JP4623383B2 - Optical disk drive device and operation control method of optical disk drive device - Google Patents

Description

  The present invention relates to an optical disc drive apparatus and an operation control method of the optical disc drive apparatus, and is suitable for application to an optical disc drive apparatus compatible with an optical disc capable of high-density recording, such as Blu-ray Disc (registered trademark).

  2. Description of the Related Art Conventionally, in an optical disk drive apparatus, an optical disk can be rotated at a high speed so that information recording / reproducing operation can be performed. At that time, the optical pickup is accurately controlled by performing focus control and tracking control. The laser beam from the pickup is accurately irradiated to the track on the signal recording surface of the optical disc.

  Further, in an optical disk drive device, an operation for correcting a relative angular deviation between the optical disk and the objective lens of the optical pickup in order to irradiate a laser beam from the optical pickup to the signal recording surface of the optical disk in an optimum state, so-called Some perform tilt control using a tilt actuator.

  Here, since the optical disk drive device has a structure in which the optical disk is chucked at the center thereof, so-called initial disk skew is likely to occur, in which the disk is warped on the outer peripheral side due to the weight of the disk itself or the temperature increase of the operating environment. Here, the initial disk skew is a warp (tilt) that the optical disk itself has from the beginning.

  At this time, the optical disc drive apparatus determines a tilt control amount that maximizes the push-pull signal and RF (Radio Frequency) signal on the inner and outer circumferences of the optical disc, and linearly complements the tilt control amount during the operation of the optical pickup. It is common to perform skew correction.

In addition, the optical disk recording / reproducing apparatus calculates the radial disk skew based on the angular velocity detected using the uniaxial angular velocity sensor, and recognizes that the radial disk skew exceeds a certain skew margin. There is one that interrupts the recording / reproducing operation at the time (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-339371

  By the way, in the optical disc recording / reproducing apparatus having such a configuration, the radial disc skew is calculated by using only the uniaxial angular velocity sensor, and therefore, a threshold value in consideration of the tangential disc skew that has actually occurred must be set. In addition, in recent disk drives with a high density and a narrow skew margin, the recording operation is frequently interrupted by panning or rolling, and there is a problem that the usability is poor.

  In this optical disc recording / reproducing apparatus, the angular velocity sensor only detects an external force due to panning or rolling, and cannot detect the initial disc skew. Therefore, a threshold value that also takes this initial disc skew into consideration. There is also a problem that the recording operation is frequently interrupted accordingly.

  The present invention has been made in consideration of the above points, and intends to propose an optical disc drive apparatus and an operation control method for the optical disc drive apparatus that are easy to use and that do not frequently stop operation with a simple configuration. It is.

In order to solve such a problem, in the present invention, the optical pickup moves along a moving axis provided in the radial direction of the rotating optical disc, and the optical beam is emitted from the optical pickup to the signal recording surface of the optical disc via the objective lens. The angular velocity around the moving axis when external force is applied from the outside is detected, and the angular velocity around the virtual axis of the virtual axis orthogonal to the moving axis is detected by the angular velocity detecting means, and the angular velocity around the moving axis is detected. Based on this, the estimated radial disk skew is calculated based on the gyro effect, and the estimated tangential disk skew is calculated based on the angular velocity around the virtual axis to determine the radial disk skew and tangential. Threshold considering skew margin when disk skew occurs simultaneously When the radial disk skew and / or tangential disk skew occurs, the sum of squares of the estimated value of the radial disk skew and the estimated value of the tangential disk skew is compared with the threshold value. Control whether to change the laser output level by the optical pickup based on the comparison result, drive the objective lens, and focus the light beam on the signal recording surface based on the reflected light from the signal recording surface The attitude of the optical pickup of the objective lens with respect to the drive means for forming a focus servo loop and adjusting the tilt according to the initial disc skew of the optical disc while irradiating the signal recording surface with the light beam from the optical pickup The gravitational acceleration in the driving direction according to the The height position of the objective lens is calculated by subtracting the signal component corresponding to the gravitational acceleration in the driving direction from the height control data for the objective lens generated in this, and the initial radial disk skew occurs among the initial disk skew. Based on the height position of the objective lens with respect to the signal recording surface of the optical disc, an adjustment amount for adjusting the tilt by the driving means is calculated, and when controlling the driving means according to the adjustment amount, in addition to the initial disc skew, the radial disc The adjustment amount is calculated in consideration of the skew estimation value .

As a result, the square sum of the estimated value of the radial disk skew and the estimated value of the tangential disk skew, which would actually occur due to the gyro effect, and the radial disk skew and the tangential disk skew occurred simultaneously. Since it is possible to control whether or not to change the laser output level by the optical pickup based on a comparison result with a threshold considering the skew margin at the time, a high laser output level during recording to a low laser output level during reproduction In addition to being able to maximize the performance of the optical disk drive device without unnecessarily interrupting the recording operation, driving the objective lens with respect to the driving means according to the attitude of the optical pickup The signal component corresponding to the gravitational acceleration in the direction is The height position of the objective lens relative to the signal recording surface of the optical disc in which the initial radial disc skew has occurred among the initial disc skews is calculated by subtracting from the height control data for the objective lens generated in the Based on the position, an adjustment amount for tilt adjustment by the driving means is calculated, and when the driving means is controlled by the tilt control means according to the adjustment amount, an estimated value of the radial disk skew is also taken into consideration in addition to the initial disk skew. Since the adjustment amount can be calculated, it is possible to irradiate the signal recording surface while maintaining the in-focus state where the angle when irradiating the light beam onto the signal recording surface is not shifted .

According to the present invention, the square sum of the estimated value of the radial disk skew and the estimated value of the tangential disk skew that would actually occur due to the gyro effect, the radial disk skew, and the tangential disk skew are Since it is possible to control whether or not the laser output level by the optical pickup is changed based on a comparison result with a threshold value considering the skew margin when they occur at the same time, a high laser output level during recording to a low level during reproduction In addition to being able to maximize the performance of the optical disk drive device without unnecessarily interrupting the recording operation by changing to the laser output level, the objective for the drive means corresponding to the attitude of the optical pickup The signal component corresponding to the gravitational acceleration in the lens drive direction is By subtracting from the height control data for the objective lens generated in the loop, the height position of the objective lens with respect to the signal recording surface of the optical disc in which the initial radial disc skew has occurred is calculated from the initial disc skew. Based on the position, an adjustment amount for tilt adjustment by the driving means is calculated, and when the driving means is controlled by the tilt control means according to the adjustment amount, an estimated value of the radial disk skew is also taken into consideration in addition to the initial disk skew. Since the adjustment amount can be calculated, it is possible to irradiate the signal recording surface with the light beam while maintaining the focused state without any deviation, and the operation is frequently stopped with a simple configuration. Optical disc drive apparatus excellent in usability and operation control method of optical disc drive apparatus It can be realized.

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

(1) Basic concept of the present invention First, a plurality of technical ideas constituting the present invention will be described.

(1-1) Occurrence of Disc Skew due to Gyro Effect When an angular velocity is applied to the optical disc drive device by panning at the time of shooting or rolling at the time of running while the optical disc drive device is mounted on a handy type video camera, a so-called gyro It is known that disk skew occurs due to the effect.

  Here, the relationship between disk skew and angular velocity will be described. As shown in FIG. 1, the tracking direction in which the triaxial actuator 5 seeks the optical pickup 4 from the inner circumference side to the outer circumference side of the optical disc 2 rotated and driven by the spindle motor 3 by the CLV (Constant Linear Velocity) method. An X axis is defined, and a virtual axis perpendicular to the X axis in a plane horizontal to the optical disc 2 is defined as a Y axis.

  FIG. 2 shows what kind of disk skew occurs when an angular velocity is applied around the X axis to the optical disk drive device that is actually driving the optical disk 2 to rotate. In this case, due to the gyro effect, a disk skew is generated in a direction shifted by about 90 degrees compared to the case where an angular velocity around the X axis is applied when the optical disk 2 is not rotated, and this is called a gyro effect factor radial disk skew.

  That is, in the optical disk drive device, when the gyro effect factor radial disk skew occurs, the recording surface of the optical disk 2 approaches or moves away from the optical pickup 4, and at this time, the irradiation angle of the laser beam with respect to the signal recording surface is shifted.

  FIG. 3 shows what kind of disk skew occurs when an angular velocity is applied about the Y-axis with respect to the optical disk drive that is driving the optical disk 2 to rotate. In this case, due to the gyro effect, a disk skew occurs in a direction shifted by about 90 degrees compared to the case where an angular velocity around the Y axis is applied when the optical disk 2 is not rotated, and this is called a gyro effect factor tangential disk skew. .

  In this case, in the optical disk drive device, when the gyro effect factor tangential disk skew occurs, the signal recording surface of the optical disk 2 does not approach or move away from the optical pickup 4. In this case, the irradiation angle of the laser beam with respect to the signal recording surface is shifted.

(1-2) Correction of Gyro Effect Factor Radial Disc Skew Such a gyro effect factor radial disc skew is caused by the rotational speed of the optical disc 2 by the spindle motor 3 and the angular velocity according to the external force applied to the optical disc drive apparatus from the outside. And factors that vary depending on the laser spot position and are not necessarily linear, such as the influence of the disk chucking force.

  However, when the laser spot position from the optical pickup 4 is fixed and the angular velocity changes, if the disc chucking force on the optical disc 2 is sufficiently larger than the Coriolis force generated by the gyro effect, Thus, it can be said that the amount of gyro effect due to the angular velocity and the amount of radial disk skew generated are generally proportional.

  Here, FIG. 4 shows the relationship between the laser spot position in the CLV method and the amount of gyro effect factor radial disk skew generated. In this case, the angular velocity due to the external force applied to the optical disk drive device is constant, and when the rotational speed of the optical disk 2 by the spindle motor 3 and the laser spot position change, between the angular velocity and the amount of gyro effect factor radial disk skew generated. In many cases, the relationship is nonlinear.

  The reason for this non-linear relationship is that although the Coriolis force generated by the gyro effect is determined by the rotational speed of the optical disk 2 by the spindle motor 3 and the angular speed applied to the optical disk drive device, the optical disk 2 is made of resin or the like. Thus, the optical disk 2 is formed in a thin shape (for example, a thickness of 1.2 [mm] with respect to a diameter of 120 [mm]), so that it is difficult to bend at the inner peripheral position and easily bent at the outer peripheral position. This is because the factor that the flexibility is different is caused.

  Therefore, when estimating the gyro effect factor radial disk skew generation amount from the angular velocity applied to the optical disk drive device, a numerical table is actually used to express the skew coefficient that indicates the relationship between the gyro effect factor radial disk skew generation amount and the angular velocity. And a method of referring to a skew coefficient table determined by the rotation speed of the optical disk 2 by the spindle motor 3 (equal speed mode or double speed mode) and the laser spot position is adopted.

  Specifically, assuming that the optical disk drive device is provided with an angular velocity sensor 52 (FIGS. 1 to 3) around the X axis and an external force is applied to the optical disk drive device while the optical disk 2 is rotated, the angular velocity sensor The relationship between the angular velocity around the X axis detected by 52 and the gyro effect factor radial disc skew of the optical disc 2 is represented by a skew coefficient corresponding to the disc radial position (hereinafter referred to as a gyro effect factor radial disc skew factor). The

  The gyro effect factor radial disc skew coefficient is multiplied by the angular velocity detected by the angular velocity sensor 52 to represent an estimated value of the gyro effect factor radial disc skew.

  As described above, the optical disk drive apparatus adopts the CLV method, and by controlling the rotational speed of the optical disk 2 as needed, the linear velocity when the laser beam follows the track on the signal recording surface is kept constant. There are a normal speed mode having a normal linear speed defined by a predetermined standard and a double speed mode in which data is recorded and reproduced at a linear speed twice that of the normal speed mode.

  Accordingly, the optical disk drive device differs depending on whether the rotation speed of the optical disk 2 is the normal speed mode or the double speed mode, and the angular speed generated by the gyro effect when the same external force is applied is also the normal speed mode or the double speed mode. Therefore, it is expected that the relationship between the angular velocity around the X axis and the gyro effect factor radial disc skew, that is, the gyro effect factor radial disc skew coefficient also differs depending on the type of the double speed mode.

  Based on these facts, the gyro effect factor radial disk skew coefficient was calculated while changing the disk radial position of the optical pickup 4 for each of the 1 × speed mode and 2 × speed mode, and the results are shown in FIGS. 5 (A) and 5 (B). The results shown were obtained. Incidentally, the disk radial position r is obtained by changing the distance from 24 [mm] to 58 [mm] in units of 0.1 [mm].

  Further, when the relationship between the disk radial position r and the gyro effect factor radial disk skew coefficients K1 and K2 in FIGS. 5A and 5B is graphed, as shown in FIG. 6, a characteristic curve Q1 (equal speed mode) and It became like characteristic curve Q2 (double speed mode).

  In this case, since the optical disk drive device is a CLV system, the rotational speed of the optical disk 2 changes according to the disk radial position r of the optical pickup 4, and the optical disk 2 bends according to the disk radial position r due to the initial radial disk skew. It is considered that the gyro effect factor radial disk skew coefficients K1 and K2 non-linearly change according to the disk radius position r due to the combined change of the amount and the like. For this reason, as shown in FIG. 6, it is estimated that the characteristic curves Q1 and Q2 are difficult to approximate with a simple function or the like.

  The initial radial disc skew is a radial warp (tilt) that the optical disc 2 itself has from the beginning regardless of the external force.

  As described above, the optical disk drive apparatus sequentially calculates the gyro effect factor radial disk skew coefficients K1 and K2 while changing the disk radius position r of the optical pickup 4 for each of the normal speed mode and the double speed mode. Gyro effect factor radial disk skew coefficient tables TBL1 and TBL2 (FIG. 6) associated with the gyro effect factor radial disk skew coefficients K1 and K2 are generated and held.

  The optical disk drive apparatus uses such gyro effect factor radial disk skew coefficient tables TBL1 and TBL2, and if the disk radius position r and the double speed mode are instructed, the gyro effect factor radial disk skew coefficient K1 or K2 at that time is designated. Is recognized and multiplied by the angular velocity data detected from the angular velocity sensor 52, the gyro effect factor radial disk skew estimated value can be calculated.

  Then, the optical disc drive apparatus drives and controls the triaxial actuator 5 of the optical pickup 4 based on the estimated value of the gyro effect factor radial disc skew, so that the objective lens 4A is adjusted to the optimum tilt angle in accordance with the gyro effect factor radial disc skew. It is made to be able to adjust to.

  That is, in the optical disk drive device, if the tilt actuator control signal corresponding to the magnitude of the angular velocity around the X axis is supplied to the triaxial actuator 5 to accurately control the tilt of the objective lens 4A, the effect of the gyro effect factor radial disk skew can be reduced. The excluded good information can be recorded or reproduced.

  Incidentally, as shown in FIGS. 7A and 7B, the optical disk drive device generates and holds the gyro effect factor radial disk skew coefficient tables TBL1 and TBL2, as shown in FIGS. 7A and 7B. Gyro effect factor tangential disk skew coefficients K3 and K4 are sequentially calculated while changing the disk radius position r of the optical pickup 4, and the disk radius position r and the gyro effect factor tangential disk skew coefficients K3 and K4 are obtained. The associated gyro effect factor tangential disk skew coefficient tables TBL3 and TBL4 can be generated and held.

  Therefore, the optical disk drive device uses the gyro effect factor tangential disk skew coefficient table TBL3 or TBL4, and if the disk radial position r and the double speed mode are instructed, the gyro effect factor tangential disk skew coefficient K3 or A gyro effect factor tangential disk skew estimated value can be calculated by recognizing K4 and multiplying it by the angular velocity around the Y axis detected from the biaxial angular velocity sensor.

  Also in this case, since the optical disk drive device is a CLV system, the rotational speed of the optical disk 2 changes according to the disk radial position r of the optical pickup 4, and the optical disk 2 is moved to the disk radial position r by the initial tangential disk skew. It is considered that the gyro effect factor tangential disk skew coefficients K3 and K4 change nonlinearly according to the disk radial position r due to the combined change in the amount of deflection due to the above. For this reason, as shown in FIG. 8, it is estimated that the characteristic curves Q3 and Q4 are difficult to approximate by a simple function or the like.

  However, since the optical disk drive device cannot tilt the objective lens 4A in the tangential direction by the triaxial actuator 5, in order to adjust the tilt angle of the objective lens 4A in accordance with the gyro effect factor tangential disk skew, The gyro effect factor tangential disk skew coefficient tables TBL3 and TBL4 cannot be used.

(1-3) Disc Skew and Recording Margin For the optical disc drive apparatus, information on the optical disc 2 is generated regardless of whether the gyro effect factor radial disc skew (FIG. 2) or the gyro effect factor tangential disc skew (FIG. 3) occurs. The recording conditions of the recording medium deteriorate, and the recording quality necessary for reproduction cannot be obtained.

  Also, in the optical disk drive device, when such a gyro effect factor radial disc skew and a gyro effect factor tangential disc skew occur at the same time, only one of the gyro effect factor radial disc skew or the gyro effect factor tangential disc skew occurs. In comparison with the case where the gyro effect factor radial disc skew occurs, the margin that can continue recording even when the gyro effect factor radial disc skew occurs (hereinafter referred to as the gyro effect factor radial disc skew margin), the gyro effect factor tangential disc skew A margin that can continue recording even when it occurs (hereinafter referred to as a gyro effect factor tangential disk skew margin) becomes narrow.

  That is, when the disk skew is estimated by the uniaxial angular velocity sensor 52, the angular velocity sensor 52 is generally installed in a direction in which the angular velocity that generates the gyro effect factor radial disk skew is detected. In this case, as a matter of course, it is impossible to obtain information on the angular velocity that causes the gyro effect factor tangential disk skew.

  Accordingly, the maximum value of the angular velocity applied to the virtual axis (Y axis) perpendicular to the detection axis (X axis) of the angular velocity sensor 52 is estimated, and the gyro effect factor tangential disk skew that would occur at that time does not become a problem. In addition, it is necessary to set a threshold value with a margin in the gyro effect factor radial disk skew margin.

  In this case, the entire optical disc drive apparatus has a threshold setting that takes into account the gyro effect factor tangential disc skew even when no gyro effect factor tangential disc skew occurs. When a smaller angular velocity is detected, the recording operation on the optical disc 2 must be interrupted.

  In order to avoid such a situation, in the optical disc drive apparatus, as shown in FIG. 9, when the horizontal axis is the gyro effect factor radial disc skew and the vertical axis is the gyro effect factor tangential disc skew, the gyro effect factor radial Disc skew and gyro effect factor Tangential disc skew The gyro effect factor radial disc skew margin and the gyro effect factor tangential disc skew margin can be recorded even when one or both of them occur. Set the margin area (shaded area).

  This skew margin area is a gyro effect factor radial that is capable of continuing the recording operation on the optical disc 2 if the generation amount of the gyro effect factor radial disc skew and the gyro effect factor tangential disc skew is within this range. Disk skew and gyro effect factor This indicates that tangential disc skew has only occurred, and if it is out of this range, the recording operation must be stopped immediately. Radial disk skew and gyro effect Factor Indicates that tangential disk skew has occurred.

  Therefore, the optical disk drive apparatus is provided with a biaxial angular velocity sensor (hereinafter referred to as a biaxial angular velocity sensor), and a gyro effect factor radial estimated based on an angular velocity around the X axis detected by the biaxial angular velocity sensor. Both the disk skew estimated value and the gyro effect factor tangential disk skew estimated value estimated based on the angular velocity around the Y axis are considered, and based on these, the gyro effect factor radial disk skew margin and the gyro effect factor tangential If a recording condition is determined by generating a substantially circular skew margin area (FIG. 9) represented by a disc skew margin, a recording interruption threshold closer to the original recording ability of the drive can be set.

  This is considered to be an important performance improvement and usability improvement when considering that an optical disk drive device is incorporated in a handy video camera in which an external force may be applied from any direction.

(1-4) Correction of Initial Radial Disc Skew By the way, the optical disc 2 has the angular velocity around the X axis and the angular velocity around the Y axis applied to the optical disc drive device by panning at the time of shooting and rolling at the time of running as described above. The gyro effect factor radial disc skew and the gyro effect factor tangential disc skew can be estimated by detecting with the biaxial angular velocity sensor. The initial radial disc skew of the optical disc 2 is originally a biaxial angular velocity sensor. Can not be detected by.

  It is necessary to detect such an initial radial disk skew with high accuracy and to perform optimum tilt control in real time, and the basic concept will be described.

  First, when considering the distribution of the initial radial disc skew, the initial radial disc skew on the inner peripheral side of the optical disc 2 pressed by the chucking plate is small, and the initial radial disc gradually increases as the optical disc 2 moves toward the outer peripheral side. The skew is expected to increase. Actually, when the temperature / humidity conditions are rapidly changed and the behavior of the initial radial disk skew generated in the optical disk 2 at that time is measured, a result consistent with this prediction is obtained.

  Assuming a specific initial radial disc skew distribution that gradually increases from the inner circumference side to the outer circumference side of the optical disc 2, the objective lens 4A is driven by the triaxial actuator 5 during focusing at a certain disc radial position r. The height and the initial radial disc skew have a one-to-one relationship.

  In other words, if the driving height of the objective lens 4A at a certain disk radial position r is known, it is an initial radial disk skew which means that an upward warp has occurred, or a downward warp has occurred. It is possible to estimate whether the initial radial disc skew means, and as a simplest approximation, this relational expression can also be considered as proportional. In this case, even if an error occurs, the direction of the initial radial disk skew is not mistaken.

  It is known that the driving height of the objective lens 4A by the triaxial actuator 5 at the time of focusing corresponds to the low frequency component of the control amount of the triaxial actuator when the focus servo is applied. Actually, when the initial radial disc skew does not occur in the optical disc 2, the low frequency component of the control amount of the three-axis actuator hardly changes on the inner and outer circumferences of the disc.

  When a large initial radial disc skew has occurred on the optical disc 2, the low-frequency component of the control amount of the three-axis actuator on the outer peripheral side is large depending on the direction of the initial radial disc skew (upward warping or downward warping). Become smaller or smaller. Using this characteristic, tilt control of the objective lens 4A by the triaxial actuator 5 can be performed.

(1-5) Frequency Division Control Method for Simultaneously Performing Gyro Effect Factor Radial Disc Skew Correction and Initial Radial Disc Skew Correction By the way, gyro effect factor radial disc skew and gyro effect factor tangential disc skew occur. Therefore, it is necessary that a certain degree of angular velocity be given to the optical disc drive apparatus.

  In the experimental environment, it is possible to keep rotating at a constant angular velocity, but considering the practical environment of a handheld video camera equipped with an optical disk drive device, assuming panning during shooting and rolling during driving It is sufficient for practical use.

  In practice, the frequency when a human rotates a handy video camera is about 1 [Hz] when the rotation is slow and about 5 [Hz] even when the rotation is fast. When the frequency at which the handy video camera is rotated is low, the angular velocity is generally small. That is, when the frequency is lower than 1 [Hz], the angular velocity hardly occurs in the optical disc drive apparatus.

  In consideration of such a practical environment, the output of the biaxial angular velocity sensor does not require a low frequency component very close to direct current lower than the frequency 1 [Hz]. For example, 0.3 [Hz] is the cut-off frequency. It is considered that the gyro effect factor radial disc skew and the gyro effect factor tangential disc skew can be estimated without problems even through the high-pass filter. In general, many biaxial angular velocity sensors have a built-in high-pass filter, and the angular velocity around the X axis and the angular velocity around the Y axis can be obtained by the output of the built-in high-pass filter.

  On the other hand, the initial radial disc skew of the tilt control by the three-axis actuator 5 according to the low-frequency component of the three-axis actuator control amount as in the “correction of the initial radial disc skew” described in the section (1-4). For correction, it is necessary to set the cut-off frequency of the low-pass filter for extracting the low-frequency component to 0.3 [Hz].

  That is, in the “optical disk drive device”, as described above in “Gyro effect factor radial disk skew correction” described in the section (1-3), the cutoff frequency of the high-pass filter built in the biaxial angular velocity sensor is set to 0.3 [ [Hz], the cut-off frequency of the low-pass filter is divided into frequencies by setting it to the same or lower frequency band, and the gyro effect factor radial disk skew and the initial radial disk skew are detected twice. It is made so that it can be avoided.

  The configuration of an actual optical disc drive apparatus that combines a plurality of technical ideas constituting the present invention will be specifically described below.

(2) Configuration of Optical Disk Drive Device As shown in FIG. 10 in which parts corresponding to those in FIG. 1 are assigned the same reference numerals, 1 denotes an optical disk drive device of the present invention as a whole, and the optical disk drive device 1 is a handy video camera. It is mounted and used (not shown).

  In this optical disk drive device 1, for example, an optical disk 2 having a diameter of 12 cm, such as Blu-ray Disc (registered trademark), is chucked at the central portion thereof, and the optical disk 2 is rotationally driven via a spindle motor 3.

  Incidentally, the optical disk drive apparatus 1 adopts the CLV system, and keeps the linear velocity when the laser beam of the light beam follows the track on the signal recording surface by controlling the rotational speed of the optical disk 2 as needed. It is made like that.

  Further, the optical disc drive apparatus 1 performs data at a normal double speed mode in which this linear velocity is set to a normal linear velocity defined by a standard or the like, and by rotating the optical disc 2 at a higher speed than normal, at a normal double linear velocity. And a double speed mode for recording and reproducing.

  The optical pickup 4 is emitted from a laser diode, condenses laser light through various optical components (not shown) by the objective lens 4A, and irradiates the signal recording surface of the optical disc 2. The optical pickup 4 receives the reflected light reflected by the signal recording surface of the optical disc 2 through various optical components (not shown), and then receives the light by a photodetector, and sends it to the analog front end IC 6 as a light reception signal.

  By the way, on the signal recording surface of the optical disc 2, tracks are formed in a spiral shape, and information is recorded in a state of being divided into blocks each having a predetermined size. Addresses are sequentially assigned to the blocks from the inner peripheral side of the optical disc 2. For this reason, when reading the desired information, the optical disc drive apparatus 1 irradiates a laser beam in accordance with a track (hereinafter referred to as a desired track) in which the desired information is recorded using this address as an index. ing.

  The analog front-end IC 6 converts the received light signal supplied from the optical pickup 4 into a focus error signal FE by executing an appropriate addition / subtraction calculation process (matrix calculation process), which is converted into a servo DSP (Digital Signal Processor). 7 to the analog-digital conversion circuit 8.

  The servo DSP 7 performs the above-described correction of the gyro effect factor radial disc skew, the correction of the initial radial disc skew, the correction of the gyro effect factor radial disc skew and the correction of the initial radial disc skew simultaneously according to an operation control program (not shown). Various processes such as a frequency division control method are executed.

  Here, the focus error signal FE represents the amount of deviation between the focus position of the laser beam and the signal recording surface of the optical disc 2, and indicates the degree that the laser beam is not focused on the recording surface.

  The analog-digital conversion circuit 8 converts the focus error signal FE into digital focus error data FED and sends it to the phase compensation filter 9. The phase compensation filter 9 performs a phase lead compensation calculation and a phase delay compensation calculation based on the focus error data FED, and an objective lens 4A for eliminating a focus error based on the phase lead compensation value and the phase delay compensation value obtained as a result. Height control data CONT1 is generated, converted into an analog height control signal CONT2 via the digital-analog conversion circuit 10, and then sent to the actuator driver 11 at the subsequent stage.

  The actuator driver 11 generates a drive signal FAD for driving and controlling the triaxial actuator 5 in response to the height control signal CONT2, and supplies this to the triaxial actuator 5. The triaxial actuator 5 drives the objective lens 4A of the optical pickup 4 in the focus direction according to the drive signal FAD so that the laser light emitted from the optical pickup 4 can be focused on the signal recording surface of the optical disc 2. Has been made.

  As a result, the optical disc drive apparatus 1 forms a focus servo loop via the three-axis actuator 5, the analog / digital conversion circuit 8, the phase compensation filter 9, the digital / analog conversion circuit 10 and the actuator driver 11, and is irradiated from the optical pickup 4. Laser light can be applied to the signal recording surface of the optical disc 2 while maintaining the focused state.

  In addition to such a configuration, the optical disc drive apparatus 1 supplies the height control data CONT1 generated by the phase compensation filter 9 not only to the digital-analog conversion circuit 10 but also to the low-pass filter 12. The low-pass filter 12 extracts only the low frequency component data LD of 0.3 [Hz] or less from the height control data CONT1, and sends this to the tilt controller 13 as an actuator control amount for initial radial disk skew correction. To do.

  Here, the reason for extracting only the low-frequency component data LD from the low-pass filter 12 as the actuator control amount is that the tilt control moves much slower than the focus control, and the high-frequency component (this is included in the height control data CONT1). In this case, there is no special need for 0.3 [Hz] or more.

  Further, it is desirable that the low-pass filter 12 has its cut-off frequency set lower than the natural frequency of the triaxial actuator 5. The reason for this is that when the frequency characteristics of the sensitivity of the three-axis actuator 5 are viewed, as shown in FIG. 11, for example, a resonance point exists around 50 [Hz], and the gain rapidly decreases in a higher frequency band beyond that. This is because the linear characteristic can be obtained in the low frequency band of less than about 50 [Hz].

  Therefore, in the frequency band close to the natural frequency of the triaxial actuator 5, the gain characteristic of the triaxial actuator 5 greatly fluctuates. Therefore, when estimating the driving height of the objective lens 4A by the triaxial actuator 5 from the actuator control amount, While an inverse characteristic filter is required to cancel the gain characteristics that fluctuate greatly, low frequency component data LD in a low frequency band (in this case, 0.3 [Hz] or less) in which a linear characteristic is obtained is obtained. If it is used as the actuator control amount, it is possible to simplify the configuration without requiring an inverse characteristic filter when estimating the driving height of the objective lens 4A.

  In the optical disk drive device 1, an acceleration sensor 14 for detecting gravitational acceleration in the Z-axis direction in the objective lens 4A of the optical pickup 4 is attached to a base unit (not shown) of the optical pickup 4, The acceleration sensor output ZG from the acceleration sensor 14 is sent to the analog-digital conversion circuit 8 of the servo DSP 7.

  The analog-digital conversion circuit 8 converts the acceleration sensor output ZG into digital acceleration sensor output data ZGD, and sends this to the tilt controller 13.

  By the way, the low-frequency component data LD output from the low-pass filter 12 of the servo DSP 7 is used to focus the laser light from the optical pickup 4 on the signal recording surface of the optical disc 2 by the triaxial actuator 5. Furthermore, it is data for driving the objective lens 4A including its own weight.

  However, the object on which the optical disk drive device 1 is mounted is a handy type video camera and is used in a state where the handy type video camera is held in various postures by the user. In some cases, the weight of the objective lens 4A is applied to the triaxial actuator 5 as a load, or may not be applied as a load at all.

  Therefore, when the objective lens 4A is loaded as a load on the triaxial actuator 5 depending on the attitude of the handy type video camera, the tilt controller 13 subtracts the load from the low frequency component data LD of the low pass filter 12 in advance. The acceleration sensor output data ZGD (corresponding to the load of the objective lens 4A) supplied from the acceleration sensor 14 via the analog-digital conversion circuit 8 is subtracted from the low-frequency component data LD of the low-pass filter 12. ing.

  Thereby, the tilt controller 13 subtracts in advance the load on the triaxial actuator 5 of the objective lens 4A in the optical pickup 4, and the pure drive height of the objective lens 4A relative to the optical disc 2 at the time of focusing is determined by the handy video camera. It is designed to make accurate guesses regardless of posture.

  Further, the optical disc drive device 1 is provided with a biaxial angular velocity sensor 70 for detecting an angular velocity applied by an external force from the outside, and 0.3 [Hz] output by a high-pass filter built in the biaxial angular velocity sensor 70. ] Based on the above frequency components, an angular velocity around the X-axis (hereinafter referred to as the X-axis angular velocity) signal RAS and an angular velocity around the Y-axis (hereinafter referred to as the Y-axis angular velocity) signal TAS are detected. Then, the X-axis angular velocity signal RAS and the Y-axis angular velocity signal TAS are sent to the analog-digital conversion circuit 8 of the servo DSP 7.

  The analog-digital conversion circuit 8 converts the X-axis rotation angular velocity signal RAS and the Y-axis rotation angular velocity signal TAS into digital X-axis rotation angular velocity data RASD and Y-axis rotation angular velocity data TASD, and these are converted into a gyro effect factor disk skew estimation circuit 71. To send.

  As shown in FIG. 12, in the tilt controller 13, the low frequency component data LD from the low pass filter 12 is input to the subtraction circuit 81, and the acceleration sensor output data ZGD from the acceleration sensor 14 is input to the focus actuator drive sensitivity reciprocal multiplication circuit 86. Entered.

  The focus actuator drive sensitivity reciprocal multiplication circuit 86 divides the acceleration sensor output data ZGD by the low-frequency sensitivity (acceleration / unit control amount) of the triaxial actuator 5 to obtain a load that changes according to the attitude of the objective lens 4A. The corresponding drive current Di is obtained and sent to the subtraction circuit 81.

  Here, the low-frequency sensitivity (acceleration / unit control amount) of the triaxial actuator 5 is a coefficient indicating the amount of current required to give the minimum unit of acceleration to the objective lens 4A.

  The subtraction circuit 81 subtracts the drive current Di from the low-frequency component data D1, thereby canceling the Z-axis direction component of the gravitational acceleration of the objective lens 4A according to the attitude of the handheld video camera and reducing the actuator control amount. Of the frequency component data LD, only the focus height component data Hi that contributes to the focus position of the objective lens 4 is obtained, and this is sent to the next arithmetic circuit 82.

  Incidentally, in the drive voltage radial disk skew conversion gain table 87, address information ADD indicating the disk radius position r with respect to the signal recording surface of the optical disk 2 on which the optical pickup 4 is currently irradiating the laser beam is stored in the drive system controller 73 (FIG. 10).

  Accordingly, the drive voltage radial disk skew conversion gain table 87 supplies a predetermined gain based on the relationship between the drive voltage for the objective lens 4A at the disk radial position r based on the address information ADD and the initial radial disk skew at that time to the arithmetic circuit 82. Supply.

  The arithmetic circuit 82 multiplies the focus height component data Hi by the gain supplied from the drive voltage radial disk skew conversion gain table 87, thereby driving the objective lens 4A to the height position indicated by the focus height component data Hi. In this case, an initial radial disk skew estimated value FD indicating how much the initial radial disk skew is generated is calculated and sent to the adding circuit 83.

  On the other hand, the gyro effect factor disk skew estimation circuit 71 inputs the address information ADD supplied from the drive system controller 73 to the normal speed mode radial disk skew coefficient reading section 91 and the double speed mode radial disk skew coefficient reading section 92. .

  The radial disk skew coefficient reading unit 91 for the normal speed mode has a gyro effect factor radial disk skew coefficient for the normal speed mode in which the correspondence between the disk radius position r and the gyro effect factor radial disk skew coefficient K1 in the normal speed mode is represented. The table TBL1 is stored in the table storage unit 91A in advance.

  Similarly, the radial disk skew coefficient reading unit 92 for the double speed mode is a gyro effect factor radial disk for the double speed mode in which the correspondence relationship between the disk radius position r and the gyro effect factor radial disk skew coefficient K2 in the double speed mode is represented. The skew coefficient table TBL2 is stored in advance in the table storage unit 92A.

  The radial disk skew coefficient readout unit 91 for the normal speed mode calculates the disk radius position r by the conversion process from the address information ADD, and uses the gyro effect factor radial disk skew coefficient K1 associated with the disk radius position r as the normal speed. The mode gyro effect factor radial disk skew coefficient table TBL 1 is read out and sent to the coefficient switching unit 93.

  Similarly, the radial disk skew coefficient reading unit 92 for the double speed mode calculates the disk radial position r by the conversion process from the address information ADD, and the gyro effect factor radial disk skew coefficient K2 corresponding to the disk radial position r is doubled. The mode gyro effect factor radial disk skew coefficient table TBL2 is read out and sent to the coefficient switching unit 93.

  The coefficient switching unit 93 acquires the double speed mode information MI indicating whether it is the constant speed mode or the double speed mode from the drive system controller 73, thereby recognizing which of the double speed modes at this time point is. Depending on the type of the double speed mode, the gyro effect factor radial disk skew coefficient K1 or K2 is switched to one, and this is sent to the coefficient multiplier circuit 94 as the gyro effect factor radial disk skew coefficient KR.

  As a result, the coefficient multiplication circuit 94 is supplied with the gyro effect factor radial disk skew coefficient KR corresponding to the disk radial position r and the double speed mode of the optical pickup 4 at this time.

  The coefficient multiplying circuit 94 multiplies the X-axis angular velocity data RASD supplied from the biaxial angular velocity sensor 52 via the analog-digital conversion circuit 8 by the gyro effect factor radial disk skew coefficient KR, thereby obtaining a gyro effect factor radial disk. The skew estimated value JRS is calculated and supplied to the subtracting circuit 95 and the adding circuit 83 of the tilt controller 13.

  The adding circuit 83 of the tilt controller 13 adds the initial radial disk skew estimated value FD supplied from the arithmetic circuit 82 and the gyro effect factor radial disk skew estimated value JRS supplied from the gyro effect factor disk skew estimating circuit 71. As a result, the added radial disk skew estimated value data TRD, which is the addition result of both the initial radial disk skew and the gyro effect factor radial disk skew, is generated and sent to the saturation circuit 84.

  The saturation circuit 84 obtains angle data α for tilting the objective lens 4A of the optical pickup 4 in accordance with the added radial disk skew estimated value data TRD, and if the angle data α exceeds the tilt controllable range, the range is obtained. Is sent to the sensitivity gain multiplication circuit 85 and the subtraction circuit 95 of the gyro effect factor disk skew estimation circuit 71.

  Here, the tilt controllable range is to guarantee optical performance when the objective lens 4A of the optical pickup 4 is tilt-driven and the objective lens 4A is tilt-driven beyond this range. It is a range that cannot be done.

  Therefore, when the angle data α for tilting the objective lens 4A exceeds the tilt controllable range, the saturation circuit 84 generates angle data α1 in which the angle data α is limited to be within the range and outputs this. By doing so, the optical performance can be maintained when the objective lens 4A is actually driven to tilt.

  Incidentally, the saturation circuit 84 subtracts the angle data α as it is from the sensitivity gain multiplication circuit 85 and the gyro effect factor disk skew estimation circuit 71 when the angle data α to tilt the objective lens 4A does not exceed the tilt controllable range. 95.

  The sensitivity gain multiplication circuit 85 multiplies the angle data α or α1 by a predetermined gain coefficient to obtain tilt control amount data TC for tilting the objective lens 4A of the optical pickup 4, and obtains the tilt control amount data TC from the subsequent digital-analog conversion. Send to circuit 10.

  The digital-analog conversion circuit 10 converts the tilt control amount data TC into an analog tilt control amount signal TCS and sends it to the actuator driver 11. The actuator driver 11 (FIG. 10) performs tilt control of the objective lens 4A via the three-axis actuator 5 in accordance with the tilt control amount signal TCS supplied from the tilt controller 13 via the digital / analog conversion circuit 10. A drive signal TAD (FIG. 10) is generated and supplied to the triaxial actuator 5.

  The triaxial actuator 5 is a case where both the initial radial disk skew and the gyro effect factor radial disk skew are generated by adjusting the tilt angle of the objective lens 4A of the optical pickup 4 according to the drive signal TAD. In addition, the laser beam emitted from the optical pickup 4 can be irradiated while maintaining a focused state with no angular deviation with respect to the signal recording surface of the optical disc 2.

  On the other hand, the gyro effect factor disk skew estimation circuit 71 supplies the address information ADD supplied from the drive system controller 73 to the tangential disk skew coefficient reading unit 101 for the double speed mode and the tangential disk skew coefficient reading unit 102 for the double speed mode. input.

  The tangential disc skew coefficient reading unit 101 for the normal speed mode is a gyro effect factor tangential for the normal speed mode in which the correspondence between the disk radius position r and the gyro effect factor tangential disk skew coefficient K3 in the normal speed mode is represented. A disk skew coefficient table TBL3 is stored in the table storage unit 101A in advance.

  Similarly, the tangential disk skew coefficient reading unit 102 for the double speed mode is a gyro effect factor for the double speed mode in which the correspondence relationship between the disk radius position r and the gyro effect factor tangential disk skew coefficient K4 in the double speed mode is represented. The tangential disk skew coefficient table TBL4 is stored in the table storage unit 102A in advance.

  The tangential disk skew coefficient reading unit 101 for the normal speed mode calculates the disk radius position r by the conversion process from the address information ADD, and uses the gyro effect factor tangential disk skew coefficient K3 associated with the disk radius position r. The gyro effect factor tangential disk skew coefficient table TBL3 for the normal speed mode is read out and sent to the coefficient switching unit 103.

  Similarly, the tangential disk skew coefficient reading unit 102 for the double speed mode calculates the disk radius position r by the conversion process from the address information ADD, and sets the gyro effect factor tangential disk skew coefficient K4 corresponding to the disk radius position r. The gyro effect factor tangential disk skew coefficient table TBL4 for the double speed mode is read out and sent to the coefficient switching unit 103.

  The coefficient switching unit 103 acquires the double speed mode information MI indicating that the drive mode controller 73 is in the normal speed mode or the double speed mode, thereby recognizing which of the double speed modes at this time point is, Depending on the type of the double speed mode, the gyro effect factor tangential disk skew coefficient K3 or K4 is switched to one, and this is sent to the coefficient multiplier circuit 104 as the gyro effect factor tangential disk skew coefficient KT.

  As a result, the coefficient multiplication circuit 104 is supplied with the gyro effect factor tangential disk skew coefficient KT corresponding to the disk radial position r and the double speed mode of the optical pickup 4 at this time.

  The coefficient multiplication circuit 104 multiplies the gyro effect factor tangential disk skew coefficient KT by the Y axis rotation angular velocity data TASD supplied from the biaxial angular velocity sensor 52 via the analog-digital conversion circuit 8 to thereby obtain a gyro effect factor tanger. The local disk skew estimated value JTS is calculated and sent to the square sum circuit 111 of the write stop determination circuit 72.

  The subtraction circuit 95 of the gyro effect factor disk skew estimation circuit 71 receives the gyro effect factor radial disk skew estimation value JRS from the coefficient multiplication circuit 94 and the angle data α or α1 from the saturation circuit 84 of the tilt controller 13. The gyro effect factor radial disk skew estimate value JRS1 is generated by subtracting the angle data α or α1 from the gyro effect factor radial disc skew estimate value JRS. Output to the circuit 111.

  Here, since the angle data α is data in a range that can guarantee the optical performance of the optical pickup 4 even when the objective lens 4A is tilted, gyro effect factor radial disk skew estimation is performed. When the angle data α is subtracted from the value JRS, the gyro effect factor radial disk skew estimated value JRS1 is effectively “0”.

  On the other hand, as described above, the angle data α1 is data that is limited from the angle range that should be tilt-driven in order to maintain the optical performance. Therefore, from the gyro effect factor radial disk skew estimated value JRS. When the angle data α is subtracted, the gyro effect factor radial disc skew estimated value JRS1 corresponds to the remaining amount that the radial skew correction cannot be completed by the tilt control by the tilt controller 13.

  On the other hand, in the optical disc drive apparatus 1, since the objective lens 4A cannot be tilted in the tangential direction by the three-axis actuator 5, the gyro effect factor tangential is different from the gyro effect factor radial disc skew estimated value JRS1. The radial skew estimated value JTS is the final value.

  Accordingly, the square sum circuit 111 of the write stop determination circuit 72 is provided with the gyro effect factor radial disk skew estimate value JRS1 and the gyro effect factor tangential radial skew estimate value JTS, and these gyro effect factor radial disk skew values. The estimated value JRS1 and the gyro effect factor tangential radial skew estimated value JTS are used as materials for determining whether or not to stop the writing operation on the optical disc 2.

  The sum-of-squares circuit 111 of the write stop determination circuit 72 does not actually correct by calculating the sum of squares of the gyro effect factor radial disk skew estimated value JRS1 and the gyro effect factor tangential disk skew estimated value JTS. The remaining gyro effect factor radial disc skew and the gyro effect factor tangential disc skew are generated, and a gyro effect factor disc skew estimated value JS is generated and sent to the threshold comparison circuit 112.

  The threshold value comparison circuit 112 presets a threshold value determined by the relative relationship between the gyro effect factor radial disk skew and the gyro effect factor tangential disk skew as shown in FIG. 9, and the threshold value and the gyro effect factor disk skew are set. If the estimated value JS is compared with the estimated value JS and the estimated value of the gyro effect factor disk skew JS is smaller than the threshold value, the gyro effect factor radial disk skew and / or the gyro effect factor tangential disk skew are generated. This indicates that it is within the range of the gyro effect factor radial disc skew margin and the gyro effect factor tangential disc skew margin that can continue to be recorded even at times. It sends a command signal to the drive system controller 73.

  On the other hand, if the gyro effect factor disk skew estimated value JS is larger than the threshold value, the threshold determination circuit 112 records when the gyro effect factor radial disc skew and / or the gyro effect factor tangential disc skew occur. This means that it is impossible to continue. At this time, a command signal for instructing to stop recording is sent to the drive system controller 73 as a determination result.

  The drive system controller 73 controls whether the laser driver IC 74 (FIG. 10) continues or stops the emission of the laser light from the optical pickup 4 in accordance with the command signal supplied from the threshold determination circuit 112. Thus, erroneous recording of information due to continuing the recording operation when a large disk skew has occurred on the optical disk 2 for some reason can be prevented in advance.

(3) Operation and Effect In the above configuration, the optical disc drive apparatus 1 calculates the gyro effect factor radial disc skew estimate value JRS1 and the gyro effect factor tangential disc skew estimate value JTS due to the application of the angular velocity. Controlling the laser output level of the laser light from the optical pickup 4 based on the comparison result between the multiplication sum and the threshold value considering the skew margin (FIG. 9) when the radial disk skew and the tangential disk skew occur simultaneously. Therefore, compared with the recording operation determination using the conventional uniaxial angular velocity sensor, the recording performance of the optical disc drive device 1 can be maximized without unnecessarily interrupting the recording operation.

  That is, the optical disc drive apparatus 1 relaxes the recording stop condition to the limit at which the erroneous recording operation does not occur even when the gyro effect factor radial disc skew or the gyro effect factor tangential disc skew occurs due to the angular velocity. By preventing the recording operation from being interrupted unnecessarily within a range where no erroneous recording operation is performed, the user's usability can be greatly improved.

  At this time, the optical disc drive apparatus 1 uses the remaining gyro effect factor radial disc skew estimate value JRS1 obtained by subtracting the amount of actual tilting operation of the objective lens 4A in the radial direction from the gyro effect factor radial disc skew estimate value JRS. By determining whether or not to continue the operation by the write stop determination circuit 72, it is possible to perform an accurate write stop determination in consideration of the remaining gyro effect factor radial disk skew that has not actually been corrected. I can do it.

  Further, the tilt controller 13 of the optical disc drive apparatus 1 can drive the objective lens 4A to tilt based on the added radial disc skew estimated value data TRD obtained by adding the initial radial disc skew and the gyro effect factor radial disc skew. Even when radial disk skew and / or radial disk skew are generated, the laser beam from the optical pickup 4 is always irradiated with no angular deviation with respect to the signal recording surface of the optical disk 2. can do.

  Further, the optical disc drive apparatus 1 calculates the initial radial disc skew estimated value FD by the low-pass filter 12 based on the low frequency component having a cutoff frequency of 0.3 [Hz] or less, and the gyro effect factor radial disc skew estimated value JRS. Is calculated based on a high-frequency component having a cutoff frequency of 0.3 [Hz] or higher by a high-pass filter built in the biaxial angular velocity sensor 52, so that the frequency is set at a cutoff frequency of 0.3 [Hz]. Therefore, the tilt control for the initial radial disk skew and the tilt control for the gyro effect factor radial disk skew can be performed simultaneously without contradiction.

  Further, the optical disk drive device 1 previously stores gyro effect factor radial disk skew coefficient tables TBL1 and TBL2 and gyro effect factor tangential disk skew coefficient tables TBL3 and TBL4 corresponding to the double speed mode, respectively, and is notified by the address information ADD. The gyro effect factor radial disc skew coefficient K1 or K2, the gyro effect factor tangential disc skew K3 or K4 corresponding to the disc radius position r to be read, and the gyro effect factor radial disc skew estimate JRA and the gyro effect factor tangential disc skew estimate Since the value JTS can be calculated instantaneously, it is immediately determined whether or not the recording operation to the optical disc 2 by the optical pickup 4 is continued, and erroneous recording is performed. It is possible to prevent the deer.

  According to the above configuration, the optical disc drive apparatus 1 calculates the gyro effect factor radial disc skew estimate value JRS1 and the gyro effect factor tangential disc skew estimate value JTS, and sums these squares, the radial disc skew and the tangential disc. A high laser output level at the time of recording is controlled by controlling whether or not to change the laser output level of the laser light by the optical pickup 4 based on a comparison result with a threshold considering the skew margin when the skew occurs simultaneously. By changing the laser output level from low to low during playback, the recording operation can be maximized without unnecessarily interrupting the recording operation, and thus the recording operation can be performed with a simple configuration. Can greatly improve the usability of .

(4) Other Embodiments In the above-described embodiment, in order to simultaneously perform tilt control for the initial radial disk skew and tilt control for the gyro effect factor radial disk skew without any contradiction, a cutoff frequency of 0.3 [Hz However, the present invention is not limited to this, and as long as it is about 1 [Hz] or less, the frequency may be divided at other cutoff frequencies. .

  In the above-described embodiment, the triaxial actuator 5 that cannot tilt the objective lens 4A in the tangential direction is used. However, the present invention is not limited to this, and the tilt operation in the tangential direction can be performed. A tilting operation may be performed in both the radial direction and the tangential direction by using an actuator having a structure that can be used.

  Further, in the above-described embodiment, the case where the Blu-ray Disc (registered trademark) is targeted as the optical disc 2 has been described. However, the present invention is not limited to this, and a DVD (Digital Versatile Disc), a CD (Compact Disc) is used. ) And other various optical disks 2 may be targeted, and the diameter of the optical disk 2 is not limited to 120 [mm] but may be 80 [mm] or the like.

  Further, in the above-described embodiment, when the angle data α for tilting the objective lens 4A exceeds the tilt controllable range, the angle data α1 is limited by the saturation circuit 84 so that the angle data α is within the range. However, the present invention is not limited to this, and the angle data α is output without limitation without using the saturation circuit 84, and the three axes are used. The tilt driving range of the actuator 5 with respect to the objective lens 4A may be limited to a range in which the optical performance can be maintained.

  However, in this case, since the angle data α1 cannot be obtained, the subtraction circuit 95 subtracts the angle data α1 from the gyro effect factor radial disc skew estimated value JRS to generate the gyro effect factor radial disc skew estimated value JRS1. However, the accuracy of tilt control considering both the initial radial disc skew and the gyro effect factor radial disc skew does not change, and the configuration can be simplified.

  At the same time, in this case, the optical disc drive apparatus 1 does not require the subtracting circuit 95, and the gyro effect factor radial disc skew estimated value JRS and the gyro effect factor tangential disc skew estimated value JTS without subtracting the angle data α1. Since the write stop determination is performed using the square sum of the above, the accuracy of the write stop determination is slightly lowered, but the configuration can be simplified correspondingly.

  Further, in the above-described embodiment, the objective radial disk skew estimated value FD and the gyro effect factor radial disk skew estimated value JRS are added by the adder circuit 83 and the objective radial disk skew estimated value data TRD is used. Although the case where the lens 4A is driven to tilt is described, the present invention is not limited to this, and only one of the initial radial disk skew estimated value FD and the gyro effect factor radial disk skew estimated value JRS is not added. The objective lens 4A may be tilt-driven using

  Further, in the above-described embodiment, the gyro effect factor radial disk skew coefficients K1 and K2 are stored in a table format like the gyro effect factor radial disk skew coefficient tables TBL1 and TBL2, and the gyro effect factor tangential disk skew coefficient K3 and Although the case where K4 is stored in a table format like the gyro effect factor tangential disk skew coefficient tables TBL3 and TBL4 has been described, the present invention is not limited to this, and the characteristic curves Q1, Q2 and Q3, Q4 are respectively shown. As a function of the disk radius position r, it is approximated by a mathematical expression and stored, and by substituting the disk radius position r into the mathematical expression, the gyro effect factor radial disk skew coefficients K1 and K2, gyro effect factor tangency Le disc skew coefficient K3 and K4 may be calculated instantaneously.

  Further, in the above-described embodiment, the gyro effect factor radial disk skew coefficients K1 and K2, the gyro effect factor tangential disk skew coefficients K3 and K4 are used as the gyro effect factor radial disk skew coefficient tables TBL1 and TBL2, and the gyro effect factor tanger. However, the present invention is not limited to this, and the disk radius position r is not limited to the gyro effect factor radial disk skew factor tables TBL1, TBL2, or the gyro effect factor tanger. When the value is not present in the local disk skew coefficient tables TBL3 and TBL4 (for example, 24.15), the gyro at the disk radial position r (for example, 24.1 and 24.2) in the vicinity thereof is performed. The gyro effect factor radial disk corresponding to the disk radius position r (24.15) by arithmetic processing such as linear interpolation using the effect factor radial disc skew coefficient K1 or K2 or the gyro effect factor tangential disc skew coefficient K3 or K4. The skew coefficients K1 and K2 and the gyro effect factor tangential disk skew coefficients K3 and K4 may be calculated.

  Furthermore, in the above-described embodiment, the optical disk drive device 1 is adapted to the two types of the normal speed mode and the double speed mode, the gyro effect factor radial disk skew coefficient tables TBL1, TBL2, the gyro effect factor tangential disk skew coefficient table TBL3, Although the case where TBL4 is held has been described, the present invention is not limited to this, and the gyro effect factor radial disk skew coefficient table and the gyro effect factor tangential disk have three or more types of double speed modes, respectively. A skew coefficient table may be held.

  Further, in the above-described embodiment, the case where the optical disc drive apparatus 1 that changes the rotational speed of the optical disc 2 so as to keep the linear velocity constant by the CLV method is applied to the present invention has been described. However, the present invention is not limited to this, and an optical disk drive device that keeps the rotation speed of the optical disk 2 constant by, for example, the CAV (Constant Angular Velocity) method may be applied to the present invention.

  Furthermore, in the above-described embodiment, when the optical disk drive device 1 is mounted on a handy type video camera and the attitude of the handy type video camera changes, the driving current Di corresponding to the gravitational component of the objective lens 4A is obtained as low frequency component data. Although the case where subtraction is performed from the LD has been described, the present invention is not limited to this, and the present invention is a case where the apparatus is mounted on a stationary optical disc player in which a vertical or horizontal type can be freely selected. The drive current Di corresponding to the gravitational component of the objective lens 4A may be subtracted from the low-frequency component data LD when the objective lens 4A is changed from the horizontal position to the horizontal position type. Can respond.

  Further, in the above-described embodiment, the case where the optical disk drive device 1 is mounted on a handy type video camera has been described. However, the present invention is not limited to this, and the optical disk drive device 1 is, for example, a portable portable Blu-ray. It may be mounted on a disc player or an in-car audio system.

  Furthermore, in the above-described embodiment, the optical pickup 4 as the optical pickup, the biaxial angular velocity sensor 52 as the angular velocity detection means, the gyro effect factor disk skew estimation circuit 71 as the estimation means, and the threshold comparison circuit 112 as the threshold comparison means. The case where the optical disk drive device 1 as the optical disk drive device of the present invention is configured by the drive system controller 73 as the operation control means has been described, but the present invention is not limited to this, and the optical pickup according to various other configurations. The optical disk drive device of the present invention may be constituted by the angular velocity detection means, the estimation means, the threshold comparison means, and the operation control means.

  The optical disc drive apparatus and the operation control method of the optical disc drive apparatus according to the present invention can be applied to the case where operation control is performed on, for example, an HD DVD (registered trademark) optical disc other than a Blu-ray disc.

It is a basic diagram regarding the definition of the X-axis and the Y-axis in this invention. It is an approximate line figure used for explanation of generation of a gyro effect factor radial disk skew by rotation around the X axis. It is an approximate line figure used for explanation of generation of a gyro effect factor tangential disk skew by rotation around the Y axis. It is a characteristic curve figure which shows the relationship between the skew generation amount by a gyro effect, and a disk radial position. It is a basic diagram which shows a gyro effect factor radial disk skew coefficient table. It is a basic diagram which shows the relationship between a disk radius position and a gyro effect factor radial disk skew coefficient. It is a basic diagram which shows a gyro effect factor tangential disk skew coefficient table. It is a basic diagram which shows the relationship between a disk radius position and a gyro effect factor tangential disk skew coefficient. It is a basic diagram which shows a skew margin when a gyro effect factor radial disc skew and a gyro effect factor tangential disc skew occur simultaneously. 1 is a schematic block diagram showing a configuration of an optical disc drive apparatus according to the present invention. It is a characteristic curve figure which shows the frequency characteristic of the sensitivity of a triaxial actuator. It is a rough block diagram which shows the structure of a tilt control controller, a gyro effect factor disk skew estimation circuit, and a write stop judgment circuit.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical disk drive device, 2 ... Optical disk, 3 ... Spindle motor, 4 ... Optical pick-up, 5 ... 3-axis actuator, 6 ... Analog front end IC, 7 ... Servo DSP, 8 ... Analog digital Circuit: 9: Phase compensation filter, 10: Digital analog circuit, 11: Actuator driver, 12: Low pass filter, 13: Tilt control controller, 52: 2-axis angular velocity sensor, 71: Gyro effect factor disk Skew estimation circuit 72... Write stop judgment circuit 73... Drive system controller 74... Laser driver IC 81 .. subtraction circuit 82 .. arithmetic circuit 83. , 85... Sensitivity gain multiplication circuit, 86... Focus actuator drive sensitivity reciprocal multiplication , 87... Driving voltage radial disk skew conversion gain table, 91... Radial disk skew coefficient reading section for normal speed mode, 92... Radial disk skew coefficient reading section for double speed mode, 93 and 103. 94, 104... Coefficient multiplication circuit, 111... Square sum circuit, 112.

Claims (5)

An optical pickup that moves along a moving axis provided in the radial direction of the rotated optical disc and emits a light beam to the signal recording surface of the optical disc via an objective lens;
Angular velocity detection means for detecting an angular velocity around the moving axis when an external force is applied from the outside and detecting an angular velocity around the virtual axis of the virtual axis orthogonal to the moving axis;
Based on the angular velocity around the moving axis, the estimated radial disk skew is calculated based on the gyro effect, and on the basis of the angular velocity around the virtual axis, the estimated tangential disk skew is calculated based on the gyro effect. An estimating means for calculating;
A threshold value is set in consideration of a skew margin when the radial disk skew and the tangential disk skew occur at the same time, and when the radial disk skew and / or the tangential disk skew occurs, the radial disk skew Threshold comparison means for comparing a sum of squares of an estimated value of skew and an estimated value of the tangential disk skew with the threshold value;
Operation control means for controlling whether or not to change the laser output level by the optical pickup based on the comparison result of the threshold value comparison means;
The objective lens is driven to form a focus servo loop so that the light beam is focused on the signal recording surface based on the reflected light from the signal recording surface, and the light beam from the optical pickup is formed. Driving means for adjusting the tilt in accordance with the initial disc skew of the optical disc,
Detecting means for detecting gravitational acceleration in the driving direction of the objective lens relative to the driving means according to the attitude of the optical pickup;
Calculating means for calculating a height position of the objective lens by subtracting a signal component corresponding to gravitational acceleration in the driving direction from height control data for the objective lens generated in the focus servo loop;
Based on the height position of the objective lens with respect to the signal recording surface of the optical disc in which an initial radial disc skew has occurred among the initial disc skews, an adjustment amount for the tilt adjustment by the driving means is calculated and the adjustment is performed. Tilt control means for controlling the drive means according to the amount,
The tilt control means calculates the adjustment amount in consideration of the estimated value of the radial disk skew calculated by the estimation means in addition to the initial disk skew. The optical disc drive apparatus is
The amount of adjustment when the angle of the objective lens is actually adjusted by the driving means according to the adjustment amount in consideration of the estimated value of the radial disc skew in addition to the initial disc skew is based on the gyro effect. Subtracting means for subtracting from the estimated radial disk skew,
The operation control means includes
Based on the comparison result of the threshold value comparing means between the estimated value of the radial disk skew corresponding to the remaining amount subtracted by the subtracting means and / or the estimated value of the tangential disk skew and the threshold value. The optical disc drive apparatus according to claim 1, wherein it controls whether to change a laser output level by an optical pickup. The optical disk drive device according to claim 1, wherein the angular velocity detection means detects an output of a predetermined frequency band or more by an internal high-pass filter as an angular velocity around the moving axis and an angular velocity around the virtual axis. The optical disc drive apparatus is
Initial radial disk skew estimation means for estimating the initial radial disk skew based on an output of the predetermined frequency band or less among the height control data for the objective lens generated in the focus servo loop;
An optical disk drive device according to claim 3 comprising: An optical processing step in which the optical pickup moves along a moving axis provided in a radial direction of the rotated optical disc and emits a light beam from the optical pickup to the signal recording surface of the optical disc via an objective lens;
An angular velocity detection step of detecting an angular velocity around the moving axis when an external force is applied from the outside and detecting an angular velocity around the virtual axis of the virtual axis orthogonal to the moving axis by an angular velocity detecting means;
Based on the angular velocity around the moving axis, the estimated radial disk skew is calculated based on the gyro effect, and on the basis of the angular velocity around the virtual axis, the estimated tangential disk skew is calculated based on the gyro effect. An estimation step to calculate;
A threshold value is set in consideration of a skew margin when the radial disk skew and the tangential disk skew occur at the same time, and the radial disk skew and / or the tangential disk skew are A threshold comparison step for comparing the sum of squares of the estimated value of the skew and the estimated value of the tangential disk skew with the threshold value;
An operation control step for controlling whether to change the laser output level by the optical pickup based on the comparison result of the threshold comparison step;
The objective lens is driven to form a focus servo loop so that the light beam is focused on the signal recording surface based on the reflected light from the signal recording surface, and the light beam from the optical pickup is formed. Detecting means for detecting the gravitational acceleration in the driving direction according to the attitude of the optical pickup of the objective lens with respect to the driving means for adjusting the tilt when the signal recording surface is irradiated according to the initial disk skew of the optical disk. Gravity acceleration detection step to detect by,
Calculation step for calculating the height position of the objective lens by subtracting a signal component corresponding to gravitational acceleration in the driving direction from the height control data for the objective lens generated in the focus servo loop. When,
Based on the height position of the objective lens with respect to the signal recording surface of the optical disc in which an initial radial disc skew has occurred among the initial disc skews, an adjustment amount when the tilt adjustment is performed by the drive unit is performed by a tilt control unit. A tilt control step of calculating and controlling the drive means by the tilt control means according to the adjustment amount;
In the tilt control step, the adjustment amount is calculated in consideration of the estimated value of the radial disk skew calculated in the estimation step in addition to the initial disk skew.

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