Abstract: An optical head device includes a first light source and a second light source which respectively emits a first light beam and a second light beam, a luminous flux separating section which selectively separates the first and second light beams for which the same optical path is used, to first and second optical paths, respectively, a first objective lens for converging the first light beam that has been separated to the first optical path on the first optical information recording medium, a second objective lens made of resin for converging the second light beam separated to the second optical path on the second optical information recording medium, and a first filtering section formed on a beam exit face of the second objective lens, for reducing the transmittance of the first light beam to be lower than transmittance of the second light beam.

Abstract: An optical disc apparatus includes a light separator configured to separate a light beam emitted from a light source into a main beam and a sub-beam, an objective lens configured to, when the light beam is condensed and irradiated to an optical disc having a uniform recording layer in which a track is formed by record marks, irradiate at least part of the sub-beam to an area where the main beam is not irradiated in a radial direction which is defined as a direction of radius of the optical disc, and a signal generating unit configured to generate a mark layer distance signal, representing a distance between a focus of the light beam and a mark layer to which the track belongs, based on a return light beam resulting from at least one of the main beam and the sub-beam, which has been irradiated to the track.

Abstract: An aberration correcting device includes: a first transparent electrode; a second transparent electrode; and a liquid crystal layer disposed between the first transparent electrode and the second transparent electrode, having refractive index varying according to an electric field applied to the liquid crystal layer, wherein the first transparent electrode has a first circular dividing line and a second circular dividing line formed outside the first circular division line arranged to be concentric with the second circular dividing line, and wherein a region between the first circular dividing line and the second circular dividing line is radially divided by plural radial dividing lines.

Abstract: An optical pickup apparatus is provided with an angle adjusting element. The angle adjusting element changes a propagation direction of luminous fluxes of four luminous flux regions set about an optical axis of the laser light, out of laser light reflected by a disc, and mutually disperses the luminous fluxes. A signal light region in which signal light only is present appears on a detecting surface of a photodetector. A sensor pattern for signal light is placed at a position irradiated with the signal light within this region. A sensor pattern for a spherical aberration detection is placed on an inner side of this region.

Abstract: An optical pickup apparatus is provided with an angle adjusting element. The angle adjusting element changes a propagation direction of luminous fluxes of four luminous flux regions set about an optical axis of the laser light, out of laser light reflected by a disc, and mutually disperses the luminous fluxes. A signal light region in which signal light only is present appears on a detecting surface of a photodetector. A sensor pattern for signal light is placed at a position irradiated with the signal light within this region. A sensor pattern for a coma aberration detection is placed on an inner side of this region.

Abstract: An apparatus includes a component having a first surface, a first waveguide for directing electromagnetic radiation to a focal point adjacent to the first surface, a storage medium positioned adjacent to the first surface, a detector for detecting electromagnetic radiation reflected from the storage medium, and a structure positioned adjacent to the focal point for collecting the reflected electromagnetic radiation and for transmitting the reflected electromagnetic radiation toward the detector, wherein the structure comprises a second waveguide including a first cladding layer positioned adjacent to a first side of the first waveguide and having a first end positioned adjacent to the first surface and a second cladding layer positioned adjacent to a second side of the first waveguide and having a first end positioned adjacent to the air bearing surface.

Abstract: The optical recording medium has a recording layer sensitive for recording at a first wavelength and sensitive for reading at a second wavelength, the recording layer having a groove structure, wherein at the first wavelength the groove structure has a diffraction efficiency into a first diffraction order sufficiently large to generate a push-pull signal, and at the second wavelength it has a diffraction efficiency into a first diffraciton order close to zero. The optical pickup for recording on an optical recording medium intended to be read with a second wavelength and a second numerical aperture is characterized in that it has a light source for generating a light beam at a first wavelength and a numerical aperture given by the second numerical aperture multiplied with a ration of the first wavelength and the second wavelength.

Abstract: A connection structure of Flexible printed circuits comprising: first and second Flexible printed circuits, respectively, including a base formed of a resin, a plurality of wiring patterns arranged side by side on the base, a cover formed of a resin to cover opposite sides of the wiring patterns to the base, and a connection portion in which the plurality of wiring patterns are not covered by the cover, the connection portions of the first and second Flexible printed circuits being connected with each other. The wiring patterns in the connection portions include a large width portion which is larger in width than the wiring patterns covered by the cover. The large width portions on the first Flexible printed circuit and the large width portions on the second Flexible printed circuit are connected to each other by means of soldering.

Abstract: The present invention relates to composite optical elements, and particularly to a composite optical element including a first optical component and a second optical component coupled to the first optical component. The present invention is advantageous in enhancing optical properties. A composite optical element (1) includes a first optical component (10) and a second optical component (20). The first optical component (10) is made of first glass and has a lens surface (12). The second optical component (20) is made of a material different from the first glass, is coupled to the first optical component (10) at a lens surface (22), and has a lens surface (22) at a side opposite to the first coupling surface (21). The lens surface (12) partially has a first uneven region (12a). The lens surface (22) partially has a second uneven region (22a).

Abstract: An optical pickup apparatus comprising: a laser-light source that selectively emits first and second laser lights parallel with each other; a diffraction grating that includes a plurality of periodic structures joined to be different in phase from each other in a direction optically corresponding to an optical-disc-tracking direction, and generates 0th-order and ±1st-order-diffracted lights by diffracting the first or second laser light; an objective lens that focuses the 0th-order and ±1st-order-diffracted lights generated from the diffraction grating on the same track of the disc; and a photodetector to which reflected light of the 0th-order and ±1st-order-diffracted lights focused on an optical disc is applied through the objective lens, and which generates a differential-push-pull signal, a direction of a straight line connecting light-emitting points of the first and second laser lights in the laser-light source being inclined relative to the direction optically corresponding to the optical-disc-tracking

Abstract: Influences of reflected light, which result in crosstalk from adjacent layers in a multi-layered optical disk, are mitigated. In an astigmatic optical system of an optical pickup, a first composite segmented wave plate having a segmentation direction that is in the same direction as the focal line that is close to the astigmatic optical system, a second composite segmented wave plate of the same segmentation direction, and an analyzer are inserted.

Abstract: [Problems] In an objective lens driving device used for an optical disc and the like, a moving speed of the objective lens is changed corresponding to amount of vertical deviation of the optical disc, and when the vertical deviation is small, time for aligning the focus is reduced. [Means for Solving Problems] In a case that an objective lens is moved from a bottom limit to an upper limit in a specific range for aligning the focus, when the objective lens is positioned nearer a point (basic focusing position) where light is focused on an optical disc 11 having no vertical deviation than a position away from the basic focusing position, the servo signal processor 5 moves the objective lens faster.

Abstract: An optical pickup apparatus reads an information signal recorded on a recording surface of an optical disk along a track by projecting a light beam. Said optical pickup apparatus has: an objective lens for converging said light beam onto said recording surface; an objective lens moving device for moving said objective lens in a radial direction of said optical disk; and a divisional photosensing device for receiving return light reflected by said optical disk, in a plurality of divided regions.

Abstract: An optical pickup apparatus is provided with an optical system for guiding a laser light emitted from a laser light source to an objective lens and also for guiding the laser light reflected by a recording medium to a photodetecting section as a convergent light. The photodetecting section is provided with first and second photodetectors disposed at positions at which a first part of the target laser light and a second part different from the first part are respectively received, the positions being separated further from the optical system than a convergence position of a target laser light reflected by an irradiation-target recording layer, out of the laser light reflected by the recording medium, and a third photodetector disposed at a position closer to the optical system than the convergence position of the target laser light, the position being bridging more over the second part than the first part.

Abstract: An optical disk reproduction apparatus according to the present invention is an optical disk reproduction apparatus capable of reading information from the NBCA of an optical disk 101 having an NBCA, and includes: an optical pickup 103 having an objective lens 120 for converging a light beam onto the optical disk 101, a lens actuator 170 for controlling a position of the objective lens 120, and a photodetector for generating an electrical signal from at least a portion of the light beam having been reflected by the optical disk 101; a transport mechanism 106 for moving the optical pickup 103 along a radial direction of the optical disk; and an NBCA in/out determination section 104 for, based on electrical signal, determining whether an irradiated position of the light beam on the optical disk 101 is located within the NBCA or not.

Abstract: An optical information recording medium, which has recording layers that include substrates of the same thickness and that correspond to laser light at two difference wavelength, has excellent compatibility. An optical disk, in which recoding or reproduction is performed from one plane through the substrate, has two recoding layers, and the recording density of a first layer is different from the recording density of a second layer. First recording layer 101 and second recording layer 102 are stacked on substrate 1. The laser beam for recording or reproduction is incident through substrate 1. Structurally, the disk is formed by laminating two recording layers on the side opposite to the laser beam incident side. Intermediate layer 103 which is transparent to a second laser beam is formed between the first and second layers. Laser beam with different wavelengths is used to record or reproduce the first and second layers.

Abstract: An optical pickup apparatus comprising: a diffraction grating configured to diffract laser light from a laser diode so that signals recorded in first and second optical discs are selectively reproduced, thicknesses of protective layers between surfaces and signal recording surfaces of the first and second optical discs being different from each other; a polarization beam splitter configured to divide laser light from the diffraction grating into first and second laser lights whose light amounts are substantially the same; a first objective lens configured to focus the first laser light onto the signal recording surface of the first optical disc; a second objective lens configured to focus the second laser light onto the signal recording surface of the second optical disc; and a photodetector configured to be applied with return lights of the first and second laser lights reflected from the signal recording surfaces of the first and second optical discs.

Abstract: An optical disc apparatus includes an optical pickup for outputting an output signal according to reflected light from an optical disc medium and a comparison signal output unit for outputting a comparison signal indicating whether a level of the output signal is higher than a threshold value, relatively moves an objective lens with respect to a surface of the medium within a predetermined range to measure a maximum level of the output signal, sets a value determined according to the maximum level as a threshold value used by the comparison signal output unit, and measures a level of a reflected signal corresponding to reflected light from each of a plurality of signal surfaces based on the output signal in a time period in which the comparison signal indicates that the level of the output signal is higher than the set threshold value, while moving the objective lens.

Abstract: An optical information recording/reproducing device is provided with a first light source 20a for emitting recording light 22a, a second light source 20b for emitting reproducing light 22b, an objective lens 6 for focusing the emitted lights from the both light sources 20a, 20b on an information recording medium including a recording region 3 capable of three-dimensional recording and photodetectors 19a, 19b for detecting reflected lights 7a?, 7b? from the information recording medium, and records information on recording layers 1a to 1e utilizing a nonlinear absorption phenomenon. At the objective lens 6, an average rim intensity of the recording light 7a is lower than that of the reproducing light 7b.

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: A method and a device for simultaneously reading information from a plurality of data tracks (14) of an optical disc (22) by means of a detector illuminating said plurality of data tracks with laser spots (25), wherein light reflected from the laser spots is collected by means of a servo lens (29), further providing the detector with a plurality of detector elements (28a, 28b, 28c, 31a, 42a, 28bc, 28cc, 32a, 32b, 42ac, 51a, 52a, 52b) spaced apart from each other, arranging each detector element to detect (read) light reflected from a data track allotted to each element, arranging at most two detector elements (28bc, 28cc, 32a, 32b, 42ac, 52a, 52b) to be segmented detectors for providing both a power signal for the allotted track and an output signal for focus error control in a servo system guiding said detector along said tracks, reading only the power signal for each track by means of second detector elements (28a, 28b, 28c, 31a, 42a, 51a) and arranging each one of said second detector elements to be of sub

Abstract: Light emitted from a radiation light source 1 passes through a diffraction grating 3a and is separated into transmitted light a, +1st order diffracted light b, and ?1st order diffracted light c. The transmitted light a, +1st order diffracted light b, and ?1st order diffracted light c are collected through an objective lens 7 on tracks on the signal plane 8a of an optical disc 8 in a partially overlapped state. Light reflected by the tracks on the signal plane 8a passes through the objective lens 7 and is incident upon light diverging means 13a.

Abstract: This optical disc drive can read and/or write data from/on an optical disc 20 with multiple information layers including first and second information layers. The drive includes: a light source 3, 4 that emits the light beam; an objective lens 1; an actuator 2 for moving the objective lens perpendicularly to the information layers; a focus error generator 7 for generating a focus error signal representing how much the light beam has been converged on a target one of the information layers; and focus control means for forming a focal point of the light beam on the target information layer by driving the actuator in accordance with the focus error signal. According to the present invention, while a focus jump is being made to shift the focal point of the light beam from the first information layer of the optical disc 20 to the second information layer thereof by moving the objective lens 1, wavelengths and/or numerical apertures for the light beam are changeable while the objective lens 1 is moving.

Abstract: An optical head unit is configured as an optical head unit corresponding to an optical recording medium of BD standard, and an optical recording medium of HD DVD standard. A magnification-variable lens includes convex lens, concave lens, and convex lens. The magnification-variable lens allows each lens to be movable along the optical axis direction, and has the function of changing the ratio of diameter of light incident from the convex lens to the diameter of light that exits from the convex lens within a specific ratio. The magnification-variable lens emits light having a diameter corresponding to the numerical aperture, 0.85, of the objective lens towards the objective lens upon recording/reproducing on a disk of BD standard, and emits light having a diameter corresponding to the numerical aperture, 0.65, of the objective lens upon recording/reproducing on a disk of HD DVD standard.

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

Abstract: An optical pickup, having an optical pickup housing made of resin, for maintaining the heat radiation performance or capacity of a semiconductor laser, also an objective lens driving mechanism, and further a driver IC for the semiconductor laser, while keeping small-size and light-weight thereof, comprises a pickup housing, in which an optical part and a semiconductor laser are fixed; an objective lens, which is attached within the pickup housing; and an objective lens driving mechanism, which is configured to drive the objective lens, further comprising: a metal-made bottom cover, which is configured to cover a lower surface of the pickup housing and a side surface of an inner periphery of an optical disc, wherein the metal-made bottom cover and the semiconductor laser are thermally connected with each other.

Abstract: An objective lens unit for use in an optical pickup device, includes: a first lens section; a first flange section positioned peripheral of the first lens section; and a support section which supports a second objective lens having a second lens section provided in parallel to the first lens section with an optical axis different from that of the first lens section, wherein the first lens section, the first flange section and the support section are integrally formed.

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: An optical controller includes a light source for emitting light, an object lens for condensing light emitted from the light source, a light detection unit for receiving light reflected on an optical information recording medium and outputting a signal corresponding to the amount of the light, and a laser control unit for controlling the amount of the light emitted from the light source to the information recording surface on which information is to be recorded or reproduced, based on the recording state of an information recording surface disposed closer to the object lens than an information recording surface on which the information is to be recorded or reproduced.

Abstract: In a focus optical system for optical discs or optical disc master exposure apparatuses, a relative positional relation between a cylindrical lens and a 4-division detector in an astigmatic optical system is adjust so that an interference fringe appearing in reflected light derived from an optical disc master is made to be incident on a dead zone of the 4-division detector. Thus, an astigmatic focus servo free from effects of variations in a focus error signal due to the interference fringe is realized. As a result of this, effects of the interference fringe appearing in the reflected light derived from an optical disc or optical disc master can be suppressed.

Abstract: An objective lens system for an optical pickup apparatus, includes in order from an object side: a first lens group having negative paraxial power P1 (mm?1); and a second lens group having positive paraxial power P2 (mm?1) for converging a light flux emitted from the first lens group on an information recording surface of an optical information recording medium.

Abstract: There is disclosed an optical head apparatus and an optical information recording or reproducing apparatus capable of obtaining a high light output at a recording time, and a high S/N at a reproducing time with respect to any of disks of next-generation, DVD, and CD standards. Light having a wavelength of 400 nm emitted from a semiconductor laser is almost all reflected by a beam splitter, and condensed on a disk of the next-generation standard. Light having a wavelength of 660 nm emitted from a semiconductor laser is almost all reflected by a beam splitter, almost all transmitted through the beam splitter, and condensed on the disk of the DVD standard. Light having a wavelength of 780 nm emitted from a semiconductor laser is almost all reflected by a beam splitter, almost all transmitted through the beam splitters and condensed on the disk of the CD standard. Reflected light from the disk is almost all transmitted through the beam splitters and received by a photodetector.

Abstract: A pickup lens has a plurality of ring zones on at least one surface, and steps are formed respectively between the plurality of ring zones. The plurality of steps have step differences causing laser light to have a phase difference to reduce aberration occurring in the pickup lens due to a change in ambient temperature. Further, when a numerical aperture of the pickup lens is NA, a focal length is f (mm) and a working distance is WD (mm), the pickup lens is fabricated to satisfy NA=0.85, 1.1=f=1.8 and WD=0.3.

Abstract: An optical pickup according to the present invention includes: an objective lens 1 for converging laser light onto a signal plane of an optical disc 14; a lens actuator 3, 4, 5 capable of moving the objective lens 1 in a direction at least perpendicular to the signal plane of the optical disc 14; and an actuator base 8 for supporting the lens actuator 3, 4, 5. This optical pickup further includes: an adjustment mechanism 10a, 10b, etc., for defining a height of the actuator base 8 within the optical pickup and defining a tilting angle of the actuator base 8 along a tangential direction 15 of the optical disc 14; and a tilt generating mechanism 6a, 6b, 6c, 6d for changing a tilting angle of the objective lens along a radial direction of the optical disc according to a height of the objective lens 1 relative to the actuator base 8.

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: An optical information recording/reproducing device includes a liquid optical element containing a liquid crystal polymer layer in an optical head. A liquid crystal optical element drive unit drives a liquid crystal optical element having a first pattern electrode divided into a plurality of region at one side of the liquid crystal polymer layer in the optical axis direction. The first pattern electrode includes a first region arranged to surround the optical axis and second to ninth regions arranged outside the first regions in such a manner that the circumference is divided eight portions. The liquid crystal optical element drive unit applies a first effective voltage to the first region, a second effective voltage to the second and the sixth region, a third effective voltage to the third and the seventh region, a fourth effective voltage to the fourth and the eighth region, and a fifth effective voltage to the fifth and the ninth region.

Abstract: This invention discloses a micro optical pickup apparatus for providing an incident light to an optical recording medium, receiving a reflected light from the optical recording medium, and thereby accessing data of the optical recording medium.

Abstract: A method of manufacturing a synthetic resin lens, comprising: adjusting a degree of change in transmittance of a lens member made of synthetic resin for a blue violet laser beam with accumulated application of the blue violet laser beam, by applying to the lens member an electromagnetic wave shorter in wavelength than the blue violet laser beam.

Abstract: The invention relates to a suspension arm actuator for an optical scanning device, comprising a suspension arm designed as a two-arm lever and allocated to an optical recording carrier. The suspension arm is, in known manner, mounted to a support between the lever arms such that it can be pivoted about an axis extending perpendicularly to said suspension arm. On its end side, one of the lever arms supports an optical head having optical components, in particular having an objective lens, while a magnetic drive initiating a swivel motion about the axis is allocated to the other lever arm. In addition, the suspension arm actuator comprises a magnetic drive initiating a motion perpendicular to this swivel motion and electric connections between a control unit arranged outside of said suspension arm actuator and the electrical and optical components.

Abstract: An optical head device compatible to different types of optical discs and capable of guaranteeing a sufficiently wide dynamic range for a low density optical disc, and the like are provided. The optical head device includes a plurality of light sources switchably usable; an objective lens for converging light emitted from one of the plurality of light sources to an information recording layer of an optical disc; and a light detector for receiving the light reflected by the information recording layer and outputting an electric signal based on the amount of the received light. The plurality of light sources include a first light source for emitting light having a first wavelength and a second light source for emitting light having a second wavelength shorter than the first wavelength.

Abstract: An optical-pickup apparatus comprising: a laser diode to emit laser light forward and backward; an objective lens to focus the laser light emitted forward from the laser diode onto a signal-recording layer of an optical disc; a spherical-aberration correction element that is arranged on an optical path between the laser diode and the objective lens, and is so movable in an optical-axis direction of the laser light as to correct spherical aberration; a movement-position detection unit to detect a movement position of the spherical-aberration correction element, and output a detection signal indicating the movement position of the spherical-aberration correction element; a photodetector to receive the laser light emitted backward from the laser diode, and output a monitor signal corresponding to a light-receiving level of the laser light; and a control unit to control intensity of the laser light emitted from the laser diode based on the monitor and detection signals.

Abstract: An optical-pickup apparatus comprising: a laser diode; an objective lens made of a synthetic resin to focus laser light emitted from the laser diode onto a signal-recording layer of an optical disc; a collimating lens that is arranged in an optical path between the laser diode and the objective lens, and is so movable in an optical axis direction of the laser light as to correct spherical aberration; a temperature sensor to detect a temperature of the objective lens; and an aberration-correcting device to move the collimating lens from a first position where the spherical aberration is a predetermined value on a positive side to a second position where the spherical aberration is a predetermined value on a negative side, when an amount of change in temperature detected by the temperature sensor reaches a predetermined amount after an operation of reproducing a signal from the signal-recording layer is started.

Abstract: An optical disc storage system employs a read/write pick-up head assembly in which the optical path between the disc and the read/write light source, usually a laser diode, includes both a conventional objective lens formed of glass or plastic, with a fixed focus, and a liquid crystal lens which is electrically tunable to vary its refractive index and focal distance. The optical signal reflected from the disc is passed through this hybrid pick-up head assembly and demodulated to detect errors in the focus of the pick-up head and the tracking, and to adjust the focus by modifying the electrical signals applied to the LCD lens, and move the pick-up head in the plane of the disc to address the appropriate track.

Abstract: A structure according to the present invention is an optical pickup apparatus including a first light source, a second light source, a third light source, a first objective optical system, a second objective optical system, an incidence optical system for emitting the first to third light fluxes into the first objective optical system or the second objective optical system, and an optical detector. The optical pickup apparatus converges a light flux emitted from the first light source onto an information recording surface of a first optical information recording medium or a second optical information recording medium, by using the first objective optical system.

Abstract: An image pickup apparatus has a construction in which a diffraction element is provided in an observation optical system. Zero-order light that is transmitted straight through the diffraction element and one of the +1st-order diffracted light and the ?1st-order diffracted light that is diffracted by the diffraction element are imaged onto an image pickup surface of an image pickup apparatus. The imaging areas of the zero-order light and one of the +1st-order diffracted light and the ?1st-order diffracted light that is diffracted by the diffraction element do not overlap on the image pickup surface of the image pickup apparatus. With this construction, a small image pickup apparatus that provides a high-resolution spectral image and a color image of an object can be obtained.

Abstract: An optical pickup including a light source, a light focus device, a diffraction element, an optical split element, a ¼ wavelength board, a light reception device and a correction element wherein the correction element is divided into multiple areas in a surface vertical to an optical axis, each area of the multiple areas has a sub-wavelength convexo-concave structure having a pitch equal to or shorter than a wavelength of the outgoing light beam and the sub-wavelength convexo-concave structures of the multiple areas adjacent to each other have groove directions perpendicular to each other, and the filling factors of adjacent areas of the multiple areas are determined to substantially equalize effective refractive indices with regard to the polarization direction of the outgoing beam emitted from the light source and impart a phase difference of ? with regard to a polarization direction perpendicular to the polarization direction of the outgoing beam.

Abstract: A switchable optical element having an optical path (OP) for a radiation beam and having a first state and a second state, the element comprising: a first fluid (12) and a second, different, fluid (14) which are immiscible and which are separated from each other by a fluid meniscus (16); a first, transparent, wall part and a second, transparent, wall part spaced from each other along the optical path; and a fluid switching system which is arranged to apply forces to the first and/or the second fluid in order to switch the element between the first and the second state. The first wall part includes a non-planar wavefront modifier (28), and wherein the fluid switching system is arranged to apply the forces so that when the element is in the first state, the first wall part is covered by the first fluid (12); and when the element is in the second state, the first wall part is covered by the second fluid (14).

Abstract: A method of adjusting the tilt of objective lenses in an optical pickup having a plurality of light sources, an optical pickup component with a plurality of objective lenses which converge light from the plurality of light sources on an optical information recording medium and a movable part which holds the plurality of objective lenses, an actuator which drives the movable part of the optical pickup component, and a base on which the actuator is arranged and an optical system which introduces light emitted from the plurality of light sources to the plurality of objective lenses is constituted, which are capable of producing an optical pickup with a plurality of objective lenses while tilt is being simply adjusted, the method includes: a first tilt adjustment step of adjusting the tilt of the plurality of objective lenses with respect to the optical information recording medium with the optical pickup component temporarily arranged at a predetermined position on the base; and a tilt detecting step of detectin

Abstract: A method and apparatus for recording/reproducing data is disclosed. The apparatus for recording/reproducing data comprises a diffraction element splitting light diffracted or reflected from a recording medium into a main beam and first and second sub beams, the main beam and the first and second sub beams having no interference from one another; a light-receiving part detecting the main beam and the first and second sub beams; and a controller controlling a position of the diffraction element based on at least one light capacity of the detected beams or the detected position.

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.