JP2005322410A - Device and method for recording and reproducing optical information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for recording and reproducing optical information capable of performing high speed/high precision and low power consumptive skew servo according to operation. <P>SOLUTION: This optical information recording and reproducing device is provided with a skew sensor 5 for detecting a skew of an optical disk 1, a current-voltage converter circuit 6 for controlling to keep an optical axis of a laser beam perpendicular to the surface where the information signal of the optical disk 1 is recorded, a differential amplifier circuit 7, a window comparator 8, a CPU 9, a driver 10, and a skew motor 11, and is so arranged as to change the control according to a recording/reproducing state of the information signal or a skew state detected by the skew sensor 5, therefore, a skew angle can be corrected with high speed and high precision by switching between high precision control and control considering a life of a skew mechanism, power consumption, and heat generation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical information recording / reproducing apparatus and an optical information recording / reproducing method, and can be applied to, for example, a compact disc (CD), a digital video disc (DVD), and a recording / reproducing device for these discs.

  2. Description of the Related Art Conventionally, for example, in a compact disk recording apparatus composed of this type of optical information recording medium, after processing data to be recorded, EFM (Eight-to-Fourteen Modulation) modulation is performed to obtain a predetermined basic period T. On the other hand, a pit train having a period of 3T to 11T is formed, and thereby audio data and the like are recorded.

  Correspondingly, the compact disc player receives a return light by irradiating the compact disc with a laser beam, thereby obtaining a playback signal whose signal level changes according to the amount of the return light, and this playback signal is predetermined. A binarized signal is generated by binarizing according to the slice level. Further, a PLL circuit is driven from the binarized signal to generate a reproduction clock, and the binarized signal is sequentially latched by the reproduction clock, whereby a period 3T to 11T corresponding to a pit string formed on the compact disc. Generate playback data.

  The compact disc player decodes the reproduction data generated in this way by data processing corresponding to the data processing at the time of recording, and reproduces audio data and the like recorded on the compact disc.

  With respect to such a conventional compact disc (CD), if the disc is tilted (skew) in the radial direction with respect to the plane orthogonal to the optical axis of the objective lens, the optical axis of the reflected beam shifts, and the adjacent recording track. Information leaks and crosstalk occurs.

  For this reason, when it is detected that there is a skew in the disk, the skew servo is performed so as to perform control so that the optical axis of the optical pickup laser beam and the signal surface of the disk are kept vertical.

  However, in the above-described conventional optical disc apparatus, when performing skew servo, constant control is always performed regardless of operations such as reading and seeking. Frequent control is performed during seeking, resulting in heat generation problems and increased power consumption. Conversely, if the control accuracy is lowered in order to suppress heat generation during seek, etc., high accuracy control cannot be performed during reading. As a result, there is an inconvenience that it is impossible to perform skew servo with high speed, high accuracy, and low power consumption.

  In addition, since the skew error signal band is switched between read and seek, it is necessary to add hardware for this purpose, and it is difficult to switch the band for each band. There was an inconvenience that became complicated.

  The present invention has been made in consideration of the above points, and intends to propose an optical information recording / reproducing apparatus and an optical information recording / reproducing method capable of performing skew servo with high speed, high accuracy, and low power consumption according to the operation. To do.

  In order to solve such a problem, the optical information recording / reproducing apparatus of the present invention records information signals by forming pits on an optical recording medium by turning on or off a laser beam with a recording power, and lasers with the reproducing power in the pits. In an optical information recording / reproducing apparatus for reading the information signal by irradiating a beam and reproducing the information signal, an inclination detecting means for detecting an inclination of the optical recording medium, an optical axis of the laser beam, and an optical recording medium Control means for controlling the surface on which the information signal is recorded to be kept perpendicular, and the control by the control means is changed according to the recording / reproducing state of the information signal or the inclination state by the inclination detection means. It is a thing.

  In the optical information recording / reproducing method of the present invention, a laser beam is turned on or off with a recording power to form a pit on an optical recording medium to record an information signal, and the pit is irradiated with the laser beam with a reproducing power. In an optical information recording / reproducing method for reading the information signal and reproducing the information signal, an inclination detecting step for detecting an inclination of the optical recording medium, an optical axis of the laser beam, and the information signal of the optical recording medium And a control step for controlling the recorded surface so as to be kept vertical, and the control by the control step is changed according to the recording / reproducing state of the information signal or the tilt state by the tilt detection step. is there.

The optical information recording / reproducing apparatus of the present invention operates as follows.
When the optical recording medium is loaded into the optical information recording / reproducing apparatus and a predetermined operation is designated, the optical recording medium rotates and a laser beam is irradiated onto the information signal surface of the optical recording medium. The reflected light of the laser beam irradiated on the information signal surface of the optical recording medium is detected, predetermined tracking servo and focus servo operations are performed, and the reproduction RF signal is reproduced to perform a predetermined operation.

At this time, if two signals indicating a skew (tilt) in the radial (radius) direction of the optical recording medium are detected by the tilt detecting unit, the two signals detected by the tilt detecting unit are converted into two signals by the control unit. The change in current is converted into a change in voltage, the difference between the voltages of the two signals is taken, the difference is amplified to a level that allows signal processing in the subsequent stage, and the skew error signal SE is output.
The control means slices the skew error signal SE at a predetermined threshold level to generate two signals, a skew high level signal SKH and a skew low level signal SKL.

When the skew state obtained from the two signals detected by the tilt detecting means is inappropriate (minus) when the optical recording medium is skewed to one side, the skew error signal SE is lower than the low threshold LS lower than 0. Becomes a lower value, the skew high level signal SKH becomes the low level L, and the skew low level signal SKL becomes the high level H.
In addition, when the optical recording medium is not skewed and the skew state obtained from the two signals detected by the inclination detecting means is appropriate, the skew error signal SE is lower than the high threshold HS higher than 0 and the low threshold LS. The skew high level signal SKH becomes a low level L, and the skew low level signal SKL becomes a low level L.

  When the skew state obtained from the two signals detected by the tilt detecting means is inappropriate (plus) when the optical recording medium is skewed to the other side, the skew error signal SE is higher than 0. The skew high level signal SKH is at a high level H, and the skew low level signal SKL is at a low level L.

  The control means generates a control signal so that both of the two signals of the skew high level signal SKH and the skew low level signal SKL are at a low level. A drive signal is generated based on the control signal. The skew servo is controlled by controlling the skew angle so that the optical axis of the laser beam and the signal surface of the optical recording medium are kept perpendicular by the drive signal. In this case, skew servo control is performed according to the recording / reproducing state of the information signal or the tilt state of the optical recording medium.

Moreover, according to the optical information recording / reproducing method of the present invention, the following operations are performed.
When two signals indicating the skew (tilt) in the radial (radius) direction of the optical recording medium are detected by the tilt detection process, the two signals detected by the tilt detection process are changed in the current of the two signals by the control process. Is converted into a change in voltage, the difference between the voltages of the two signals is taken, the difference is amplified to a level that allows signal processing in the subsequent stage, and a skew error signal SE is output.

  In the control process, it is determined whether or not the skew high level signal SKH is at the high level H. When the skew high level signal SKH is not the high level H, it is determined whether or not the skew low level signal SKL is at the low level L. When the skew low level signal SKL is not the low level L, a control signal for controlling the skew angle is generated on one side. When the optical recording medium is skewed to one side, the skew state obtained from the two signals detected by the tilt detection process is inappropriate (minus), and the skew threshold signal LS with the skew error signal SE lower than 0 is obtained. When the skew high level signal SKL is at the low level L and the skew low level signal SKL is at the high level H.

  When the skew high level signal SKH is at the high level H, a control signal for controlling the skew angle is generated on the other side. When the optical recording medium is skewed to the other side, the skew state obtained from the two signals detected by the tilt detection process is inappropriate (plus), and the skew error signal SE is higher than zero. The skew high level signal SKH is at the high level H and the skew low level signal SKL is at the low level L.

When the skew low level signal SKL is at the low level L, a control signal that does not control the skew angle is generated. When the optical recording medium is not skewed, the skew state obtained from the two signals detected by the inclination detection process is appropriate, and the skew error signal SE is lower than the high threshold HS higher than 0 and lower than the low threshold LS. The skew high level signal SKH is at the low level L, and the skew low level signal SKL is at the low level L.
By the control process, the control signal is generated so that both of the two signals of the skew high level signal SKH and the skew low level signal SKL are at a low level. A drive signal is generated based on the control signal. The skew servo is controlled so that the optical axis of the laser beam and the signal surface of the optical recording medium are kept vertical by the drive signal. In this case, skew servo control is performed according to the recording / reproducing state of the information signal or the tilt state of the optical recording medium.

  In the optical information recording / reproducing apparatus of the present invention, a pit is formed on an optical recording medium by turning a laser beam on or off with a recording power to record an information signal, and the pit is irradiated with a laser beam with a reproducing power. In the optical information recording / reproducing apparatus that reads the information signal and reproduces the information signal, tilt detection means for detecting the tilt of the optical recording medium, the optical axis of the laser beam, and the information signal of the optical recording medium are recorded. Control means for controlling the surface to be kept vertical, and the control by the control means is changed according to the recording / reproducing state of the information signal or the inclination state by the inclination detection means. The radial tilt (skew angle / tilt angle) of the recording medium is detected, and the optical axis of the laser beam and the signal surface of the optical recording medium are kept perpendicular. When controlling, the control method is changed by changing the control method according to the recording / reproducing state of the signal (during read or seek) and the warp of the optical recording medium, or the skew is controlled. By switching whether to perform control in consideration of the lifetime of the mechanism, power consumption, and heat generation, there is an effect that the skew angle can be corrected with high speed and high accuracy.

In the optical information recording / reproducing apparatus of the present invention, the drive method of the control operation by the control unit is changed in the above, and the drive method of the control operation by the control unit is the same as that at the time of seeking. Since the drive means is switched according to the playback time, more accurate control is performed by shortening the control interval, and thinning control is performed by increasing the control interval during seeking to suppress power consumption and heat generation. There is an effect that can be done.
In the optical information recording / reproducing apparatus of the present invention, in the above description, the drive method of the control operation is the first drive method having a predetermined drive force and the second drive force smaller than the first drive method. Since the driving method is switched, power consumption and heat generation can be suppressed.

In the optical information recording / reproducing apparatus of the present invention, in the above-described control, the control means controls so that the range of the dead zone at the time of seek is longer than the range of the dead zone when the information signal is reproduced sequentially. Since the range of operation is changed, when signals are played back sequentially at low speed, the vibration of the optical pickup and optical recording medium is minimized by using a smoother drive method for control operation. It is possible to reduce the tilt of the optical recording medium quickly by performing a control with higher accuracy and performing a large torque driving method during high-speed seek.
In the optical information recording / reproducing apparatus of the present invention, in the above description, the control means sets the control operation interval during seek longer than the control operation interval during sequential reproduction of the optical recording medium. Since the optical recording medium has a small warp and it is not necessary to perform the skew control operation, the skew control mechanism is initialized (initialized) only once before the operation, and the skew control operation is performed thereafter. By not performing it, there is an effect that unnecessary control can be omitted and control can be performed at high speed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. First, before describing the block diagram of the skew servo of the optical disk apparatus according to the embodiment of the present invention, the optical disk apparatus will be briefly described. In a compact disk recording apparatus which is an optical information recording medium, data to be recorded is processed, and then EFM (Eight-to-Fourteen Modulation) modulation is performed, whereby a period 3T to a predetermined basic period T An 11T pit row is formed so that audio data and the like are recorded.

  Correspondingly, the compact disc player receives a return light by irradiating the compact disc with a laser beam, thereby obtaining a playback signal whose signal level changes according to the amount of the return light, and this playback signal is predetermined. A binarized signal is generated by binarizing according to the slice level. Further, a PLL circuit is driven from the binarized signal to generate a reproduction clock, and the binarized signal is sequentially latched by the reproduction clock, whereby a period 3T to 11T corresponding to a pit string formed on the compact disc. Generate playback data.

  The compact disc player decodes the reproduction data generated in this way by data processing corresponding to the data processing at the time of recording, and reproduces audio data and the like recorded on the compact disc.

  With respect to such a conventional compact disc (CD), if the disc is tilted (skew) in the radial direction with respect to the plane orthogonal to the optical axis of the objective lens, the optical axis of the reflected beam shifts, and the adjacent recording track. Information leaks and crosstalk occurs.

  Therefore, in the skew servo circuit of the present embodiment, when it is detected that there is a skew in the disk, the optical axis of the laser beam of the optical pickup and the signal of the disk according to the recording / reproducing state of the information signal or the tilt state of the disk The skew servo is performed so as to perform control so as to correct the skew angle (angle formed by the optical axis of the laser beam and the signal surface of the disk) so as to keep the surface vertical.

Next, a block diagram of a skew servo circuit of the optical disk apparatus according to the embodiment of the present invention applied to the above-described optical disk apparatus will be described with reference to FIG.
In FIG. 1, a skew servo circuit irradiates a laser beam on a signal surface of an optical disk 1 provided on an optical disk 1 as an optical information recording medium, a spindle motor 2 that rotates the optical disk 1, and a sub chassis 3. An optical pickup 4, a skew sensor 5 that detects two signals indicating a radial (radius) skew of the optical disk 1, and a current / voltage that converts a change in current of the two signals detected by the skew sensor 5 into a change in voltage. The conversion circuit 6, the differential amplifier circuit 7 that takes the difference between the voltages of the two signals and amplifies the difference to a level that allows signal processing in the subsequent stage and outputs the skew error signal SE, and the skew error signal SE at a predetermined threshold level. Slice to generate two signals, a skew high level signal SKH and a skew low level signal SKL Based on the window comparator 8, a CPU (Central Processing Unit) 9 that outputs a control signal so that both of the two signals of the skew high level signal SKH and the skew low level signal SKL are at a low level, and the control signal. A driver 10 that generates a drive signal, a skew motor (stepping motor) 11 that is rotationally driven by a drive current, a cam gear 12 that moves in accordance with the rotation of the skew motor 11 and moves the sub chassis 3 up and down, It is comprised.

The operation of the skew servo circuit of the optical disc apparatus according to the embodiment of the present invention configured as described above will be described.
In FIG. 1, when an optical disk 1 is loaded into the optical disk apparatus and a predetermined operation is designated, the spindle motor 2 rotates and the optical disk 1 rotates as the spindle motor 2 rotates. A laser beam is irradiated onto the signal surface of the optical disc 1 from the optical pickup 4 provided on the sub chassis 3. In this way, the reflected light of the laser beam irradiated onto the signal surface of the optical disk 1 by the optical pickup 4 is detected by a photodetector (not shown), and predetermined tracking servo and focus servo operations are performed to reproduce the RF signal. Then, a predetermined operation is performed.

  At this time, if the skew sensor 5 detects two signals indicating the radial (radius) skew of the optical disc 1, the two signals detected by the skew sensor 5 are supplied to the current / voltage conversion circuit 6. A change in current of two signals detected by the skew sensor 5 in the current / voltage conversion circuit 6 is converted into a change in voltage. The voltage of the two signals converted by the current / voltage conversion circuit 6 is supplied to the differential amplifier circuit 7. In the differential amplifier circuit 7, the difference between the voltages of the two signals is taken and the difference is amplified to a level that allows signal processing in the subsequent stage, and the skew error signal SE is output.

  The skew error signal SE is supplied to the window comparator 8. In the window comparator 8, the skew error signal SE is sliced at a predetermined threshold level to generate two signals, a skew high level signal SKH and a skew low level signal SKL.

  Specifically, when the optical disk 1 is skewed to the left as shown in FIG. 5A and the skew state obtained from the two signals detected by the skew sensor 5 is NG (minus), as shown in FIG. 5B. In addition, the skew error signal SE generated by the differential amplifier circuit 7 becomes a value lower than the low threshold LS lower than 0, and the skew high level signal SKH generated by the window comparator 8 is low as shown in FIG. 5C. The skew low level signal SKL generated by the window comparator 8 becomes the high level H as shown in FIG.

  Further, when the skew state obtained from the two signals detected by the skew sensor 5 is OK when the optical disc 1 is not skewed as shown in FIG. 5A, it is generated by the differential amplifier circuit 7 as shown in FIG. 5B. The skew error signal SE generated is lower than the high threshold HS higher than 0 and lower than the low threshold LS, and as shown in FIG. 5C, the skew high level signal SKH generated by the window comparator 8 becomes low level L. As shown in FIG. 5D, the skew low level signal SKL generated by the window comparator 8 becomes the low level L.

  Further, when the optical disk 1 is skewed to the right as shown in FIG. 5A and the skew state obtained from the two signals detected by the skew sensor 5 is NG (plus), the differential as shown in FIG. 5B. The skew error signal SE generated by the amplifier circuit 7 has a value higher than the high threshold HS higher than 0, and the skew high level signal SKH generated by the window comparator 8 becomes high level H as shown in FIG. As shown in FIG. 5D, the skew low level signal SKL generated by the window comparator 8 becomes the low level L.

  Two signals, a skew high level signal SKH and a skew low level signal SKL, are supplied to the CPU 9. In the CPU 9, a control signal is generated so that both of the two signals of the skew high level signal SKH and the skew low level signal SKL are at a low level.

Here, the operation of the skew interrupt in the CPU 9 will be described using the flowchart shown in FIG.
In FIG. 8, starting, it is determined whether or not the skew high level signal SKH is at the high level H in step S1. If the skew high level signal SKH is not the high level H in step S1, the process proceeds to step S2. In step S2, it is determined whether or not the skew low level signal SKL is at a low level L. When the skew low level signal SKL is not the low level L in step S2, the process proceeds to step S3. In step S3, a CW (clock wind: clockwise) one-step drive control signal, which is a control signal for driving the skew motor 11 one step clockwise, is generated and returned. Specifically, as shown in FIG. 5A, the skew state obtained from the two signals detected by the skew sensor 5 when the optical disc 1 is skewed to the left is NG (minus), and the skew error signal SE Is lower than the low threshold LS lower than 0, the skew high level signal SKH is at the low level L, and the skew low level signal SKL is at the high level H.

  If the skew high level signal SKH is at the high level H in step S1, the process proceeds to step S4. In step S4, a CCW (counter clock wind: counterclockwise) one-step drive control signal, which is a control signal for driving the skew motor 11 in one counterclockwise direction, is generated and returned. Specifically, as shown in FIG. 5A, when the optical disk 1 is skewed to the right and the skew state obtained from the two signals detected by the skew sensor 5 is NG (plus), the skew error signal SE Is higher than the high threshold HS higher than 0, the skew high level signal SKH is at the high level H, and the skew low level SKL signal is at the low level L.

  If the skew low level signal SKL is at the low level L in step S2, the process proceeds to step S5. In step S5, a control signal for powering off the skew motor 11 is generated and the process returns. Specifically, as shown in FIG. 5A, when the optical disk 1 is not skewed and the skew state obtained from the two signals detected by the skew sensor 5 is OK, the skew error signal SE is higher than zero. The value is lower than the high threshold HS and higher than the low threshold LS, the skew high level signal SKH is at the low level L, and the skew low level SKL signal is at the low level L.

  The control signal described above is supplied to the driver 10. In the driver 10, a drive signal is generated based on the control signal. The drive signal is supplied to the skew motor 11. The skew motor 11 is rotationally driven by a drive signal. Then, the cam gear 12 rotates in conjunction with the rotation of the skew motor 11, and the subchassis 3 is moved up and down following the rotation of the cam gear 12. Thereby, the optical pickup 4 provided on the sub-chassis 3 is moved up and down, and skew servo control is performed so that the optical axis of the laser beam of the optical pickup 4 and the signal surface of the optical disc 1 are kept vertical. . In this case, skew servo control is performed in accordance with the recording / reproducing state of the information signal or the tilt state of the disc.

Next, a mechanical unit used for skew servo will be described.
FIG. 2 shows an external perspective view of a base unit assembly used for the skew servo, and FIG. 3 shows an external perspective view of the base unit assembly.
As shown in FIG. 3, an optical pickup 4, a skew sensor 5, and a main shaft 21 that guides the optical pickup 4 in the radial direction are provided on the subchassis 3. Further, on the main chassis 20, the spindle motor 2, the sled motor 22 that sends the optical pickup 4 in the radial direction via the main shaft 21, the skew motor 11, and the cam gear 12 that rotates as the skew motor 11 rotates. Is provided. The sub chassis 3 is configured to be attached to the main chassis 20.

A skew mechanism of the base unit assembly configured as described above will be described with reference to FIG.
In FIG. 4, first, a skew pulley gear 40 is attached to the skew motor 11 so as to transmit the rotation of the skew motor 11 in the arrowed (1) direction to the cam gear 12. Further, the cam gear 12 is provided with a long hole 41 in the circumferential direction on the inner peripheral side, and a skew cam shaft 43 is fitted into the long hole 41 of the cam gear 12, and the skew cam shaft 43 extends along the long hole 41. Thus, the skew shaft 43 is configured to move up and down in the direction of the arrow (2) with respect to the cam gear 12. Further, the rotation shaft 44 of the sub chassis 3 is rotatably attached to the hole 42 of the main chassis 20, so that the sub chassis 3 rotates in the arrowed (3) direction with respect to the main chassis 20. Has been.

The operation of the skew mechanism of the base unit assembly configured as described above will be described.
In FIG. 4, first, when the skew motor 11 rotates, the skew pulley gear 40 rotates accordingly, and the rotation of the skew motor 11 in the direction indicated by the arrow (1) is transmitted to the cam gear 12. Next, since the skew cam shaft 43 is fitted and inserted into the long hole 41 provided in the circumferential direction on the inner peripheral side of the cam gear 12, the skew cam is guided by the long hole 41 when the cam gear 12 rotates. The shaft 43 moves along the long hole 41. Then, the skew shaft 43 moves up and down in the direction indicated by an arrow (2) with respect to the cam gear 12. Further, since the rotation shaft 44 of the sub chassis 3 is rotatably attached to the hole 42 of the main chassis 20, the sub chassis 3 rotates in the direction indicated by an arrow (3) with respect to the main chassis 20. As a result, the optical pickup 4 provided on the subchassis 3 is moved up and down, and skew servo control is performed so that the optical axis of the laser beam of the optical pickup 4 and the signal surface of the optical disc 1 are kept vertical. .

  As described above, in the optical disc apparatus capable of recording and reproducing, control is performed so that the optical axis of the optical disc 1 is detected in the radial direction and the optical axis of the laser beam and the signal surface of the optical disc 1 are kept vertical. In order to improve the reliability at the time of recording / reproducing, a skew servo is necessary, but these controls are not always necessary.

Therefore, the necessary skew servo is performed according to the recording / reproducing operation. The contents of the control will be described below.
Actually, high-accuracy and continuous skew servo is necessary when signals are being reproduced sequentially, and such high-accuracy and continuous skew servo is not necessary during seek. Further, when the optical disc 1 itself is not warped so much, the above-described skew servo mechanism initialization (initialization) operation is not necessary after reproducing the signal. Therefore, in consideration of the life of the skew mechanism, power consumption, heat generation, and the like due to the skew servo, it is not preferable to always apply the skew servo. Therefore, the control is switched as described below.

First, the first control method will be described.
The first control method is a method of switching the control interval. In this method, the CPU 9 monitors the skew error signal (or skew high level signal SKH and skew low level signal SKL) at certain intervals, and performs control according to the skew error signal (tilt of the optical disk). . The control interval at this time can be freely changed by the CPU 9. Therefore, at the time of sequential read, more accurate control is performed by shortening this control interval, and the reliability at the time of signal reproduction is improved. On the other hand, at the time of seek, on the contrary, the control interval is set a little longer to suppress power consumption and heat generation. Further, when the warp of the optical disk 1 is small and the skew control is not required, the skew mechanism is initialized (initialized) only once before reproduction, and the control is not performed thereafter.

Next, the second control method will be described.
The second control method is a method for switching the control range. In this method, when performing the skew servo, a certain dead zone is provided so that no control is performed within that range. This dead zone is a range in which reliability at the time of data reproduction is not impaired even if control is not performed. The range of the dead zone is determined by the slice level in the window comparator 8. Further, when the skew error signal is directly taken into the CPU 9 via the A / D converter, it is determined by the firmware of the CPU 9. Therefore, by widening or narrowing the range of the dead zone, it is possible to switch between performing control with high accuracy or performing control in consideration of the life of the skew mechanism, power consumption, and heat generation.

Further, the third control method will be described.
The third control method is a method of switching the excitation method of the skew motor 11. As the skew motor 11 for adjusting the skew angle, a stepping motor is used in this embodiment in consideration of the lifetime, power consumption, and the like. As a driving method of this stepping motor, a one-phase excitation method shown in FIG. 6A, a two-phase excitation method shown in FIG. 6B, a 1-2 phase excitation method shown in FIG. 6C, a micro-step drive method shown in FIG. It is roughly classified into a pseudo micro step drive system.

  The step angle of the one-phase excitation method shown in FIG. 6A and the two-phase excitation method shown in FIG. 6B are the same, but the two-phase excitation method is more excited than the one-phase excitation method. , Big torque and high power consumption. In addition, the 1-2 phase excitation method illustrated in FIG. 6C is a method in which the 1 phase excitation method and the 2 phase excitation method are alternately repeated, and the step angle is half that of the 1 phase excitation method and the 2 phase excitation method. Further, since the step angle is narrow, it can be rotated smoothly. Further, the microstep driving method shown in FIG. 7A can make the step angle extremely small as compared with other excitation methods, and finer, high-precision and smooth driving is possible. In addition, the microstep driving method is driven smoothly with all the duties, but the pseudo microstep driving method shown in FIG. 7B is driven smoothly with the first half duty and is driven with pulses with the half duty. Thereby, by switching between the micro-step driving method and the pseudo micro-step driving method, it is possible to switch between high-accuracy control or control considering the life of the skew mechanism, power consumption, and heat generation. .

  In this manner, appropriate skew servo can be realized by properly using the above-described excitation methods. Specifically, when signals are reproduced sequentially, the drive method of the skew motor 11 is made smoother, for example, the microstep drive method, etc., and the vibration to the optical disk is minimized. Further, at the time of seeking, a driving method with a larger torque such as a two-phase excitation method is adopted, and the tilt of the optical disk is corrected quickly.

  According to the above-described embodiment, in the optical disk drive capable of recording / reproducing, the radial tilt (skew angle / tilt angle) of the optical disk 1 is detected, and the optical axis of the laser beam and the signal surface of the optical disk 1 are detected. When controlling so as to keep the vertical direction, the control method is changed depending on the recording / reproducing state of the signal (during reading or seeking) and the warping condition of the optical disc 1, Alternatively, it is possible to switch between performing control considering the life of the skew mechanism, power consumption, and heat generation.

  Further, according to the present embodiment, when signals are reproduced sequentially, control is performed with higher accuracy by shortening the control interval to about 10 msec, for example, and control intervals are set to about 100 msec at the time of seek, for example. By extending the length, it is possible to perform thinning control and suppress power consumption and heat generation.

  Further, according to the present embodiment, when signals are reproduced sequentially, the control range is shortened to, for example, about 0.05 degrees of the rotation angle of the optical disc 1, thereby performing more accurate control. During seek, for example, by extending the control range to about 0.2 degrees, thinning control can be performed to suppress power consumption and heat generation.

  In addition, according to the present embodiment, when signals are reproduced sequentially, the optical pickup 4 and the optical disc 1 can be obtained by making the drive method of the skew motor 11 smoother by, for example, a microstep drive method or the like. Thus, the tilt of the optical disc 1 can be corrected quickly by performing a more accurate control and performing a larger torque driving method such as a two-phase excitation method during seek.

  In the above-described optical disc apparatus according to the present embodiment, the laser beam is turned on or off with the recording power to form a pit on the optical disc 1 to record the information signal, and the pit is irradiated with the laser beam with the reproduction power. In an optical disc apparatus that reads an information signal and reproduces the information signal, control is performed so that the tilt skew sensor 5 that detects the tilt of the optical disc 1 and the optical axis of the laser beam and the surface on which the information signal of the optical disc 1 is recorded are kept vertical. A current / voltage conversion circuit 6, a differential amplifier circuit 7, a window comparator 8, a CPU 9, a driver 10, and a skew motor 11 as control means for controlling the information signal according to the recording / reproducing state of the information signal or the inclination state by the skew sensor 5. Since the control by the control means is changed, the optical disc 1 When the tilt in the radial direction (skew angle / tilt angle) is detected and control is performed so that the optical axis of the laser beam and the signal surface of the optical disc 1 are kept vertical, the signal recording / reproducing state (during read or seek) ) And changing the control method according to the warp of the optical disc 1, by switching between performing control with high accuracy or performing control in consideration of the life of the skew mechanism, power consumption, and heat generation, The skew angle can be corrected at high speed and with high accuracy.

  In the optical disk apparatus according to the present embodiment, the control operation intervals of the current / voltage conversion circuit 6, the differential amplifier circuit 7, the window comparator 8, the CPU 9, the driver 10, and the skew motor 11 as control means are set as described above. Since the control interval is changed, more accurate control can be performed by shortening the control interval, and thinning control can be performed by increasing the control interval during seeking to suppress power consumption and heat generation.

  In the optical disk apparatus of the present embodiment, the range of control operations by the current / voltage conversion circuit 6, the differential amplifier circuit 7, the window comparator 8, the CPU 9, the driver 10, and the skew motor 11 as control means is described above. Since the control range is shortened, more accurate control can be performed by shortening the control range, and by thinning the control range by increasing the control range during seek, power consumption and heat generation can be suppressed.

  In the optical disk apparatus according to the present embodiment, the driving method of the control operation by the current / voltage conversion circuit 6, the differential amplifier circuit 7, the window comparator 8, the CPU 9, the driver 10, and the skew motor 11 as the control means is described above. Therefore, when signals are sequentially played back at low speed, the vibration of the optical pickup 4 and the optical disk 1 can be minimized by making the driving method of the control operation smoother. Therefore, more accurate control can be performed, and a large torque driving method can be performed during high-speed seek to correct the tilt of the optical disc 1 quickly.

  Further, in the optical disc apparatus of the present embodiment, in the above description, the current / voltage conversion circuit 6, the differential amplifier circuit 7, the window comparator 8, the CPU 9, and the like as control means according to the tilt state of the optical disc 1 by the skew sensor 5. Since the control by the driver 10 and the skew motor 11 is changed, when the warp of the optical disk 1 is small and the skew control operation is not required, the skew mechanism is initialized (initialized) only once before the operation. Thereafter, by preventing the skew control operation from being performed, useless control can be omitted and control can be performed at high speed.

  In the optical information recording / reproducing method of the present embodiment, the laser beam is turned on or off with the recording power to form a pit on the optical disc 1 to record the information signal, and then the laser beam is applied to the pit with the reproducing power. In an optical information recording / reproducing method for reading an information signal by irradiating and reproducing the information signal, the inclination of the optical disc 1 is detected in the inclination detection process, and the information signal is recorded or reproduced or tilted by the skew sensor 5 in the control process. Accordingly, since the control method is changed so that the optical axis of the laser beam and the surface on which the information signal of the optical disc 1 is recorded are kept vertical, the radial tilt (skew angle / tilt angle) of the optical disc 1 is changed. And control to keep the optical axis of the laser beam and the signal surface of the optical disc 1 vertical. In this case, the control method is changed according to the signal recording / reproducing state (during reading or seeking) and the warping condition of the optical disc 1, thereby performing high-precision control or the life and consumption of the skew mechanism. By switching whether to perform control in consideration of electric power and heat generation, it is possible to perform skew angle correction processing at high speed and with high accuracy.

  Further, in the optical information recording / reproducing method of the present embodiment, since the control operation interval by the control process is changed in the above, more accurate control is performed by shortening the control interval. By increasing the control interval, thinning control can be performed to suppress power consumption and heat generation.

  Further, in the optical information recording / reproducing method of the present embodiment, since the range of the control operation by the control process is changed in the above, more accurate control is performed by shortening the control range, and at the time of seek By extending the control range, thinning control can be performed to suppress power consumption and heat generation.

  Further, in the optical information recording / reproducing method of the present embodiment, in the above-described optical information recording / reproducing method, the driving method of the control operation by the control processing is changed, so that the signal is reproduced sequentially at a low speed operation. When the control operation is performed, the vibration of the optical pickup 4 and the optical disc 1 can be minimized by making the driving method of the control operation smoother, and the control is performed with higher accuracy. A torque driving method can be used to quickly correct the tilt of the optical recording medium.

  Further, in the optical information recording / reproducing method of the present embodiment, since the control by the control process is changed according to the tilt state of the optical disk 1 by the skew sensor 5 in the above, the skew control operation of the optical disk 1 is small. If it is not necessary to perform the control, the skew mechanism is initialized (initialized) only once before the operation, and the skew control operation is not performed thereafter. It can be performed.

It is a block diagram which shows the structure of the skew servo of the optical disk apparatus based on embodiment of this invention. 1 is an external perspective view of a base unit assembly according to an embodiment of the present invention. It is a disassembled perspective view which shows the structure of the base unit assembly of embodiment of this invention. It is a perspective view which shows the skew mechanism of embodiment of this invention. 5A and 5B are diagrams illustrating an operation principle of a skew servo according to an embodiment of the present invention, in which FIG. 5A is a skew state, FIG. 5B is a skew error signal SE, FIG. 5C is an SKH signal, and FIG. It is a figure which shows the excitation system of the skew motor of embodiment of this invention, FIG. 6A is a 1 phase excitation system, FIG. 6B is a 2 phase excitation system, FIG. 6C is a 1-2 phase excitation system. 7A and 7B are diagrams illustrating an excitation method of a skew motor according to an embodiment of the present invention, in which FIG. 7A is a microstep driving method, and FIG. It is a flowchart which shows the operation | movement of the skew interruption of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Spindle motor, 3 ... Subchassis, 4 ... Optical pick-up, 5 ... Skew sensor, 6 ... Current / voltage conversion circuit, 7 ... Differential amplification circuit, 8 ... Window Comparator, 9 ... CPU, 10 ... driver, 11 ... skew motor (stepping motor), 12 ... cam gear, 20 ... main chassis, 21 ... main shaft, 22 ... thread motor, 40 ... skew pulley Gear 41, long hole 42, hole 43, skew cam shaft 44, rotating shaft, SE, skew error signal, SKH, skew high level signal, SKL, skew low level signal

Claims (12)

By turning the laser beam on or off with the recording power, pits are formed on the optical recording medium to record information signals, and when the pits are irradiated with the laser beam with the reproduction power, the information signals are read and the information signals are reproduced. In the optical information recording / reproducing apparatus to
Tilt detecting means for detecting the tilt of the optical recording medium;
Control means for controlling the optical axis of the laser beam and the surface on which the information signal of the optical recording medium is recorded to be vertical;
An optical information recording / reproducing apparatus characterized in that the control by the control means is changed according to the recording / reproducing state of the information signal or the inclination state by the inclination detecting means. The optical information recording / reproducing apparatus according to claim 1.
An optical information recording / reproducing apparatus characterized in that the drive system of the control operation by the control means is changed. The optical information recording / reproducing apparatus according to claim 2.
An optical information recording / reproducing apparatus characterized in that the driving method of the control operation by the control means switches the driving means in accordance with seek and sequential reproduction. The optical information recording / reproducing apparatus according to claim 2 or 3,
The optical information recording / reproducing apparatus is characterized in that the driving method of the control operation is switched between a first driving method having a predetermined driving force and a second driving method having a driving force smaller than that of the first driving method. The optical information recording / reproducing apparatus according to claim 1.
The optical information recording characterized in that the range of the control operation by the control means is changed so that the range of the dead zone at the time of seek is longer than the range of the dead zone when the information signal is reproduced sequentially. Playback device. The optical information recording / reproducing apparatus according to claim 1.
An optical information recording / reproducing apparatus characterized in that the control means changes the control operation interval during seek longer than the control operation interval during sequential reproduction of the optical recording medium. By turning the laser beam on or off with the recording power, pits are formed on the optical recording medium to record information signals, and when the pits are irradiated with the laser beam with the reproduction power, the information signals are read and the information signals are reproduced. In the optical information recording / reproducing method to
A tilt detecting step for detecting the tilt of the optical recording medium;
A control step for controlling the optical axis of the laser beam and the surface on which the information signal of the optical recording medium is recorded to be perpendicular;
An optical information recording / reproducing method characterized in that the control by the control step is changed in accordance with the recording / reproducing state of the information signal or the inclination state by the inclination detecting step. The optical information recording / reproducing method according to claim 7.
An optical information recording / reproducing method characterized in that the drive system of the control operation by the control step is changed. The optical information recording / reproducing method according to claim 8,
An optical information recording / reproducing method characterized in that the driving method of the control operation by the control step switches the driving means in accordance with the seek time and the sequential reproduction time. The optical information recording / reproducing method according to claim 8 or 9,
The optical information recording / reproducing method is characterized in that the driving method of the control operation is switched between a first driving method having a predetermined driving force and a second driving method having a driving force smaller than that of the first driving method. The optical information recording / reproducing method according to claim 7.
An optical information recording characterized in that the range of the control operation by the control step is changed so that the range of the dead zone at the time of seek is longer than the range of the dead zone at the time of reproducing the information signal sequentially. Playback method. The optical information recording / reproducing method according to claim 7.
An optical information recording / reproducing method characterized in that, in the control step, the control operation interval during seek is changed longer than the control operation interval during sequential reproduction of the optical recording medium.

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