Optical pickup apparatus and laser diode chip
First Claim
1. A laser diode chip for an optical pickup apparatus in which a plurality of light emitting portions having laminate structures are formed on a substrate for emitting laser beams of different wavelengths, wherein respective light emitting points of said plurality of light emitting portions are located at positions separated by different lengths in the laminate direction from the same plane of said substrate.
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Accused Products
Abstract
A laser diode chip for an optical pickup apparatus, in which a plurality of laminated light emitting portions which emit laser beams having different wavelengths are formed on a substrate, and light emitting points of the plurality of light emitting portions are placed at positions separated by different lengths from each other in the laminate direction from the same plane of the substrate.
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Citations
11 Claims
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1. A laser diode chip for an optical pickup apparatus in which a plurality of light emitting portions having laminate structures are formed on a substrate for emitting laser beams of different wavelengths,
wherein respective light emitting points of said plurality of light emitting portions are located at positions separated by different lengths in the laminate direction from the same plane of said substrate.
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5. An optical pickup apparatus comprising:
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a light emitting device in which a plurality of light emitting portions having laminate structures for emitting laser beams having different wavelengths are formed on a substrate and the laser beams are selectively emitted from one of said plurality of light emitting portions; and
an optical system for guiding the laser beams emitted from said light emitting device to a recording surface of a recording medium and guiding a laser beam reflected by the recording surface of said recording medium to a photosensing device, wherein respective light emitting points of said plurality of light emitting portions are located at positions separated by different lengths in the laminate direction from the same plane of said substrate, said optical system includes an astigmatism element for supplying astigmatism to said laser beam, said light detecting device has four-split light receiving portions corresponding to the respective laser beams having the different wavelengths in an arranged manner, and all the center parting lines of the light receiving surfaces in the array direction of the respective four-split light receiving portions are arranged to form the same straight line, said light emitting device is placed so that the sum of an angle formed by the major axis line of an elliptic spot formed on said recording medium by the laser beam and the tangential line of the track of said recording medium and an angle formed by said same plane and a straight line connecting the light emitting points of said plurality of light emitting portions becomes a predetermined angle, and said light detecting device is placed to make said center parting line parallel to the tangential line of said track on said light receiving surface. - View Dependent Claims (6, 7, 8, 9, 10)
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11. An optical pickup apparatus comprising:
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a light emitting device in which a plurality of light emitting portions having laminate structures for emitting laser beams having different wavelengths are formed on a substrate and the laser beams are selectively emitted from one of said plurality of light emitting portions; and
an optical system for guiding the laser beams emitted from said light emitting device to a recording surface of a recording medium and guiding a laser beam reflected by the recording surface of said recording medium to a photosensing device, wherein respective light emitting points of said plurality of light emitting portions are located at positions separated by different lengths in the laminate direction from the same plane of said substrate, said optical system includes an astigmatism element for supplying astigmatism to said laser beam, said light detecting device has four-split light receiving portions corresponding to the respective laser beams having the different wavelengths in an arranged manner, and all the center parting lines of the light receiving surfaces in the array direction of the respective four-split light receiving portions are arranged to form the same straight line, said light emitting device is placed so that an angle formed by the major axis line of an elliptic spot formed on said recording medium by the laser beam and the tangential line of the track of said recording medium is equal to an angle formed by said same plane and a straight line connecting the light emitting points of said plurality of light emitting portions, and said light detecting device is placed to make said center parting line perpendicular to the tangential line of said track on said light receiving surface.
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Specification