Abstract: Provided is a highly reliable optical recording head which has a small fluctuation of a quantity of light applied on a recording medium due to temperature. The optical recording head is provided with a light guide section for guiding light applied from a light source, a slider relatively moving to the recording medium, and a light transmitting section, which is arranged on the slider, transmits the light outputted from the light guide section and outputs the light toward the recording medium. The optical recording head is further provided with an adhesive layer, which is sandwiched between the light transmitting section and the light guide section and fixes the positions of the light transmitting section and the light guide section, and an elastic cohesive layer, which is sandwiched between the portions other than the light transmitting section of the slider and the light guide section.

Abstract: An optical pickup device for recording and reproducing information by tilting and horizontally driving a lens holder, holding an objective lens, to irradiate an optical disk with a recording/reproducing laser light from a light source. The optical pickup device has a reflector for reflecting a portion of the recording/reproducing laser light led to the lens holder from the light source; a detector fixedly placed at a position at which the amount of received light for detection, which is the recording/reproducing laser light reflected by the reflector, varies according to the tilt angle of the lens holder; and tilt angle acquisition means for acquiring the tilt angle of the objective lens from the light receiving amount detected by the detector.

Abstract: A flat pre-board plate including connection electrodes, internal interconnections, and external-connection portions is prepared. This pre-board plate is cut at portions each located between adjacent ones of the connection electrodes, thereby forming trenches. A plurality of semiconductor elements are placed in each of the trenches. Electrode pads and the connection electrodes are connected to each other by metal wires. Transparent lids are placed on, and bonded to, spacers to cover the semiconductor elements. Thereafter, two lines of the connection electrodes arranged between adjacent ones of the trenches are separated from each other. Subsequently, adjacent ones of the semiconductor elements are also separated from each other.

Abstract: An optical pickup apparatus which conducts reproducing and/or recording information for a first optical information recording medium by using a light flux having a wavelength ?1 (350??1 (nm)?480) and a second optical information recording medium. The optical pickup apparatus comprises an output angle conversion element which is a fixedly arranged single lens which can convert an output angle of the first light flux and the second light flux. The optical detector equipped in the optical pickup apparatus can receive both of the first light flux and the second light flux. And, both optical surfaces of the output angle conversion element are refractive surfaces.

Abstract: A phase correction element comprising a first phase correction layer formed in a region of numerical aperture NA2, and a first phase plate; the first phase correction layer comprising a concavo-convex portion having a rotational symmetry with respect to the optical axis of incident light and having a cross-sectional shape of a saw-tooth-form or a saw-tooth-form whose convex portions are each approximated by a step form; the first phase plate generating a birefringent phase difference of about an odd number times of ?/2 for linearly polarized light of ?1; and the phase correction element that does change a transmitted wavefront of ?1 and changing a transmitted wavefront of the ?2 or transmitted wavefront of both wavelengths of ?2 and ?3 when three types of incident light at ?1=410 nm, ?2=650 nm and ?3=780 nm respectively, are incident.

Abstract: There is provided an optical pickup apparatus that can obtain a stable servo signal by reducing stray light generated by diffraction in a recording layer other than a recording layer on which light is condensed. A hologram element provided in an optical pickup apparatus for recording information onto a recording medium and/or reproducing information on the recording medium by use of light includes fourth and fifth divisions where at least first-order diffracted light among diffracted light beams obtained by reflection and diffraction on a recording layer other than a light-condensed recording layer on which light is condensed by an objective lens so as not to be directed toward first and second light-receiving elements for detecting focus position information and third to eighth light-receiving elements for detecting track position information.

Abstract: An optical element irradiated with a light flux having a wavelength of 350 nm to 450 nm, is provided with a synthetic resin base material; and an antireflection film provided on the synthetic resin base material and including a contact layer being in contact with the synthetic resin base material, wherein the contact layer is a film made of a material containing no oxygen atom or a film made of a mixed material or a material containing no oxygen atom and a material containing an oxygen atom in which the mixed material contains the material containing an oxygen atom less than 10%.

Abstract: A method for designing an optical pickup is provided. The optical pick includes a monolithic laser diode that emits a laser light beam for DVD recording and a laser light beam for CD playback, two photodetective portions, and an objective lens, for each of the emitting portions of the monolithic laser diode for emitting the DVD recording and CD playback laser light beams respectively, the specification of the error of the emission direction thereof is determined according to the following formula: |(???1×??1×Dpd1/Dob1????2×??2×Dpd2/Dob2)×Kpd2|??, where, “1” corresponds to the DVD recording laser light beam and “2” corresponds to the CD playback laser light beam, ??? represents the emission angle; ?? represents the sensitivity; Dob represents the diameter of the light beam; Dpd represents the diameter of the spot formed by the light beam; Kpd represents the sensitivity; and ? represents the tolerable value.

Abstract: An optical element feeding device driving method and an optical disk apparatus capable of detecting biting in a stepping motor and conducting restoration. The optical disk apparatus includes an optical element feeding device including a movable frame for supporting a spherical aberration correcting lens to move the lens in optical axis direction, a spring for applying force to the frame in the direction, a sensor for detecting a lens reference position, a stepping motor, and a lead screw and a nut for converting motor rotation into the direction, a motor driving circuit, a decision circuit for judging abnormality when an output of the sensor does not change even if the driving circuit outputs a driving signal to the motor after reference position detection, and a changeover circuit for lowering a driving frequency than in ordinary operation, based on an abnormality signal.

Abstract: In a particular type of high-density optical recording systems, a solid immersion lens (SIL) is used in the objective system to focus a radiation beam onto an information layer of an optical record carrier. The distance between the exit surface of the SIL and the entrance surface of the record carrier is typically 25 nm to allow evanescent coupling of the radiation from the SIL to the optical record carrier for a system using a blue laser as radiation source. Such a system is also called a near-field system, deriving its name from the near field formed by the evanescent wave at the exit face of the SIL. A suitable gap signal, representing the width of the gap, is used to control the width of the gap during operation of the system. Tolerances in the optical elements and opto-mechanical components of the optical system of the optical recording system can lead to an offset in the position of the focus point of the objective system.

Abstract: An optical disk apparatus includes an optical pickup and a disk-rotation driving unit configured to rotationally drive the optical disks. The optical pickup includes a first emission unit configured to emit a first wavelength beam; a second emission unit configured to emit a second wavelength beam; a third emission unit configured to emit a third wavelength beam; an objective lens configured to focus the first to third wavelength beams emitted from the first to third emission units, respectively, at a signal recording surface of an optical disk; a light-path combining unit configured to combine an optical path of the first wavelength beam emitted from the first emission unit and an optical path of the second and third wavelength beams emitted from the second and third emission units, respectively; and an aberration correcting unit provided on the optical path of the second and third wavelength beams.

Abstract: An optical information recording/reproducing apparatus includes a spatial light modulator that converts an irradiation beam emitted from a light source to a single information beam that carries information; an optical system that causes the single information beam to be collected on an optical-information recording medium including an information recording layer capable of recording the information as hologram by using interference fringes produced due to interference between the single information beam and a plurality of reference beams, and causes each of the reference beams to be irradiated to the optical-information recording medium from mutually different directions so as to intersect with the single information beam in the information recording layer; and a controller that controls to cause the light source to emit the irradiation beam and performs angular multiplexing recording of the information in the information recording layer while controlling to drive either one of the optical-information recordi

Abstract: An optical phase controller includes an optical phase control element so that a phase of incident light applied to the optical phase control element is controlled. The optical phase control element includes a metal structure having anisotropy in a first direction and a second direction perpendicular to the first direction within an electric-field vibration plane of the incident light, the wavelength of the incident light includes a plasmon resonance wavelength possessed by the metal structure, and the incident light is linearly polarized light or elliptically polarized light simultaneously having polarized components in the first direction and the second direction perpendicular to the first direction.

Abstract: An optical module having a laser element which emits a laser beam, include an optical path setting material which reflects a part of the laser beam in a predetermined direction; and a shield element which blocks the laser beam that is reflected by the optical path setting material.

Abstract: An optical pickup apparatus for reproducing information from an optical information recording medium or for recording information onto an optical information recording medium, is provided with a first light source for emitting first light flux having a first wavelength; a second light source for emitting second light flux having a second wavelength, the first wavelength being different from the second wavelength; a converging optical system having an optical axis and a diffractive portion, and a photo detector; wherein in case that the first light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the first light flux is greater than that of any other ordered diffracted ray of the first light flux, and in case that the second light flux passes through the diffractive portion to generate at least one diffracted ray, an amount of n-th ordered diffracted ray of the second light flux is greater than that of any other ordered diffracted

Abstract: According to one embodiment, an optical pickup unit which can record, reproduction and erase information in/from an information recording medium has tracks with different pitches, the dividing means has at least a part of a dividing boundary line placing between an end of a 1st order diffraction light with the largest diffraction angle and an end of a 1st order diffraction light with the smallest diffraction angle of the reflected laser beam.

Abstract: An optical pickup apparatus comprising: an objective lens configured to apply a laser beam for recording or reproducing information to a plurality of layers of information recording surfaces selectively, the plurality of layers of information recording surfaces being included in an optical disc mounted on a turn table; and a spherical aberration correction lens configured to be movable on a light path on the side where the laser beam is incident on the objective lens, so as to correct spherical aberration when the laser beam is applied from the objective lens to any one of the plurality of information recording surfaces in the optical disc, a distance between the spherical aberration correction lens and the objective lens on each light path when the laser beam is focused on each of the plurality of layers of information recording surfaces in the optical disc with movement of the spherical aberration correction lens, including a distance at which optical magnification of an optical system including the spheric

Abstract: An optical pickup apparatus comprises a photo detector that receives light reflected from a medium; and a housing that is mounted with the photo detector. The photo detector is fixed to the housing with the use of an adhesive to mount the photo detector on the housing. The housing is provided with a displacement preventer that prevents displacement of the photo detector or the adhesive relative to the housing. The displacement preventer has fixing portions that extend along a plurality of directions. The photo detector is mounted on the housing by applying the adhesive to the displacement preventer.

Abstract: This invention relates to equipment for the optical playback of sound media which includes resources (1) that has engraves grooves, (3, 9) for generating at least one light beam that presents a light spectrum variation according to its incidence angle on an area of the sound media and an image sensor (7) placed so that it recovers the light reflected by said area of the sound media.

Abstract: An objective lens according to the present invention is an objective lens used for an optical pickup apparatus, and the objective lens includes a superimposed structure on a surface of a lens with a power in which a first optical path difference providing structure changing spherical aberration in under-corrected direction when a wavelength of an incident light flux becomes longer, and a second optical path difference providing structure changing spherical aberration in over-corrected direction when a wavelength of an incident light flux becomes longer are superimposed.

Abstract: An optical pickup (1) includes a light source (6) capable of emitting laser beams of various wavelengths and an objective optical system (2). The objective optical system (2) includes at least two wavefront conversion surfaces (13a) and (16a) and an objective lens (10). The at least two wavefront conversion surfaces (13a) and (16a) convert a wavefront of any laser beam entered therein into a different wavefront in response to the kind of an optical information recording medium (3) corresponding to the laser light. The objective lens (10) focuses the laser beam came out of the wavefront conversion surface (16a) on an optical information recording surface (3R). The optical pickup (1) satisfies the following condition for every wavelength of the corresponding laser beams: |SCMAX|<0.036??(1) wherein SCMAX is the maximum value of an offence against the sine condition of the objective optical system (2).

Abstract: An optical information apparatus includes a laser which emits a light beam, an objective lens and the like which converge a light beam emitted from the laser on an optical recording medium, spherical aberration correction instrument which is arranged on an optical axis of the light beam which links the laser and the objective lens, and corrects a spherical aberration generated on the optical recording medium. Correction is performed so that outgoing power of the laser changes according to a correction amount by the spherical aberration correction instrument.

Abstract: An object of the invention is to provide a splitter, a light emitter, and an optical pickup apparatus which can realize a stable track servo. Because of the structure of an optical system including an objective lens (27) and a hologram pattern (25), even when the hologram pattern (25) is irradiated with a reflected light from one recording layer other than another recording layer in a focused state, first and second TES splitting portions (35, 36) are not irradiated with the reflected light from the one recording layer, but the reflected light is led to an axis vicinity portion (38) only. Accordingly, light reception by first and second TES light receiving portions (45, 46) is prevented, accurate track position information and deviation information can be positively acquired, and troubles such as the objective lens (27) being driven beyond a movable range can be eliminated.

Abstract: An objective optical element for use in an optical pickup apparatus, includes two or more optical elements having a first surface having a first phase difference providing structure and a second surface having a second phase difference providing structure, wherein each of the first and second phase difference providing structures emit a diffracted light flux corresponding to each of the entering first-third light fluxes, or emit a transmitting light flux which is not applied a diffractive action corresponding to each of the entering first-third light fluxes, and the first-third light fluxes enter into the objective optical element as an almost infinite parallel light flux for information reproducing and/or recording on the first-third optical information recording media respectively.

Abstract: Embodiments of the invention provide fabrication processes for the co-fabrication of microprobe arrays along with one or more space transformers wherein the fabrication processes include the forming and adhering of a plurality of layers to previously formed layers and wherein at least a portion of the plurality of layers are formed from at least one structural material and at least one sacrificial material that is at least in part released from the plurality of layers after formation and wherein the space transformer includes a plurality of interconnect elements that connect one side to the array of probes that has a first spacing to another side that has a second spacing where the second spacing is greater than the first spacing. In some embodiments, the fabrication process includes a plurality of electrodeposition operations.

Abstract: When a phase shift is to be evaluated, based on a difference between an output from a waveform equalization circuit to equalize an input reproduced signal to a predetermined target equalization characteristic and the target equalization characteristic, the phase shift of the reproduced signal relative to a channel clock, a group delay characteristic with respect to the frequency of the waveform equalization circuit is fixed. Hence, an equalized waveform as an output from the waveform equalization circuit can preserve phase shift information of the inputted reproduced signal to correctly detect the phase shift of the reproduced waveform using the equalized waveform. It is hence possible to realize, with high precision, optimal value learning of various parameters for the recording, reproduction, and servo by use of the phase shift as an index.

Abstract: An optical pickup (100) includes: an irradiating device (101) for irradiating a laser beam (LB); a first light focusing device (104) for focusing the laser beam on the recording medium (10); a collimator device (102) which is disposed on the optical path between the irradiating device and the first light focusing device and which can be displaced along the optical path of the laser beam; a splitting device (103) which reflects one portion of the laser beam and transmits therethrough another portion of the laser beam; a light receiving device (111) for receiving the reflected one portion of the laser beam; and a second light focusing device (112) for focusing, on the light receiving device, the reflected one portion of the laser beam, the light receiving device and the first light focusing device is disposed at a position at which rate of change in light density of the laser beam on the first light focusing device before and after displacement of the collimator device is substantially the same as that on the l

Abstract: In a lens holding member for holding a solid immersion lens, when a difference-in-level portion and/or slant face is constructed at least on a part of the objective side surface, a tilt margin which can be applied to a near field optical recording and reproduction solid immersion lens can be maintained. In a focusing lens using such lens holding member, the optical pickup apparatus and the optical recording and reproducing apparatus, stable transportation between the lens and the optical recording medium can be improved.

Abstract: A method is provided for monitoring degradation of a data storage medium. Multiple reactive elements are provided in the data storage medium. Properties of each one of these elements is determined, prior or subsequent to data being stored in the medium, to generate a baseline map of the medium. Updated properties of at least one of the elements are determined in order to generate an updated map of the medium. A determination can then be made as to whether degradation of the medium has occurred by comparing the baseline map to the updated map.

Abstract: An optical data carrier is presented comprising first and second recordable media located in at least one first portion and at least one second portion of the data carrier, respectively. These first and second recordable media differ from each other in a storage capacity and a data recording rate.

Abstract: The object of the present invention is to provide an information recording/reproduction device for implementing high-density information recording and reading using mutual interaction of a recording medium with near field light, and particularly to a near field optical head with a high optical efficiency and a manufacturing method thereof. This is achieved by enabling an energy propagation mechanism via a plasmon by forming a layer dispersed with metal particulate at a microscopic opening generating near field light, and therefore increase optical efficiency.

Abstract: An optical pickup is provided which is capable of minimizing an astigmatism thereof with a simple configuration. The optical pickup includes a collimate lens for transferring optical beams outputted from a laser diode to parallel light, and an objective lens for collecting the optical beams transferred to parallel light with the collimate lens and applying the optical beams to an optical disk, wherein mounting angles of the collimate lens and the objective lens are adjusted so that astigmatisms of the collimate lens and the objective lens may be offset by each other. Thus the astigmatism of the optical pickup can be minimized with a simple configuration without need for separately providing an element for correcting aberration.

Abstract: A light flux from the first light source forms a converged spot on first optical information recording medium by only a refraction action of the aspheric surface, or by a combination of the refraction action and an optical action given by at least one of the first phase structure and the second phase structure, a light flux from the second light source forms a converged spot on second optical recording medium by a combination of a refraction action of the aspheric surface and an optical action given by at least one of the first phase structure and the second phase structure, and a light flux from the third light source forms a converged spot on third optical recording medium by a combination of a refraction action of the aspheric surface and an optical action given by at least one of the first phase structure and the second phase structure.

Abstract: The present invention provides an optical pickup device and optical recording medium information reproduction device that are capable of reproducing information that is recorded on a plurality of kinds of optical discs having different track pitches. With the present invention, an optical pickup device generates a main beam and sub beams that are made up from pairs of semi sub beams, such that the distance in the radial direction between center positions of a pair of semi sub spots on an optical disc where a pair of semi sub beams are formed is an odd multiple of half the track pitch of the optical disc, and the distance in the radial direction between center positions of semi sub spots that correspond to another pair of sub semi sub beams is an odd multiple of half the track pitch of another optical disc.

Abstract: An optical disk drive (101) for optically recording and/or reproducing information signals is provided in which the power of a light beam emitted from an optical head (104) to an optical disk (102) is controlled by an optical-coupling efficiency varying elements (214, 215) correspondingly to the type of the optical disk, recording layer in a multilayer optical disk and a mode of operation selected while a variation of the optical-coupling efficiency is being detected by a light-detecting element (216), thereby positively varying the optical-coupling efficiency in a minimum necessary time. Thus, the power of the light beam focused on the optical disk can be varied in a wide range without having to extremely raise the ratio in output power between modes of operation at a light source (212).

Abstract: An optical pickup apparatus comprises an orbicular zone forming lens group 14 for forming the section of the laser beam, which is irradiated to an optical disc DK having plural recording layers, into an annular shape, a condenser lens 35 that converges the reflected beam from the optical disc DK, and a pinhole plate 36 having formed thereto a pinhole 36a with a size corresponding to a flux diameter of the reflected beam converged by the condenser lens 35. The orbicular zone forming lens group 14 refracts the laser beam irradiated to the optical disc DK so as to form the section of the laser beam into an annular shape in order that the internal diameter of the annular converged flux formed on the pinhole plate 36a by the reflected beam from the recording layers other than the recording layer having an optical spot formed thereon becomes greater than the diameter of the pinhole 36a.

Abstract: The present invention relates to an optical system for performing radial tracking on an optical record carrier (100). The optical system contains light dividing means, e.g. a grating, for separating a light beam into a main beam (52) for reading and/or recording information as readable effects on the carrier, and a plurality of auxiliary beams (52a, 52b) applicable for radial tracking. The carrier contains readable effects arranged in multiple tracks in one or more spiral (s), where the one or more spiral (s) are separated by one or more guard band(s) (5, 15) in that two guard bands enclose multiple tracks.

Abstract: A device (100; 200; 300; 400) comprising a sealed cavity (210) containing n volumes of fluids (80, 87; 220, 230; 320, 332; 420, 422, 430, 432) is described, where n is an integer and n?2. Each volume of fluid is substantially immiscible with every contiguous volume of fluid. The cavity is defined by an interior surface divided into n continuous areas (60, 170; 260, 270; 360, 362, 370; 460, 462, 470, 472), each continuous area corresponding to and being in contact with a respective one of the volumes of fluid. The wettability of each area is such that each volume of fluid preferentially adheres to the corresponding continuous area rather than any one of the continuous areas adjacent to the corresponding area.

Abstract: An optical pickup apparatus according to an embodiment of the present invention, comprises an optical unit for projecting a plurality of wavelengths of light, the light including a celadon light, toward a recording medium and receiving the light reflected from the recording medium to thereby detect an information signal and an error signal, and a compatible objective lens for focusing a light projected from the optical unit to thereby form an optical spot on a recording surface of the recording medium and applying at least three light having different wavelength ranges to be compatibly used for both the high-density and the low-density recording mediums. Accordingly, the optical pickup apparatus is capable of compatibly employing a high-density recording medium, which uses a celadon light and is slimmer than a digital versatile disc (DVD), and at least one low-density recording medium.

Abstract: An object of the invention is to increase a transfer rate in data recording or data reproduction. A beam spot 10 is cyclically moved in a track set with a predetermined pattern. The track set is constituted of adjacent tracks of a predetermined number. In recording, the power of a laser beam is impulsively controlled with a predetermined intensity when the beam spot 10 crosses the middle of each of tracks 11, 12, and 13 to record data in the track set constituted of the tracks 11, 12, and 13. In reproduction, the data recorded in the track set constituted of the tracks 11, 12, and 13 is reproduced by sampling a reproduction signal to be generated in receiving reflected light of the light beam when the beam spot 10 crosses the middle of each of the tracks 11, 12, and 13.

Abstract: An optical information reproducing apparatus includes a light-receiving unit that receives a first reproduction light of an information output from a first region of an information recording layer and a second reproduction light of an information output from a second region of the information recording layer, the first region and the second region being formed by dividing the information recording layer with a line segment that intersects a plane of incidence of the reference light and a plane of the information recording layer, and outputs a first reproduction signal that is a reproduction signal of the first region and a second reproduction signal that is a reproduction signal of the second region.

Abstract: Provided is an optical pickup device capable of suppressing an increase in the number of parts and complication of an optical system while a diffraction grating is used as an optical axis correcting element. Three kinds of blue, red, and infrared laser light beams are emitted from laser element provided in the same CAN package. A blue light emitting point (wavelength: 405 nm) and an infrared light emitting point (wavelength: 780 nm) are arranged in a layer forming direction of the laser elements such that an interval (d2) between the light emitting points becomes shorter than an interval (d1) between each of the light emitting points and a red light emitting point. An optical axis of the laser light beam emitted from the red light emitting point (wavelength: 650 nm) is aligned with an optical axis of the laser light beam emitted from the blue or infrared light emitting point by using the diffraction grating.

Abstract: An optical compensator for use in an optical scanning device for scanning optical record carriers, there being at least two different information layer depths within two different ones of the carriers, the optical record carriers including a first optical record carrier (3?), a second optical record carrier and a third optical record carrier, the scanning device including a radiation source system (7) for producing first, second and third radiation beams for scanning the first, second and third record carriers, respectively, the first, second and third radiation beams having different predetermined wavelengths.

Abstract: Disclosed herein is a recording medium on or from which the recording or reproduction of data is stably performed. On the recording medium, data are recorded three-dimensionally by the irradiation of a recording laser beam. The recording medium includes a reflection control layer including a plurality of reflection layers stacked in a film thickness direction, each reflection layer having a connection terminal, each reflection layer exhibiting reflectivity and transmissivity changeable in response to an electrical signal supplied to the connection terminal and a recording layer disposed at a beam incidence side of the reflection control layer.

Abstract: An optical head device includes a light source which emits a light beam, an objective lens which condenses the light beam on the optical disk, a condensing lens which condenses reflected light from the optical disk, a liquid crystal panel disposed near a focal point of the condensing lens and having pixels, a driver which drives the pixels of the liquid crystal panel to pass the reflected light from a reproduction layer of the optical disk and partially interrupt the reflected light from a non-reproduction layer of the optical disk, and a photodetector which detects light passed through the liquid crystal panel.

Abstract: The soldered connection of an end portion of a cable extending from each element with a main substrate is prevented from being broken. An end portion of a cable t1 extending from a light source element LD that is fixed to a standing frame 2A on a slide base 2 movable back-and-forth in the radial direction of a disk passes through an insertion opening 9 in the slide base 2 to be connected by soldering 8b to a main substrate 3, and an extended portion 15 extending from the peripheral edge of the insertion opening 9 close to the main substrate 3 is formed integrally with the slide base 2, the clearance “?” between the leading end face 15A of the extended portion 15 and the main substrate 3 being set slightly greater than the thickness “d” of the cable t1, so that the cable t1, if tensioned when positioning the light source element LD, is brought into contact with the edge 15a of the leading end face 15A.

Abstract: A system and method is provided for adjusting a depth of focus in a refractive material without introducing spherical aberration as a result of the focal adjustment. The system and method provide a novel optical path in which a ramped prism is situated between an objective lens and a refractive material. The bottom surface of the prism is positioned parallel to and in close proximity with the top surface of the recording medium. The objective lens and, as appropriate, one or more associated mirrors are positioned so that light exiting the lens is directed along an optic axis that is oriented substantially perpendicular with respect to the ramped top surface of the prism. In operation, light passes through the objective lens and is focused at a fixed optical depth in the refractive block consisting of the prism and recording medium. The objective lens and other optics in the optical path may be moved up or down the prism ramp to adjust the physical depth of focus in the recording medium.

Abstract: In order to prevent a spectrum of a wavelength channel from becoming narrower, a device according to the present invention includes a light dividing section capable of dividing a wavelength spectrum in an input light beam and outputting a plurality of divided light beams, which are spatially separated and have wavelength spectrum portions different from each other, and a wavelength-to-special-position-converter capable of spatially multiplexing the wavelength spectrum portions of the plurality of divided light beams from the light dividing section.

Abstract: The present invention relates to a phase retardation plate including a thin organic film with a phase retardation function due to birefringence and a fixed substrate bonded to at least one surface of the thin organic film using an adhesive, and to an optical pickup device having the phase retardation plate. In the phase retardation plate and the optical pickup device using the same, a liner thermal expansion coefficient (L1) of the thin organic film, a liner thermal expansion coefficient (L2) of the adhesive and a liner thermal expansion coefficient (L3) of the fixed substrate satisfy a relationship of L1>L2>L3; and the thin organic film retards the phase of incident light with a wavelength in a range of 400 to 800 nm by ?/2 or ?, the thin organic film having a phase retardation value between 0 and ?.

Abstract: In a optical head, a beam is emitted from a light emitting element in which a plurality of light sources are integrally formed, the light sources being able to emit beams having different wave lengths from one another. An optical system converges the beam coming from any one of the light sources onto an optical information storage medium. An optical separator separates a reflected beam coming from the optical information storage medium from the beam coming from the light source. A light receiving element detects light quantities of the reflected beam separated by the optical separator.