Abstract: An objective lens formed of a synthetic resin material having characteristics of substantially not reducing transmittance of the objective lens when a first laser beam having a first wavelength passes through the objective lens, and reducing the transmittance according to an elapsed time to apply a second laser beam when the second laser beam having a second wavelength shorter than the first wavelength and longer than a wavelength of ultraviolet light passes through the objective lens, the objective lens being irradiated with the ultraviolet light in advance for a predetermined time such that a change in the transmittance for the second laser beam is set within a predetermined range.

Abstract: An optical head device and an optical recording and reproducing apparatus using this optical head device, which can record information and reproduce the recorded information at any of optical recording media, such as a next generation optical recording medium, in which the wavelength of the light source is made to be shorter, the numerical aperture of the objective lens is made to be higher, and the thickness of the recording medium is made to be thinner, and conventional recording media of DVD and CD standards, are provided. A light having wavelength of 405 nm, emitted from one of optics, is inputted to an objective lens as a collimated light, and is focused on a disk having thickness of 0.1 mm. A light having wavelength of 650 nm, emitted from the other of optics, is inputted to the objective lens as a diverged light, and is focused on a disk having thickness of 0.6 mm.

Abstract: An optical pickup device includes a first light source emitting first light with a first wavelength, a second light source emitting second light with a second wavelength, a third light source emitting third light with a third wavelength, an objective lens having a step structure, the objective lens being disposed to satisfy predetermined conditions, at least one first coupling lens making the first light and the second light incident onto the objective lens as converged light, a second coupling lens making the third light incident onto the objective lens as diverging light, and a liquid crystal aberration correcting element.

Abstract: An optical pickup includes: a plurality of object lenses mounted in a central portion; a lens holder having tracking and focusing coils distributed between two side portions; a fixed base having a plurality of magnets paired with the tracking and focusing coils and a plurality of stand-up mirrors each facing a different one of the object lenses; a plurality of wires supporting the two side portions of the lens holder; a coil substrate having a winding pattern as a tracking coil and integrated with the lens holder so as to cross through the central portion of the lens holder and project beyond the two side portions while avoiding the object lenses and the stand-up mirrors. A plurality of through holes are formed in the coil substrate for electrically connecting the plurality of wires as leads to the tracking and focusing coils.

Abstract: An optical element includes: an element body including a resin containing a polymer having an alicyclic structure. The optical element is treated by one of heat treatment and wet-heat treatment for 15 hours or longer at a temperature lower by 10C.° to 30C.° than a glass transition temperature of the resin after being formed by injecting the resin in a mold. The optical element body has a length along an optical axis of the optical element in a range of 0.5 to 3 mm, and a length in a perpendicular direction to the optical axis in a range of 3 to 5 mm.

Abstract: An optical disk device of the present application includes: a turntable 30 including plural induction grooves 31a to 31h as concave portions radially extending from vicinity of a center of the turntable 30 and having open portions in an outer periphery of the turntable 30 and plural through-holes 32a to 32h penetrating bottom faces 33a to 33h on the vicinity of the center side of the plural induction grooves 31a to 31h and a top face of the turntable 30; and an outer rotor type spindle motor 35 provided with plural fins 36a to 36h as convex portions on a rotor on a side face thereof. The optical disk device of the present application utilizes an airflow generated by rotation of the rotor of the spindle motor 35 and the turntable 30 in conjunction therewith as a dust removing wind for removing dust attaching to an objective lens side area.

Abstract: A complex objective lens composed of a hologram and an objective lens, capable of realizing stable and high-precision compatible reproducing/recording of a BD with a base thickness of about 0.1 mm for a blue light beam (wavelength ?1) and a DVD with a base thickness of about 0.6 mm for a red light beam (wavelength ?2). In an inner circumferential portion of the hologram, a grating is formed, which has a cross-sectional shape including as one period a step of heights in the order of 0 time, twice, once, and three times a unit level difference that gives a difference in optical path of about one wavelength with respect to a blue light beam, from an outer peripheral side to an optical axis side. The hologram transmits a blue light beam as 0th-order diffracted light without diffracting it, and disperses a red light beam passing through an inner circumferential portion as +1st-order diffracted light and allows it to be condensed by an objective lens.

Abstract: An optical pickup device to provide a stable operation in both low-speed and high-speed modes by controlling a change in natural frequency, the optical pickup device including: a lens holder to support an objective lens; a supporting unit spaced apart from the lens holder; and a plurality of suspension members each having one end fixed to the lens holder and another end supported by the supporting unit to enable a movement of the lens holder, wherein the supporting unit includes a fixing member, a coupling portion provided in the fixing member to couple each suspension member, magnetic fluid received in the coupling portion, and an excite device to apply a magnetic field to the magnetic fluid.

Abstract: An optical pickup comprising: an objective lens 16 for converging laser light and directing it to an information recording medium 17; a rotational frame member 19 which surrounds the periphery of the objective lens 16, has a circular-shaped outer peripheral edge around an optical axis of the objective lens 16 and rotates in conjunction with the objective lens 16; a lens holder 15 which has a concave stepped portion 10 for rotatably supporting the rotational frame member 19 and is coupled to the rotational frame member 19 after rotation adjustments; and a protruding portion 20 protruded from the rotational frame member 19 toward the information recording medium 17. The optical pickup can facilitate operations for adjusting the rotation of the objective lens and certainly prevent both the objective lens and the information recording medium from being damaged.

Abstract: An image pickup apparatus having a lens unit configured to include a plurality of lenses and a variable aperture mechanism capable of varying an aperture opening diameter, the image pickup apparatus including: in the lens unit, a variable aperture unit configured by integrating the variable aperture mechanism and the single lenses of the lens unit using a fixing portion.

Abstract: A disk motor which rotationally drives an optical disk; a rotational phase detector which detects a rotational phase thereof; an optical head having a collecting lens which collects an optical bean; a light detector and an LE signal generator which detect a position of the collecting lens in the optical head as a position signal; an LE signal memory recorder and an LE signal memory which store, in synchronization with a rotational phase to be detected by the rotational phase detector, the positional signal from the LE signal generator; an LE signal memory regenerator which outputs as a correction signal, in synchronization with a rotational phase to be detected, the positional signal which has already been detected; a subtractor; an LE signal filter, a drive circuit and a Tk actuator which move the collecting lens using a signal from the subtractor; and a low pass filter which reduces a high-frequency component of the correction signal are provided.

Abstract: The type of a disc is determined by detecting focus error signals and the amount of returned light while emitting light with a wavelength such as infrared light which maximizes the focal length and moving an objective lens in the direction of an optical axis. If the S shape and AS immediately after the surface are greater than those at the surface, the optical disc is determined to be an optical disc with a largest capacity. It is determined whether or not there is a reflective layer at a depth equal to or less than 0.1 mm. If there is no reflective layer thereat, it is determined whether or not there is a reflective layer at a depth of 0.6 mm. If there is a reflective layer thereat, the type of the reflective layer is determined based on TE and RF signals with blue light. If the blue light is not adaptable to the layer, red light is emitted, and replay of the recording layer at a depth of 0.6 mm is performed.

Abstract: An optical pickup apparatus is provided for recording and/or reproducing information on an optical disc including at least one reference layer and at least one recording layer in which information can be recorded at recording positions each located at a different distance from an optical disc surface. The optical pickup apparatus includes: a light source; a relay lens system for emitting a converged light flux; an objective lens arranged at a predetermined distance from the reference layer, for converging the converged light flux onto one of the recording positions; and a photodetector. The relay lens system changes a convergence angle of the converged light flux to enter the objective lens by moving in a direction of an optical axis thereof so as to select a recording position where information is recorded and/or reproduced.

Abstract: An optical pickup includes: an objective lens that collects a first beam and a second beam and emits the first and second beam toward an optical information recording medium on which information can be recorded as a recording mark as a result of being exposed to the first beam; a section that drives the objective lens to focus the second beam on a reflection layer formed on the optical information recording medium, the reflection layer at least partly reflecting the second beam; and a section that changes the convergence state of the first beam to position a focal point of the first beam a distance away from a focal point of the second beam in the direction of depth in order to place the focal point of the first beam at a target depth.

Abstract: An optical information recording device, which emits a first beam to one side of an optical information recording medium and a second beam to the other side and forms a recording mark or a hologram by putting together the first and second beams, includes: a section that collects and emits the first beam to the recording medium; a section that moves a focal point of the first beam so that the focal point is positioned at a target depth and is aligned with a target track; a section that makes a diameter of the second beam around its focal point larger than a diameter of the first beam around its focal point; and a section that puts the focal point of the second beam at the target depth and moves the focal point of the second beam such that the second beam strikes the target track.

Abstract: A recording and/or playback apparatus and method and a method of moving tracks, and more particularly, an apparatus and method for efficiently seeking a track and recording and/or playback data on/from a recording medium, are disclosed. The method of moving tracks includes changing a gap between a lens part and a recording medium in correspondence with a distance of moving tracks when the lens moves from a current track to another track. Accordingly, it is possible to minimize or prevent the collision between the lens part and the recording medium and to efficiently seek the track to perform recording/reproduction when recording and/or playback data on/from the recording medium.

Abstract: A high density optical disc that can be driven changeably with the existent optical disc by the same driving apparatus. On the recording surface of the optical disc, a light transmissive layer with a thickness of about 0.2 to 0.4 mm is formed. The recording face is accessed by allowing a light beam with a wavelength of 395 to 425 nm in a spot shape to be irradiated onto it. Also, the light beam is converged in a spot shape by an objective lens having the numerical aperture of about 0.62 to 0.68.

Abstract: A zone phase correcting lens wherein a change in the third-order spherical aberration or the like is small in the case of a change in temperature and an optical head device having the zone phase correcting lens used as an objective lens. A minus sign is appended to the height measurement of a step formed so as to make the lens thickness in the optical axis thinner toward the outer region and a plus sign is appended to a step formed so as to make the lens thickness thicker toward the outer region. Supposing that D is an absolute value of the sum of the height measurements of the steps having the minus sign on the first surface and the second surface and E is an absolute value of the sum of the height measurements of the steps having the plus sign on the first surface and the second surface, a wavelength ?1 and a refractive index N1 of the lens for a first laser beam satisfy the following conditions: 10×?1<{D×(N1?1)}<30×?1 2×E<D.

Abstract: An optical pickup apparatus comprising: a collimating lens configured to convert laser light having Gaussian distribution property emitted from a laser diode from divergent light to parallel light; an objective lens configured to focus the laser light from the collimating lens onto a signal recording layer of an optical disc; and an adjustment film formed on a surface of an incident face of the collimating lens on which the laser light is incident, and configured to adjust transmittance of the laser light passing through the collimating lens, the adjustment film being formed on the surface of the incident face so that the transmittance is lower on the inner side of the incident face than on the outer side of the incident face.

Abstract: The invention relates to an optical scanning device for scanning at least one information layer (101, 102) in an information carrier (10), comprising means (1) for generating a radiation beam (11) intended to be focused on the information layer (101, 102). A spherical aberration (SA) compensation module (40) is arranged in the light path of the radiation beam (11) and comprises a SA compensation means (41) and a reflective means (42) for folding the light path of the radiation beam (11).

Abstract: An optical disc device that irradiates an optical beam to an optical disc including a recording layer for recording information and a positioning layer provided with a track for identifying a recording position of the information on the recording layer, includes: objective lens that converges a predetermined positioning optical beam to adjust the optical beam to a desired track on the positioning layer and converges an information optical beam that shares an optical axis with the positioning optical beam on the recording layer; moving section that moves the objective lens in a tracking direction which is substantially orthogonal to the track to make a focal point of the positioning optical beam to follow the desired track; a detection section that detects a moving amount of the objective lens to the tracking direction; and correction section that corrects a converging position of the information optical beam in accordance with the moving amount.

Abstract: A laminated wave plate having a wider bandwidth at a desired retardation is provided. A laminated wave plate 1 includes a first wave plate 2 and a second wave plate 3 that are laminated each other so that respective optical axes of the first wave plate and the second wave plate are intersected each other at an angle of 51.5 degrees when the first wave plate has a retardation ?1 of 360 degrees and an in-plane azimuth of ?8 degrees, while the second wave plate has a retardation ?2 and an in-plane azimuth of 43.5 degrees. Thus the laminated wave plate 1 functions as a desired retardation ?2 in a wavelength from 600 nm to 800 nm as a whole.

Abstract: An optical pickup apparatus comprising: an objective lens formed so that a first and second laser beams different in wavelength are respectively focused onto signal recording layers of a first and second optical discs; and a photodetector including a square-shaped light-receiving portion for being irradiated with return light, as a spot, of the first or second laser beam respectively reflected from the signal recording layers of the first or second optical discs, to generate a focus error signal, a length of a diagonal line of the light-receiving portion being substantially equal to a longer diameter of an elliptical spot formed in a direction of the diagonal line when the focus error signal is at a maximum level for an optical disc that is either one of the first and second optical discs, to which a laser beam shorter in wavelength out of the first and second laser beams is focused.

Abstract: A device reads and/or records marks in a track on a record carrier via near field optical recording. The device has a head including a lens to be positioned at a near field distance from a surface of the record carrier. An air gap controller is for controlling an air gap (81) between the lens and the surface, and has an approach mode for bringing the lens from a remote distance in the far field to the near field distance. Thereto the controller provides an increasing periodical excitation signal (83) for generating a sequence of approach instants at which the lens approaches the surface. At the approach instants the lens has substantially zero velocity (84). The sequence of approach instants brings the lens subsequently closer to the surface. When the lens enters in the near field range at one of the approach instants, the air gap controller is switched to closed loop mode.

Abstract: In an optical head operable to record to and read from an optical recording medium, a beam emitted by a light-emitting element is reflected toward the light-emitting element by a first reflective mirror, and this reflected beam is reflected toward the optical recording medium by a second reflective mirror and focused on a recording surface of the optical recording medium. In this case, the first reflective mirror blocks a principal ray of the beam traveling toward the optical recording medium from the second reflective mirror, and the second reflective mirror consists of a plurality of concentric annular mirrors centered on the principal ray of the beam and separated from each other by a predetermined interval.

Abstract: An optical information recording-reproducing apparatus comprising a light source, an objective lens for condensing a light beam from the light source on a recording layer of an optical recording medium, a divergence angle-converting element provided in an optical path from the light source to the optical recoding medium for converting a divergence angle of the light beam to be introduced to the objective lens, a focus error detecting optical system including a photodetector for detecting a focus error of the light beam, an optical element for introducing a part of the light beam emitted from the divergence angle-converting element to the focus error detecting optical system, a circuit for detecting the divergence angle of the light beam emitted from the divergence angle-converting element from output from the photodetector, and a circuit for compensating spherical aberration in the recording layer of the optical recording medium by driving the divergence angle-converting element in accordance with the detecti

Abstract: An optical recording and reproducing apparatus for recording and/or reproducing an optical recording medium by irradiating light from a light source to the optical recording medium as near-field light from a near-field light irradiating unit includes a light source for emitting light, a first light-receiving unit for receiving and detecting returned light from the optical recording medium, a second light-receiving unit for receiving and detecting returned light from the near-field light irradiating unit, a control unit for detecting a relative skew between the optical recording medium and the near-field light irradiating unit based on a plurality of gap detection signals generated from divided detection signals of the second light-receiving unit and a drive control unit for outputting a drive signal to correct a skew of at least the near-field light irradiating unit to a drive unit in response to a skew detected in the control unit.

Abstract: A multi-focal objective lens for use in an optical pickup apparatus for recording and/or reproducing information using a first light flux with a wavelength ?1 on a first and second optical discs, includes a first optical surface including a first diffractive structure. The multi-focal objective lens converges a diffracted light flux with one of the m-th diffraction order and the n-th diffraction order on an information recording surface of the first optical disc for recording and/or reproducing information of the first optical disc, and converges a diffracted light flux with another of the m-th diffraction order and the n-th diffraction order on an information recording surface of the second optical disc for recording and/or reproducing information of the second optical disc.

Abstract: An objective lens actuator includes a lens holder for holding an objective lens, a holder support member for holding the lens holder movably along a direction of an optical axis of the objective lens and rotatably about a rotation axis that is parallel to the direction of the optical axis, and a base for holding the holder support member. A gap is provided between the holder support member and the base, the gap extending around a junction which connects the holder support member with the base, wherein a plurality of piezoelectric elements are inserted in the gap.

Abstract: In an optical disc apparatus, a CPU controls a focus control circuit, and a focus offset for adjusting a height of an objective lens is set. A spindle motor control circuit, a laser driver circuit, and an RF amplifier are controlled. When an optical disc is rotated by using the set focus offset in a state where a tracking servo is not performed, an envelope of a full addition signal or a RF signal obtained from each focused focal point corresponding to the objective lens in a land and a groove is detected. An amplitude level of the envelope is measured, and a focus control circuit is controlled. By using the focus offset with which the amplitude level of the envelope of the full addition signal or the RF signal is minimized, a focus offset used when recording or reproduction of the optical disc is performed is determined.

Abstract: According to one embodiment, a focus position control method includes irradiating a beam to an optical disc via an objective lens, receiving reflected light and outputting a signal, generating a focus error signal, detecting an amplitude of a signal high-pass-filtering the signal, detecting an intensity of a signal low-pass-filtering the signal, supplying a driving voltage corresponding to the focus error signal to a drive coil configured to move the objective lens to an optical axis direction of the beam when the amplitude is larger than the first value, or when the amplitude is not larger than the first value and the intensity is smaller than the second value, and supplying a driving voltage having a constant voltage value to the drive coil when the amplitude is not larger than the first value and the intensity is not smaller than the second value.

Abstract: An optical disc apparatus, which discriminates types of optical discs having different thicknesses of transparent layers by using the same wavelength of laser light, includes an aberration correction unit for correcting spherical aberration, an objective lens for condensing the laser beam onto a recording surface of an optical disc, an actuator for moving the objective lens with respect to the optical disc, a signal detection unit for delivering a focus error signal or a sum light signal, a control unit for controlling the aberration correction unit, the actuator and the signal detection unit.

Abstract: A disc device includes a lens that focuses a laser light on an optical disc surface, a focus drive unit that drives the lens in a focusing direction, a focus control unit that controls to focus the laser light on the optical disc surface, a focus displacement detecting unit that detects a displaced amount in the focusing direction, a differentiation unit that differentiates a focus displacement detected signal, and a unit that inverts a sign of a differentiated signal, thereby, the disc device is driven intermittently to restrain a motion of an objective lens in a focusing direction and avoid colliding the objective lens with the optical disc surface.

Abstract: An objective optical system for use in an optical pickup apparatus for converging first and second parallel light fluxes includes: a first lens group having a phase structure; and a second lens group, wherein the first lens group and the second lens group are arranged in the objective optical system in this order from a longer conjugate distance side of the objective optical system, and a wavefront aberration of the first lens group WL1?1, a wavefront aberration of the second lens group WL2?1, a magnification of the second lens group M, a wavefront aberration of the second lens group WL2?2, a wavefront aberration of the objective optical system WOBJ?2 are satisfy predescribed expressions.

Abstract: An optical element to be arranged in an optical pickup apparatus for conducting information recording and/or reproducing and to converge laser light beams having a plurality of wavelengths including a wavelength of ?1 onto information recording media, includes one or more of optical element main bodies; and an antireflective film which is arranged on at least one surface on the optical element main bodies and on which an optical functional surface is formed, wherein, when the optical functional surface and a first laser beam having the wavelength ?1 makes an angle ?1 in the range of 0°??1?60°, the optical element satisfies |Rp1?Rs1|?2% where Rp1 and Rs1 are respectively P polarized light and S polarized light reflectivities of the first laser light on the optical functional surface.

Abstract: An optical disk drive according to the present invention includes: an optical pickup 6 including a light source 23 that radiates a light beam 21 to irradiate an optical disk 100, at least one objective lens 22 for converging the beam 21, and an actuator that can move the lens 22 perpendicularly to the disk 100; a transport stage 11 for displacing the pickup 6 in a disk radial direction; a rim detecting section 30 for sensing if the irradiated position of the beam 21 has passed an outer edge of the disk 100 while the pickup 6 is being displaced from an inner area of the disk toward the outer edge thereof to conduct a seek operation; and a control section 40 for getting the lens 22 retracted away from the disk 100 by the actuator and getting the pickup 6 displaced toward the inner area of the disk by the transport stage 11 if the irradiated position of the light beam 21 has been sensed to have passed the outer edge of the disk 100.

Abstract: Disclosed is an objective lens for an optical pickup apparatus which records and/or reproduces information with a light beam emitted from a light source, including: a substrate; and an anti-reflection coating comprising at least one layer, formed on a surface of the substrate at a side of the light source, wherein a refractive index of the anti-reflection coating at a peripheral part where an outer edge of an effective light beam transmits is smaller than a refractive index of the anti-reflection coating at a center part where a light beam on an optical axis transmits.

Abstract: An optical disc device includes a control part for causing processing of determining a type of an optical disc to be executed. The processing caused by the control part to be executed for determining the optical disc includes: signal acquisition processing of acquiring a pull-in signal (sum signal of reflected signal) and an RF signal (reproduced signal) by moving an objective lens in either of a direction approaching the optical disc and a direction separating from the optical disc; and determination processing of deciding whether or not to correct the pull-in signal acquired in the signal acquisition processing and determining the type of the optical disc by using either of amplitude of the acquired pull-in signal and a correction value with which the amplitude of the acquired pull-in signal is corrected by using a predetermined value obtained from the acquired RF signal.

Abstract: An optical pickup apparatus includes: an optical pickup actuator including an objective lens for converging an optical beam emitted from a light source to a surface of a recording medium, a lens holder for holding the objective lens, an elastic support member for elastically supporting the lens holder at its one end to be capable of driving the lens holder, and a base member for fixing and holding the other end of the elastic support member; a casing that supports the base member of the actuator; a flexible substrate for taking a signal from the optical beam; a substrate pressing member for restricting floating of the flexible substrate; and an actuator restricting holding part that is mounted integrally with the substrate pressing member and holds the base member while restricting operation of the base member to a predetermined operation.

Abstract: An optical pickup apparatus is provided for recording and/or reproducing information on an optical disc in which information can be recorded at recording positions. The optical pickup apparatus includes: a light source; a relay optical system; an objective lens for converging a light flux onto one of the plurality of recording positions; a photodetector for receiving a light flux from the optical disc; a detector; a first actuator; and a second actuator. The detector is provided for detecting information for keeping a distance between the optical disc and the objective lens a predetermined value. The first actuator is provided for driving the objective lens for keeping the distance between the optical disc and the objective lens the predetermined value. The second actuator is provided for driving the relay optical system corresponding to one of the plurality of recording positions where information is recorded and/or reproduced.

Abstract: An optical head is provided that increases the light utilization efficiency and that can be adapted to high-speed recording and double-layer disks. A beam-shaping lens that shapes an elliptical beam emitted from a light source into a substantially circular beam has a pair of cylindrical surfaces that are curved in the same direction. The cylindrical surface that is closer to the light source is an aspherical surface, and the cylindrical surface that is closer to the light source is a spherical surface. Thus, an optical head is obtained, with which aberrations can be kept low, even when the beam-shaping magnifying power is about a factor 2.

Abstract: An optical data storage system for recording and/or reading, using a radiation beam having a wavelength X is described. The radiation beam is focused onto a data storage layer of an optical data storage medium. The medium has a cover layer that is transparent to the focused radiation beam. The cover layer has a thickness h smaller than 5 ?m. A cover layer with thickness variation of substantially less than the focal depth, i.e. 50 nm, eliminates the need of dynamic focus control of the objective which is otherwise required in addition to the gap servo. Further a method of optical recording is described using such an optical data storage system by which a static focus control and spherical aberration correction to accommodate medium-to-medium variance is achieved. The static focus control can be realised by optimising the modulation depth of a known signal, e.g. from a lead-in track.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength ?1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength ?2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: A light emitting module and method and an optical pickup apparatus employing the same are provided. The light emitting module includes a base, a semiconductor laser that is disposed on the base and emits a laser beam of a predetermined wavelength, a cap surrounding the semiconductor laser, a beam shaping window that is fitted with a predetermined portion of the cap corresponding to the propagation path of the laser beam and shapes a transmitted laser beam while reflecting a portion of an incident beam, and a quarter wave plate that is disposed in the propagation path of the laser beam and in front of the beam shaping window and transforms a laser beam horizontally polarized after passing through the beam shaping window into a circularly polarized beam while converting a beam reflected from an optical disc into a vertically polarized beam.

Abstract: An optical head device and an optical recording and reproducing apparatus using this optical head device, which can record information and reproduce the recorded information at any of optical recording media, such as a next generation optical recording medium, in which the wavelength of the light source is made to be shorter, the numerical aperture of the objective lens is made to be higher, and the thickness of the recording medium is made to be thinner, and conventional recording media of DVD and CD standards, are provided. A light having wavelength of 405 nm, emitted from one of optics, is inputted to an objective lens as a collimated light, and is focused on a disk having thickness of 0.1 mm. A light having wavelength of 650 nm, emitted from the other of optics, is inputted to the objective lens as a diverged light, and is focused on a disk having thickness of 0.6 mm.

Abstract: An imaging lens unit comprising, in order from the object side, a first lens having a meniscus shape with its convex surface on the object side, an aperture stop and a second lens having a meniscus shape with its convex surface on the image side. A maximal value of a tangent angle within a range of a lens surface effective diameter of the surface on the object side of the first lens is 70 to 90 degrees. A maximal value of a tangent angle within a range of a lens surface effective diameter of the surface on the image side of the second lens is 70 to 90 degrees.

Abstract: An optical pickup configured so as to reproduce signals recorded in optical disks of plural standards by means of a single laser beam. The optical pickup has an objective lens for gathering a laser beam emitted from a semiconductor laser—which emits a laser beam of single wavelength—onto a signal recording layer provided in each of optical disks of first and second standards whose cover layers differ from each other in terms of a thicknesses. The first standard is; for example, a CD, and the second standard is; for example, a DVD. An optical path length correction member—in which there is formed an optical path length correction section for making a correction to an optical path length falling within a range smaller than the diameter of a light beam passing through the objective lens—is provided in an optical path between the semiconductor laser and the objective lens. The optical path length correction section may also be formed on a lens plane of the objective lens facing the semiconductor laser.

Abstract: An optical pickup device has: a light source; an objective lens that condenses laser light emitted from the light source on a recording layer of an optical disc; and a movable lens that is disposed between the light source and the objective lens and that is movable along the optical axis. The movable lens is moved to correct for spherical aberration. Between the light source and the objective lens, a RIM intensity adjusting element is also disposed that adjusts the RIM intensity by changing the range within which, as the movable lens is moved, the intensity of the laser light incident on the objective lens can be varied.

Abstract: A multiplexing optical system includes collimator lenses, a first condensing lens, a second condensing lens and an optical fiber. The collimator lenses collimate divergent laser beams that have been emitted from semiconductor lasers. The first condensing lens condenses laser beams transmitted through the collimator lenses in only one of a plane including the stripe width direction of the semiconductor lasers and a plane including a direction perpendicular to the stripe width direction. The second condensing lens condenses laser beams transmitted through the first condensing lens. The optical fiber is arranged in such a manner that the condensed laser beams enter the optical fiber. In the multiplexing optical system, an anamorphic lens is used as the second condensing lens, and the anamorphic lens condenses the laser beams in the two planes in cooperation with the first condensing lens.

Abstract: Both of two permanent magnets which are arranged in an objective lens driving device are multipole magnetized magnets having rectangular parallelepiped shapes. The two permanent magnets have inverse N-S polarity at a part of surfaces which face each other. Focusing coils and tracking coils which are set up on a lens holder are disposed such that effective portions which are sides of the respective coils that face each other to generate driving force by electromagnetic force action with the permanent magnets, act with different direction magnetic fields respectively.