Abstract: An optical pickup device or an optical disk device includes: a light source 11 that emits a laser beam toward an optical disk 25; an optical receiver 18 that detects light reflected from the optical disk 25; and an astigmatism-generating element 31 that generates light used for focus control in a condition where a focusing position on one of two perpendicular cross sections including an optical axis of the light reflected from the optical disk 25 is located ahead of the optical receiver 18 and a focusing position on the other cross section is located behind the optical receiver 18. The astigmatism-generating element 31 is a Fresnel mirror 31a configured to include a plurality of reflecting mirrors, and an imaginary surface 31d that connects the tips of the reflecting mirrors is curved in a concave shape toward a light incidence side.

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: A light source emits light with a first wavelength and light with a second wavelength longer than the first wavelength toward an optical disk from adjacent positions. An optical receiver detects light reflected from the optical disk. An astigmatism-generating element generates light used for focus control in a condition where a focusing position on one of two perpendicular cross sections including an optical axis of the light reflected from the optical disk is located ahead of the optical receiver and a focusing position on the other cross section is located behind the optical receiver are included. The astigmatism-generating element is a Fresnel mirror configured to include a plurality of reflecting mirrors. A level difference between the reflecting mirrors adjacent to each other is distributed in a range from a depth of substantially (natural number/2) times the first wavelength to (natural number/2) times the second wavelength.

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: An optical pickup device or an optical disk device includes: a light source 11 that emits a laser beam toward an optical disk 25; an optical receiver 18 that detects light reflected from the optical disk 25; and an astigmatism-generating element 31 that generates light used for focus control in a condition where a focusing position on one of two perpendicular cross sections including an optical axis of the light reflected from the optical disk 25 is located ahead of the optical receiver 18 and a focusing position on the other cross section is located behind the optical receiver 18. The astigmatism-generating element is a Fresnel mirror 31a configured to include a plurality of reflecting mirrors, and an imaginary surface 31d that connects the tips of the reflecting mirrors is curved in a concave shape toward a light incidence side.

Abstract: A light source emits light with a first wavelength and light with a second wavelength longer than the first wavelength toward an optical disk from adjacent positions. An optical receiver detects light reflected from the optical disk. An astigmatism-generating element generates light used for focus control in a condition where a focusing position on one of two perpendicular cross sections including an optical axis of the light reflected from the optical disk is located ahead of the optical receiver and a focusing position on the other cross section is located behind the optical receiver are included. The astigmatism-generating element is a Fresnel mirror configured to include a plurality of reflecting mirrors.

Abstract: An optical pickup device includes light sources for respectively emitting a plurality of different wavelengths of light, a unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and a focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part. The optical pickup device and optical disk device are capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser.

Abstract: To provide an optical pickup device and optical disk device capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser. An optical pickup device comprising light sources for respectively emitting a plurality of different wavelengths of light, unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part.

Abstract: To provide an optical pick-up apparatus and an optical disc apparatus preventing a polarization hologram from being deteriorated by incidence of laser light having a wavelength for a blue laser into the polarization hologram for a CD or a DVD, an optical pick-up apparatus includes a first objective lens 10 converging first laser light having a long wavelength and irradiating it onto a first optical disc, a second objective lens 13 disposed adjacent to the first objective lens 10, which converges second laser light having a shorter wavelength than the first laser light and irradiates it onto a second optical disc, a standing mirror 9 allowing the first laser light to be irradiated onto the first objective lens 10 and transmitting the second laser light, and a filter film 11g provided between the first objective lens 10 and the standing mirror 9, which transmits the laser light and screens the second laser light.

Abstract: Provided is a focus and tracking control method for an optical pick-up apparatus which is used for recording and reproduction of a small-sized optical disc and which can carry out stable focus control and stable tracking control. A focus control method for an optical pick-up apparatus comprising a light source, an objective lens, a light receiving means having divided four light receiving zones and a polarizing means having divided for lattice zones, characterized in that when the reflected light beam is incident upon the four light receiving zones by way of the four lattice zones, focus control is carried out in accordance with a difference signal between the groups, in the radial direction, of the four light receiving zones which are divided into two groups in the radial direction by the division line in parallel with the tangential direction, respectively through the four lattice zones which are divided into two groups in the tangential direction by a division line in parallel with the radial direction.

Abstract: An optical pickup device, comprises a first light source emitting light with a short wavelength; a second light source emitting s light with a wavelength longer than that of the first light source; an optical member guiding the light from the first light source and the light from the second light source on almost the same optical path; a focusing member focusing the light from the optical member; a movable lens provided between the optical member and the focusing lens; and a drive member driving the movable lens, wherein a position of the lens when at least one of recording and reproducing of information is carried out on a medium using the light from the first light source is made different from a position of the lens when at least one of the recording and reproducing of information is carried out on the medium using the light from the second light source.

Abstract: To provide an optical pickup device and optical disk device capable of realizing at least one of thickness reduction, size reduction and suppression against characteristic deterioration even where coping with various wavelengths of laser including a blue laser. An optical pickup device comprising light sources for respectively emitting a plurality of different wavelengths of light, unit structured for causing at least a part of the light emitted from the light sources to pass a same optical path; and focusing unit for focusing the light. The focusing unit includes at least first and second focusing parts, the first focusing part being to focus mainly a wavelength of light different from a wavelength of light to be mainly focused by the second focusing part.

Abstract: Provided is a focus and tracking control method for an optical pick-up apparatus which is used for recording and reproduction of a small-sized optical disc and which can carry out stable focus control and stable tracking control. A focus control method for an optical pick-up apparatus comprising a light source, an objective lens, a light receiving means having divided four light receiving zones and a polarizing means having divided for lattice zones, characterized in that when the reflected light beam is incident upon the four light receiving zones by way of the four lattice zones, focus control is carried out in accordance with a difference signal between the groups, in the radial direction, of the four light receiving zones which are divided into two groups in the radial direction by the division line in parallel with the tangential direction, respectively through the four lattice zones which are divided into two groups in the tangential direction by a division line in parallel with the radial direction.

Abstract: Provided are an optical pickup apparatus which is used for recording and reproducing a small-sized optical disc and which is small-sized, lightweight and inexpensive, and an optical disc unit, including an optical head which comprises a lens holder engaged and fixed to an arm, an objective lens fixed to that side which is opposed to the optical disc, a semiconductor laser arranged on a surface side which is in rear of the former surface, and a reflection mirror for guiding a light beam to the objective lens, the semiconductor laser being arranged on an OEIC through the intermediary of a submount, on that surface side which is on the rear surface side of the lens holder.

Abstract: In an optical pickup, light, emitted from a light-emitting element, is transmitted through a first beam splitter film with polarization selectivity, and a zero-order diffraction beam and two (.+-.) first order diffraction beams are produced. These beams are applied in a condensed manner to an optical disk through a condensing element, and the return light beam from the optical disk is fed to a photodetector through a second beam splitter film with polarization selectivity, thereby effecting the recording and reproduction of information, the tracking and the focusing. A diffusion angle conversion hologram is provided between the light-emitting element and the first beam splitter film, and with respect to the diffusion angle conversion hologram, the relation between the diffusion angle of the incident beam and the diffusion angle of the outgoing beam is specified.

Abstract: In an optical pickup, light, emitted from a light-emitting element, is transmitted through a first beam splitter film with polarization selectivity, and a zero-order diffraction beam and two (.+-.) first order diffraction beams are produced. These beams are applied in a condensed manner to an optical disk through a condensing element, and the return light beam from the optical disk is fed to a photodetector through a second beam splitter film with polarization selectivity, thereby effecting the recording and reproduction of information, the tracking and the focusing. A diffusion angle conversion hologram is provided between the light-emitting element and the first beam splitter film, and with respect to the diffusion angle conversion hologram, the relation between the diffusion angle of the incident beam and the diffusion angle of the outgoing beam is specified.

Abstract: A light source beam is incident on an optical guide block and converted in its diffusion angle by a diffusion angle conversion film on a second inclined portion of the optical guide block, and reflected by a reflecting film on a first inclined portion. Then, the light is incident on a first beam splitter film on the second inclined portion and split into transmitted light and reflected light. The reflected light is focused an optical disk light reflected from the disc passes through the first beam splitter film, and then is transmitted and reflected by a second beam splitter film on a third inclined portion. This transmitted light is incident on a polarization plane conversion plate between the third inclined portion and a fourth inclined portion, so that P and S polarization components and are transmitted through and reflected by its polarized light splitting portion, respectively. The S polarization component is reflected by its reflecting surface toward light-receiving elements.