Abstract: An information recording method using a recording medium includes forming a plurality of recording pulses in accordance with both a reference waveform having been stored in the recording medium and data regarding a shifting value relying on material of the recording medium also having been stored in the recording medium in a table manner, and recording information included in the plurality of recording pulses to the recording medium. The recording information is arranged to be stored according to the material of the recording medium.

Abstract: A disc apparatus is disclosed that includes a jitter-value detection unit configured to detect a jitter value based on a signal to be read from a medium. A detrack-value setting unit is configured to set a detrack value for focusing an objective lens in the medium based on the jitter value. A detrack-value adjusting unit is configured to detect the jitter value every time the detrack value is changed stepwise within a predetermined range of the detrack value including a reference value of the detrack value, to obtain an optimum detrack value to be set in the detrack-value setting unit, based on a maximum jitter value and a minimum jitter value of the detected jitter values.

Abstract: An optical disc drive includes a disc holder, a pickup head, a focus servo, an S-curve identifying unit, a first counter, a second counter, a judging unit, a disc identifying unit, and a system controller. The optical disc drive can detect whether a disc exhibits vertical deviation. Upon detection, the optical disc drive restricts the maximum speed of data reading and writing. The judging unit determines whether the disc exhibits vertical deviation based on a comparison result of the number of the one or more S curves with a first preset value.

Abstract: A tilt sensor includes a photodetector having a photosensitive plane and detecting a light beam in multiple areas and outputting detection signals representing its intensities and a tilt detector for generating a tilt error signal, including information about the tilt of a disk, based on the detection signals. The light beam forms a beam spot on the photosensitive plane. The beam spot includes a +first-order light area in which zero-order and +first-order light rays, diffracted by a track on the disk, are superposed, ?first-order light area in which zero-order and ?first-order light rays are superposed, and a zero-order light area which is sandwiched between the +first-order and ?first-order light areas, includes neither the +first-order nor ?first-order light ray, but includes a zero-order light ray. The photodetector generates the detection signals except for light entering an opaque area provided for at least part of the zero-order light area.

Abstract: It is an object of the present invention to provide an optical pickup device being capable of correcting coma aberration induced in a light-condensing optical system including an objective lens for an optical disc and having a reduced size and a reduced thickness in comparison with the conventional art. The present invention includes a first coma-aberration correction actuator (6) including a first tilt drive portion for inclining an objective lens in a first tilt direction, and a second coma-aberration correction actuator (7) including a second tilt drive portion for inclining, in a second tilt direction, a coma-aberration correction lens placed between a light source and a raising mirror for reflecting emitted light toward the objective lens.

Abstract: There are provided an optical disk device and tilt correction processing method for performing recording/reproduction by rapidly acquiring an optimal tilt correction value for an optical disk having a plurality of recording/reproducing layers. In an optical disk device capable of recording or reproducing information by irradiating a laser beam to each of a plurality of recording/reproducing layers of an optical disk, the tilt value is stepwise set within a predetermined range at a predetermined radius position of the recording/reproducing layer located at the farthest distance from the laser beam irradiation side so that an optimal tilt correction value can be obtained from the quadratic function by the method of least squares of the jitter or the like obtained from the disk. By applying the optimal tilt value obtained to the other recording/reproducing layer, it is possible to start recording or reproduction in a short time.

Abstract: An optical pickup includes: a light source emitting a beam having a predetermined wavelength; a plastic objective lens condensing the emitted beam on an optical disc; a light detector receiving and detecting the beam reflected by the optical disc; an objective-lens driving unit driving the objective lens in the tilt direction to tilt the objective lens; and a tilt-sensitivity sensing unit sensing a tilt sensitivity denoted by ?WLT/??, where ?WLT [?rms] is a coma aberration amount ?? [deg] is a tilt amount at the time of tilting the objective lens, wherein, in the case where the sensed tilt sensitivity is equal to or larger than a predetermined value, tilt is corrected by tilting the objective lens so that signal quality detected by the light detector is improved, and in the case where the sensed tilt sensitivity is smaller than the predetermined value, tilt is not corrected.

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: Provided is an optical disk device installed in a personal computer, including: an information creation unit that creates identification information for identifying the type of the personal computer based on a command transmitted from the personal computer; and a parameter selection unit that conducts switching, for parameter selection, concerning a parameter indicating an amount of unbalance of an optical disk, which has previously been determined depending on the type of the personal computer, in accordance with the identification information created by the information creation unit.

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: An optical pickup inspection device 3 sends to an actuator drive circuit 16 a command for changing defocus offset amount to set defocus offset amounts, and calculates jitter values for each of the defocus offset amounts based on a reproduction signal from a reproduction signal generation circuit 14. Then, the device 3 determines a quadric approximating curve of jitter values relative to the defocus offset amounts and calculates a correlation coefficient R2 of the quadric approximating curve and measured values. If the correlation coefficient R2 is lower than a threshold value, the setting of defocus offset amounts and the calculation of jitter values are executed once again, otherwise, a defocus offset amount corresponding to a bottom value of jitter in the quadric approximating curve is determined as an optimum value of the defocus offset amount. Thus, a less-error, high-accuracy optimum value of the defocus offset amount can be obtained.

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: 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: An optical disk apparatus which can carry out tilt control using a signal of a focus control system so as to improve the recording/reproducing performance of an optical disk. The optical disk apparatus includes a motor which rotates the optical disk, an optical pickup which reads at least information from the optical disk being rotated by the motor, a first memory which uses information of a rotation angle of the optical disk from the optical pickup as an address, a second memory which stores an offset by which information stored in the first memory should be shifted and then read, and a control portion which reads the information stored in the first memory after shifting the information by the offset stored in the second memory and which carries out tilt control using the read information.

Abstract: For achieving an improvement on recording/reproducing quality of information, with enabling more adequate tilt adjustment, even for an optical disc to be used under a circumstance having a large temperature change, an optical disc apparatus for conducting recording or reproducing of video information onto/from the optical disc 2, through buffers 17 and 18, while conducting a tilt adjustment through a learning of a tilt amount, comprises a temperature sensor 4 for detecting temperature within an optical pickup 1, wherein a control unit determines whether a relearning of the tilt amount of the optical pickup, upon basis of a change of temperature detected, a movement amount of the optical pickup between the time when a previous learning is done and the time when a present learning is done, and a remaining memory capacity of the buffers.

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: 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: 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: 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: An optical disc drive device has an FE signal generator which generates a focus error signal, a TE signal generator which generates a tracking error signal, a return beam detector which detects a return beam reflected by an optical disc after irradiated by an optical pickup to generate a return beam level signal, a return beam gain setting part which sets amplitude adjustment amount of the return beam level signal so that a signal level of the return beam level signal generated by the return beam detector coincides with a predetermined reference level, an FE gain setting part which sets amplitude adjustment amount of the focus error signal in accordance with the signal level of the return beam level signal adjusted by the return beam gain setting part so that a signal amplitude of the focus error signal is constant, and a TE gain setting part which sets amplitude adjustment amount of the tracking error signal in accordance with the signal level of the return beam level signal adjusted by the return beam gain

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: 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: A focus servo apparatus for an optical disc apparatus including an objective lens to converge laser beam on an information recording surface of an optical disc, and an actuator to move the objective lens in a focusing direction crossing the information recording surface, the focus servo apparatus comprising: a retaining unit configured to retain control data for driving the actuator; and a setting unit configured to set the control data retained by the retaining unit as initial data for driving the actuator, in the case of driving the actuator, to detect a position of the objective lens where the laser beam is focused on the information recording surface, as a target position when performing focus servo.

Abstract: In a method and device for performing tilt control, a focus and a tilt controlling output is generated, and a focusing and tilt state of an optical recording/reproducing beam is controlled by determining a radial tilt value based on a differentiation of focus control values obtained at different radii of said optical disk (1). The combination of, e.g., a 3D actuator with the dz/dr tilt measurement provides the advantage that focus and tilt adjustment can be performed in the same element. Thereby, influences or measurement variations caused by environmental conditions and/or circuit characteristics can be minimized to reduce compensations requirements. Furthermore, a 3D actuator (11) with a split coil arrangement may be used to provide a three-dimensional focus adjustment. Thereby, the 3D actuator (11) can be used for feed-forward tilt compensation without offset or gain errors and without any additional sensor.

Abstract: An optical disk device has: a detector (11) that converts a reflected light from an optical disk (5) and a reflected light of an incident light from a light source (1) side of a solid immersion lens (4), into electric signals and outputs the signals; a subtracter (15) that computes the output signal of the detector (11) according to a predetermined rule and outputs the result as a tilt detection signal; a CPU (21), an amplifier/phase compensation circuit (16), a switch (17) and an actuator (13) that perform tilt control for controlling tilt of the solid immersion lens (4) with respect to the optical disk (5) using the tilt detection signal; and the CPU (21), a nut (24), a feed screw (25), a decelerator (26) and a stepping motor (27) that perform gap adjustment for changing the gap of the solid immersion lens (4) and optical disk (5), and in the process of adjustment of gap between the solid immersion lens (4) and optical disk (5), the CPU (21) enables tilt control by closing the switch (17) according to the t

Abstract: A recording device (1T or the like) is provided with (i) recording elements (50, 40) for recording data by irradiating a recording medium with laser beams; (ii) driving members (33T, 33F, 55T, 55F, 54) for performing tracking process or focusing process; (iii) a servo elements (31T, 31F) for automatically controlling the driving members based on an error signal; (iv) specifying elements (21, 22) for specifying an area where a recording medium characteristic (core eccentricity or the like) is not good, based on a high frequency component included in the error signal; and (v) a control unit (10) for (v-i) controlling the servo unit to change the gain in the automatic control, and for (v-ii) controlling the recording elements to change the recording power of the laser beams, in the specified area.

Abstract: A holographic storage and reproduction system and method with a servo are provided, wherein a servo mechanism is provided, such that the holographic interferogram is continuously stored in the holographic recording medium. When a reproduced signal is to be obtained, it can be retrieved quickly and accurately through the servo mechanism. Also, the intensity distribution of the reference light reflected by the holographic recording medium can be monitored and controlled, such that the relative distance and oblique angle between the storage and reproduction system and the holographic recording medium are analyzed and adjusted.

Abstract: An optical information recording and reproducing apparatus for performing, using a light beam, recording of information or reproducing of recorded information with respect to a plurality of recording layers of an information recording medium. An objective lens condenses a light beam onto the recording layers. A light beam expander corrects spherical aberration caused by a difference in substrate thickness by changing one of a divergent angle and a convergent angle of a light beam entering the objective lens. A coma aberration correcting device corrects coma aberration caused by tilt of the recording medium.

Abstract: There is provided an optical system for an optical disc which requires a numerical aperture larger than or equal to 0.60. The optical system is provided with a light source, an objective lens, and a driving system that controls a position and an attitude of the objective lens. The driving system operates to move the objective lens in a direction perpendicular to a central axis of the objective lens for a tracking operation, and to change the attitude of the objective lens during the tracking operation so that the central axis on a light source side tilts toward the light source.

Abstract: A method is used for adjusting a tilt of an optical pickup head. The method includes: identifying initial coordinates of the first static spot, the second static spot, and the dynamic spot in an image generated from three reflected light beams from the optical pickup head; turning one of the adjustable screws a predetermined calibrated rotation angle; recording current coordinates of the first static spot, the second static spot, and the dynamic spot in another image generated from three reflected light beams from the optical pickup head; calculating a total needed rotation angle of the one adjustable screw according to the initial coordinates, the predetermined calibrated rotation angle, and the current coordinates; and turning the one adjustable screw a remaining rotation angle computed by subtracting the predetermined calibrated rotation angle from the total needed rotation angle. An adjusting system is also disclosed.

Abstract: A method is used for detecting a tilt of an optical pickup head. The method includes the steps of: capturing a plurality of images; converting the images to bitmap images; superposing the bitmap images together to form an superimposed bitmap image; setting a two-dimensional coordinating system of the superimposed bitmap image; determining coordinates of a first static spot, a second static spot, and dynamic spot; calculating a first distance between the first static spot and the dynamic spot, and a second distance between the second static spot and the dynamic spot based on the coordinates to determine a maximum distance; and comparing the maximum distance with a first standard distance to attain a conclusion whether the tilt is in an acceptable range.

Abstract: The method for estimating recording power Pow_tilting of a tilting part of a tilting disk is shown based on a power compensation formula: Pow_comp=A*(A*K). After a focus error (FE) signal of the tilting part of the tilting disk is manipulated as a focus servo output (FOO) signal, the parameter A is derived by low-pass filtering the FOO signal. Thereafter, another parameter K is then derived from a reference lookup table by using curve fitting approach based on parameter A such that the power compensation Pow_comp could be estimated by substituting parameters A and K into the above formula. A recording power Pow_tilting of the tilting part of the tilting disk could be estimated by adding a given recording power Piwrtpwr to the power compensation Pow_comp.

Abstract: There is provided an apparatus for recording/reproducing data on/from a recording medium including: a pickup unit including an objective lens and a solid immersion lens(SIL) to allow a light to be incident onto a recording medium; a photoelectric element for receiving the light reflected from the recording medium to output a controlling signal; and a controller to control the pickup unit using the controlling signal outputted from the photoelectric element, wherein the controlling signal includes a tilting error signal by skew of the recording medium.

Abstract: The whole reflection signal and a tracking error signal are detected while an objective lens is being moved in the radial direction of an optical disk, and the temporal difference between a time at which the value of the whole reflection signal becomes a maximum and a time at which the value of the tracking error signal becomes zero is detected in a predetermined time period. In addition, a value which is obtained by dividing the temporal difference by the time period of one cycle of the tracking error signal is acquired as a tilt appearance magnitude. Relational information in which a tilt appearance magnitude and a tilt correction magnitude corresponding to the tilt appearance magnitude are associated is read out, and the relational information read out and the current tilt appearance magnitude detected by a tilt-appearance-magnitude detection circuit are compared, thereby to determine the tilt correction magnitude necessary for a tilt correction.

Abstract: [Problems] To effectively perform optimal tilt adjustment. [Means for Solving the Problems] A tilt adjusting method adjusts a tilt angle of an actual incident light and reflected light with respect to an incident light and a reflected light under optimal tilt when recording and reproducing data onto/from an information recording medium. Two or more output signals having a balance between a signal component and a noise component changing with respect to a parameter of a correction object are extracted from the reproduction signal of the information recording medium and the signal component and the noise component are evaluated for performing signal correction, thereby calculating a first and a second coefficient. When the first coefficient is out of a set reference range, the tilt adjustment is performed by the first coefficient and when the first coefficient in the set reference range, the tilt adjustment is performed by the second coefficient.

Abstract: The optical pickup includes two objective lenses, and an objective lens holder that holds the two objective lenses. The objective lens holder has two fixture holes that pass through from the lower surface to the upper surface to which the two objective lenses are attached at an upper portion with space between them. The fixture hole is provided with a fixed lens supporting portion and two movable lens supporting portions for supporting the objective lens and adjusting tilt degree thereof. The movable lens supporting portion includes a through hole that passes through to the upper portion of the fixture hole and a column member that is inserted in the through hole in a slidable manner.

Abstract: A recording apparatus (1) is provided with: a recording device (11) for recording a data pattern onto a recording medium (100); a first controlling device (22) for stopping the recording; a reading device (11) for reading the data pattern which is recorded immediately before the recording is stopped, thereby obtaining a read signal; a measuring device (19) for measuring jitter of the read signal; an adjusting device (21) for adjusting a recording condition such that the jitter satisfies a desired condition, and a second controlling device (22) for restarting the recording of the data pattern by using the adjusted recording condition.

Abstract: An optical pickup actuator includes a lens holder on which a plurality of object lenses to use in recording/reproducing information onto/from different kinds of optical media are mounted, a tilting unit tilting the lens holder, and a controller controlling the tilting unit to tilt the lens holder about one of the object lenses that is appropriate to use in recording/reproducing information onto/from a kind of optical medium to be used.

Abstract: A reproducing apparatus includes a head unit operable to direct a laser light beam onto a recording medium, the head unit having a focus servo mechanism and a spherical aberration correction mechanism for laser light; an evaluation signal generating unit operable to generate an evaluation signal serving as an index of quality of a reproduced signal; a focus servo unit operable to perform a focus servo operation by driving the focus servo mechanism in response to a focus error signal; a spherical aberration correction unit operable to perform spherical aberration correction by driving the spherical aberration correction mechanism in response to a spherical aberration correction value; a focus bias unit operable to add a focus bias to a focus loop containing the focus servo unit; and a control unit operable to control adjustment of a spherical aberration correction value and a focus bias value to be set in the spherical aberration correction unit and the focus bias unit, respectively.

Abstract: A method and apparatus for controlling tilt in an optical disc device are provided. The method includes determining tilt offset values corresponding to different positions of an optical disc for a first tilt control mode, and deciding whether to switch to a static tilt control mode, based on a difference between the detected tilt offset values. If the disc is subject to defect management, a static tilt control mode is selected so that stable focus and tracking servo operations are maintained. If the disc is not subject to defect management, a dynamic tilt control mode is selected so that tilt control optimal for the skew of the optical disc, which gradually increases towards the outer perimeter of the disc, is performed. If the difference between tilt offset values detected respectively for inner and outer peripheral areas of the disc is small when the dynamic tilt control mode is selected, the device determines that the skew is low and changes the tilt control mode to the static tilt control mode.

Abstract: The light emitted from a semiconductor laser is divided by a diffractive optical element into three light beams which are 0th-order light as the main beam and ±1st-order diffracted lights as the sub-beams, and the track error signals by the main beam and the sub-beams are detected, respectively, by a differential phase detection method. By the effect of the diffractive optical element, the light intensity distributions of the main beam and the sub-beams become different when making incidence on an objective lens. Therefore, when there is radial tilt in a disk, the phases of the track error signals by the main beam and the sub-beams are shifted with each other. Based on the shift in the phases of the track error signals, radial tilt of the disk is detected.

Abstract: There are provided: an optical recording method containing a deviation detecting step, a horizontal location controlling step, and an interference image recording step; an optical recording apparatus containing a derivation detecting unit, a horizontal location controlling unit, and an interference image recording unit; an optical recording medium recorded in accordance with the optical recording method; and an optical reproducing method reproducing a recorded information recorded in accordance with the optical recording method.

Abstract: A holographic memory system is disclosed. The holographic memory system comprises: a light source configured to generate a light beam; a photosensitive holographic storage medium configured to at least partially reflect the light beam; and an alignment module configured to determine an angular orientation of the storage medium based on the reflected light beam.

Abstract: A method for adjusting a tilt angle of a light beam emitted by an optical pickup unit of an optical disc drive, the method includes steps of adjusting the tilt angle of the light beam according to test parameters preinstalled in the optical disc drive; detecting focusing error signals, the focusing error signals being generated based on the light beam reflected from an optical disc; generating current parameters based on the focusing error signals; storing the current parameters; adjusting the tilt angle of the light beam according to the current parameters.

Abstract: An optical disc drive apparatus may include an optical pickup that moves along a transportation shaft provided along a radial direction of an optical disc and picks up reflected light after emitting an optical beam via an objective lens to the optical disc; a drive section that controls the objective lens to adjust an angle of the optical beam; an angular velocity detection section that detects an angular velocity around the transportation shaft; storage means for storing coefficients from which the skew of the optical disc around a virtual axis perpendicular to the transportation shaft is calculated using the angular velocity; a skew estimation section that calculates a skew estimate value by multiplying the coefficient by the angular velocity; and a drive signal generation section that generates a drive signal based on the skew estimate value to enable the drive section to adjust the angle of the optical beam.

Abstract: An optical information reproducing apparatus and an optical information reproducing method using the same are provided. The optical information reproducing apparatus includes: a light source; a beam splitter which splits a beam emitted from the light source into a reference beam and a temporary beam; a temporary beam splitter which splits the temporary beam into a pair of assistant beams; an incident optical system which inputs the reference beam and the assistant beams to a recording medium in which optical information is recorded; a reproduction beam detector which detects reproduction beams reproduced in response to the reference beam, sets the position of the reproduction beam having the largest light intensity as a reference position, and sets a signal region on the basis of the reference beam; and an assistant beam detector which compares the light intensity of the assistant beams incident on the signal region with each other and sets an incident angle of the reference beam.

Abstract: An optical recording/reproducing apparatus, medium, and method and a controlling apparatus, medium, and method thereof. The recording/reproducing apparatus includes an optical pickup actuator including a holder formed on a base, a blade connected to the holder with a plurality of elastic supporters, a pair of focus coils for operating the blade in a focus direction, track coils for operating the blade in a tracking direction, magnets, a memory for storing a lookup table for the height of the blade according to electric current, a lookup table for the tilt of the blade according to the electric current supplied to the focus coils, a lookup table for the actual tilt of an optical disk according to the height of the blade, and a controller for computing a tilt difference between the optical disk and the blade and controlling the electric currents supplied to the focus coils to compensate for the tilt difference.

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.