Abstract: A method for detecting a defect of an optical disc includes steps of: confirming an optical pickup head being accessing data in a track on state; determining a defective region of the optical disc according to a peak-to-peak value of a wobble signal; and, maintaining the optical pickup head being unchanged when the defective region is detected.

Abstract: An optical disc apparatus reliably executes a seek operation even if an optical disc is warped. Tilt adjustment values spanning from the inner circumference to the outer circumference of an optical disc are stored. When seeking from a start address to a destination address, a tilt adjustment value A at the start address and a tilt adjustment address C at the destination address are not directly used. A tilt adjustment value k·C (k<1) is used during a coarse seek operation until the neighborhood of the destination address and a tilt adjustment value C is used during a fine seek operation from the neighborhood of the destination address to the destination address.

Abstract: An optical axis shift correcting device is provided in an optical information device including an irradiation element for applying a laser, an optical system for guiding a laser applied to an optical disc having a recording track, and a light reception element for receiving the light from the optical disc generated by the guided laser via the optical system. The optical axis shift correcting device includes a jitter acquisition element, an optical axis modification element modifying the direction of the optical axis with respect to the light reception element, and a control element controlling the optical axis modification element to reduce the shift when the acquired jitter amount exceeds a predetermined threshold value. The optical axis shift correcting device thus corrects the optical axis light shift on the surface of the light reception element with respect to the radial direction of the optical disc set in the optical information device.

Abstract: Defocus detection device and method capable of detecting a defocus accurately during recording of information to an optical disk having a plurality of recording layers and an optical disk unit using the device and method are provided. A temporal restriction is imposed on defocus detection and besides, in comparison with a level for detection of a first change of a focus error signal developing during a defocus, a level for detection of a successively occurring second change of a polarity inverse to that of the first change is made to be smaller. When the first level is exceeded and thereafter the second level is exceeded within a restricted time, a defocus is detected.

Abstract: An optical disc drive according to the present invention can write information on an optical disc, which includes a substrate on which a number of pre-pits 2 have been formed on its tracks and a recording film that is supported on the substrate. The drive includes an optical pickup and a writing control section for controlling the optical pickup so that marks 3 are recorded so as to overlap with some of the pre-pits 2 on the tracks and for making the optical pickup irradiate the recording film with a writing light beam. The writing control section changes the interval of each pair of recorded marks that are adjacent to each other along the radius of the optical disc according to the optical power of the writing light beam. Thus, the optical disc drive of the present invention can record a mark on an optical disc on which pre-pits have already been formed even if the optical disc has a simplified structure.

Abstract: An optical pickup actuator independently drivable in focusing, tilting and tracking directions. The optical pickup includes a lens holder movably installed on a base, and mounted with an objective lens for transmitting an incident light to an optical information recording medium; and a magnetic circuit to independently driving the lens holder in the focusing, tilting and tracking directions. The magnetic circuit includes opposing magnets; a focusing coil and tilting coils interposed between the magnets, mounted inside the lens holder, and wound around respective axes parallel to the focusing direction; and a plurality of tracking coils mounted outside the lens holder, interposed between the magnets and wound around respective axes transverse to the focusing direction. The magnetic fields of the magnets are guided by outer yokes partially encompassing the magnets and inner yokes positioned within the focusing coil and the tilting coils.

Abstract: In an optical disk apparatus according to an exemplary embodiment of the invention, a management information retaining unit retains an information group which should regularly be recorded as disk management information. The disk management information is obtained from a disk loaded in the optical disk apparatus, and the obtained disk management information and the information group retained by the management information retaining unit are compared with each other to detect an error in the disk management information obtained from the disk. The detected error of the disk management information is corrected into regular information, and recording and reproducing operations are performed to the disk based on the corrected disk management information.

Abstract: An optical disk apparatus irradiates first and second lights, which are emitted from an identical light source, on a disk-like volumetric recording medium from both sides thereof with first and second object lenses corresponding to the first and second lights, respectively, such that the lights are focused in an identical focal point position and records a standing wave. The optical disk apparatus includes an aberration adding unit that adds complementary aberrations to the first and second lights made incident on the volumetric recording medium, respectively.

Abstract: An optical disc apparatus in which a bias of a focusing error signal is changed to a value according to a recording power at timing corresponding to a predetermined address position before starting the recording and a defocus of an opposite polarity is preliminarily caused so as to set off a defocus which occurs at the start of the recording.

Abstract: An optical recording medium driving apparatus includes an optical pickup which irradiates first and second laser lights from one object lens with respect to an optical recording medium having a bulk layer and a tilt detection surface; a focus control portion that performs the focus control relative to each predetermined position of the optical recording medium in regard to each of the first and second laser lights; a tracking control portion that controls the position of the object lens to perform the tracking control of the first and second laser lights relative to the optical recording medium; and a tilt control portion.

Abstract: An information recording apparatus (1) is provided with: a first judging device (191) for judging whether or not a tracking error signal is greater than or equal to a first threshold value; a detecting device (192) for detecting, as a detection angle, a rotation angle of an information recording medium (100) when it is judged that the tracking error signal is greater than or equal to the first threshold value; and a second judging device (193) for judging whether or not the judgment that the tracking error signal is greater than or equal to the first threshold value is performed in synchronization with rotation of the information recording medium and at the same detection angle in a row.

Abstract: A gap pull-in method and an optical disc apparatus. Whether light condensed on a disc as an actuator ascends is near-field light is determined using a gap error signal. The range of an actuator driving voltage value during a section where the decrease rate of the gap error signal is constant is obtained when it is determined that the light condensed on the disc is near-field light. Gap pull-in is performed on the disc during a section where the actuator driving voltage value is within the obtained range.

Abstract: An optical pickup apparatus comprising: a laser diode; an objective lens configured to focus laser light emitted from the laser diode on a signal recording layer of an optical disc; a first aberration correction element arranged in an optical path between the laser diode and the objective lens; and a second aberration correction element arranged in the optical path between the laser diode and the objective lens and having an aberration correction speed lower than the aberration correction speed of the first aberration correction element, the first aberration correction element and the second aberration correction element being selectively operated according to the required aberration correction speed.

Abstract: An optical pickup device such that the driving force of the drive unit provided on the same optical base as that of the objective lens exerts no adverse influence on controlling of the objective lens is provided. The optical pickup device 1 has an objective lens 11 that condenses laser light onto an optical disk 3, a first drive mechanism 15 that moves the objective lens 11 on the optical base 6, a second drive mechanism 8 that moves a movable member 9 different from the objective lens 11 on the optical base 6, first control means 27 that outputs a first driving signal TDS to operate the first drive mechanism 15, and second control means 25 that outputs a second driving signal EDS to operate the second drive mechanism 8. A derivative value of the second driving signal EDS is added to the first driving signal TDS and inputted to the first drive mechanism 15.

Abstract: A tracking apparatus for an optical information reproduction apparatus includes the following: a photoelectric detector (1) in which a far-field pattern of a light spot converged on a recording medium is formed across a divided light-receiving cell; an arithmetic unit (2) for outputting at least a pair of arithmetic signals from the output of the photoelectric detector (1); a phase comparator (4) for detecting a phase difference between the output signals of the arithmetic unit (2); an absolute value detector (8) for detecting an absolute value of the output signal of the phase comparator (4); a level detector (9) for generating a signal that indicates whether or not a convergence position of the light spot is located off an information track by detecting a predetermined number of times or more the output signal of the absolute value detector (8) has become larger than a predetermined value; a sensitivity detector (10) for detecting and outputting the sensitivity of the level detector (9) by observing the out

Abstract: A method for assembling an optical pickup apparatus for recording/reproducing a high density DVD, DVD and CD including two objective lens and three laser light sources, the objective lenses being provided on the lens holder having an actuator base for supporting the actuator, the method for assembling the optical pickup apparatus comprises the steps of adjusting a first tilt angle of the actuator base so that a coma aberration of a spot formed by the first light beams decreases when the first light beams are converged onto the first recording medium via the first objective lens, and adjusting a second tilt angle formed between the second objective lens and the lens holder so that a coma aberration of a beam spot formed by the second light beams decreases when the second light beams are converged onto the second recording medium via the second objective lens.

Abstract: An optical head apparatus of an optical information recording/reproducing apparatus is provided with a light source. An objective lens focuses an output light emitted by said light source on a disc optical recording medium for which a groove or a pit for tracking is provided. T photo-detector receives a reflected light reflected by said optical recording medium. A polarizing splitter unit splits said output light and said reflected light. A quarter-wave plate disposed between said polarizing splitter section and said objective lens. A birefringence compensating unit reduces a change in an amplitude of a track error signal caused by birefringence in a protective layer of said optical recording medium.

Abstract: A pickup device splits and detects a light beam reflected from a disc with the use of a grating. The grating has first to six areas, wherein the first area and the second area, the third area and the fifth area, and the fourth area and the sixth area are arranged in point symmetry with respect to the center of the grating, respectively. The first area is interposed between the fourth area and the fifth area and the second area is interposed between the third area and the sixth area. Further, the centers of the first area and the second area are arranged to be spaced by a distance d in a direction perpendicular to the displacement direction of the optical pickup device. Even though the center of an optical disc is not located on a straight line in the displacement direction of the optical pickup device, objective lens can obtain a stable servo signal.

Abstract: An optical information apparatus according to the present invention includes: an optical system that includes a solid immersion lens (SIL) 11 and that produces near-field light to be incident on an optical disc 10; a first actuator for displacing the SIL 11; a second actuator 29 for varying the distance between the optical disc 10 and the first actuator 12 by moving the first actuator 12; a gap detecting section 18 for outputting a gap signal 19 representing the magnitude of the gap 17 between the SIL 11 and the optical disc 10; and a gap control system for controlling the first actuator 12 in response to the gap signal 19 such that the gap is maintained at a predetermined setting. The gap control system works so as to control the second actuator 29 in accordance with a signal representing the magnitude of displacement of the SIL 11 caused by the first actuator 12.

Abstract: A method for compensating the coma aberration in a pickup of a recording and reproducing device that records or reproduces data on or from an optical disc using the pickup is provided. The method includes a first coma aberration compensating step to compensate coma aberration in a body of an optical system including an objective lens for emitting a light beam to an optical disc including a plurality of recording layers and a second coma aberration compensating step to compensate coma aberration caused by relative inclination of the optical system with respect to the optical disc.

Abstract: An optical unit includes an optical system for shining a laser beam on an optical recording medium having a recording layer and a focus control reference surface. The optical system is composed of an objective lens for focusing a recording/reproducing beam emitting from a first light source in the recording layer and focusing a focus control beam emitted from a second light source on the focus control reference surface, a first lens system disposed along an optical path of the recording/reproducing beam and capable of discretely varying a focus position of the recording/reproducing beam in a direction of a thickness of the recording layer, and a second lens system disposed along an optical path common to the recording/reproducing beam and the focus control beam and capable of continuously varying focus positions of the recording/reproducing beam and the focus control beam in a direction of a thickness of the recording layer.

Abstract: Proposed is an optical disk device capable of optimally adjusting a current value of a direct current and a high frequency superimposed current for driving a laser diode. This optical disk device includes a laser driver for superimposing a high frequency current on a direct current to obtain a drive current and supplying the drive current to the laser beam source and driving the laser beam source, and a control unit for adjusting a current value of the direct current and/or the high frequency superimposed current supplied by the laser driver to the laser beam source based on the servo signal or the reproduction signal.

Abstract: The present invention provides an optical disc apparatus that reduces access time while suppressing the emanation of heat from a beam expander. A microcomputer manages the operation time and pause time of a stepping motor constructed to move the movable lens of the beam expander, and in accordance with the duration of an immediately previous pause, limits the number of successive stepping-motor driving actions following the pause time, below a maximum permissible count. When the pause duration is shorter than a threshold value or when the number of successive stepping-motor driving actions reaches the maximum permissible count, the microcomputer starts next driving of the stepping motor after a required waiting time.

Abstract: An optical disc apparatus comprises an overcurrent detector and when the overcurrent detector detects an overcurrent during a recording operation or a reproduction operation and during an operation for controlling a focus of an objective lens, a rotation speed of an optical disc is reduced and an actuator is controlled to cause the objective lens to be in a retracted state under the condition that a disc motor exerts brake force. The objective lens is in the retracted state until the rotation speed of the optical disc becomes equal to or smaller than a predetermined value and when the rotation speed of the optical disc is equal to or smaller than the predetermined value, the objective lens is released from the retracted state.

Abstract: A method for calibrating an SA compensation level of an optical drive is provided. The method includes steps of providing a plurality of SA compensation levels; obtaining a peak-to-peak value of an S curve corresponding to each of the SA compensation levels; selecting a maximum of the peak-to-peak values of the S curves and the SA compensation level corresponding to the maximum; and setting the selected SA compensation level to be an optimal SA compensation level.

Abstract: An apparatus for compensating for a defect of a storage medium of an optical driving includes a memory to store sample values of a servo driving signal during at least one track sampled by a first signal and cycle information about the first signal; a servo driving signal estimator to estimate a servo driving signal during at least one next track using the sample values, the cycle information about the first signal, and cycle information based on a second signal; and a transmitter to transmit the servo driving signal estimated by the servo driving signal estimator to a servo driver of the optical driving device during a defect section of the storage medium; wherein the first signal is synchronized with a radial direction of the storage medium; and the second signal has a frequency higher than the first signal.

Abstract: An optical disc apparatus of the present application has a lens position signal generator for generating a lens position signal representative of a position of an objective lens in a disc radial direction, an amplitude corrector for correcting an amplitude of a tracking error signal, and a tracking controller for generating an actuator drive signal for controlling an actuator, from an output of the amplitude corrector, wherein the amplitude corrector corrects an amplitude of the tracking error signal in accordance with the lens position signal to make approximately constant a tracking error detection sensitivity relative to a displacement between an optical spot and a track.

Abstract: An optical disc apparatus including means for calculating a spherical aberration correction quantity of an object lens, reproduced information signal generation means and spherical aberration correction means conducts spherical aberration correction, finds a spherical aberration correction quantity suitable for another layer by calculation on the basis of the obtained spherical aberration correction quantity, and sets the correction quantity as an initial correction quantity of spherical aberration correction. An optical disc apparatus including tilt correction quantity calculation means, reproduced information signal generation means and tilt adjustment means conducts tilt adjustment, finds a tilt correction quantity suitable for another layer by calculation on the basis of the obtained tilt correction quantity, and sets the correction quantity as an initial correction quantity of tilt adjustment.

Abstract: A system and method for adjusting the radial tilt, tangential tilt, or a combination of radial and tangential tilt of an optical detection unit in an optical disc reading system can include applying different weighting factors to different signal components depending on which detection area detects the component, measuring a value of a signal characteristic, such as signal-to-noise ratio, of two signals with different sets of weighting factors, and determining an adjustment factor to the radial tilt as a function of the of the measured signal characteristic values.

Abstract: An adjusting system for adjusting a tilt of an optical pickup head includes a collimator, a processing device, and a controller. The collimator receives reflected light beams from the optical pickup head and generating images from the reflected light beams. The processing device processes the images and generates an adjust signal. The controller receives the adjust signal and adjusting a position of the optical pickup head based on the adjust signal.

Abstract: A focus error signal is generated by a first-order diffracted light diffracted by regions 23b, 24b on a hologram plane 2a, and an offset of a tracking error signal is canceled by first-order diffracted light diffracted by regions 21a, 22a, 23a, 24a on the hologram plane 2a. Consequently, even when there is an error in the substrate thicknesses of optical discs, jitter of a reproduction signal at a focus control point can be reduced by decreasing the distance between the focus control point and the point where the jitter is minimized.

Abstract: An optical pickup apparatus comprises a first light source for emitting a first light flux having first wavelength ?1 (430 nm>?1>380 nm), a second light source for emitting a second light flux having second wavelength ?2 (?2>?1), an objective optical system having phase structure thereon, and at least one moving optical element for guiding the light flux into the objective optical system, the moving optical element being moved in a direction parallel to an optical axis corresponding to the first light wavelength ?1 and the second light wavelength ?2, wherein the objective optical system has phase structure and satisfies M1=M2=0, where, M1 and M2 denote a first and second magnifications of the objective optical system for recording and/or reproducing the information on or from the first and second optical information media.

Abstract: An optical disc drive apparatus includes a rotatably supporting drive unit supporting an optical disc, an optical pickup, an angular velocity sensor detecting the magnitude and direction of an angular velocity, a skew estimating section estimating disc skew from the result of detection by the angular velocity sensor, such that one estimated skew value in a case where the angular velocity is applied in a direction in which the optical disc moves away from the optical pickup differs from another estimated skew value in a case where the angular velocity of the same magnitude but in the opposite direction, in which the optical disc approaches the optical pickup, is applied, and a tilt drive section changing the tilt of the light beam in accordance with the estimated skew value and correcting a shift, occurring because of the angular velocity, in a light beam applying position on the optical disc.

Abstract: There is provided an assembling method for expanding a maximum admissible astigmatism of objective lens which includes defining a maximum admissible astigmatism for the entire optical system, installing the collimator lens on the optical system to cause a predetermined amount of astigmatism lying within a range of up to the maximum admissible astigmatism by tilting the collimator lens from a condition where a point source of the semiconductor laser lies on an optical axis of the collimator lens, and installing the objective lens on the body case of the optical system to bring a total amount of astigmatism of the entire optical system to a level smaller than or equal to the maximum admissible astigmatism for the entire optical system by rotating the objective lens from a condition where the point source of the semiconductor laser and the center of the collimator lens lie on the optical axis of the objective lens.

Abstract: A method for determining runout disc is disclosed. The method comprises: focusing on a focal point on a disc; driving the disc to spin the disc; generating a crossover signal according to a track of the disc crossing the focal point; and determining that the disc is a runout disc when the frequency of the crossover signal exceeds a pre-determine value.

Abstract: Methods and apparatus to correct a curved Petzval focusing surface to a plane using a convex lens, a concave lens, and a space arranged between the curved side of the convex lens and the curved side of the concave lens. The method and apparatus may also include a Fresnel lens arranged between the concave lens and a pixel array.

Abstract: An optical disc apparatus has: a spherical aberration correction unit (7) which corrects the spherical aberration generated in a light spot on a recording layer; a control unit (52) which focuses a light beam on a predetermined recording layer, and shifts the focal point position of the light beam from the current recording layer to another recording layer; and a focus jump control unit (60) which controls correction of spherical aberration and shift of the focal point position based on the interlayer distance between the current recording layer and a recording layer which adjoins in a direction opposite to a direction of shifting the focal point position of the light beam. By this configuration, focus jump is stably executed.

Abstract: An optical disc apparatus for shortening time necessary for adjustment while maintaining an accuracy of a result of adjustment, determines “A” pieces (A?1, A<N, and “A” is an integer) of recording layers, upon arrangement of the recording layers of an optical disc having “N” pieces (N?3, “N” is an integer) of recording layers. With remaining “B” pieces (B?1, B<N, B=N?A, and “B” is an integer) of recording layers, the “B” pieces of correction values corresponding to the respective recording layers are calculated, upon basis of the correction values of a result of adjustment of other recording layers, on which the adjustment is executed, and thickness of substrate of the recording layers. On each recording layer, it is determined on whether the correction value is obtained with the adjustment process or the correction value is obtained with calculation, depending on an arrangement of the recording layers on the optical disc.

Abstract: An optical disc drive for recording and/or reading information on or from an optical disc is disclosed. The optical disc drive includes: a position controller which controls the position of the objective lens based on the position-controlling light beam reflected by the reflective surface by condensing the position-controlling light beam by the objective lens such that the position-controlling light beam is brought to a focus at a target guide position on the reflective surface corresponding to the target recording position; a tilt angle detector which detects tilt angle of the optical disc relative to optical axis of the position-controlling light beam; and a focal position corrector which makes a correction such that a focal position obtained when the information light beam is condensed by the objective lens is aligned to the target recording position according to the tilt angle.

Abstract: A disc device capable of achieving a slimming down of a tilt adjusting portion is provided. A tilt adjusting member 404 of a tilt adjusting portion 400 moves an optical pickup driving portion 307 along a guide face 401a to adjust a light beam 303b emitted from an optical pickup 303 such that an optical axis 303c is set perpendicularly to a disc 200. Since the tilt adjusting member 404 is moved in a direction oblique to the guide face 401a and a direction perpendicular to the optical pickup driving portion 307, an amount of movement of the tilt adjusting member 404 can be reduced smaller than a necessary amount of tilt adjustment of the optical pickup driving portion 307 and also a slimming down of the tilt adjusting portion 400 can be achieved.

Abstract: Spherical aberration, astigmatism and coma can be corrected by a single liquid-crystal optical element, the electrode patterns in the optical element can be simplified, and the optical element can be controlled in a simple manner. The present invention provides an optical pickup including a light source to emit a light beam of a predetermined wavelength, an objective lens to focus the light beam emitted from the light source onto the signal recording surface of an optical disk, a liquid-crystal optical element provided between the light source and objective lens to correct spherical aberration, astigmatism and coma by varying the refractive index thereof, and a photodetector to detect return light from the signal recording surface of the optical disk.

Abstract: A method and system for removing periodic disturbances pertaining to turntable and spindle motor errors during recording of a blank optical information carrier. The periodic disturbances are determined in advance and removed only during recording by a repetitive control/learning feedforward control circuit (88).

Abstract: A tilt control method of a recording medium comprises fixing the recording medium to a recording reproducing apparatus; performing first tilt compensation in a state that the recording medium is stopped; and performing second tilt compensation in a state that the recording medium in which the first tilt compensation has been performed is rotated.

Abstract: An optical disc drive according to the present invention can read data from any of multiple types of optical discs, of which the information storage layers are located at mutually different depths under their surface. When this drive is loaded with an optical disc, the servo controller of the drive changes a first type of drive signal to adjust a focus position by changing distances from the lens to the disc and/or a second type of drive signal to adjust tilt of the lens by changing the angles defined by the lens with respect to the disc a number of times, thereby changing settings to be determined by a combination of the focus position and the tilt. A signal quality rater measures multiple index values to rate the quality of a reflected light signal as the settings are changed. Then, the optical disc drive recognizes the type of the given optical disc based on those index values and reads data from the optical disc recognized.

Abstract: The invention provides an optical disk apparatus and an optical disk that are applicable to a multilayer optical disk, and enable tilt detection with a high precision. The optical disk has a transparent planar disk base member, a recording layer formed on the disk base member, and a reflecting layer in a certain positional relation to the recording layer. The optical disk apparatus includes a laser pointer 61 for irradiating a laser beam onto the recording layer of the optical disk by way of the disk base member to form a focusing spot on the recording layer, a photo-sensor array 6G for receiving a reflected beam from the reflecting layer, and an aberration mode detecting circuit 6H for detecting tilt of the optical disk by using an output from the photo-sensor array 6G.

Abstract: An optical disc apparatus includes a multilayer optical disc having a reproduction-only recording layer and a recording layer of the recordable area, on the disc, to record and reproduce the disc by the same wavelength laser light, so that a seek operation is performed rapidly, and a generation method tracking error signal (TE) is switched over by using a DPD method and push-pull method in response to a target layer to which a focus jump is applied, for a time period during which a tracking servo loop is opened in association with a focus jump.

Abstract: An optical recording/reproducing apparatus is arranged so that, upon recording or reproducing a recording medium having a plurality of recording layers, the gap of the lens groups at the time of forming a converged light spot on this first recording layer is DIS (1), the gap of the lens groups at the time of forming the converged light spot on the N-th layer (the furthest layer from the surface of the recording medium) is DIS (N) and the neutral point of the spherical-aberration correcting mechanism is set at a position satisfying the following expression: lens group gap dst (3)=((DIS (1)+DIS (N))/2.

Abstract: In an optical pickup apparatus, a collimator lens is rockably supported by edges of two protruding portions formed on opposing sides of a groove of an optical base. The collimator lens is urged against the edges of the two protruding portions by a leaf spring. The position in vertical direction of one end of the leaf spring is adjusted by a position adjustor. In this manner, a tilt angle of the collimator lens is adjusted. Therefore, astigmatism of the light spot can precisely be compensated for irrespective of variations among apparatuses to achieve an excellent light spot.

Abstract: An optical pickup apparatus reading signal recorded on signal recording layer of first and second optical discs different in distance from incident surface of laser light to the layer, comprising: an objective lens to be changed in numerical aperture for reading signal from the discs; a focus coil to displace the lens in direction toward surfaces of the discs; a tracking coil to displace the lens in radial direction of the discs; a tilt coil to correct optical-axis angle of the lens to the surfaces; a numerical aperture changing element to change the numerical aperture so that the light is focused on the layers of the discs; an incident angle changing element to change incident angle of the light to the lens so that the light is focused on the layers; and a tilt control unit to control driving of the tilt coil to correct coma aberration.

Abstract: An optical storage system includes a pickup head for picking up data from a storage medium. Firstly, the maxima of a tracking error signal and runout are obtained in a calibration procedure in a close loop formed by an optical pickup head, a pre-amplifier, a compensator, a band-pass filter and a maximum detector. A calibration factor is then defined and derived by using the obtained maxima and nominal factors of a power amplifier and the optical pickup head of the optical storage system. The path formed by the series-connected band-pass filter and maximum detector is then disabled, while the calculated calibration factor is then stored in the compensator. The optical storage system may operate in a close loop formed by the optical pick head, pre-amplifier, compensator, a power amplifier under a normal operation procedure so that the optical storage system may record or read data onto/from an optical disc under the compensation provided by the calibration factor.