Abstract: A first diffractive optical element pattern with a pattern pitch that is no greater than a wavelength of incident light is formed on a first main surface of substrate such as a glass plate. Second diffractive optical element patterns are formed at positions that are respectively incident to positive first-order diffracted light and negative first-order diffracted light produced by the first diffractive optical element pattern. Negative first-order diffracted light produced by each second diffractive optical element pattern is incident upon a boundary face of the substrate at an angle that is smaller than the critical angle, and so exits the substrate.

Abstract: A semiconductor laser device is provided which can carry out recording and reproduction with respect to optical disks with different formats. In this semiconductor laser device, a receiving/emitting optics integrated substrate, in which two semiconductor laser elements with different emission wavelengths and a plurality of receiving optics are integrated, is disposed in a case and is sealed with a hologram element. A composite prism is placed on the hologram element. The distances, when measured in air, from the two semiconductor laser elements to a focusing means, for example, a collimator lens are set to be substantially equal. Thus, a small and inexpensive semiconductor laser device can be obtained. In addition, a single collimator lens can be employed, and thus the optical configuration is facilitated.

Abstract: A cold cathode tube driving device using a piezoelectric transformer in which an output voltage varies depending on a frequency of an input voltage, as a booster transformer for driving a cold cathode tube, includes: a frequency dividing means which generates a driving pulse of an average frequency corresponding to frequency data outputted from a frequency setting means at a distribution cycle which is a driving pulse N cyclic period; a controller which controls a control cycle so as to perform the same driving for predetermined number of times A (A≧2) at the average frequency; and a burst pulse generating means which generates a pulse having a duty width in accordance with a dimming level externally applied thereto and having a frequency outputted from the controller.

Abstract: 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.

Abstract: 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.

Abstract: A first diffractive optical element pattern with a pattern pitch that is no greater than a wavelength of incident light is formed on a first main surface of substrate such as a glass plate. Second diffractive optical element patterns are formed at positions that are respectively incident to positive first-order diffracted light and negative first-order diffracted light produced by the first diffractive optical element pattern. Negative first-order diffracted light produced by each second diffractive optical element pattern is incident upon a boundary face of the substrate at an angle that is smaller than the critical angle, and so exits the substrate.

Abstract: 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.

Abstract: A lens holding member carrying an objective lens is movable and supported by a fixed member via a plurality of supporting members. Each supporting member includes a bent part in its base portion on the side of the fixed member. The bent part is bent in a first direction (focusing direction) and a second direction (tracking direction) that are perpendicular to each another. Each supporting member is shaped so as to make all the principal planes of the supporting member parallel to the second direction. The fixed member includes a concave, which is impregnated with a gel material so that the bent part is covered with the gel material.

Abstract: A semiconductor laser device includes a semiconductor laser element, a light beam branching element for branching a light beam emitted from the semiconductor laser element and reflected by an optical recording medium into a plurality of light beams, a light beam reflector for reflecting the light beam branched by the light beam branching element, and a photodetector portion for detecting the light beam reflected by the light beam reflector. The light beam branching element and the photodetector portion are formed on the same substrate. The miniature semiconductor laser device can be assembled without complicated position adjustment and has less deterioration of characteristics arising from misregistration during and after assembly.

Abstract: An optical pickup that is equipped with a photodetector unit, irradiates an optical disc with a laser beam, and receives returning light reflected by the optical disc, where the optical pickup is constructed to (1) divide the laser beam into a main beam, a preceding sub-beam, and a succeeding sub-beam, (2) direct the main beam, the preceding sub-beam, and the succeeding sub-beam toward the optical disc, and (3) divide returning lights of the main beam, the preceding sub-beam, and the succeeding sub-beam respectively into first-fourth main returning lights, first-fourth preceding returning lights, and first-fourth succeeding returning lights, and the photodetector unit includes: first-fourth main photodetectors that respectively receive the first-fourth main returning lights; first-fourth preceding photodetectors that respectively receive the first-fourth preceding returning lights; and first-fourth succeeding photodetectors that respectively receive the first-fourth succeeding returning lights.

Abstract: An optical pickup is equipped with: an enclosure which contains an optical system including a semiconductor laser and an objective lens; a fixed member; and an elastic supporting member which has conductivity and movably supports the enclosure. A plurality of pairs of driving coils are each positioned in the enclosure so as to be symmetrical with respect to an optical axis of a laser beam. The plurality of pairs of driving coils generate magnetic forces with a plurality of magnets or the like, to drive the enclosure in a focusing direction and a tracking direction.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In a lens driving device for an optical recording/reproducing apparatus, a lens is held by a platelike damping member that is made of silicone porous material, for example, and both ends of the damping member are fixed to a base. This construction prevents undesired oscillations. Also, in order to drive the lens, two magnets are attached to an outer edge of the lens opposite to each other with the lens interposed in between them, and driving coils are attached to the base facing the magnets. The driving coils have two coils that drive the lens in the tracking and focusing directions, respectively.

Abstract: 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.

Abstract: 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.

Abstract: A 3-beam-generating grating 2, a collimating lens 3, a polarizing beam splitter 4, a rising mirror 5 and an objective lens 6 are arranged sequentially in the optical path between a semiconductor laser device 1 and an information recording medium 7. The reflecting face of the polarizing beam splitter 4 has a reflection characteristic such that the reflectance is minimum for return light L2 at an angle of 45 degrees whereas the reflectance increases as the incident angle of the return light L2 deviates from 45 degrees. This realizes an optical head device that is not likely to cause the decrease in tracking error signals even if the objective lens shifts in radial directions of the recording medium.

Abstract: 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.