摘要:
A lead frame includes a die pad including a die pad main portion having a large thickness and a die pad peripheral portion having an intermediate thickness smaller than that of the die pad main portion, provided on at least one side of the die pad main portion, at least one support lead connected to the die pad, and at least two first inner leads having a small thickness smaller than that of the die pad peripheral portion, arranged such that end portions thereof are opposed to the die pad peripheral portion. The thick die pad provides good heat release properties, and reducing the thickness of the leads allows fine pitched leads to be produced. Such a lead frame can be manufactured easily by press stamping after belt-shaped regions having different thickness are formed by rolling.
摘要:
An optoelectronic device that provides an excellent reproduction signal and a stable servo control while preventing deterioration of S/N ratio caused by stray light. The optoelectronic device has a semiconductor laser (101) that emits light beams on an information-recording medium (105), a hologram optical element (102) having a diffraction grating region (108) and located between the semiconductor laser (101) and the information-recording medium (105), and a photodetector (106) for receiving light that is diffracted at the diffraction grating region (108) of the hologram optical element (102), among returning light beams from the information-recording medium (105), and the optoelectronic device has also a diffraction grating region (107) in the vicinity of the diffraction grating region (108) of the hologram optical element (102) so as to prevent stray light other than diffracted light from the diffraction grating region (108) from entering the photodetector (106).
摘要:
An optoelectronic apparatus includes an optoelectronic device, a mounting portion, a frame member surrounding a periphery of the mounting portion, and an optical component. The optical component is placed on an optical component placement portion. The frame member includes a pair of first side walls and a pair of second side walls. Each of the pair of second side walls has a recessed portion and a protruded portion. The optical component is disposed between the protruded portions, and is fixed with an adhesive filled in the recessed portions.
摘要:
An optoelectronic apparatus includes an optoelectronic device, a mounting portion, a frame member surrounding a periphery of the mounting portion, and an optical component. The optical component is placed on an optical component placement portion. The frame member includes a pair of first side walls and a pair of second side walls. Each of the pair of second side walls has a recessed portion and a protruded portion. The optical component is disposed between the protruded portions, and is fixed with an adhesive filled in the recessed portions.
摘要:
A movable enclosure contains optical components, such as an objective lens, a semiconductor laser, a mirror, and a photodetector. The movable enclosure is supported by a fixed member via a plurality of wires that are positioned in parallel. This construction allows the movable enclosure to move in a tracking direction and a focusing direction. The plurality of wires are insulated from one another to be also used as power-supplying lines and signal lines for the semiconductor laser and the photodetector.
摘要:
An optical device includes a light-emitting element for irradiating light onto an information recording medium, a diffraction grating for splitting light emitted from said light-emitting element into a plurality of beams, a focussing member for focussing the plurality of beams onto the information recording medium, a deflection member for deflecting the plurality of beams after they have been reflected from the information recording medium; and a photodetector for receiving the plurality of beams after they have been deflected by the deflection member. The diffraction grating has a first grating region and a second grating region, which have different diffraction efficiencies. The zero-order diffraction light in the first grating region is used as the main beam for reproducing the information signal, and the +1-order or −1-order diffraction light in the second grating regions is used as sub-beams for reproduction of the tracking error signal. Thus, the light amount of both the main beam and the sub-beams can be increased without increasing the light emission of the semiconductor laser element 1, and the S/N ratio of the main beam and the sub-beams can be enhanced.
摘要:
A semiconductor light-emitting unit includes: a semiconductor laser diode; a photodetector functioning as a sub-mount for mounting the diode thereon; and a heating member, incorporated with the photodetector, for heating the diode. If the ambient temperature of the diode falls within a range where kinks are possibly caused in the low-temperature I-L characteristic of the diode, then current is supplied to the heating member, thereby heating the diode. The heating member may be either a doped region defined within a semiconductor substrate or a doped polysilicon film formed on the substrate. Also, the heating member is preferably located under the laser diode with a heat-dissipating layer and an insulating layer interposed therebetween. The semiconductor light-emitting unit with this structure can effectively eliminate kinks from the low-temperature I-L characteristic of the semiconductor laser diode.
摘要:
A semiconductor laser device comprising a first lead having a chip mounting part provided at the front end, at least one second lead separated from the first lead, a semiconductor laser element mounted on the chip mounting part, connecting means for electrically connecting the electrode of the semiconductor laser element and at least one second lead, and a frame body made of insulating material disposed so as to surround the semiconductor laser device and connecting means, and fixed to the first lead and second lead. In this semiconductor laser device, transparent resin is not used for sealing, and hence deterioration of light exit characteristic does not occur. Besides, because of the structure of fixing the leads to the frame body, it is rigid and excellent in reliability, and a multiplicity can be manufactured at once, so that it is easy to manufacture and is excellent in mass producibility.
摘要:
An optical device includes a light-emitting element for irradiating light onto an information recording medium, a diffraction grating for splitting light emitted from said light-emitting element into a plurality of beams, a focussing member for focussing the plurality of beams onto the information recording medium, a deflection member for deflecting the plurality of beams after they have been reflected from the information recording medium; and a photodetector for receiving the plurality of beams after they have been deflected by the deflection member. The diffraction grating has a first grating region and a second grating region, which have different diffraction efficiencies. The zero-order diffraction light in the first grating region is used as the main beam for reproducing the information signal, and the +1-order or −1-order diffraction light in the second grating regions is used as sub-beams for reproduction of the tracking error signal. Thus, the light amount of both the main beam and the sub-beams can be increased without increasing the light emission of the semiconductor laser element 1, and the S/N ratio of the main beam and the sub-beams can be enhanced.
摘要:
A diffraction element includes a diffraction grating for dividing a light beam, emitted from a light source along a predetermined path, into a principal light beam and at least two auxiliary light beams, and a hologram for separating the beam, which has been reflected from an optical information recording medium, from the predetermined path. The diffraction grating and the hologram are integrated together by being formed in alignment with each other in opposite portions of a block of glass or plastics. A slide is provided at at least a portion of the diffraction element and includes a peripheral wall in sliding engagement with a cylindrical surface coaxial with an optical axis of the diffraction element to permit the diffraction element to be rotatable about the optical axis.