摘要:
Providing an objective lens with a large numerical aperture (NA), the present invention records or plays conventional optical disks such as CDs and DVDs using an optical head capable of recording or reproducing high-density optical disks. An optical element (8) is provided between a first and second laser light source and an objective lens (18) for the purpose of converting a wave front of a second optical beam 32. Furthermore, the optical element (8) and the objective lens (18) are fixed to move as a single piece.
摘要:
An optical information device is provided with a first scattering medium (9), a second scattering medium (10), a third scattering medium (11); a diffraction element (4) which generates a plurality of light beams; an objective lens (6) which guides, to the first scattering medium (9) and to the third scattering medium (11) out of the first scattering medium (9), the second scattering medium (10), and the third scattering medium (11), two light beams out of the plurality of the light beams; and an arithmetic circuit (17) which detects a gap interval between the first scattering medium (9) and the third scattering medium (11), and an information medium (12), based on a change in an amount of reflected light from the first scattering medium (9) and from the third scattering medium (11).
摘要:
An objective lens unit according to the present invention includes a first objective lens 41; and a first lens holder 2 for supporting the first objective lens 41. The first lens holder 2 is formed of a material which transmits ultraviolet. Preferably, the first lens holder 2 includes a through-hole, having first and second openings 2a and 2b, through which light incident on the first objective lens 41 passes, and an opening limiting section 3 provided along a circumferential direction of the through-hole and projecting toward a central axis of the through-hole. The first objective lens 41 is supported so as to block the first opening 2b. The opening limiting section 3 guides light incident thereon from the second opening 2a in a direction away from an optical axis of the first objective lens.
摘要:
An optical pickup, an optical disk drive device, an optical information recording device, and an optical information reproduction device in which a reproduction signal, a focus error signal, and a gap error signal can be detected with high accuracy when information is recorded/reproduced on/from an optical information medium having a plurality of information recording layers.
摘要:
A small optical pickup of wide spherical aberration correction range includes a rising mirror for perpendicularly deflecting a light beam and guiding the light beam to an objective lens; a spherical aberration correction lens having one surface formed to a larger curvature than the other surface; a lens holder for holding the correction lens so that the surface of large curvature projects towards the rising mirror side; an axially extending guide member; and a slidable part slidable along the guide member. The projecting portion of the slidable part is configured to be fitted within the side surface of the reflecting surface of the rising mirror, and the projecting portion from the lens holder of the spherical aberration correction lens overlaps the reflecting surface of the rising mirror when the spherical aberration correction lens approaches the rising mirror the most.
摘要:
An optical information medium measurement method, for measuring a degree of modulation in an optical information medium of a multilayered structure having a plurality of information layers, includes a first step of measuring a modulation degree of each layer of the optical information medium, and a second step of obtaining a thickness between layers of the optical information medium. Further, the method includes a third step of obtaining a reflectance of each layer of the optical information medium, and a fourth step of converting the modulation degree of each layer, as measured in the first step, into a modulation degree at a reference optical system differing from the measurement optical system, based on a value indicative of the thickness between layers, the thickness being obtained in the second step, and a value indicative of the reflectance of each layer, as obtained in the third step.
摘要:
An optical head according to the present invention includes: a first light source that emits light with a first wavelength; a beam splitter that splits the light emitted from the first light source into a first light beam traveling in a first direction and a second light beam traveling in a second direction different from the first direction; a first collimator lens for changing degrees of divergence of the first light beam; a first mirror that changes the traveling directions of the first light beam, of which the degrees of divergence have been changed; a first objective lens for converging the first light beam, which has had its traveling directions changed, toward a storage layer of a first optical disk; a mover that holds the first objective lens; a first photodetector that receives the first light beam reflected from the storage layer of the first optical disk and converts it into an electrical signal; a condenser lens for condensing the second light beam; and a second photodetector that receives the second light beam condensed by the condenser lens and converts it into an electrical signal.
摘要:
An optical pickup includes: a laser light source which outputs an divergent beam having an elliptical far-field pattern; a beam shaping element having at least one cylindrical plane and which shapes the divergent beam outputted from the laser light source into an divergent beam having a prescribed shape in which at least the length in the major axis direction of the elliptical shape is shortened; a light collecting portion having a beam splitter which perpendicularly collects the divergent beam that is outputted from the beam shaping element and which has a prescribed shape on the recording surface of an optical disk , and a mirror or the like; and a light detecting portion The optical axis of the divergent beam is rotated so that the direction in which the major axis of the divergent beam having a prescribed shape is shortened conforms to the radial direction of an optical information recording medium.
摘要:
An optical pickup device which can improve heat radiation efficiency and an optical disk apparatus including the optical pickup device are provided. The optical pickup device having a base (110), a laser unit (141), an optical system (140) which propagates a laser beam, and an adjusting member (142) includes a heat radiation part (146) which is fixed to a heat radiation surface (141b) of the laser unit and which conducts heat from the heat radiation surface to the adjusting member. Therefore, heat generated by the laser unit is transmitted to the adjusting member and then the base through the heat radiation part to make it possible to efficiently perform heat removal for the laser unit.
摘要:
In an optical beam transmissive adjusting mechanism (110) included in an optical pickup device, arrangement positions of a first transmissive element (111) having a first transmittance and a second transmissive element (112) having a second transmittance higher than the first transmittance are switched by a rotational drive unit (105), and an optical beam having a first optical power and an optical beam having a second optical power are output selectively. Furthermore, since a transmissive element of a non-transmissive side for an optical beam is arranged at an angle inclined to an optical axis of the optical beam, the transmissive element does not obstruct a path of the optical beam to be diffused.