摘要:
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.
摘要:
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.A control cycle is A times (natural number) the distribution cycle and the driving is performed A times at the same average frequency, whereby a digital driving system using the frequency distribution of the driving pulse is achieved. Consequently, a space for the driving circuit can be saved and cost can be reduced. Further, a frequency distribution system is adopted, thereby obtaining frequency resolution required for satisfactory dimming performance and lighting performance. Moreover, a burst dimming system is adopted, thereby suppressing brightness flicker seen in a tube current control system. Additionally, there is no electric power loss seen in a system in which a power source is turned on or off and further a shield circuit is unnecessary because of a system in which the driving pulse is turned on or off. In particular, the control cycle is A times the distribution cycle and the burst dimming is performed in which the driving is executed A times at the same average frequency, whereby the brightness flicker can be prevented by controlling the tube current to be constant with high dimming resolution assured.
摘要:
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.
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 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.
摘要:
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.
摘要:
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.
摘要:
A semiconductor laser element which is composed of a compound semiconductor consisting of GaAs or the like, a silicon laser mount which is disposed beneath the semiconductor laser element so as to position the element, and on which an electrode layer as an electrode for the semiconductor laser element is formed, a heat sink which is disposed beneath the laser mount so as to dissipate, through the laser mount, the heat generated by the semiconductor laser element are mutually secured through hot contact bonding. The laser mount has a concave portion on the side opposite to its main surface on which the semiconductor layer element is secured, and the concave portion contains a heat dissipating body which is integrated thereinto and is made of copper having higher thermal conductivity than silicon.
摘要:
Radiating light from a semiconductor laser element is radiated in a direction normal to the surface of a photodetector substrate. The semiconductor laser element and photodetector are disposed on the same plane. Specifically, a reflecting mirror surface formed of a slanting surface of (111) lattice plane having a ridge line of direction is disposed on a silicon substrate of (100) lattice plane having an off-angle of 4.degree. to 14.degree. about an axis of direction or on a silicon substrate of (511) lattice plane having an off-angle of 1.degree. to 11.degree. about an axis of direction. The semiconductor laser chip is disposed at a position opposing to the reflecting mirror surface.