Abstract: An optical pickup includes a hologram element. The hologram element is provided with a hologram pattern including a splitting section for focus which splits light used for the detection of an FES and a splitting section for tracking which splits light used for the detection of a TES. The splitting section for tracking is formed in a region excluding a region interposed between a first virtual straight line and a second virtual straight line. The first virtual straight line is drawn on the hologram element in parallel to an X direction and passes through an optical axis of reflected light entering the hologram element in a state where the objective lens is in a neutral position, and the second virtual straight line is drawn in parallel to the first virtual straight line, while being spaced at a distance d from the first virtual straight line.

Abstract: In order to provide an optical pickup apparatus that has a relatively simple configuration and that can carry out recording and/or reproduction of information in a s compatible manner for different optical information storage medium, the optical surface of the first objective lens OBJ1 is formed only by a refracting surface, and hence it is possible to form it at a low cost even if it is made of glass. In addition, said first objective lens OBJ1 can be designed by optimizing it for the first light flux with the wavelength ?1 and the protective substrate t1 of said first optical disk OD1.

Abstract: According to one embodiment, it is possible to obtain a compensation SPP signal, which compensates a push-pull signal obtained by a ± first-order light or a lens shift compensation signal generated by other method according to phases of a motor to rotate a recording medium, from a MPP signal which is a component indicating the amount of de-tract in a reflected light from any one of recording layers of an optical disc detected by a photodetector, and it is possible to obtain a tracking signal with a high signal-to-noise ratio, by the following equation by using a compensation SPP signal and a MPP signal: MPP?compensation SPP×k where k is a constant.

Abstract: A quarter-wave plate includes a base member including a ridge and trough periodic structure with a structural period of ?min/2<P<?min arranged on one side of the base member, where ?min is the minimum wavelength among the wavelengths of a plurality of light fluxes which pass the quarter-wave plate. In the quarter-wave plate, refractive index of a ridge portion of the ridge and trough periodic structure for the wavelength ?min and a light transmittance have predetermined values. The ridge and trough periodic structure satisfies the predetermined condition relating to the structural height and the structural width of the ridge portion.

Abstract: An optical pickup apparatus comprising: a diffraction grating that a laser beam enters, the diffraction grating being configured to generate a main beam that is 0th order light and sub-beams that are +1st order diffracted light and ?1st order diffracted light; an objective lens configured to focus the main beam and the sub-beams onto a signal recording layer; a main-beam light-receiving portion that the main beam reflected by the signal recording layer is applied to; and sub-beam light-receiving portions that the sub-beams reflected by the signal recording layer are respectively applied to, each light-receiving area of the sub-beam light-receiving portions being smaller than a light-receiving area of the main-beam light-receiving portion.

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

Abstract: A multi-stage lens driving device for driving an optical lens so as to perform the functions of zooming and/or focusing comprises: a front cover, a rear cover, a plurality of yokes, a plurality of driving coils, a lens seat, and a plurality of permanent magnets. The front cover is a hollow annular cover having a plurality of recesses formed on an inner periphery thereof and a plurality of holders on an outer periphery thereof. The rear cover can be combined with the front cover, thereby forming a receiving space therebetween. The lens seat is a hollow housing disposed in the receiving space. The yokes are provided in the recesses formed on the inner periphery of the front cover. The permanent magnets are surrounding and embedded in an outer periphery of the lens seat, disposed in correspondence to the yokes and spaced therefrom by a predetermined distance. The driving coils are provided respectively on the holders of the front cover, and correspond respectively to the yokes received in the recesses.

Abstract: A grating portion has a plurality of convex portions provided on at least one principal plane of a transparent substrate having a first layer containing a first transparent material and a second layer containing a second transparent material, and extended in parallel to each other in a first direction as well as periodically arranged in a second direction orthogonal to the first direction. A filling portion fills a third layer containing a third transparent material at least between the plurality of convex portions. Assuming that the change rate of the refractive index with the change of temperature of the first transparent material is ?A, the change rate of the refractive index with the change of temperature of the second transparent material is ?B, and the change rate of the refractive index with the change of temperature of the third transparent material is ?C, the relationship ?A<?C<0 and |?C|>|?B| is satisfied.

Abstract: Multi layer near-field optical recording using a moderate numerical aperture (NA) is superior to the high-NA (NA=2.0) first-surface single-layer technique. The use of very flat and thin spacer layers limits spherical aberration due to difference in layer depth. The thin spacer layers may have a high refractive index because their thickness allow for a relatively high absorption constant. This makes possible in principle an m-layer system, e.g. m=4, with NA=1.6 which may include a flat, protective cover layer. Further a medium for use in such a system is described.

Abstract: The present invention relates to an optical recording apparatus capable of writing information on an optical medium in a writing mode and capable of writing a label image on an optical medium in a label mode. The apparatus has a displaceable optical head with a radiation source capable of emitting radiation. The apparatus further contains one or more processing means adapted to: analyze radiation reflected from the medium, control the radial position of the optical head, control the focal point of the radiation relative to the optical medium, and control the radiation source. In label mode, the optical recording apparatus is adapted to turn off at least one of the processing means for a pre-defined period of time in order to reduce the power consumption and in turn the temperature of the apparatus.

Abstract: When transferring an optical head in a radial direction of an optical disc, the optical head is initially transferred with a speed profile of a larger acceleration, and when abnormality is detected by an abnormality detection circuit which detects abnormality of a focus control system, the optical head is again transferred with a speed profile of a smaller acceleration, whereby preventing a movable part of a lens actuator from colliding with a fixed part when transferring the optical head in the radial direction of the optical disc, resulting in an optical head transfer device, an integrated circuit for the optical head transfer device, a focusing lens driving device, and an integrated circuit for the focusing lens driving device which can avoid an increase in the start-up time of the device, a reduction in the data reading speed from the optical disc, and the like.

Abstract: Optical pick-up units (OPU), which require several light sources for reading newer formats, such as Blu-Ray, and legacy formats, such as DVD and CD, require a series of beam splitters/combiners for directing the various source light beams from the light sources along a common path. A two-mirror reflector sub-unit, in which at least one mirror includes a thin film dielectric retarder element, is used to redirect the beams traveling along the common path onto the disc-media, while imposing a 90° retardation onto the polarized light incidence, whereby light returning from the disc-media undergoes a 90° orientation change in the state of polarization from one linear polarization to the other orthogonal linear polarization.

Abstract: In order that thickness reduction, weight reduction, and mass productivity improvement should be achieved in an objective lens even in the case where NA is high, an objective lens according to the present invention is a bi-convex single lens having at least one aspheric surface, and satisfies conditions: (1) 3.5<DH-S/DH-H?<4.2; (2) 3.5<DH?-T2/DT1-H<50; (3) 0.9<d/f<1.1 (NA?0.85).

Abstract: An optical element for use in an optical pickup device to conduct reproducing and/or recording information for a first disk including a protective substrate by the use of a first light flux emitted from a first light source and to conduct reproducing and/or recording information for a second disk including a protective substrate by the use of a second light flux emitted from a first light source, the optical element includes: an optical surface on which a first phase structure is formed to have a function to correct a spherical aberration; an optical surface on which a second phase structure is formed such that when the wavelength of the first light flux changes, the second phase structure generates a spherical aberration in a direction reverse to the direction of a spherical aberration generated by the first phase structure.

Abstract: An optical storage interface apparatus comprises a lens module (LM). The lens module (LM) may comprise, for example, a solid immersion lens for near-field optical readout or near-field optical recording, or both. The lens module (LM) forms a light spot (SP) on an optical information carrier (DSK) in response to a light beam (BO) that is projected on the lens module (LM). A lens actuator (LA) moves the lens module (LM) from a rest position, which is relatively distant from the optical information carrier (DSK), to a read position, which is relatively close to the optical information carrier (DSK). A controller verifies whether the lens module (LM), when moving from the rest position to the read position, has a velocity that is below a velocity threshold or not. If not, the controller causes the lens actuator (LA) to pull back the lens module (LM) with respect to the optical information carrier (DSK).

Abstract: A near field optical recording/reproducing apparatus includes a light source, an objective lens to form a spot by focusing light emitted from the light source, a solid immersion lens to generate an evanescent wave by using the spot formed by the objective lens, a photodetector to measure an amplitude of a gap error signal that is totally reflected by the solid immersion lens, and an operating unit to generate a normalized gap error signal by using an amplitude of a driving signal applied to the light source and the amplitude of the gap error signal measured by the photodetector.

Abstract: An address format for appropriately controlling the recording linear density and the number of information recording layers is provided in order to increase the recording capacity of an information recording medium such as an optical disc or the like in a range in which a necessary S/N ratio can be guaranteed. An optical disc includes an information recording layer having a concentric or spiral track, and has a format for describing a track address, which is pre-recorded on the track or is to be added to data that is to be recorded on the information recording layer. The format includes layer information regarding the information recording layer and address information regarding the track address.

Abstract: A multi-channel optical pick-up and a multi-channel optical recording and/or reproducing apparatus employing the same, the multi-channel optical pick-up including: a plurality of light sources including a center light source closest to an optical axis from among the plurality of light sources and at least one off-axis light source farther than the center light source to the optical axis; an objective lens to condense a plurality of light beams respectively emitted from the plurality light sources onto a plurality of tracks of an information storage medium; and an optical path length changing element to compensate for defocus that occurs due to the at least one off-axis light source distanced from the optical axis when a center light beam from the center light source and at least one off-axis light beam from the at least one off-axis light source form spots on the information storage medium.

Abstract: The present invention has a beam shaping element for converting the light source 11 into a light flux whose emitting angle is almost equal and for projecting it, and a generation amount of the astigmatism generated by the temperature change is suppressed by a linear expansion of the beam shaping element.

Abstract: An optical pickup apparatus for use with a semiconductor laser which outputs a light beam, the optical pickup apparatus has; a diffraction grating for diffracting the light beam into diffracted light; a collimator lens for rendering the diffracted light diffracted by the diffraction grating as a parallel beam; an objective lens for focusing the parallel beam towards an optical information recording medium; a hologram element for diffracting return light reflected from the optical information recording medium; a plurality of light receiving elements for receiving the diffracted light diffracted by the hologram element; and an incidence preventing area placed between the hologram element and the light receiving elements for, in the case where the light beam is focused on the recording surface on a side close to the objective lens out of recording surfaces of multilayer of the optical information recording medium, substantially preventing reflected light from the recording surface on a side remote from the ob

Abstract: An optical pickup device divides signal light so as to detect the divided signal light. A photodetector contains two regions constructed of a region “A” and another region “B.” Among diffracted light diffracted from a track on an optical disc, only zeroth-order diffraction light enters to the region “A” of the photodetector, whereas the zeroth-order diffraction light, + first-order diffraction light, and ? first-order diffraction light enter to the region “B” thereof. A focusing error signal from the photodetector is produced based upon a signal detected by the photodetector, whereas a tracking error signal is produced based upon signals detected from the regions “A” and “B.” A stable focusing error signal and a stable tracking error signal can be detected with respect to a dual layer optical disc, or a multi layer optical disc.

Abstract: An optical recording device includes a light source, a light-converging optical system, a moving unit, detection unit, and an acquisition unit. In the optical recording device, interference fringes from a recording light are shift multi-recorded as a plurality of pages of holograms within each of a plurality of planes corresponding to a plurality of convergence positions based on light exposure amount of each page, acquired by the acquisition unit, for each of the convergence positions.

Abstract: An optical disk apparatus appropriately adjusts the optical paths of a reference light beam and information light beam in an optical path forming section of an optical pickup, condenses the reference light beam and information light beam using an objective lens, and performs position control of the objective lens in the focusing and tracking directions so as to focus the reference light beam onto a reference track in a target mark layer, thereby focusing the focal point of the information light beam condensed by the objective lens onto a target track TG in the target mark layer.

Abstract: In a data recording and readingout system in which data is recorded and readout, or is readout on, or from an optical recording medium 1 by irradiating a laser beam having a wavelength “?” via an objective lens of a numerical aperture “NA” onto said optical recording medium, while the optical recording medium contains a layered structure formed by sandwiching a dielectric layer 6 between a recording layer 7 and an optical absorption layer 5, with respect to the optical recording medium 1 arranged in such a manner that data recorded by a recorded mark train can be readout and the recorded mark train contains a recorded mark smaller than, or equal to a limit of resolution, the laser beam is irradiated via the objective lens and a solid immersion lens having a refractive index “n” which is positioned between the optical recording medium and the objective lens, so that the data is recorded and readout, or is readout with respect to the optical recording medium by a recorded mark train which contains a recorded ma

Abstract: An information recording medium of the present invention is an information recording medium characterized by and including a substrate; and a recording unit capable of recording three-dimensionally a recording pit on the substrate; in which the recording unit has n number of recording layers (n is an integer equal to or larger than 4) and a plurality of intermediate layers laminated with the recording layers one on another; the recording is performed by the condensed recording light using a two photon absorption phenomenon; each of the plurality of intermediate layers is substantially transparent at a wavelength ?1 of the recording light and at a wavelength ?2 of the reproduction light, respectively; the light intensity of the recording light incident into the recording layer nearest to the substrate is more than 0.707 fold as much as the light intensity of the recording light incident into the recording layer farthest from the substrate.

Abstract: A detection signal is asserted when a surface of an optical disc or an information recording layer is detected. An asserting (masking) time interval of the detection signal is set such that the number of times of asserting the detection signal becomes at most two times when a focal position of the objective lens passes at least the surface of the optical disc.

Abstract: A disk drive apparatus includes: an optical pickup irradiating a laser beam onto an optical disk having one or more recording layers through an objective lens and receiving the laser beam reflected from the optical disk; a driving unit moving the objective lens in an optical axial direction of the laser beam to the optical disk in accordance with a driving signal; an interlayer distance measuring unit measuring interlayer distances of a plurality of recording layers of the optical disk; and a spherical aberration correcting unit obtaining a spherical aberration correction value for correcting a spherical aberration due to the objective lens to one of the recording layers of the optical disk. A spherical aberration correction value to another one of the recording layers is obtained on the basis of the measured interlayer distances and the obtained spherical aberration correction value to the one recording layer.

Abstract: A convex portion is provided on the objective side of a solid immersion lens so as to protrude toward an optical recording medium and a difference-in-level portion or a concave portion is provided at least on a part of this convex portion. Then, there are provided a solid immersion lens for satisfactorily holding the bonding state of a lens holding member, a focusing lens using this solid immersion lens, an optical pickup apparatus, an optical recording and reproducing apparatus and a method of forming a solid immersion lens.

Abstract: An optical pickup apparatus comprising: a laser diode emitting laser light having a first wavelength; an objective lens focusing the laser light having the first wavelength emitted from the laser diode to each signal recording layer of a first optical disc for which the laser light having the first wavelength is specified as laser light for reproducing a signal and a second optical disc for which laser light having a second wavelength different from the first wavelength is specified as laser light for reproducing a signal; and a spherical aberration correction element disposed in an optical path between the laser diode and the objective lens, the spherical aberration correction element correcting each spherical aberration of the first optical disc and the second optical disc to reproduce a signal recorded in each signal recording layer of the first optical disc and the second optical disc.

Abstract: There is provided an objective lens for information recording/reproducing for three types of optical discs, which includes a first area contributing to converging a third light beam onto a record surface of a third optical disc. The first area includes a phase shift structure having refractive surface zones concentrically formed about a predetermined axis. The phase shift structure includes first and second step groups. The first step group is configured such that an optical path length difference ?OPD1 (nm) given by each step of the first step group to a first light beam satisfies a condition: 2N1+1.10<|?OPD1/?1|<2N1+1.40, where N1 is an integer or zero, and the second step group is configured such that an optical path length difference ?OPD2 (nm) given by each step of the second step group to the first light beam satisfies a condition: 2N2?0.10<|?OPD2/?1|<2N2+0.10, where N2 is an integer.

Abstract: An optical disc drive according to the present invention can read and/or write data from/on an optical disc with information layers including first and second information layers (L0 and L1). The drive includes: an objective lens for converging a light beam; a lens actuator for driving the lens; a photodetector section that receives the beam reflected from the disc and converts it into an electrical signal; and a control section for determining the values of a first group of parameters, which are set to read data from the first layer (L0), and those of a second group of parameters, which are set to read data from the second layer (L1), during a disc loading process.

Abstract: An optical pickup 1 includes a collimator lens 13 for changing the shape of a laser light by moving on the optical axis AX from a base point. An objective lens 15 is set so as to form a spot of which size, when the collimator lens 13 is located at the base point, is minimum at a point apart from the light source side surface of an information recording medium 20 by a distance of Lc defined by an expression (1): Lc=(L0+Ln)/2??(1), wherein Lc is named as a thickness to the designed center; L0 is a distance between the light source side surface of the information recoding medium and an information recording face located nearest to the light source side surface; and Ln is a distance between the light source side surface of the information recording medium and an information recording face located farthest from the light source side surface.

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 optical disc apparatus can make the focus of an information light beam converged by an objective lens agree with a target track of a target mark layer of an optical disc by appropriately predefining the distance between the focus of a servo light beam and that of the information light beam with regard to the direction of the thickness and a radial direction of the optical disc by means of the optical pickup of the apparatus and then operating for focus control and tracking control of the objective lens so as to make focus of the servo light beam converged by the objective lens agree with a reference track of a reference mark layer.

Abstract: An optical reading apparatus with aberration-correcting functionality includes a light source, a lens, a liquid crystal layer and an electrode set. The light source of the optical reading apparatus emits light, which is converged onto a storing medium by the lens for accessing data stored in the storage medium. The liquid crystal layer is disposed in an optical path between the light source and the storage medium. The electrode set provides a variable electrical field across the liquid crystal layer for changing the refractive index of the liquid crystal layer. Aberration of the optical reading apparatus can thus be corrected.

Abstract: According to one embodiment, an optical recording medium according to one embodiment of the invention is an optical recording medium to be processed using a light beam having a wavelength ? and a lens having a numerical aperture NA, which includes one of a track and a pit array, and in which a width TP of the track or pit satisfies a condition 0.480?TP×NA/?<1.026.

Abstract: An optical disk unit capable of correcting a spherical aberration without using special patterns is provided. Also provided is an aberration correcting method used for such an optical disk unit. An objective lens 7 is moved along an optical axis by a predetermined distance from an in-focus position in a first direction, and then, is moved by the predetermined distance from the in-focus position in a second direction that is opposite to the first direction. In each of the objective lens moved states, a random signal having a plurality of amplitudes and periods is reproduced from an optional area of an information recording layer 12 of an optical disk 11.

Abstract: An optical data storage system includes a light emitting and receiving device (30), a light transmission device (31) having an input port (32) and an output port (33). The input port is disposed adjacent to the light emitting and receiving device. Furthermore, a micro window is provided at the output port, and a diameter of the micro window is in a range of 5 to 70 nanometers. Therefore, in the optical data storage system, the spot size of the light beams is close to the diameter of the micro window. Accordingly, the size of the beam spot is small enough to write information at a higher density with respect to an optical storage medium.

Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.

Abstract: An objective lens 8 consists of a single lens element. A light source side surface 8a is formed into a convex surface having a large curvature, and an optical recording medium side surface 8b has a small curvature. Also, the objective lens satisfies the following expressions (1) and (2) ?A/?B<5.0 ??(1) 7.69??A/?B+19.33×bf?/f??9.45 ??(2) where ?A denotes an effective diameter (mm) of the light source side surface of the objective lens 8, ?B denotes an effective diameter (mm) of the optical recording medium side surface of the objective lens 8, bf? denotes a back focal length (mm) of the objective lens 8, and f? denotes a focal length (mm) of the objective lens 8.

Abstract: In laser welding an optical part to a pickup case of an optical pickup device, outgas deposition on a lens surface can be inhibited, and positional shifting of the optical part can be reduced. The optical part has a lens surface facing in an optical axis direction and a protruding part formed, to be joined to the pickup case, at an end portion thereof in a direction perpendicular to the optical axis. A joint surface between the protruding part and the pickup case extends in a direction parallel to the optical axis, and the joint surface is fixed by a weld portion formed by laser irradiation. The joint surface is parallel to a bottom surface of the pickup case, and the height from the bottom surface is approximately equal to the height of the center of the lens surface.

Abstract: A combined aspherical lens has an aspherical shape with an intermediate substrate thickness between the substrate thicknesses of a BD and an HD in a numerical aperture (NA) range for the HD, and an aspherical shape dedicated to the BD in an NA range for the BD only. The lens is designed such that wave aberration occurring through the NA range for the HD for BD reproduction has the same aberration form as but has an opposite sign to wave aberration occurring through this range for HD reproduction. Further, in the NA range for the HD, a pattern of annular transparent electrodes is optimized for a spherical aberration wavefront defocused to minimize the maximum inclination of the wave aberration. A phase shift applied is within plus or minus half wave excluding an integer wavelength of aberration.

Abstract: A gap controller according to the present invention can set a reference level reasonably for a gap control that needs to be done to keep the gap between a solid immersion lens (SIL) and an optical disc constant. With the gap varied at a substantially regular step, gap detection signal levels are logged to find an extreme value of its second-order difference. And the gap control reference level is determined by the gap detection signal level that results in that extreme value.

Abstract: An objective lens consists of a single lens element, and has a light source side surface formed into a convex surface having a large curvature and an optical recording medium side surface has a small curvature. The both surfaces are aspheric surfaces. Also, the objective lens satisfies the following expressions (1) to (3): 0.7<NA<0.98 ??(1) 0.70<d/f<1.40 ??(2) 0.48<X<0.55 ??(3). where NA denotes a numerical aperture of the objective lens on an optical recording medium side, d denotes a thickness of the objective lens on an optical axis in mm, and f denotes a focal length of the objective lens in mm. X is equal to (X1?X2)·(n?1)/(NA·f), where X1 and X2 denote values relating to sag amounts in the respective surfaces, and n denotes a refractive index.

Abstract: An objective lens consists of a single lens element. A light source side surface is formed into a convex surface having a large curvature, and an optical recording medium side surface has a small curvature. The both surfaces are formed into aspheric surfaces. Also, the objective lens satisfies the following expressions (1) to (3): 0.70<NA<0.98 ??(1) 0.70<d/f<3.00 ??(2) 0.50<g/d<0.80 ??(3) where NA denotes a numerical aperture of the objective lens on an optical recording medium side, d denotes a thickness, in mm, of the objective lens on an optical axis, and g is a distance, in mm, from a tangential plane that is perpendicular to the optical axis and is tangent to a vertex of the light source side surface of the objective lens, to a center of gravity of the objective lens.

Abstract: An optical disc apparatus corrects spherical aberration by moving a movable lens along an optical axis direction.

Abstract: An optical pickup includes a semiconductor laser, a beam splitter, a collimating lens, an objective lens, an aperture and a front monitor. The beam splitter splits a light beam emitted by the semiconductor laser into transmitted light and reflected light. The front monitor detects luminous energy of the transmitted light. The front monitor is disposed near an optical axis of the transmitted light so that the following is satisfied: 1?(S×L)/(s×f)?6.8. S is an area of an entrance pupil of the objective lens, f is an optical distance from an emission portion of the semiconductor laser to the collimating lens, s is an effective receiving area of the front monitor, and L is an optical distance from the emission portion of the semiconductor laser to the front monitor.

Abstract: An optical disc apparatus includes: a first signal generating portion which generates a first signal that is obtained by processing signal which is output from the photo detecting portion, and which shows a peak in case where a focus position of an objective lens is matched on a recording surface of an optical disc; a second signal generating portion which generates a second signal that is obtained by slicing the first signal at a prescribed level to be digitalized; and a movement stopping portion which stops moving of the objective lens if the second signal is asserted by existence of the recording surface that is a target to be reproduced or to be recorded, then it is negated, and the state to be negated is continued for a prescribed time interval when focus control is performed.

Abstract: The invention relates to a new method for focus capture in an optical drive comprising a collimator lens. Use is made of the pre-programmed collimator lens position to secure a baseline position of the laser spot at a position with respect to an optical record carrier placed in the optical drive such that the correct information layer on the optical record carrier is captured efficiently and accurately.

Abstract: An optical pickup device according to the present invention includes: a first light source that outputs a first laser beam; a second light source that outputs a second laser beam; and an optical system that irradiates an information medium with the first and second laser beams. The information medium includes: an information layer on which user data is written; and a recording layer on which visible information, which is directly visible to a user, is recorded. The optical pickup device is characterized by outputting the first laser beam in writing the user data on the information layer but outputting the second laser beam in recording the visible information on the recording layer.