Abstract: An optical pickup apparatus comprising: an objective lens configured to focus laser light having the Gaussian distribution properties emitted from a laser diode to a signal recording layer of an optical disc; and an adjustment coating formed on a surface of an incident face of the objective lens on which the laser light is to be made incident, the adjustment coating being configured to adjust transmittance of the laser light passing through the objective lens, the adjustment coating being formed on the surface of the incident face such that the transmittance is lowered as a numerical aperture of the objective lens is reduced.

Abstract: An optical pickup unit comprises a diffraction grating that divides light into at least three luminous fluxes and condenses the three luminous fluxes to apply at least three focusing spots, independent of each other, onto a signal side of a medium. The diffraction grating is divided into at least four regions, a first region, a second region, a third region, and a fourth region.

Abstract: An optical-pickup apparatus includes: a laser diode having a first-laser element, which emits a first-laser beam, and a second-laser element, which emits a second-laser beam having a wavelength shorter than a wavelength of the first-laser beam, arranged in the same package; an objective lens to condense the first- and second-laser beams emitted from the laser diode to signal-recording layers of first- and second-optical discs, respectively, the second-optical disc being of a standard different from a standard of the first-optical disc; and a collimating lens arranged in an optical path between the laser diode and the objective lens, the collimating lens configured to change the first- and second-laser beams from divergent light to parallel light, the collimating lens being inclined with respect to optical axes of the first- and second-laser beams so that astigmatism in the first- and second-laser beams is corrected.

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

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

Abstract: A laser attachment device of the present invention is formed of a LD package and a LD holder housing it. A first inner wall of the LD holder to come into contact with a side surface of the LD package is an inclined surface. This allows the facing direction of the LD package to be corrected by the first inner wall being the inclined surface, even when a laser beam emitted from a light emitting chip housed in the LD holder is inclined with respect to an optical axis. Thus, the traveling direction of the laser beam is corrected to the optical axis side.

Abstract: A photodetector comprising: a first light-receiving surface configured to receive reflected light of zero-order light generated based on a laser beam, from one information recording layer of a multilayer optical disc; a second light-receiving surface that is adjacent to the first light-receiving surface with a predetermined interval, the second light-receiving surface being configured to receive reflected light of diffracted light generated based on the laser beam, from the one information recording layer; and a third light-receiving surface for canceling out reflected light of the zero-order light from other information recording layer of the multilayer optical disc, received by the first light-receiving surface or the second light-receiving surface, the third light-receiving surface being configured to receive the reflected light of the zero-order light from other information recording layer.

Abstract: An optical pickup apparatus comprising: an objective lens focusing laser light emitted from a laser diode to a signal recording layer of an optical disc; a photodetector including a substantially square light-receiving region made of first to fourth sensors divided by boundaries in a first direction corresponding to a tracking direction and a second direction crossing the first direction, the light-receiving region being irradiated with reflected light of the laser light which is reflected from the signal recording layer thereof; and a half mirror reflecting the laser light in a direction of the objective lens and allowing the reflected light to pass therethrough in a direction of the photodetector, the boundary in the second direction for dividing the first to fourth sensors in the light-receiving region being set according to a shape of a spot of the reflected light directly applied from the half mirror to the light-receiving region.

Abstract: An objective lens includes: a diffraction area having a diffraction structure provided thereon concentrically around an optical axis of the objective lens; and a first non-diffraction area provided outward an outer circumference of the diffraction area, the objective lens being configured to focus first laser light on a signal recording surface of a first optical recording medium by refraction in the first non-diffraction area; focus second laser light, different in wavelength from the first laser light, on a signal recording surface of a second optical recording medium by diffraction in the diffraction area; and focus third laser light, different in wavelength from the first laser light and the second laser light, on a signal recording surface of a third optical recording medium by diffraction in the diffraction area.

Abstract: An optical pickup apparatus includes: a laser diode configured to generate a laser beam; and an objective lens having an annular diffraction zone formed on an incident surface thereof on which the laser beam is incident, the annular diffraction zone being a zone configured to focus the laser beam on each of signal recording layers of first to third optical discs so that a signal recorded in each of the signal recording layers of the first to third optical discs are read, the first optical disc having the signal recording layer at a first distance from a surface thereof, the second optical disc having the signal recording layer at a second distance longer than the first distance from a surface thereof, the third optical disc having the signal recording layer at a third distance longer than the first distance and shorter than the second distance from a surface thereof.

Abstract: Provided is a lens holder comprising: a mounting hole into which a condenser lens part of the objective lens is to be inserted; a peripheral part which surrounds the mounting hole and on which a flange part of the objective lens is to be mounted; and three protrusions provided in the peripheral part to be spaced apart from each other and to protrude higher than a main surface of the peripheral part. Also provided is an optical pickup apparatus comprising the lens holder and an objective lens supported with a condenser lens part inserted into the mounting hole of the lens holder, and with the flange part being in contact with the three protrusions.

Abstract: A laser attachment device of the present invention is formed of a LD package and a LD holder housing it. A first inner wall of the LD holder to come into contact with a side surface of the LD package is an inclined surface. This allows the facing direction of the LD package to be corrected by the first inner wall being the inclined surface, even when a laser beam emitted from a light emitting chip housed in the LD holder is inclined with respect to an optical axis. Thus, the traveling direction of the laser beam is corrected to the optical axis side.

Abstract: In a laser attachment device of the preferred embodiment of the invention, a pair of protruding portions are formed on a seating surface of a LD holder by which the position of a CAN package is fixed. The CAN package inserted in a through-hole comes into contact with the pair of protruding portions, and then is fixedly bonded to the inside of the LD holder while being inclined with the protruding portions being the starting point of the inclination. This structure allows the luminance adjustment of a laser beam to be performed without causing displacement of the emitting direction of the laser beam from an optical axis of an optical pick-up device. Thus, the laser attachment device having an improved workability and being suitable for mass production is achieved.

Abstract: Provided are an optical pick-up device which can appropriately correct an optical path of a laser beam emitted from a light-emitting chip arranged with a mounting error, and a method of manufacturing the same. An optical pick-up device includes: a first light-emitting chip and a second light-emitting chip which emit laser beams having predetermined wavelengths; a PDIC which receives the laser beams emitted from the first and the second light-emitting chips; and a first optical correction component and a second optical correction component provided between the PDIC and the light-emitting chips. The first and the second optical correction components incline a first laser beam by diffraction, while transmitting a second laser beam and a third laser beam without inclining these beams. With the diffraction of the first laser beam by these two correction components, the optical path of the first laser beam is corrected to a predetermined position.

Abstract: An optical-pickup apparatus includes: a first-objective lens; a second-objective lens; a lens holder including a first-lens barrel having the first-objective lens mounted on an end face thereof and a second-lens barrel having the second-objective lens mounted on an end face thereof; an actuator unit having the lens holder mounted thereon; and a housing having the actuator unit mounted thereon, the first and second objective lenses each being mounted on the lens holder such that a direction, in which wavefront of coma aberration on each lens face is most advanced in phase, is aligned with a radial direction of an information-recording medium, the actuator unit being mounted on the housing such that an optical axis of the first-objective lens is inclined in the radial direction at an inclination angle of the axis toward a recording surface of the medium required to cancel coma aberration of the first-objective lens to the surface.

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

Abstract: An optical pickup device comprises a first objective lens fixed on a lens holder and configured to focus a first laser beam on a signal recording layer provided in an optical disc, the lens holder supported by support wires so that the lens holder is movable toward a signal surface of an optical disc and in a radial direction of the optical disc, and a second objective lens fixed on the lens holder and configured to focus a second laser beam on a signal recording layer provided in an optical disc. Bearing surfaces of the first and second objective lenses are tilted at predetermined angles, respectively, generation directions of coma aberrations by the first and second objective lenses are broadly divided by a simple method, and the objective lenses are fixed with the directions of the coma aberrations aligned.

Abstract: In the present invention, to improve CD read/write characteristics having poor image height characteristics, a third light emitting source emitting a third laser beam for CD is disposed on an optical axis of an objective lens. Thereby, the third laser beam emitted from the third light emitting source travels along the optical axis of the objective lens, thus generating no coma aberration in the third laser beam. Furthermore, in the present invention, a second light emitting source emitting a second laser beam for DVD and a first light emitting source emitting a first laser beam for BD are disposed across the third light emitting source. Thereby the phase propagation directions of coma aberrations in the first and second laser beams coincide with each other. Adjustment of the coma aberration in one of the laser beams enables the coma aberration in the other laser beam to be adjusted.

Abstract: An optical-pickup apparatus includes: a three-wavelength-laser diode including first-, second-, and third-laser elements to emit first-, second-, and third laser beams having first, second, and third wavelengths, respectively, the three laser elements housed in the same case; an objective lens to focus the three laser beams onto first- to third-optical-disc-signal-recording layers, respectively; a first photodetector to be irradiated with first-return light reflected from the first-optical-disc-signal-recording layer, a second photodetector to be irradiated with second- and third-return lights respectively reflected from the second- and third-optical-disc-signal-recording layers; a polarizing-beam splitter to reflect the three laser beams toward the lens, and allow the three return lights having passed through the lens to pass therethrough; a semitransparent mirror on which the three return lights having passed through the polarizing-beam splitter are incident, and which guide the first-return light toward th

Abstract: An optical pickup apparatus comprising: a laser diode; an objective lens configured to focus laser light emitted from the laser diode on a signal recording layer of an optical disc; a first aberration correction element arranged in an optical path between the laser diode and the objective lens; and a second aberration correction element arranged in the optical path between the laser diode and the objective lens and having an aberration correction speed lower than the aberration correction speed of the first aberration correction element, the first aberration correction element and the second aberration correction element being selectively operated according to the required aberration correction speed.