Abstract: An optical pickup apparatus including a swing arm pivotably installed in a tracking direction with respect to a disc, and an optical pickup unit supported by the swing arm and driven in a focusing direction, wherein the optical pickup unit includes a laser diode, an objective lens to focus light emitted from the laser diode on a recording surface of the disc, and a heat sink plate to dissipate heat generated from the laser diode, wherein the heat sink plate is provided close to the disc so as to be directly exposed to wind generated during rotation of the disc.

Abstract: An optical pickup device includes an objective lens (2), with a numerical aperture (NA) being not less than 1, having a solid immersion lens (1) which is made up by a spherical portion (1a) and a flat portion (1b) parallel to a surface (101a) of an optical disc (101). The component of the reflected light from the optical disc in the polarized state perpendicular to the polarized state of the reflected light which prevails when the distance between the surface of the optical disc and the flat portion of the solid immersion lens is zero is detected. The so detected light intensity is associated with the distance between the optical disc surface and the solid immersion lens to accurately detect the minute gap between the optical disc and the solid immersion lens.

Abstract: Due to the axial runout of an optical disc, a frequency of a high-frequency current to be superimposed onto a DC current could not be maintained. In order to solve the problem described above, a drive signal is generated by superimposing a high-frequency signal onto a DC current, the drive signal is applied to a laser beam light source, thereby the light source is driven; and a servo signal at a signal level corresponding to a defocus amount of the laser beam relative to the surface of the optical disc is generated based on a reflected light of the laser beam from the recording surface of the optical disc, and a low-frequency component of the servo signal is extracted, and thereby the frequency of the high-frequency signal to be superimposed onto the DC current in the light source driver is controlled based on the low-frequency component of the servo signal.

Abstract: The present invention relates to an optical recording and reproducing device comprising an optical pick-up unit, position means for moving roughly the optical pick-up unit with respect to a desired position on an optical disc, an actuator for moving the optical pick-up unit relative to the position means in a radial direction of the optical disc, and a servo processor for delivering a control signal (u(k)) from a measured radial error signal (x(k)) derived from the optical pick-up unit. Said servo processor further comprises: —a state estimator (SEST) for delivering an estimated radial error signal ( ) and a predicted radial error signal ( ) on the basis of the measured radial error signal (x(k)) and of the control signal (u(k)); and—a shock detector (SDET) for delivering a shock indication (S_out) on the basis of the estimated radial error signal, of the predicted radial error signal, and of a sum (CA(k)) of the signals delivered by the at least two regions of the optical sensor.

Abstract: A method for pre-calibrating a balance gain of an analog front end in an optical disk drive to calibrate a variation of a focus balance. The method includes the steps of: adjusting the balance gain of the focus balance; moving a lens and getting an S curve; and comparing a positive half cycle of the S curve with a negative half cycle of the S curve. When the positive half cycle is equal to the negative half cycle, it represents that the balance gain of the focus balance is optimized and the procedure ends; or otherwise the above-mentioned steps are repeated to adjust the balance gain of the focus balance again. Because the balance gain is pre-calibrated, the optimal power calibration, the successful disk-reading possibility, the write-in quality and the stability of the disk judging mechanism can be enhanced and the consistency and the stability of the product can be improved.

Abstract: For providing a built-in type optical disc apparatus, to be installed in a part of an electronic equipment having plural kinds of electric power source portions within a housing thereof, enabling to protect from a malfunction or breakdown of parts thereof when power source is one-sided, thereby to achieve a desired operation with certainty, the optical disc apparatus comprises: a first electric power source portion, to convert a first power source voltage, which is supplied from an electric power source portion provided within the housing of the electronic equipment, into a predetermined voltage, to be supplied to a part of the respective portions, which build up said optical disc apparatus; and a second electric power source, to convert a second power source voltage, which is supplied from another electric power source portion provided within the housing of the electronic equipment, into another predetermined voltage, to be supplied to other part of the respective portions, which build up the optical disc ap

Abstract: An optical pick-up and a disc apparatus having the same to overcome an inferiority of a tracking signal caused by an adjacent layer during the recording and/or reproducing of an optical disc with multiple recording layers, the optical pick-up including: a light source to emit light with a wavelength corresponding to a type of the optical disc; a light collecting unit to focus the light emitted from the light source to form a light spot on a signal recording layer of an optical disc having a plurality of recording layers; a photodetector to receive a signal light reflected by the signal recording layer and a noise light reflected by an adjacent recording layer different from the signal recording layer, and to detect a signal from the signal light; and an optical member to change an optical transmission of the noise light according to an incident angle of the noise light so as to decrease an intensity of the noise light entering the photodetector.

Abstract: An optical pick-up and a disc apparatus having the same. The inferiority of a tracking signal caused by an adjacent layer during the recording and/or reproducing of an optical disc with multiple recording layers is effectively prevented. The optical pickup includes a light source to emit light with a predetermined wavelength, a light collecting unit to collect the light emitted from the light source to form a light spot on a signal recording layer of an optical disc having a plurality of recording layers, a photodetector to receive the light reflected by the optical disc to detect a signal, and an optical member to change the optical transmission of the light reflected by the optical disc according to an incident angle of the reflected light to decrease an optical transmission of a noise light entering the photodetector.

Abstract: An optical head device including a photo detector and an optical system which converges a laser beam emitted by a laser light source onto an optical recording medium and also guides a returning beam from the optical recording medium to the photo detector. The optical head device further includes a base on which the laser light and the photo detector are mounted. An optical element is mounted on the base via an optical element holder which has the same linear expansion coefficient as that of the base and is fixed with adhesive directly to the base. The optical element is fixed on a surface which is perpendicular to a device optical axis of the element holder.

Abstract: A system for page-based optical data storage includes a sensor array positioned to track a data page when the data page is optically read from or recorded to a storage medium. A servo mechanism is used to position the sensor array. A plurality of alignment points are defined relative to the photodetector pixel array. An alignment arrangement is located at each alignment point. The sensor array further includes servo-feedback signal generation logic operative to drive the servo mechanism based on error signals from the alignment arrangements, thereby aligning the two-dimensional photodetector array with respect to the two-dimensional data page.

Abstract: According to one embodiment, a device which identifies the types of recording media different in recording density including, a light source which outputs light at a predetermined wavelength, a photodetector which detects reflected light from one information recording layer of a recording medium having at least two information recording layers provided with a first recording density or a second recording density higher than the first recording density, a lens which condenses the light from the light source to present a minimum spot on one of the information recording layers of the recording medium, and a signal processing circuit which acquires a component containing characteristics peculiar to the information recording layer of the recording medium having the second recording density out of the reflected light detected by the photodetector.

Abstract: In an information recording apparatus using a hologram, a signal area of the light flux to be recorded is secured to be as wide as possible and the optical power loss is depressed during reproduction process. For this reason, almost the entire surface of the spatial light modulator is allocated as a signal area and the reference beam is collected on a micro mirror placed on its optical axis.

Abstract: The present invention provides an optical disk recording and reproducing apparatus having a circuit configuration whereby it is possible to prevent tracking drive signals from being offset even when the temperature of a tracking actuator drive circuit is increased.

Abstract: For a reproduction of optical sound information in a double variable-area track (DZ) an optoelectronic converter device scans the optical sound track of a film. The converter device generates a digital image signal for buffer storage in the memory of a program-controlled data processing device. The data processing device derives the profile of the two edges of the double variable-area track from data values of the buffer-stored image signal. Audio data for a sound reproduction are generated using data about the edge profile determined.

Abstract: Methods and systems for formatting of optical media used for data or information storage.

Abstract: A fixture plate is fixed by a screw onto an optical housing of the optical head device at a portion corresponding to where a monitor signal path portion and an act signal path portion are arranged overlapping one another. The two signal path portions are portions of two types of signal paths discretely formed on a flexible wiring board. The fixture plate is composed of a conductive material. One of the monitor signal path portion and the act signal path portion is covered by the fixture plate and fixed by a screw onto the optical housing together with the fixture plate, while the other of the monitor signal path portion and the act signal path portion is hooked in place by a hook provided on the fixture plate. The fixture plate is interposed between the monitor signal path portion and the act signal path portion.

Abstract: The invention is disclosed a method for promptly protecting a voice coil motor in an optical disk drive. A step (A) allows a data signal processor (DSP) to execute a protect module of the voice coil motor every preset time interval. In a step (B), the DSP executes following further steps during executing the protect module. A step (b1) reads tracking error (TE)/focusing error (FE) and determines if the TE/FE is over a safety range. A step (b2) starts a gain decrease operation of a signal amplifier if the TE/FE in step (b1) has been over the safety range for more than the first preset number of times so as to lower the control current outputting to the voice coil motor. A step (b3) starts an operation of speed reduction and a low current operation of a controller to secure the voice coil motor being safe if the TE/FE in step (b1) has been over the safety range for more than a second preset number of times.

Abstract: A control circuit of an optical storage device includes a loop phase calculation unit for calculating a closed loop phase of a servo system according to at least one error signal of the servo system and a system control unit coupled to the loop phase calculation unit for generating an optimized control parameter according to the closed loop phase to perform compensation control, wherein the servo system comprises a tracking servo control system or a focusing servo control system, the compensation control is radial tilt control or focus balance adjustment, and the optimized control parameter is at least one optimized control parameter determined according to a plurality of closed loop phases calculated by the loop phase calculation unit.

Abstract: An optical pickup actuator includes a bobbin, support members, and a pair of magnetic circuits. An objective lens is mounted on the bobbin. The support members have first ends fixed on sides of the bobbin and second ends fixed to a holder placed on a portion of a base to allow the bobbin to move with respect to the base. The magnetic circuits are installed on two sides of the bobbin and on the base. Each magnetic circuit includes a tracking coil which moves the bobbin in a tracking direction, a plurality of focusing/tilting coils which moves the bobbin in at least one direction of a focusing direction and a tilting direction having a focusing component, and a magnet which faces the focusing/tilting coils and the tracking coil and have a polarized structure to move the bobbin in the tracking direction and at least one direction of the focusing direction and the tilting direction having the focusing component.

Abstract: According to one embodiment, there is provided an optical disk apparatus including: a first determination unit configured to set a reference tracking offset and determine a reference recording power by an optimum power control processing; a tracing unit configured to trace a predetermined area in an optical disk by changing the tracking offset through use of an erase power calculated from the reference recording power; an acquisition unit configured to acquire an address information acquisition rate serving as a rate for reading address information, when data are traced in the predetermined area of the optical disk by changing the tracking offset within a predetermined range by the tracing unit; a second determination unit configured to determine, from the address read rate, a recording-operation tracking offset used during processing for recording the data into the optical disk; and an adjustment unit configured to adjust the recording-operation tracking offset.

Abstract: A method and an apparatus for scanning data stored along a track (16) on an optical storage medium (10) are provided. A light beam (12) is projected on the optical storage medium, thereby creating a scanning spot (14) that essentially follows the track (10). The relative position of the scanning spot (14) and the track (16) are varied in a radial direction. The variation of this positions occurs at a frequency v of v =?. S.4- NA/?, wherein NA is the numerical aperture of the light beam (12), X is the C wavelength of the light, S is the scanning speed, and ??0.01. The scanning spot is generated by a wavelength change is translated into a displacement of the beam by a pair of gratings.

Abstract: An optical pickup apparatus is provided with a dividing element having a plurality of regions. The dividing element is capable of dividing a light flux reflected by the optical disc into a plurality of light fluxes having different outgoing directions. Each region of the dividing element and light receiving parts of a light detector are structured such that when a target information recording layer of the optical disc is brought into focus, a light flux reflected from the target information recording layer is focused on the light receiving parts of the light detector, and a light flux reflected from other information recording layer than the target information recording layer is not irradiated onto the light receiving parts of the light detector.

Abstract: An optical scanning device for scanning an information carrier comprising tracks with a track pitch q, the closest track to the center of the information carrier having a radius r. The optical scanning device comprises a radiation source for generating a radiation beam and means for generating three spots on the information carrier from said radiation beam. The means for generating three spots are arranged in such a way that the distance s between two consecutive spots on he information carrier is such that equation (I) where s and q are in micrometers and r in millimeters, r is inferior to 10 millimeters and ? is superior to 0.2.

Abstract: An optical pickup apparatus includes a semiconductor laser for emitting a laser light, an objective lens for irradiating the light flux emitted from the semiconductor laser onto an optical disc, and a light detector for receiving the light flux reflected from the optical disc. The light detector has a light receiving part that comprises a region 1, a region 2, a region 3, a region 4, a region 5, a region 6 and a region 7.

Abstract: An optical disc includes tracking polarity information. The optical disc includes a clamping area, a lead-in area, a data area, and a burst cutting area (BCA). The BCA is present between the clamping area and the lead-in area and in which information regarding the optical disc is recorded, and the information is read before performing tracking in the data area. Accordingly, it is possible to obtain the tracking polarity information and/or reflectivity information without trial and error and directly record or reproduce user data in a data area of the optical disc.

Abstract: In order to fix a photodetector to an optical base with the photodetector held, a PD holder has a pair of engaging slots at which the PD holder is sandwiched between a pair of adjustment pints at both ends thereof and a pair of concave portions which are formed in a rear surface of the PD holder at both ends thereof and at which an adhesive is applied. The PD holder includes a substantially rectangular plate-shaped base extending in parallel with a plane defined by an X-axis direction and a Y-axis direction and a pair of protrusion portions extending forwards at both sides in the X-axis direction of the plate-shaped base. The pair of engaging slots are formed in the pair of protrusion portions and the pair of concave portions are formed in the rear surface of the pair of protrusion portions.

Abstract: An optical disk apparatus includes an optical pickup head (PUH) which outputs a laser beam through an objective lens. When a control unit receives an instruction to halt data read-out from an optical disk, the control unit moves the PUH to a predetermined position, stores a focus driving voltage corresponding to a position of the objective lens in a memory unit, and halts the output of the laser beam from the PUH. When the control unit receives an instruction to resume the data read-out, the control unit resumes the output of the laser beam from the PUH, starts a focus search on the basis of the focus driving voltage that is stored in the memory unit, moves the objective lens in a direction toward the optical disk, and achieves focus adjustment.

Abstract: A tilt adjusting mechanism adjusts a tilt of at least one of a plurality of objective lenses arranged to face an optical disc so that they have the same inclination state. The tilt adjusting mechanism includes a lens retaining cylinder to which an objective lens to be a target of the tilt adjustment is fixed, and a protector member to which the lens retaining cylinder is fixed from a slidable state for the tilt adjustment. In addition, as a surface for sliding movement of the lens retaining cylinder with respect to the protector member, there is provided a sliding surface that is a part of a spherical surface having a center that is a principal point of the objective lens or its adjacent, and the protector member has a portion protruding toward the optical disc so as to prevent a collision between the objective lens and the optical disc.

Abstract: A polarizing diffraction element is disposed between a photodetector and a liquid crystal lens to impart diffraction action to light reflected from a disk. The polarizing diffraction element is configured such that a focal distance of diffracted light having a predetermined order of the reflected light when the liquid crystal lens is in a first driving state is equalized to a focal distance of 0-order diffracted light of the reflected light when the liquid crystal lens is in a second driving state.

Abstract: An optical pickup device 50 comprising a laser diode 1, a photo detector 2, a housing 3 having an optical system for guiding light from the laser diode 1 to an optical disk and guiding light reflected on the optical disk to the photo detector, a wiring 5 to supply current to the laser diode 1, and a metallic cover 9 provided outside of the housing 3, wherein the laser diode 1 is bonded to the housing 3 by adhesive, a metallic member 10 is mounted on the surface of the laser diode 1 by connecting thermally, and the metallic member 10 is thermally connected to the cover 9 by solder.

Abstract: Of the two coil units 2-1 and 2-2 constituting an upper-stage coil unit, the coil unit 2-1 is passed through the winding of a coil unit 1-2 that constitutes a lower-stage coil unit, together with a coil unit 1-1, from inside to outside of the winding. A wire led inwards from the coil unit 2-1 of the upper-stage coil unit is passed through the inside of the winding of the coil unit 1-1 of the lower-stage coil unit, and is pulled outside the winding of the coil unit 1-1.

Abstract: A disk recorder/player (1) including a skew adjusting means of a thin design is provided which includes a base (101), a disk rotation driving mechanism (102) for an optical disk (4), an optical pickup (103), first and second guide shafts (105, 106) to support the optical pickup (103) at opposite ends of the latter, an optical pickup moving means (104) guided by the first and second guide shafts (105, 106) in moving the optical pickup (103) radially of the optical disk (4), an elastic member (126) put in contact with the first and second guide shafts (105, 106) to force the first and second guide shafts (105, 106) in a direction generally perpendicular to the main side of the optical disk (4), an adjusting screw (127) put into contact with the first and second guide shafts (105, 106) from the opposite side of the elastic member (126) to move the first and second guide shafts (105, 106) in a direction opposite to the direction of forcing by the elastic member (126), and a skew adjusting means (109) which adjust

Abstract: An object of the present invention is to acquire optimum recording characteristics of an optical recoding medium having multiple data layers, with respect to each of the multiple data layers without increasing learning time required for learning a relation between aberration amount and optimum recording compensation with respect to each of the multiple data layers. The present invention includes a wavefront converter which is driven in such a manner as to reduce the aberration amount detected by an aberration detector. An output controller holds learned data as to the relation between the driving amount of the wavefront converter and the output of a light source, and controls the output of the light source based on the driving amount of the wavefront converter and the learned data.

Abstract: The present invention discloses an optical pickup device comprising: a first objective lens focusing laser beam generated by a laser generator; a second objective lens focusing the laser beam with a focal length different from that of the first objective lens; a first lens housing portion having a first seat whereon the first objective lens is placed; a second lens housing portion having a second seat that is substantially ring shape; a ring shaped spacer put on the second seat and holding the second objective lens; a couple of foot portions protruding to the second seat from radially opposite positions in the spacer.

Abstract: Minimum deflection acceleration point detection, focus pull-in, and layer jump methods, and an optical disc drive capable of performing the methods. The method of detecting a minimum deflection acceleration point in an optical disc drive includes rotating a disc loaded in the optical disc drive, detecting a first minimum deflection acceleration point of the disc during one rotation cycle of the disc, and detecting a second minimum deflection acceleration point of the disc during one rotation cycle of the disc. Thus, a stable focus pull-in and layer jump is available.

Abstract: An optical disk apparatus includes: a light source that emits laser light; an optical section including an objective lens group positioned in close proximity to an optical recording medium to generate near-field light from laser light emitted from the light source; a gap servo section configured to control a gap between the optical recording medium and the optical section on the basis of a return light quantity of the laser light via the optical section; a focus adjusting section configured to adjust focus of the near-field light radiated onto the optical recording medium of the optical section, in a state where gap servo is being performed by the gap servo section; and a gap servo correcting section configured to correct the gap servo by the gap servo section when focus of the near-field light is adjusted by the focus adjusting section.

Abstract: The invention provides an information recording medium including highly reliable power calibration areas, as well as an information recording and reproducing device utilizing it. The medium is an information recording medium having a recording layer including a data recordable area 50 for recording user information signals, a lead-in area provided on the inner periphery of the data recordable area 50, an inner power calibration area provided further on the inside of the lead-in area for recording test recording patterns, and a recording management area for recording recording management information related to the inner power calibration area. An outer power calibration area 70 is provided on the outer periphery of the final point of recording of the user information signal on the recording layer.

Abstract: For providing a method for conducting a real-time compensation on the recording power during that verify process, and also for providing an optical disk apparatus for achieving the high-speed recording of information and the high quality, by adopting such the method therein, the method for compensating a recording power of an optical disk apparatus, for recording/reproducing information onto/from an optical disk 100, which forms a track made of spiral-like land and groove on a information recording surface thereof, and is executed with a verify process for a defect block within a user data recording area thereof, wherein when executing a verify process, error information of data, which is written by a light irradiated from an optical pickup 200, is obtained from a reproduced signal, which is reproduced from said optical pickup, and an intensity of the light irradiated from a laser light source of said optical pickup, upon basis of a ? value, which is obtained by a ? value detecting means 240, as well as, the

Abstract: An apparatus and method are disclosed to minimize seek time for dual stage actuator from both theoretical and real application viewpoints in optical disk drive application, where 1) a head mounted on a sled is positioned by a sled actuator; 2) A lens is mounted on the head with spring connection and optically coupled to a photo-sensor. A tracking actuator positions the lens with respect to tracks on the disk. The algorithms and designs include: a) dual stage mechanical models description from the real application consideration for track following and seek modes, respectively. The dual stage mechanical models describe the motion of lens and head driven by tracking and sled actuator in each mode. Meanwhile a simplified dual stage mechanical model with reduced parameters is given to decouple the link between lens and head; b) simplified model in track following mode and LHCE estimator design in track following mode.

Abstract: An optical disc drive and a control method thereof are disclosed to prevent unstable servo-control of a pickup module caused by an abnormal control signal, when recording/reproducing/erasing of information on/from an optical disc in the optical disc drive, and in particularly, possible collision between the pickup module and the optical disc, even when the pickup module very closely approaches the surface of the optical disc during recording/reproducing/erasing of information on/from a high density optical disc. The optical disc drive includes a pickup module having an objective lens focusing a laser on the surface of a recording layer of the optical disc, and a servo-controlling unit performing the focus servo-control of the pickup module using a high frequency broadband control and a low frequency broadband control of a focus error signal where the high frequency broadband control is performed prior to the frequency broadband control.

Abstract: The present invention provides an optical pick-up device and an optical recording/reproducing apparatus both of which can realize (i) a stable component accuracy, (ii) improvement in productivity, and (iii) low cost, without damaging an optical disk. The optical pick-up device that reproduces/records information from/onto an optical information storage medium by means of a laser beam, includes: a housing, which is a cabinet covering inner components of the optical pick-up device, having an opening section at least on a surface that faces the optical information storage medium when the optical information storage medium is set in place; and a protective cover that protects the opening section of the housing, wherein the protective cover is integrally formed with the housing.

Abstract: An optical pickup apparatus comprises: a first light source; a second light source; a third light source; and an objective optical element. The objective optical element comprises at least two areas comprising first and second optical path difference providing structures. A third light flux from the third light source passing the first optical path difference providing structure forms first and second best focuses. The third light flux passing the objective optical element forms a spot comprising a central spot portion; an intermediate spot portion; and a peripheral spot portion. The central spot portion is used for recording and/or reproducing information for a third optical disk, and the intermediate and peripheral spot portions are not used for recording and/or reproducing information for the third optical disk. The peripheral spot portion is formed on the third optical disk by the third light flux through the second optical path difference providing structure.

Abstract: An optical head having: a graded index lens which receives incident light radiated from a linear optical guide at one end surface of the graded index lens and transmits the incident light from the other end surface of the graded index lens, the graded index lens is adapted to form a light spot at a position that is away from the other end surface from which the incident light is transmitted; a light path deflection section which deflects light transmitted from the graded index lens, the light path deflection section is arranged between the other end surface from which the incident light is transmitted and the position where the light spot is formed; and a slider which floats on a recording medium while moving relative to the recording medium, wherein at least the graded index lens and the light path deflection section are installed on the slider.

Abstract: An optical disk apparatus, suitable for adjusting fluctuation of a light emitted from an optical pickup in the direction thereof, by means of a tilt adjusting mechanism, irrespective of thin-sizing of the housing of the apparatus, comprises within the housing 110, a disk motor 220, a turntable 120, which is rotationally driven by the disk motor, an optical pickup 130, which is attached to be movable into a radial direction of the optical disk “D” loaded, and a tile adjusting mechanism (shafts 230 and 235, adjusting screws 231 and 236, etc.) enabling an adjustment of an inclining angle of the optical pickup with respect to the optical disk, which is loaded onto said turntable, wherein the optical pickup is attached on a chassis 210, which is attached to be in parallel within the housing, together with the tilt adjusting mechanism, and further the disk motor 220 is attached, being inclined by a predetermined angle with respect to the chassis.

Abstract: A method of controlling an optical pick-up head to access an eccentric disk. When a loaded disk is determined as an eccentric disk causing a lens of the optical pick-up head crossing between a first track being close to the inner disk and a second track being close to outer disk, a tracking on position has to be concerned. IF a target track is close to the second track, provide a first force to move the lens a distance toward the inner disk then execute a track on operation. IF the target track is close to the first track, provide a second force to move the lens a distance toward the outer disk then execute a track on operation.

Abstract: It is an object of the present invention to provide an optical pick-up device capable of being miniaturized by reducing the number of components. The present invention provides an optical pick-up device including a light-emitting device having an organic compound that emits laser light upon applying current. The light-emitting device interposes an organic compound layer between a pair of electrodes. The organic compound layer, which is a main component, has a layer configuration for emitting a laser beam. In the layer configuration, the thickness of each layer is determined in consideration of the wavelength of laser oscillation. The organic compound layer is composed of a plurality of layers, each of which has different properties such as carrier transportation properties or light-emitting properties. The organic compound layer is preferably formed to have a so-called resonator structure formed via a reflecting layer.

Abstract: An actuator of an optical disk system and an apparatus producing a signal for driving the actuator, the actuator including a light source, with which information is recorded on or reproduced from an optical disk surface. In the actuator, an inner focusing coil and an outer focusing coil are installed near an inner boundary and an outer boundary, respectively, of the optical disk surface. A first signal wire is connected to a first port of the inner focusing coil and transmits an inner coil signal. A second signal wire is connected to a first port of the outer focusing coil and transmits an outer coil signal. A common signal wire is connected to a second port of the inner focusing coil and a second port of the outer focusing coil and transmits a common reference signal. Thus, a simple, inexpensive 8-wire actuator can be obtained.

Abstract: An object of the present invention is to provide a focus out detecting apparatus which detects focus out with accuracy during reproducing or recording of data from/on an optical disc having a plurality of recording layers. Further, another object of the present invention is to provide an optical disc apparatus in which a recording or reproducing performance of data is improved by use of the focus out detecting apparatus. A focus out detection signal is output when a level of a focus error signal exceeds a first predetermined level, then reflected light quantity from the optical disc becomes lower than a third predetermined level in a predetermined period, and then the level of the focus error signal exceeds a second predetermined level of an opposite polarity to the first predetermined level.

Abstract: An optical pickup in which the position of a magnet can be adjusted with respect to a yoke is provided. The optical pickup has an objective lens, a lens holder that holds the objective lens, a magnet disposed opposite to a side surface of the lens holder, and a yoke to the inside of which the magnet is attached. The yoke has an opening at least near the bottom of the magnet, through which the magnet can be visually observed from the outside of the yoke, the bottom being on the side of the yoke that is farther from an optical disc and the top being on the side of the yoke that is closer to the optical disc along the optical axis of the objective lens.

Abstract: The present invention discloses an XY platform device with nanoscale precision including an optical pickup head for focusing and seeking the tracks of an optical data storage medium; a servo device for driving the optical pickup head to move in focusing and radial directions; a carrier platform for receiving a testing object thereon and providing a connecting member to be connected with the optical pickup head. With the focusing and radial movements of the optical pickup head, the carrier platform is driven to move accordingly, and thus achieving the high-precision and low-cost effects.