Abstract: A spot position control device includes a light irradiation and light sensing unit irradiating an optical recording medium with first light via an objective lens and sensing reflection light of the first light from the optical recording medium having a pit string where an interval between pit formable positions on one round is limited to a first interval, a tracking mechanism unit displacing the objective lens, a clock generation unit generating a clock corresponding to the interval between the pit formable positions, a timing selector signal generation unit generating a plurality of timing selector signals, a tracking error signal generation unit generating tracking error signals, a linear tracking error signal generation unit generating a linear tracking error signal indicating a tracking error amount linearly, a tracking servo control unit performing a tracking servo control, and an offset giving unit giving an offset to a tracking servo loop.

Abstract: An optical head includes a diffraction element capable of improving the quality of a TE signal by a DPP method even if light amounts of two sub-spots are unbalanced for optical discs having different groove pitches. In a three-beam optical head, a diffraction element is divided in a radial direction of an optical disc into a first area, a second area and a third area, wherein the second area is further divided into a fourth area and a fifth area. The periodic structure of the first area is displaced from that of the fourth area by a ¼ period, the periodic structure of the third area is displaced from that of the first area by a ½ period, and the periodic structure of the fifth area is displaced from that of the third area by a ¼ period and from that of the fourth area by a ½ period.

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

Abstract: A recording apparatus including: a light-illuminating/receiving-unit illuminating an optical-disc-recording-medium through a common object-lens with recording-light and ATS-light and receiving reflected-ATS-light; a rotation-driving-unit driving rotation of the medium; a tracking-mechanism driving the lens in a tracking-direction parallel to the radial direction; a tracking-error-signal-generation-unit generating a tracking-error-signal; and a tracking-servo-controller performing tracking-servo-control on the lens based on the tracking-error-signal, wherein the tracking-servo-controller includes: a servo-calculation-unit based on the tracking-error-signal in a feedback-loop as a tracking-servo-loop; and a feed-forward-controller calculating an estimated control-target-value of the tracking-servo-control based on an estimated illumination-spot-position value of the ATS-light obtained in a first-filter-process emulating a transfer-characteristic of the tracking-mechanism on an output of the servo-calculation-un

Abstract: An optical pickup includes a light source, an optical system for irradiating a recording medium including a plurality of recording layers with light from the light source, a diffraction optical element that divides light reflected from the recording medium into a plurality of optical fluxes and diffracts the fluxes, and an optical detector receiving the optical flux diffracted by the diffraction optical element. The optical detector includes a light receiving element detecting a focus error signal, wherein a longitudinal direction of the light receiving element is arranged to coincide with a circumferential direction of the recording medium, or arranged to be inclined to a circumferential or radial direction.

Abstract: A distance control circuit keeps constant the distance between a condensing member and the surface of an optical disk using return light from a region where near field light is generated. Additionally, a focus control circuit controls the focus position of the near field light to sustain it at the position of an information layer using reflection light from the information layer.

Abstract: An optical disk driving apparatus includes an optical head device having a laser light source, a converging optical system converging a light beam emitted by the laser light source onto an optical disk, a photo detector receiving reflected light reflected by the optical disk, and an aberration correcting optical system controlling aberration of the converging optical system; a motor rotating the optical disk; and a control section receiving a signal from the photo detector, wherein the converging optical system has an objective lens formed using resin as a main material, the aberration correcting optical system has a spherical aberration correcting element correcting spherical aberration, and the control section evaluates quality of a reproduction signal for information in the optical disk by using the reflected light received by the photo detector, and utilizes a result of the evaluation to perform closed loop control on the spherical aberration correcting element.

Abstract: An optical pickup is provided with a protector which prevents collision between an objective lens and an optical recording medium. The protector includes: a first sheet material which is arranged on an uppermost layer, has durability for abrasion against the collision with the optical recording medium that rotates in high speed, and is softer than a protecting member that protects a recording surface of the optical recording medium; a second sheet material which is provided in lower side than the first sheet material and has elasticity; and a plurality of adhesive sheets to perform adhesion between the sheet materials that form the protector, or adhesion between the lowermost sheet material among the sheet materials and a lens holder which holds the objective lens, or the objective lens.

Abstract: An optical disc includes a reflective film formed on concave and convex marks after the concave and convex marks are synchronized with the integral multiple of a channel bit length and formed in accordance with modulated main information. Thereafter, continuous or intermittent laser light synchronized with the integral multiple of the channel bit length is irradiated at intervals longer than the longest one of the concave and convex marks in accordance with a spiral track formed in a circumferential direction of the concave and convex marks, whereby an optical characteristic of the reflective film is changed to form a recordable mark and sub-information necessary to reproduce the main information is recorded in a superimposition manner.

Abstract: A method and apparatus for recording digital information signals on a removable rewritable medium include recording control information on defect management. The recording medium includes predefined locations for enabling booting and/or file system read/write, where at least one of the predefined locations contains the control information.

Abstract: An optical-pickup apparatus includes first and second objective lenses that focus first and second laser light on information-recording layers of first and second optical discs, the second optical disc having an information-recording format different from that of the first optical disc; and a lens holder that integrally holds the first and second objective lenses in an adjacent manner, a disc surface of the first optical disc and of the second optical disc being substantially parallel to confronting faces of the first and second objective lenses, that confront the disc surface, a minimum distance between the disc surface and the confronting faces in a direction of an optical axis of the turntable being greater than a thickness of the turntable in a direction of a rotation axis of the turntable, either one or both of the first and second objective lenses configured to focus bluish-violet laser light on an optical disc.

Abstract: An optical integrated unit according to the present invention is an optical integrated unit, including: a semiconductor laser acting as a light source; at least one light-receiving element; a light-separating section for separating light emitted by the semiconductor laser from light reflected by an optical disc and for reflecting the light reflected by the optical disc so that the light reflected by the optical disc is directed to the light-receiving element; and a support substrate, wherein a second support substrate has a concave shape, the light-separating section is constituted of at least three prisms, the prisms positioned at both ends of the light-separating section are respectively attached to two protruding sections of the concave shape of the second support substrate, and the light-receiving element is attached to the light-separating section via a cover glass.

Abstract: To provide an optical head to produce good servo and read signals by reducing the influence of interference by light reflected from a non-read layer of a multilayer optical disc. The head includes: a first optical system for converging light from a light source on a first or second storage layer; a second optical system for receiving and transmitting light reflected from the first layer and stray light reflected from the second layer when the light is converged on the first layer; a photodetector; and a calculator. The photosensitive areas of the photodetector output signals representing intensities of the light incident there through the second system. The reflected and stray light incident on the second system interfere with each other, and the first and second groups of areas are arranged so as to be equally affected by a variation in intensity caused by the interference.

Abstract: In an optical pick-up used in common with DVD/CD and BD, when the thickness is intended to be reduced by mounting a total reflection mirror, a cavity for passing through a laser light is necessary and, since this decreases the degree of freedom for arranging tracking coils and magnets and secondary resonance caused by a magnetic thrust in the tracking direction tends to be generated, an improvement therefor is necessary. In a lens coil holder of the optical pick-up having an objective lens and tracking coil mounted thereon each of the coils is arranged such that the thrust relative to the vertical center of the suspension wires that support the lens coil holder is well balanced. For example, most of the portion of the tracking coils is situated at one height relative to the suspension wire and the tilt coil is situated at the other remaining height.

Abstract: An optical pickup unit comprising: an objective lens that focuses laser light on an optical disc; a lens holder that holds the objective lens; a coil that is fitted on the lens holder and capable of driving the lens holder; and a reinforcement member that is fitted on the lens holder and reinforces strength of the lens holder.

Abstract: An optical disk apparatus includes a light source that emits a light flux. A light source drive circuit causes the light source to emit the light flux. An optical base has an optical system disposed thereon. The optical system includes an objective lens for guiding the light flux emitted from the light source to a disk-shaped recording medium. A moving mechanism moves the optical base. A first heat radiation member is connected to the light source, and a second heat radiation member is connected to the light source drive circuit and is different from the first heat radiation member. The first heat radiation member and the second heat radiation member are provided so as to face the disk-shaped recording medium. The first heat radiation member is disposed on the disk-shaped recording medium side with respect to the second heat radiation member, and the first heat radiation member has a hole provided therein, for exposing the second heat radiation member to the disk-shaped recording medium.

Abstract: An objective lens driving device includes a lens holder (3) holding an objective lens (1, 2), a stationary part (5) that supports the lens holder (3) via wires (7a, 7b), an electromagnetic coil (11a-11d, 12a-12d) provided on the lens holder, and a magnet (4a, 4b) provided on the stationary part and magnetized in a multipolar manner so that different magnetic pole surfaces are arranged on a surface of the magnet facing the electromagnetic coil. The lens holder has a convex portion (16a-16d, 17a-17d) on a surface thereof facing the magnet. The convex portion has at least one groove (601-604, 701-704) portion extending parallel to a direction of magnetic flux lines of the magnet facing the convex portion, and at least a surface of the convex portion is formed of material having magnetic property.

Abstract: In an optical tape drive system, a movable planarizer subsystem includes a tape planarizer support structure for supporting an optical tape planarizer. The support structure is moveable between an operational position and a non-operational position. The movable planarizer subsystem also includes an actuator for moving the support structure and the optical tape planarizer between the operational position and the non-operational position. The operational position of the support structure positions the optical tape planarizer to permit reading/writing of information from/to an optical tape via an optical pickup unit (OPU), and the non-operational position of the support structure positions the optical tape planarizer to permit passage of a tape leader though the tape drive system without damage to the OPU.

Abstract: There is provided an optical pickup including: an optical-system having an object-lens illuminating a first light for information recording or reproducing on a recording layer as a target and a second light on an optical-recording medium including a reference plane having a reflection-layer and the recording-layer at a layer position different from that of the reference-plane and on which information recording is performed through mark formation, and a focus-aligned-position-adjusting unit adjusting a focus-aligned position of the first light through the object-lens by changing collimation thereof incident to the object-lens; and a focusing-mechanism driving the object-lens in a focusing direction, wherein, when a depth of focus ?/NA2 defined by a wavelength ? of the first light and a numerical aperture NA of the object lens is set to ? and the maximum-surface-blur range is denoted by D, the optical-system is designed so that a use magnification ratio ? satisfies |?|??(D/?).

Abstract: An object lens actuator can improve workability and operate with high reliability by prevention of damage to the object lens actuator and a disc and sticking of a moving part caused by an excessive movement of the moving part. In a disc drive employing the object lens actuation, stable writing/reading operation is implemented by always keeping a focal point of an object lens at a predetermined track of a recording surface of the disc even when being under the action of external perturbations such as a vertical deviation or a radial deviation of the disc, resulting in improved reliability. A solder-flux adhesion prevention gadget is provided between a substrate and a stopper receiving face, which may include a stepped stage, a partition protruding from the surface of the lens holder, or alternatively a combination of them arranged in order in the range.

Abstract: To increase the speed of operations and improve vibration properties by rotating holders to wind coils in objective lens driving means of an optical pickup. In an optical pickup wherein a tracking coil and two focusing coils are wound on the same surface of a coil holder, the coil holder includes a tracking coil holder and two focusing coil holders, and each of the tracking coil holder and two focusing coil holders has a hole passing through the center of each coil.

Abstract: A lens actuator includes a cylindrical carrier having a hollow for accommodating a lens, the hollow being formed in a first direction; a driving yoke for housing the carrier; a base for holding the yoke thereon; a driving magnet and a driving coil, which are fixed either to the outer periphery of the carrier or the driving yoke; a moving magnet fixed to the driving yoke; and a moving coil fixed to the base. The carrier is movable with respect to the driving yoke in the first direction, and the driving yoke is movable with respect to the base in a second direction perpendicular to the first direction. The driving magnet and the driving coil face each other in the second direction, and the moving magnet and the moving coil face each other in the first direction.

Abstract: In a multilayer optical recording medium, it is an object to suppress generation of crosstalk while reducing an interlayer distance of recording and reading layers. In an optical recording medium including three or more recording and reading layers, a first distance, and a second distance greater than the first distance by 3 ?m or more are alternately defined as interlayer distances of recording and reading layers.

Abstract: In an optical element feeding device and an optical pickup unit using the same, in order to make the device compact and light and achieve a stable operation, the device has a main shaft and a sub shaft supporting a movable frame in which an optical element is arranged in such a manner as to be movable in a direction of an optical axis, a stepping motor, a lead screw rotating on the basis of a rotation of the stepping motor, a resin nut engaging with the lead screw and being movable in the direction of the optical axis on the basis of the rotation of the lead screw, and a spring pressing the movable frame in the direction of the optical axis so as to bring the movable frame into contact with the nut, and a cushioning material is provided between the nut and the movable frame so as to connect the nut and the movable frame.

Abstract: An optical head apparatus is made to be downsized while obtaining an sufficient driving force of an objective lens actuator. The optical head apparatus includes a first optical system including a first objective lens for focusing a light beam upon an optical disc; a second optical system including a second objective lens for focusing a light beam upon an optical disc having an information recording density smaller than the optical disc which the first optical system irradiates upon, the second objective lens having a numerical aperture smaller than the first objective lens; and an up-orienting prism including a first reflecting surface for deflecting a light beam to an optical axis of the first objective lens in the first optical system, and a second reflecting surface for deflecting a light beam to an optical axis of the second objective lens in the second optical system.

Abstract: An optical disk drive for recording information on a recording surface of an optical disk and reading information recorded in the optical disk is provided. The optical disk drive includes a spindle to rotate the optical disk and a carriage movable in parallel with a tracking direction of the optical disk. The carriage includes a laser light source to emit laser light, a collimator lens to convert divergent light into parallel light and is arranged with an optical center thereof being in a farther and offset position with respect to an optical axis of the laser light, a reflecting mirror to receive and deflect the laser light transmitted through the collimator lens in a direction perpendicular to the recording surface of the optical disk, and an objective lens to converge the laser light deflected by the reflecting mirror on a position corresponding to the recording surface of the optical disk.

Abstract: A driving apparatus includes: a driving mechanism slider-driving a head including a first optical pickup and a second optical pickup, the first optical pickup and the second optical pickup having a same specification; a calculating mechanism performing predetermined calculation using a first slide-error signal obtained by filtering a signal from the first optical pickup and a second slide-error signal obtained by filtering a signal from the second optical pickup; and an outputting mechanism outputting a signal from the calculating means as a slider control signal for driving the driving mechanism.

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 objective lens driving device is provided with an objective lens; a lens holder for holding the objective lens; a pair of linear suspension springs for supporting the lens holder at each one end; a spring holder whereupon the other ends the springs are fixed; and a driving means for at least driving the objective lens in a tracking direction together with the lens holder. The linear suspension springs have narrowed or widened end compared with the other end in plan view from an optical axis direction. The lens holder is supported to be driven in the tracking direction, by having the cross point of the two lines, which pass the suspension spring ends on one side and are vertical to the extending directions of the linear suspension springs, respectively, at the driving center.

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: An objective lens unit according to the present invention includes a first objective lens 41; and a first lens holder 2 for supporting the first objective lens 41. The first lens holder 2 is formed of a material which transmits ultraviolet. Preferably, the first lens holder 2 includes a through-hole, having first and second openings 2a and 2b, through which light incident on the first objective lens 41 passes, and an opening limiting section 3 provided along a circumferential direction of the through-hole and projecting toward a central axis of the through-hole. The first objective lens 41 is supported so as to block the first opening 2b. The opening limiting section 3 guides light incident thereon from the second opening 2a in a direction away from an optical axis of the first objective lens.

Abstract: An objective lens unit according to the present invention includes a first objective lens 41; and a first lens holder 2 for supporting the first objective lens 41. The first lens holder 2 is formed of a material which transmits ultraviolet. Preferably, the first lens holder 2 includes a through-hole, having first and second openings 2a and 2b, through which light incident on the first objective lens 41 passes, and an opening limiting section 3 provided along a circumferential direction of the through-hole and projecting toward a central axis of the through-hole. The first objective lens 41 is supported so as to block the first opening 2b. The opening limiting section 3 guides light incident thereon from the second opening 2a in a direction away from an optical axis of the first objective lens.

Abstract: Disclosed is a write-once optical disc and method for managing a spare area thereof, the write-once optical disc possibly having a temporary defect management area within one or more spare areas. The method includes the steps of: allocating one or more spare areas including the temporary defect management area at an initial status of the optical disc; and during use of the optical disc, expanding the spare area allocated including the temporary defect management area to set a new spare area. By employing the above optical disc and method, it becomes possible to establish unified regulations on the structures of the spare area and temporary defect management area applicable to the write-once optical disc, so that usage efficiency of the optical disc can be improved.

Abstract: An optical head for recording or reproducing a signal on or from an optical recording medium including a light source, an objective lens for condensing light emitted from the light source to the optical recording medium, and a light-separating device arranged between the light source and the objective lens in order to separate the light reflected from the optical recording medium from the light emitted from the light source. The light-separating device includes a first glass, a multilayer film formed on the first glass, and an adhesive layer arranged on the multilayer film in order to bond a second glass onto the multilayer film. The majority of the light emitted from the light source enters into the light-separating device through the first glass and is reflected by the multilayer film.

Abstract: An electromagnetic drive includes a drive plate disposed in a magnetic field. The drive plate includes a non-conductive medium with a first plurality of linear conductive elements arranged parallel to a first axis. The first plurality of linear conductive elements connects first and second electrical terminals supported by the non-conductive medium. The drive plate may be driven in the magnetic field along a second axis that is substantially perpendicular to the first axis when an electrical current of sufficient magnitude is passed through the first plurality of linear conductive elements.

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 layer-to-layer jumping method according to the present invention includes, after a layer-to-layer jump has been started in a multilayer optical disc, the step ST7 of detecting an S-curve signal from an information layer, which is located shallower than the target information layer of the layer-to-layer jump, with a spherical aberration correction made adaptively to that shallower information layer, and the step ST8 of generating a deceleration signal based on the S-curve signal detected to get the layer-to-layer jump done.

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: An optical pickup apparatus including a first objective lens that focuses first laser light on an information recording layer of a first optical disc in a first mounting state where the first optical disc is mounted on a turntable; a second objective lens that focuses second laser light on an information recording layer of a second optical disc in a second mounting state where the second optical disc is mounted on the turntable, the second optical disc having an information recording format different from that of the first optical disc; and a lens holder that integrally holds the first objective lens and the second objective lens in an adjacent manner on the outside and inside, respectively, along a radial direction of the first optical disc in the first mounting state and of the second optical disc in the second mounting state.

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: An optical pickup apparatus comprising: a first objective lens; and a second objective lens arranged with the first objective lens in a radial direction of an optical disc, the first objective lens being configured to focus laser light for reproduction, which is laser light for reproducing a signal recorded in a signal recording layer of the optical disc, onto the signal recording layer, the second objective lens being configured to focus laser light for recording, which is laser light for recording a signal, onto the signal recording layer.

Abstract: A light source (2) and a connection base (1) are held with a predetermined gap, solder paste melted by the thermal energy of laser light is fed into the gap, and the light source (2) and the connection base (1) are bonded together via a solder layer (32).

Abstract: An optical element is disposed on an optical path between a beam branching element and a photodetector. The optical element is disposed at a focal position of a stray light beam reflected by a recording layer except a target recording layer, and shields or attenuates the light beam in a region where the stray light beam converges.

Abstract: The present invention provides an optical pickup device employing a disc protector that includes a plurality of first protrusions and at least one second protrusion disposed on the lens holder, wherein the first protrusions are formed by applying a first adhesive to a plurality of areas of a top surface of the lens holder, wherein the first protrusions are arranged at different locations in the tracking direction such that the objective lens is sandwiched between the first protrusions, wherein the at least one second protrusion protrudes is formed by applying a second adhesive to at least one area of the top surface of the lens holder, and wherein tips of the first protrusions are closer to the optical disc than a tip of the at least one second protrusion.

Abstract: An actuator capable of providing movement forces in a first direction, a second direction, and a third direction is provided. The actuator includes two sets of repelling permanent magnets and yokes, a focusing coil, a tracking coil, and a tilting coil. The repelling and attractive fields generated by the permanent magnets enable the coils to generate independent movements in three axial directions. The two sets of permanent magnets are placed in a repelling position, with a small space between the two magnets to generate a field whose magnetic forces repel and attract within the surrounding range. The focusing, tilting and tracking coils are engaged with the lens holder whose movements in the first, second and third directions are determined by the amplitude and direction of the electric current in the focusing, tilting and tracking coils respectively.

Abstract: A driver circuit for use with a variety of OPU circuits has both a single-ended input and a differential input. The single-ended input is coupled to a single-ended signal path having a variable gain stage and a variable level shifter. The differential input is coupled to a differential signal path having a variable gain stage and a variable level shifter. The single-ended signal path and the differential signal path may be selectively coupled to an output. The respective variable gain stages and variable level shifters can be adjusted so that an output signal at the output has a desired dynamic range.

Abstract: An optical pickup including a moving unit including a lens holder on which an objective lens is positioned, a set of suspension wires to movably support the lens holder on a base of the optical pickup actuator, each suspension wire having one end fixed to a side of the lens holder, and the other end fixed to connection portions positioned at opposite sides of a tilt spring, the tilt spring including a middle portion, between the connection portions, to be connected to a holder positioned on the base, and bridge portions to connect the middle portion to each of the connection portions, the bridge portions flexibly deforming when the moving unit is driven, and a magnetic circuit installed at the lens holder and the base to drive the moving unit.

Abstract: An optical pickup includes: a slide base, having: a first surface; and a second surface; a first substrate fixed to the first surface; a standing frame disposed on the second surface; a second substrate facing the standing frame; a laser diode operable to emit a laser beam to the disk and disposed in the standing frame; an optical, element supported by the second substrate and adapted to receive a reflected beam; a flexible flat cable. The flexible flat cable is bent so that one end portion of the flexible flat cable is connected to the second substrate. A curved portion is formed with a slit elongated in a longitudinal direction of the flexible flat cable and defines an outer portion and an inner portion. A width of the inner portion is narrower than a width of the outer portion.

Abstract: An objective lens focusing light emitted from a light source onto an information surface of an optical disk, comprising: a first lens surface to be positioned on the light-source side; a second lens surface to be positioned on the optical-disc side; a first edge surface to be positioned on the light-source side, provided in an outer region of the first lens surface; and a second edge surface to be positioned on the optical-disc side, provided in an outer region of the second lens surface, a first optical axis of the first lens surface coinciding with a second optical axis of the second lens surface, the first optical axis and the second optical axis being orthogonal to the second edge surface.

Abstract: The invention provides a method for controlling spherical aberration correction for an optical disk drive. First, a collimator lens is moved to a first target position for spherical aberration correction. A driving time of motion of the collimator lens is then calculated. A prohibiting time is then determined according to the driving time. The collimator lens is then prevented from moving until the prohibiting time elapses.