Abstract: In a heat exchanger, an outer diameter of a plurality of heat transfer pipes is defined as Do, a wall thickness is defined as tP, an area represented by a numerical expression of a row pitch L1×a step pitch L2 is defined as A, and an area represented by a numerical expression of ((Do?2×tP)/2)2×? is defined as B, a relation of Do<5.5 mm, a relation of (0.2076×tP2?0.1480×tP+0.0545)×Do{circumflex over (?)}(?0.0021×tP2?0.0528×tP+0.0164)?B/A?(0.0219×tP2?0.0185×tP+0.0043)×ln (Do)+(1.6950×tP2+1.8455×tP+1.5416), and a relation of B/A<0.0076×tP2?0.0417×tP+0.0574 are satisfied.

Abstract: A heat exchanger includes: a first heat exchanger configured to transfer heat between air and refrigerant; and a second heat exchanger provided in series with the first heat exchanger in a first direction that is a flow direction of the air, and configured to transfer heat between the air and the refrigerant. The first heat exchanger includes first heat transfer tubes through which the refrigerant flows, which are spaced apart from each other in a second direction intersecting the first direction, and each of which has a tube axis extending in a third direction intersecting the first and second directions. The second heat exchanger includes: second heat transfer tubes though which the refrigerant flows, which are spaced apart from each other in the second direction, and each of which has a tube axis extending in the third direction; and a corrugated fin provided between the second heat transfer tubes.

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 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: 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: 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: An objective lens driver comprises an objective lens, a lens holder, a plurality of support members for supporting the lens holder in such a manner as to enable the objective lens to move along the focusing direction and along the tracking direction, a drive means for driving the lens holder, a fixing member provided with a viscoelastic member formed to hold each support member, each support member including a linear section linearly formed to connect to viscoelastic member provided in the fixing member and to the lens holder, and at least one arm branching from somewhere between the ends of each linear section so as to reduce resonance of each support member generated when the lens holder is driven by the drive means.

Abstract: An objective lens driver comprises an objective lens, a lens holder, a plurality of support members for supporting the lens holder in such a manner as to enable the objective lens to move along the focusing direction and along the tracking direction, a drive means for driving the lens holder, a fixing member provided with a viscoelastic member formed to hold each support member, each support member including a linear section linearly formed to connect to viscoelastic member provided in the fixing member and to the lens holder, and at least one arm branching from somewhere between the ends of each linear section so as to reduce resonance of each support member generated when the lens holder is driven by the drive means.

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: An optical fiber module for facilitating changing part of an existing electrical signal transmission system to an optical transmission system. The fiber module includes an electric connector, a laser diode (LD) semiconductor IC, an LD module, a photodiode (PD) semiconductor IC, a PD module, an optical connector, a printed circuit board, a cover, and a shielding portion. In one embodiment, the printed circuit board has a constricted portion between first and second areas of the cover. In another embodiment, the circuit board is flexible and can be folded at a central portion. The optical fiber module is easily attachable and detachable from the outside of a computer without requiring a mother board to have optical fibers mounted thereon.

Abstract: A fiber optic module includes a connector connected to a mother board of a host computer, an LD semiconductor IC for converting serial data received from the mother board to an LD electric signal for a laser diode, an LD module for converting the LD electric signal to an LD optical signal, a PD module for converting a photodiode optical signal to a PD electric signal, a PD semiconductor IC for converting the PD electric signal to PD serial data, a circuit board having the connector and carrying LD semiconductor IC and PD semiconductor IC, an LD shielding plate and a PD shielding plate for electrically shielding the LD module and the PD module, respectively, a first frame and a second frame for holding the circuit board, LD module and PD module.

Abstract: A fiber optic module includes a connector connected to a mother board of a host computer, an LD semiconductor IC for converting serial data received from the mother board to an LD electric signal for a laser diode, an LD module for converting the LD electric signal to an LD optical signal, a PD module for converting a photodiode optical signal to a PD electric signal, a PD semiconductor IC for converting the PD electric signal to PD serial data, a circuit board having the connector and carrying LD semiconductor IC and PD semiconductor IC, an LD shielding plate and a PD shielding plate for electrically shielding the LD module and the PD module, respectively a first frame and a second frame for holding the circuit board, LD module and PD module.

Abstract: A fiber optic module includes a connector connected to a mother board of a host computer, an LD semiconductor IC for converting serial data received from the mother board to an LD electric signal for a laser diode, an LD module for converting the LD electric signal to an LD optical signal, a PD module for converting a photodiode optical signal to a PD electric signal, a PD semiconductor IC for converting the PD electric signal to PD serial data, a circuit board having the connector and carrying LD semiconductor IC and PD semiconductor IC, and LD shielding plate and a PD shielding plate for electrically shielding the LD module and the PD module, respectively, a .[.first frame and a second.]. frame for holding the circuit board, LD module and PD module.