Patent application number | Description | Published |
20080212452 | OPTICAL PICKUP APPARATUS - 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. | 09-04-2008 |
20080310286 | OPTICAL PICKUP APPARATUS - 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. | 12-18-2008 |
20080316903 | OPTICAL PICKUP APPARATUS - 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. | 12-25-2008 |
20090022037 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus comprising: a first objective lens; and a second objective lens arranged with the first objective lens in a radial direction of an optical disc, the first objective lens being configured to focus laser light for reproduction, which is laser light for reproducing a signal recorded in a signal recording layer of the optical disc, onto the signal recording layer, the second objective lens being configured to focus laser light for recording, which is laser light for recording a signal, onto the signal recording layer. | 01-22-2009 |
20090022038 | OBJECTIVE LENS, AND METHOD OF MANUFACTURING THE SAME AND OPTICAL PICKUP APPARATUS - 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. | 01-22-2009 |
20090034392 | PHOTODETECTOR AND OPTICAL PICKUP APPARATUS INCLUDING THE SAME - A photodetector comprising: a substrate; a photodiode fixed to the substrate, the photodiode configured to output a signal according to a light amount of a laser beam when applied with the laser beam; and a translucent resin covering the photodiode, the translucent resin being irradiated with ultraviolet light in advance for a predetermined time such that a change in transmittance of the translucent resin for the laser beam having a predetermined wavelength is set within a predetermined range. | 02-05-2009 |
20090070794 | OPTICAL MEMBER DRIVING APPARATUS, OPTICAL PICKUP APPARATUS INCLUDING THE OPTICAL MEMBER DRIVING APPARATUS, OPTICAL DISC APPARATUS INCLUDING THE OPTICAL PICKUP APPARATUS - An optical member driving apparatus comprising: a holding member configured to have an optical member mounted thereon; a driving unit assembly configured to be capable of driving the holding member; a connecting member configured to connect the holding member and the driving unit assembly; and a jointing member configured to joint the connecting member and either or both of the holding member and the driving unit assembly. | 03-12-2009 |
20090073857 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus comprising: a collimating lens configured to convert laser light emitted from a laser diode, from diffused light into parallel light; an objective lens; and a prism configured to guide the laser light emitted from the collimating lens to the objective lens, the prism including: a first face that the laser light emitted from the collimating lens enters; a second face that reflects the laser light entering the first face; and a third face that reflects the laser light reflected from the second face in a direction of the second face, and emits the laser light reflected again from the second face in a direction of the objective lens. | 03-19-2009 |
20090129245 | Optical Pickup Apparatus - 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. | 05-21-2009 |
20090154310 | OPTICAL PICKUP APPARATUS - 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. | 06-18-2009 |
20090196146 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus comprising: a diffraction grating that a laser beam enters, the diffraction grating being configured to generate a main beam that is 0th order light and sub-beams that are +1st order diffracted light and −1st order diffracted light; an objective lens configured to focus the main beam and the sub-beams onto a signal recording layer; a main-beam light-receiving portion that the main beam reflected by the signal recording layer is applied to; and sub-beam light-receiving portions that the sub-beams reflected by the signal recording layer are respectively applied to, each light-receiving area of the sub-beam light-receiving portions being smaller than a light-receiving area of the main-beam light-receiving portion. | 08-06-2009 |
20090201791 | OPTICAL PICKUP APPARATUS - An optical-pickup apparatus comprising: a polarization beam splitter fixed to a base, which includes a first prism that laser light emitted from a laser diode enters, a second prism that return light of the laser light reflected from a signal recording layer of an optical disc enters, and a control film that is formed on either one of opposed surfaces of the first and second prisms so that the laser light and the return light are selectively passed through or reflected from the control film, the opposed surfaces being opposed to each other; and first and second positioning pins provided on the base to position the polarization beam splitter, the polarization beam splitter being fixed to the base in a state where the opposed surface of at least one of the first and second prisms is made in contact with at least one of the first and second positioning pins. | 08-13-2009 |
20090213706 | OPTICAL PICKUP APPARATUS - 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. | 08-27-2009 |
20090231984 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus comprising: a laser diode; an objective lens made of a synthetic resin configured to focus laser light emitted from the laser diode to a signal recording layer of an optical disc; and a collimating lens having a diffraction grating and arranged in an optical path between the laser diode and the objective lens, the collimating lens being so moved in an optical axis direction of the laser light as to correct spherical aberration occurring in response to a change in temperature when performing a recording operation for the optical disc, and the collimating lens correcting by the diffraction grating chromatic aberration occurring when switching from the recording operation to a reproducing operation for the optical disc. | 09-17-2009 |
20090245073 | OPTICAL PICKUP APPARATUS - 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. | 10-01-2009 |
20090290475 | OPTICAL PICKUP APPARATUS - 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. | 11-26-2009 |
20120170441 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus includes an objective lens having a numeric aperture and an incident face. An antireflection coating is formed on the incident face. A collimating lens converts laser light from a laser diode into parallel light, and causes the parallel light to be made incident on the incident face through the antireflection coating. The thickness of the antireflection coating causes a transmittance of laser light that enters the objective lens to be: set at a first predetermined transmittance value, when the numeric aperture is between zero and a first predetermined numeric aperture value; set to correlate linearly with the numeric aperture when the numeric aperture is between the first predetermined numeric aperture value and a second predetermined numeric aperture value; and set at a second predetermined transmittance value, when the numeric aperture is between the second predetermined numeric aperture value and a third predetermined numeric aperture value. | 07-05-2012 |