Abstract: The present invention involves with a dynamic distributed processing method for stream data, at least comprising: analyzing and predicting an execution mode of at least one data feature block of the data of a user stream data processing program; dynamically adjusting the execution mode based on an average magnitude of queue latency and a threshold of queue latency of the stream data; and processing corresponding said at least one data feature block based on the execution mode. By associating and combining the irrelevant data stream mode and micro-batch mode of stream data computing, the present invention successfully releases automatic shift and data process between the two modes, which advantageously has both the high throughput property and the low latency property.

Abstract: Disclosed are a laser range finding sensor and a range finding method therefor. The laser range finding sensor comprises a motor (120), a control box (130), and a coded disc (150). Under a drive of the motor, the control box rotates relative to the coded disc. The coded disc comprises a plurality of range finding teeth (151). The control box comprises a range finding unit (142), a detection portion (144), and a control unit (140). The detection portion comprises a light transmitter (1440) and a light receiver (1441) disposed opposite to each other. The control box rotates relative to the coded disc, so that the range finding teeth pass between respective positions of the light transmitter and the light receiver. The control box rotates under the drive of the motor for scanning and distance measuring and records a measured distance value in the control unit. The control unit automatically calculates a corresponding local rotation speed when the coded disc rotates by a set angle.

Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a laser configured to heat the disk while writing data to the disk. A write power is applied to the laser in order to write data to the disk during a write operation. A determination is made as to whether the laser power should be in an off state after the write operation. After the write operation, the laser power is gradually decreased to the off state based on a first decrease function.

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 optical disc device uses an optical disc (6) capable of super-resolution reproduction, and includes a semiconductor laser (1), a laser driving circuit (21) that supplies a driving current to the semiconductor laser, a light receiving element (8) that detects return light from the optical disc (6) and obtains reproduction signal of recording data of the optical disc (6), and a light emission amount control means (22) that controls a light emission amount of the semiconductor laser (1) by the laser driving circuit (21) so as to keep a peak intensity of a focused light spot formed on an information recording layer of the optical disc 6 to be greater than or equal to a peak intensity at which a super-resolution effect is obtained.

Abstract: In one embodiment, an optical pickup device includes a fixed portion 100, a movable portion 11, first and second elastic supporting members 12a and 12b, one and the other ends of which are secured to the fixed portion 100 and the movable portion 11, respectively, and an objective lens 8 secured to the movable portion 11. The objective lens 8 is arranged inside of the area that is defined between two lines that are respectively drawn from one and the other ends of the first elastic supporting member 12a perpendicularly to the first elastic supporting member 12a and outside of the area defined between the first and second elastic supporting members 12a and 12b.

Abstract: There is provided a skew detection method including supplying reproduction signals, which are respectively reproduced approximately simultaneously from at least two tracks including a first adjacent track and a second adjacent track located on both sides of a main track, to first and second filters, causing a combining unit to combine output signals of the first and second filters with a reproduction signal which is reproduced from the main track approximately simultaneously with the first adjacent track and the second adjacent track so as to cancel crosstalk, causing a coefficient control unit to obtain an error with a target value of the output signal of the combining unit and control coefficients of the first and second filters so as to reduce the error, and detecting a skew of an optical disc from values of coefficients of predetermined taps of the first and second filters.

Abstract: A management apparatus is described of a rotating motor and a load during power loss; the apparatus comprises a first switching circuit coupled with the rotating motor and a controller of said first switching circuit. The controller is configured to drive the first switching circuit so as to convert a back-electromotive force voltage developed in the rotating motor into a power supply voltage for the load. The first switching circuit is driven in accordance with a first duty cycle. The apparatus comprises a second switching circuit coupled with the load and driven in accordance with a second duty cycle. The controller is configured to vary said first and said second duty cycles to keep the power supply voltage for the load above or equal to a threshold voltage.

Abstract: An unbalanced disc determining apparatus is provided. The unbalanced disc determining apparatus includes a noise reduction unit configured to reduce noise components of a center error signal obtained from a signal configured to detect light reflected by a disc revolved by a spindle motor, and a determination unit configured to determine whether the revolving disc is unbalanced by determining whether the center error signal of which noise is reduced exceeds a reference value.

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 optical disc apparatus includes: a light irradiation/reception section to irradiate an optical disc recording medium with light via an objective lens and receive return light of the light; a tilt adjustment section to tilt the lens; a focus servo control section to exert focus servo control over the lens; a focus bias application section to apply a focus bias to a focus servo loop; a tracking direction error signal generation section to generate a tracking direction error signal representing an error between light-reception signals; and a control section to perform a tilt adjustment value search process for making a search for a tilt adjustment value with which the tracking direction error signal is maximized, a tilt adjustment value revision process for revising the tilt adjustment value found by the tilt adjustment value search process, and an adjustment control process for causing the tilt adjustment section to perform tilt adjustment.

Abstract: An optical disc device and a recording method is provided in which information can be additionally recorded on an optical disc, which has a servo layer and recording layers separately formed, by accurately correcting a relative angle between a light beam and the optical disc used in the previous recording without providing an area where recording is not performed while maintaining the stability of tracking servo. The above subject can be solved by studying with high accuracy the relative angle between the optical disc and the optical axis used in the previous recording by applying a radial tilt servo according to a signal from the recording layers with the tracking servo applied by the servo layer. Further, the additional recording can be performed stably by fixing the radial tilt at the previously studied angle when the recording is performed.

Abstract: A tilt can be detected highly accurately by minimizing the tilt detection error. An optical head includes: an objective lens for converging a light beam from a light source onto an optical disc; a photodetector section receiving the beam, reflected from the disc, at divided areas on its photodetection plane and outputting light detection signals from those areas; and a tilt detecting section for detecting a relative tilt between the lens and disc based on the detection signals.

Abstract: An optical disc apparatus in accordance with the present invention includes: a plurality of light sources; an optical system which has at least an objective lens that condenses light beam emitted from the light sources on a recording layer of an optical disc and a collimator lens that is arranged between the light sources and the objective lens; a lens tilting mechanism which tilts the objective lens; a collimator lens driving mechanism which moves the collimator lens along an optical axis direction; and a most appropriate setting deciding portion which decides in a prescribed timing a most appropriate setting about position of the collimator lens and tilting of the objective lens while changing the position of the collimator lens and the tilting of the objective lens utilizing the collimator lens driving mechanism and the lens tilting mechanism.

Abstract: An optical pickup, an inclination angle detection method, an optical information device, and an information processing device capable of reliably and accurately detecting a relative inclination angle between an end face of a solid immersion lens and a surface of an optical recording medium are provided. A convergence position modifying unit modifies convergence states of a first beam and a second beam according to layers of an optical recording medium, a first optical detector includes a first light receiving section which receives the converged first beam and a second light receiving section which receives the converged second beam, and the first optical detector detects a relative inclination angle between an end face of a solid immersion lens and a surface of the optical recording medium based on a difference in quantities of received light between the first light receiving section and the second light receiving section.

Abstract: Provided is an objective lens, which is provided in an optical pickup including a spherical aberration correction mechanism which performs a spherical aberration correction with respect to laser light applied to a recording layer of an optical recording medium, having the recording layer on which information can be recorded at a plurality of positions in a depth direction, via the objective lens, and a tilt correction unit which varies a lens tilt angle which is a tilt angle of the objective lens, thereby performing a tilt correction.

Abstract: To carry out a track control by compensating for an offset caused by a radial tilt when a track control of a main beam is carried out by detecting tracking information provided at a reference layer of a spatial recording medium by a guide beam, there are formed a first mark pair row aligned with the first mark pairs in a radius direction by a track pitch, and other mark pair row aligned with the second mark pairs in the radius direction by the track pitch. The other mark pair row is arranged in the radius direction by being shifted from the first mark pair row by a prescribed distance. The track control is made to be able to carry out by dispensing with an uncontrollable region by selecting one of plural track error signals generated from the plural mark pairs.

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 data recovery device including a filter, a tilt detection unit, a tilt cancellation unit and a data conversion unit is provided. The filter filters a radio-frequency data stream to generate an original data stream. The tilt detection unit synthesizes a tangential push-pull data stream by employing a first to a fourth data streams, and generates a tilt direction signal according to symmetry of a curve composed by the tangential push-pull data stream. The tilt cancellation unit detects a plurality of rising areas and falling areas of the original data stream, and reconstructs a plurality of data points corresponding to the rising areas or falling areas in the original data stream so as to generate a tilt repair data stream. The data conversion unit recovers the tilt repair data stream to a modulation signal.

Abstract: An optical disk apparatus driving an optical disk includes a tilt-angle adjusting unit configured to adjust a tilt angle indicating the tilt of an optical axis of laser light emitted from a pickup to detect an optimal tilt angle at which a traverse signal has the maximum amplitude and a storing unit configured to store information about the optimal tilt angle. When the optical disk has multiple recording layers on one side, the tilt-angle adjusting unit adjusts the tilt angle with respect to each of the multiple recording layers to detect the optimal tilt angle and the storing unit stores information about the optimal tilt angle with respect to each of the multiple recording layers. The tilt angle with respect to each of the multiple recording layers is controlled in accordance with the information about the optimal tilt angle with respect to each of the multiple recording layers.

Abstract: A method for detecting whether vertical deviation of an optical disc occurs is provided. First, before a pickup head is successfully focused on the optical disc, a pickup head is actuated based on an input control signal so as to generate a focus error signal with a plurality of S-curves. Then, a plurality of zero crossing points of the S-curves in the focus error signal is identified and a plurality of input control values respectively corresponding to the zero crossing points is obtained. A variation of the input control values is then calculated. Whether vertical deviation of the optical disc occurs can be determined according to the variation of the input control values.

Abstract: A recording apparatus that performs recording of data on a disc-shaped recording medium including a recording area, which is capable of recording user data therein, and a replacement area, which is replaced by a defect area included in the recording area, includes a setting section configured to replace a portion of the recording area by the replacement area, and set the portion of the recording area as an area for adjustment, and an adjustment section configured to perform adjustment by using the area for adjustment.

Abstract: The relation between the cover layer thickness of a data recording surface and ratio ? of SCO to SCD is previously calculated and stored in a storage unit, where SCD denotes coma aberration which occurs when the data recording medium is tilted by unit angle and SCO denotes coma aberration which occurs when the objective lens is tilted by unit angle. When ?1 denotes ratio ? for a data recording surface corresponding to the smallest cover layer thickness, tilting angle ?1 of the objective lens is determined based on the ?1 and a tilt adjustment of the objective lens is made. Also, when ?2 denotes ratio ? for a target data recording surface, tilting angle ?2 of the objective lens is estimated based on the ratio of ?2 to ?1 and a tilt correction of the objective lens is made.

Abstract: An objective lens driving device includes an objective lens holder that holds an objective lens, plural elastic supporting members through that support the objective lens holder, tracking coils and that drive the objective lens holder in the tracking direction, tilting coils that tilt the objective lens holder with respect to the optical axis passing through the objective lens, a tracking control circuit that drives the tracking coils, and a tilting control circuit that drives the tilting coils. The tilting control circuit drives the tilting coils using a signal yielded by multiplying a tracking driving signal from the tracking control circuit by a specific scaling factor so as to cancel out a tilting force of the objective lens holder generated by the tracking coils.

Abstract: A data recording/reproduction method for performing a data recording/reproduction process on a flexible optical disk by rotating the flexible optical disk while controlling an axial runout of the flexible optical disk with a stabilizing member that applies an aerodynamic force to the flexible optical disk, and irradiating an optical beam and focusing the optical beam to the flexible optical disk is disclosed that includes the steps of a) generating a first axial runout, b) generating a focus error signal forming an S-curve when the first axial runout is generated, c) determining a position of the optical beam according to the focus error signal, d) generating a second axial runout that is smaller than the first axial runout after step c), and e) conducting at least one of the data recording process and the data reproduction process after step d).

Abstract: In optical recording and/or reproduction using an SIL optical system that performs a tilt servo using light for recording and/or reproduction, the SIL and an optical recording medium have a high probability of colliding with each other before the tilt servo is started. To prevent the collision, an optical recording/reproduction method performs a gap servo that controls a gap between a surface of an optical recording medium and a bottom surface of an SIL using reflected light that is generated from light traveling from the bottom surface of the SIL and reflecting on the optical recording medium, a focus servo that controls a distance between a focal point of the light and the bottom surface of the SIL, and a tilt servo that controls a tilt of the bottom surface of the SIL relative to the surface of the optical recording medium using the reflected light.

Abstract: In an objective lens actuator of an optical disk drive and the like, variations in the fixed end positions of wires serving as suspensions are reduced and tilt characteristics are improved. Terminal plates 20 fixed to a lens holder are tilted relative to wires 13 for supporting the lens holder with elasticity, and are soldered at the edges of the terminal plates 20, so that variations in the fixed end positions of the wires 13 are reduced.

Abstract: An optical drive device for performing information recording or reproduction of recorded information by formation of a mark by focusing a first light at a necessary position in a recording layer of an optical recording medium by an objective lens includes a position control unit configured to focus a second light on a reflection film, in which a position guide element of the optical recording medium is formed, through the objective lens and to enable the spot position of the second light to follow the position guide element based on the reflected light of the second light focused on the reflection film so as to control the position of the objective lens. The optical drive device further includes a first focusing unit, a first light-sensing portion, and a surface reflection light deviation amount detection unit.

Abstract: An optical pickup device includes a semiconductor laser which emits a light beam, first and second objective lenses which focus the light beam onto a first and second optical disc, respectively, a grating which branches a light beam reflected from the second optical disc, an optical detector having a plurality of light receiving parts, which receives light beams branched by the grating, and an actuator which displaces the first and second objective lenses in a radial direction of the first optical disc and the second optical disc. The grating has a first area on which a 0-order diffraction light beam and a +1-order diffraction light beam upon reflection at the second optical disc enter, and a second area on which a 0-order diffraction light beam and a ?1-order diffraction light beam upon diffraction through the second optical disc enter.

Abstract: Techniques are provided for controlling the reading of optical data from a master disk in a holographic replication system. Imperfections in the master disk or movement of the disk during a recording process may cause source beams to deviate from target data tracks. In some embodiments, a detector system is used to determine the focus and alignment of the source beams on the master disk, as well as the tilt and rotation of the disk with respect to the holographic replication system. The detector system may detect deviations in the intensity distribution of the reflections of the source beams and generate an error signal corresponding to focusing, tracking, tilt, and/or rotational errors. Servo-mechanical devices may actuate optical components to compensate for such errors.

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 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: Disclosed is an adjustment apparatus for adjusting an optical pickup capable of recording and/or reproducing plural optical discs of different sorts. The adjustment apparatus is an optical disc for adjustment (1) having a first signal recording layer (5) having a physical format in common with a CD and a second signal recording layer (7) having a physical format in common with a DVD. On the first and second signal recording layers, there are concentrically recorded EFM modulated data. The respective signal recording layers are provided with recording areas (8), (9) not overlapped with each other.

Abstract: A method for detecting an obliquity of an optical disc drive is disclosed. The method includes the following steps: setting up and storing a function between the obliquity and a central error signal bias by performing a current level calibration upon a plurality of obliquities of the optical disc drive predetermined to be tested to obtain corresponding central error signal biases; performing the current level calibration upon an objective lens of the optical disc drive; obtaining a calibrated central error signal bias; and acquiring the obliquity of the optical disc drive by interpolating or extrapolating the calibrated central error signal bias according to the stored function between the obliquity and the central error signal bias.

Abstract: A method for detecting whether vertical deviation of an optical disc occurs is provided. First, before a pickup head is successfully focused on the optical disc, a pickup head is actuated based on an input control signal so as to generate a focus error signal with a plurality of S-curves. Then, a plurality of zero crossing points of the S-curves in the focus error signal is identified and a plurality of input control values respectively corresponding to the zero crossing points is obtained. A variation of the input control values is then calculated. Whether vertical deviation of the optical disc occurs can be determined according to the variation of the input control values.

Abstract: There is provided a method of recording and reproducing an optical recording medium which performs a tracking servo and a focusing servo by irradiating a laser beam onto determined positions including lands and grooves of a track of the recording medium and detecting a tracking error signal and a focusing error signal using an electric signal from an optical pickup for picking up the laser beam reflected from the recording medium. The method includes the steps of: detecting servo information in a plurality of the determined positions including lands and grooves of the track while rotating the recording medium in a state in which only the focus servo is turned on when the optical recording medium is loaded, storing the servo information of the respective determined positions as a table, and performing the servo of the corresponding positions by applying the servo information in table during an actual data recording/reproduction.

Abstract: A hologram recording/reproducing device includes an optical section which irradiates a holographic recording medium with an optical beam; and a control unit which controls the optical section. The optical section includes a laser light source which emits the optical beam, and a spatial modulator which modulates the optical beam. By controlling the spatial modulator, the control unit displays a tilt-standard reference light pixel and a tilt-standard signal light pixel, and records a tilt-standard hologram.

Abstract: An optical disk drive device has an RF equalizer configured to generate an equalized RF signal by controlling a frequency characteristic of a delay time of an RF signal read out from an optical disk based on a control input signal, a playback clock extractor configured to extract a playback clock for reproducing data recorded on the optical disk from the equalized RF signal, and an RF rate controller configured to generate the control input signal inputted to the RF equalizer, wherein the control input signal is a signal for correcting waveform distortion of the RF signal by controlling the delay time of the RF signal dependent on a frequency of the playback clock.

Abstract: A hologram device includes: a light source for applying light to a hologram recording medium having a recording layer in which information recording is performed by interference fringes between signal light and reference light; a spatial modulation unit that generates the signal light and/or the reference light and generates a marker light in a predetermined position within an incident surface of the light from the light source by performing spatial light modulation on the light from the light source; a light applying unit that applies the light subjected to spatial light modulation by the spatial light modulation unit to the hologram recording medium via an objective lens; a light receiving unit that receives the light applied via the objective lens through the hologram recording medium; and a tilt detection unit that obtains a tilt error signal representing an error from an ideal angle of a tilt angle as an incident angle of the applied light via the objective lens to an information recording surface of the

Abstract: A method for detecting whether vertical deviation of an optical disc occurs is provided. First, before a pickup head is successfully focused on the optical disc, a pickup head is actuated based on an input control signal so as to generate a focus error signal with a plurality of S-curves. Then, a plurality of zero crossing points of the S-curves in the focus error signal is identified and a plurality of input control values respectively corresponding to the zero crossing points is obtained. A variation of the input control values is then calculated. Whether vertical deviation of the optical disc occurs can be determined according to the variation of the input control values.

Abstract: An information recording and reproducing apparatus for increasing a speed of tilt control, including a portion for storing reference data, a portion for storing sample values data, a portion for obtaining positional information, a stilt servo generator, a tilt adjuster.

Abstract: An information recording and/or reproducing apparatus includes an optical head, an analog signal processor, an analog/digital converter, a controller and a digital/analog converter. The optical head is used for emitting a light beam on a medium and receiving a reflected light beam from the medium. The analog signal processor is used for processing the reflected light beam to obtain a first analog signal. The analog/digital converter is used for converting the first analog signal into a digital signal. The controller is used for applying a low-pass filtering operation on the digital signal to obtain a digital controlling signal. The digital/analog converter is used for converting the digital controlling signal into a second analog signal. The second analog signal is transmitted to the optical head for correcting a tilt between the light beam and the medium.

Abstract: An object of this invention is to measure the tilt quantity of, and perform a tilt control on, an optical disc accurately without depending on the rotation control method. An optical disc drive includes: a motor for rotating an optical disc; an optical system for irradiating the optical disc with a light beam; a moving mechanism for moving the optical system along the radius of the optical disc; a focus control section for controlling movement of the optical system perpendicularly to the optical disc based on drive values, thereby focusing the light beam onto a storage layer of the optical disc; and a tilt control section for measuring the tilt quantities of the storage layer at multiple different radial locations on the optical disc based on drive values for the respective radial locations when the focus control section focuses the light beam there.

Abstract: The optical disc apparatus according to the present invention includes a tilt detecting means; a coma aberration correcting means; and a spherical aberration correcting means. Based on the result of a tilt detection, the amount of the correction performed by the coma aberration correcting means is determined so that the amount of correction is constant for the whole circumference of an optical disc, and then a spherical aberration is corrected by the spherical aberration correcting means. Thus, it is possible to correct the spherical aberration that has occurred due to the coma aberration correcting means, while the tilt margin is secured, thereby improving the reliability of reproduction and recording by the optical disc apparatus. Further, the optical disc apparatus according to the present invention is configured, in the case where a thermal shock tilt has occurred during the activation of the apparatus, to wait until the thermal shock tilt has settled.

Abstract: With an optical disc apparatus of the present invention, the number of tracks of an optical disc crossed by a light spot when the tracking control is inactive is measured and stored in a memory for each passage of a predetermined rotation angle. When the tracking control is active, a lens tilt driving signal is generated by multiplying the value of a memory section corresponding to the disc rotation angle by a gain according to the disc rotation speed, thereby correcting the AC tilt occurring due to a lens shift.

Abstract: A disk motor which rotationally drives an optical disk; a rotational phase detector which detects a rotational phase thereof; an optical head having a collecting lens which collects an optical bean; a light detector and an LE signal generator which detect a position of the collecting lens in the optical head as a position signal; an LE signal memory recorder and an LE signal memory which store, in synchronization with a rotational phase to be detected by the rotational phase detector, the positional signal from the LE signal generator; an LE signal memory regenerator which outputs as a correction signal, in synchronization with a rotational phase to be detected, the positional signal which has already been detected; a subtractor; an LE signal filter, a drive circuit and a Tk actuator which move the collecting lens using a signal from the subtractor; and a low pass filter which reduces a high-frequency component of the correction signal are provided.

Abstract: A method for adjusting a tilt of an optical pick-up head includes the steps of: moving the optical pick-up head to a first location and focusing on; obtaining a first focus control power and a first optimum tilt angle at the first location; moving the optical pick-up head to a second location and focusing on; obtaining a second focus control power and a second optimum tilt angle at the second location; calculating an optical sensitivity according to the first and second optimum tilt angles, and the first and second focus control powers; and when the head is moved to a specific location where the tilt of the head is to be adjusted, storing a focus control power corresponding to the specific location, and calculating a tilt angle corresponding to the specific location according to the focus control power and the optical sensitivity so that the tilt of the optical pick-up head can be appropriately adjusted.

Abstract: A tilt control method for a near-field optical disc drive is provided. A gap between a lens and a disc is estimated. A tilt compensation for the lens is estimated according to a tilt signal when the lens is within a far-field region. A coarse tilt control is performed on the lens according to the tilt compensation when the lens is within the far-field region.

Abstract: A pickup apparatus including: at least a coil constituting an actuator, a signal to be sent to the coil being obtained by calculation using an algorithm on the basis of at least one of a focus error signal and a tracking error signal.

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