt actuator 4b corresponding to the amplitude amount is recorded or reproduced at the second predetermined position a2. (S108). The second drive value c2 is a drive value that can correct the influence of the warp that occurs at the second predetermined position a2 when the optical disk 50 is rotated at the rotation speed b2.

  Next, the CPU 13 reads the first constant k1 and the second constant from the memory 12 (S109). Here, the first constant k1 is a constant in which the radial position of the optical disc 50 corresponds to the A zone, and is called a rotation speed correction coefficient, and is a change amount of the drive value of the tilt actuator 4b per one rotation of the optical disc. Further, the first constant k1 is priced to be one point on the second function by multiplying the first driving value c1 by the first constant k1. The second constant k2 is a constant in which the radial position of the optical disc 50 corresponds to the B zone, and is called a rotational speed correction coefficient, and is a change amount of the drive value of the tilt actuator 4b per one rotation of the optical disc. Further, the second constant k2 is priced to be one point on the first function by multiplying the second driving value c2 by the second constant k2.

  Then, the CPU 13 multiplies the first driving value c1 by the first constant k1 to calculate a third driving value c3 that is located on the extension line of the second function and that corresponds to the first predetermined position a1. Further, the CPU 13 multiplies the second drive value c2 by the second constant k2 to calculate a fourth drive value c4 that is located on the extension line of the first function and that corresponds to the second predetermined position a2 (S110).

  Then, as shown in FIG. 4, the CPU 13 moves from the straight line connecting the third drive value c3 corresponding to the first predetermined position a1 and the second drive value c2 corresponding to the second predetermined position a2 to the outer peripheral side of the optical disc 50. The drive value of the corresponding tilt actuator 4b is calculated (S111). Further, as shown in FIG. 4, the CPU 13, on the inner peripheral side of the optical disc 50, from a straight line connecting the first drive value c1 corresponding to the first predetermined position a1 and the fourth drive value c4 corresponding to the second predetermined position a2. The drive value of the tilt actuator 4b corresponding to is calculated (S112).

  Thereafter, the CPU 13 sets the calculated drive value corresponding to the inner peripheral side of the optical disc 50 and the drive value corresponding to the outer peripheral side of the optical disc 50 in the driver 15 to drive the tilt actuator 4b (S113), and rotates the optical disc 50. The objective lens 2 is controlled while reducing the influence of warping according to the number.

  FIG. 8 is a flowchart for determining the drive value of the tilt actuator according to the first embodiment of the present invention. In FIG. 8, the jitter component is detected from the RF signal and digitized, the digitized jitter component is monitored, and the drive value of the tilt actuator 4b that minimizes the jitter component is searched for to search the tilt actuator 4b. The case where the first drive value and the second drive value are determined is shown.

  When the optical disk 50 is loaded in the optical disk apparatus, the CPU 13 rotates the spindle motor 6 via the driver 15 and causes the light source 1 to emit light via the driver 15 and the laser controller 14 (S201). Then, the CPU 13 reads from the memory 12 information relating to the first predetermined position a1, the information relating to the second predetermined position a2, and information relating to the rotational speed of the optical disc 50 corresponding to the recording or reproducing position of the optical disc 50 shown in FIG. (S202). Then, the CPU 13 moves the objective lens 2 to the first predetermined position a1 of the optical disk 50 via the driver 15, and rotates the optical disk 50 at the rotation speed b1 corresponding to the first predetermined position a1 (S203). Thereafter, the CPU 13 changes the drive value of the tilt actuator 4 b via the driver 15 to change the tilt of the objective lens 2, and the RF signal via the photodetector 5, the RF signal generation circuit 17, and the jitter detection circuit 18. The jitter component is measured (S204). The CPU 13 detects the smallest jitter component from the measured jitter components, and the first drive value c1 when the drive value of the tilt actuator 4b corresponding to the jitter component is recorded or reproduced at the first predetermined position a1. (S205). The first drive value c1 is a drive value that can correct the influence of the warp that occurs at the first predetermined position a1 when the optical disk 50 is rotated at the rotation speed b1.

  Next, the CPU 13 moves the objective lens 2 to the second predetermined position a2 of the optical disk 50 via the driver 15, and rotates the optical disk 50 at the rotation speed b2 corresponding to the second predetermined position a2 (S206). Thereafter, the CPU 13 changes the drive value of the tilt actuator 4 b via the driver 15 to change the tilt of the objective lens 2, and the RF signal via the photodetector 5, the RF signal generation circuit 17, and the jitter detection circuit 18. The jitter component is measured (S207). The CPU 13 detects the smallest jitter component from the measured jitter components, and the second driving value c2 when the driving value of the tilt actuator 4b corresponding to the jitter component is recorded or reproduced at the second predetermined position a2. (S208). The second drive value c2 is a drive value that can correct the influence of the warp that occurs at the second predetermined position a2 when the optical disk 50 is rotated at the rotation speed b2.

  Next, the CPU 13 reads the first constant k1 and the second constant from the memory 12 (S209). Here, the first constant k1 is a constant in which the radial position of the optical disc 50 corresponds to the A zone, and is called a rotation speed correction coefficient, and is a change amount of the drive value of the tilt actuator 4b per one rotation of the optical disc. Further, the first constant k1 is priced to be one point on the second function by multiplying the first driving value c1 by the first constant k1. The second constant k2 is a constant in which the radial position of the optical disc 50 corresponds to the B zone, and is called a rotational speed correction coefficient, and is a change amount of the drive value of the tilt actuator 4b per one rotation of the optical disc. Further, the second constant k2 is priced to be one point on the first function by multiplying the second driving value c2 by the second constant k2.

  Then, the CPU 13 multiplies the first driving value c1 by the first constant k1 to calculate a third driving value c3 that is located on the extension line of the second function and that corresponds to the first predetermined position a1. Further, the CPU 13 multiplies the second drive value c2 by the second constant k2 to calculate a fourth drive value c4 that is located on the extension line of the first function and that corresponds to the second predetermined position a2 (S210).

  Then, as shown in FIG. 4, the CPU 13 moves from the straight line connecting the third drive value c3 corresponding to the first predetermined position a1 and the second drive value c2 corresponding to the second predetermined position a2 to the outer peripheral side of the optical disc 50. The drive value of the corresponding tilt actuator 4b is calculated (S211). Further, as shown in FIG. 4, the CPU 13, on the inner peripheral side of the optical disc 50, from a straight line connecting the first drive value c1 corresponding to the first predetermined position a1 and the fourth drive value c4 corresponding to the second predetermined position a2. The drive value of the tilt actuator 4b corresponding to is calculated (S212).

  Thereafter, the CPU 13 sets the calculated drive value corresponding to the inner peripheral side of the optical disc 50 and the drive value corresponding to the outer peripheral side of the optical disc 50 in the driver 15 to drive the tilt actuator 4b (S213), and rotates the optical disc 50. The objective lens 2 is controlled while reducing the influence of warping according to the number.

  As described above, the first driving value c1 corresponding to the first predetermined position a1, the second driving value c2 corresponding to the second predetermined position a2, and the rotation of the optical disc 50 corresponding to the recording or reproducing position of the optical disc 50. The drive value of the tilt actuator 4b in the region sandwiched between the first predetermined position a1 and the second predetermined position a2 is determined from the number, and the number of times the drive value of the drive value is measured by actually rotating the optical disc 50 is determined. Can be suppressed. As a result, it is possible to realize an optical disc apparatus that determines the drive value of the tilt actuator 4b that varies depending on the rotational speed of the optical disc 50 in a short time.

  According to the present invention, since the driving value of the objective lens driving means corresponding to the warp of the optical disk, which varies depending on the rotation speed of the optical disk, can be determined in a short time, the optical disk apparatus for recording and / or reproducing information on the optical disk and its tilt It can be applied to control methods.

1 is a block diagram of an optical disc apparatus according to Embodiment 1 of the present invention. The figure which shows the relationship between the radial position of the optical disk in Embodiment 1 of this invention, the rotation speed of an optical disk, and the drive value of a tilt actuator. The figure which shows the relationship between the radial position of the optical disk in Embodiment 1 of this invention, the rotation speed of an optical disk, and the drive value of a tilt actuator. The figure which shows the relationship between the radial position of the optical disk in Embodiment 1 of this invention, the rotation speed of an optical disk, and the drive value of a tilt actuator. The figure which shows the relationship between the radial position of the optical disk in Embodiment 1 of this invention, the drive value of a tilt actuator, and the position of an objective lens. The figure which shows the relationship between the radial position of the optical disk in Embodiment 1 of this invention, the drive value of a tilt actuator, and the position of an objective lens. The flowchart which determines the drive value of the tilt actuator in Embodiment 1 of this invention The flowchart which determines the drive value of the tilt actuator in Embodiment 1 of this invention The figure which shows the relationship between the radial position of a disk, the rotation speed of an optical disk, and the drive value of a tilt actuator

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Objective lens 3 Lens holder 4a Focus actuator 4b Tilt actuator 4c Tracking actuator 5 Photo detector 6 Spindle motor 7 Feed motor 8 Focus error signal generation circuit 9 Tracking error signal generation circuit 10 Focus servo circuit 11 Signal amplitude amount measurement circuit 12 Memory 13 CPU
DESCRIPTION OF SYMBOLS 14 Laser control part 15 Driver 16 Tracking servo circuit 17 RF signal generation circuit 18 Jitter detection circuit 50 Optical disk 100 Optical head part 200 Pickup module

Claims (8)

Rotation driving means for rotating the optical disc;
A light source that emits laser light;
An objective lens for condensing the laser beam;
Objective lens driving means for tilting the objective lens in the radial direction of the optical disc;
A light receiving means for receiving reflected light from the optical disk through the objective lens;
Signal generating means for generating an RF signal based on the reflected light received by the light receiving means;
Signal amplitude measuring means for measuring the amplitude of the RF signal;
Storage means for storing the number of rotations of the optical disk corresponding to the recording or reproducing position of the optical disk and a predetermined position of the optical disk;
The driving value of the objective lens driving means corresponding to the warping amount of the optical disk according to the rotational speed of the optical disk, from the driving value of the objective lens driving means that maximizes the amplitude of the RF signal at a predetermined position of the optical disk. Control means for determining,
The predetermined position is two positions, a first predetermined position and a second predetermined position,
The control means determines the first drive value of the objective lens driving means corresponding to the first predetermined position by rotating the optical disc at a first rotational speed corresponding to the first predetermined position, and the second predetermined value. A second driving value of the objective lens driving means corresponding to the second predetermined position by rotating the optical disc at a second rotational speed corresponding to the position;
In a region sandwiched between the first predetermined position and the second predetermined position from the first drive value, the second drive value, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. An optical disc apparatus for determining a driving value of the objective lens driving means. The rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc is represented by two functions, a first function and a second function,
The first function corresponds to the case where the recording or reproducing position of the optical disc is on the inner circumference side, and the rotation speed of the optical disc is constant regardless of the recording or reproducing position of the optical disc,
2. The second function according to claim 1, wherein the second function corresponds to a case where a recording or reproducing position of the optical disc is on an outer peripheral side, and a rotational speed decreases as the recording or reproducing position of the optical disc is on the outer peripheral side. Optical disk device. The threshold value that separates the inner circumference side and the outer circumference side of the optical disc is:
3. An optical disc apparatus according to claim 2, wherein the optical disc device is a recording or reproducing position of the optical disc where the rotational speed of the optical disc is the maximum rotational speed of the rotation driving means. The storage means stores a first constant multiplied by the first drive value,
The control means includes
The first driving value is multiplied by the first constant to obtain a third driving value,
Calculating a driving value of the objective lens driving means corresponding to the outer peripheral side of the optical disc from the third driving value corresponding to the first predetermined position and the second driving value corresponding to the second predetermined position; 4. The optical disc apparatus according to claim 3, wherein The storage means stores a second constant to be multiplied by the second drive value,
The control means includes
The second drive value is multiplied by the second constant to obtain a fourth drive value,
A drive value of the objective lens drive unit corresponding to the inner peripheral side of the optical disc is calculated from the first drive value corresponding to the first predetermined position and the fourth drive value corresponding to the second predetermined position. The optical disc apparatus according to claim 4. Rotation driving means for rotating the optical disc;
A light source that emits laser light;
An objective lens for condensing the laser beam;
Objective lens driving means for tilting the objective lens in the radial direction of the optical disc;
A light receiving means for receiving reflected light from the optical disk through the objective lens;
Signal generating means for generating an RF signal based on the reflected light received by the light receiving means;
A jitter detection circuit for detecting and digitizing a jitter component from the RF signal;
Storage means for storing the number of rotations of the optical disk corresponding to the recording or reproducing position of the optical disk and a predetermined position of the optical disk;
A driving value of the objective lens driving unit corresponding to a warp amount of the optical disc corresponding to a rotation speed of the optical disc is determined from a driving value of the objective lens driving unit that minimizes the jitter component at a predetermined position of the optical disc. Control means,
The predetermined position is two positions, a first predetermined position and a second predetermined position,
The control means determines the first drive value of the objective lens driving means corresponding to the first predetermined position by rotating the optical disc at a first rotational speed corresponding to the first predetermined position, and the second predetermined value. A second driving value of the objective lens driving means corresponding to the second predetermined position by rotating the optical disc at a second rotational speed corresponding to the position;
In a region sandwiched between the first predetermined position and the second predetermined position from the first drive value, the second drive value, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. An optical disc apparatus for determining a driving value of the objective lens driving means. A tilt control method for an optical disc apparatus that determines a drive value of the objective lens corresponding to the amount of warp of the optical disc according to the number of rotations of the optical disc from the tilt of the objective lens that maximizes the amplitude of the RF signal at a predetermined position of the optical disc. There,
The predetermined position is two positions, a first predetermined position and a second predetermined position,
Rotating the optical disc at a first rotational speed corresponding to the first predetermined position to determine a first drive value of the objective lens corresponding to the first predetermined position;
Rotating the optical disc at a second rotational speed corresponding to the second predetermined position to determine a second drive value of the objective lens corresponding to the second predetermined position;
In a region sandwiched between the first predetermined position and the second predetermined position from the first drive value, the second drive value, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. A tilt control method for an optical disc apparatus, wherein a drive value of the objective lens driving means is determined. A tilt control method for an optical disc apparatus, which determines a drive value of the objective lens corresponding to an amount of warpage of the optical disc in accordance with the number of revolutions of the optical disc from an inclination of the objective lens at which a jitter component is minimized at a predetermined position of the optical disc,
The predetermined position is two positions, a first predetermined position and a second predetermined position,
Determining a first drive value for correcting the tilt of the objective lens corresponding to the first predetermined position by rotating the optical disc at a first rotational speed corresponding to the first predetermined position;
Rotating the optical disc at a second rotational speed corresponding to the second predetermined position to determine a second drive value of the objective lens corresponding to the second predetermined position;
In a region sandwiched between the first predetermined position and the second predetermined position from the first drive value, the second drive value, and the rotational speed of the optical disc corresponding to the recording or reproducing position of the optical disc. A tilt control method for an optical disc apparatus, wherein a drive value of the objective lens driving means is determined.

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