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OwnerKatsuhiko Izumi, Kunikazu Ohnishi +3inventors
InventorsKatsuhiko Izumi, Kunikazu Ohnishi, Kenichi Shimada, Masayuki Inoue, Shinji Fujita
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An optical pickup has a semiconductor laser having two laser sources of different wavelengths disposed in the same package, one diffraction grating and one optical detector. A plurality of light reception areas each having four divisional light reception planes of a -character shape are disposed at positions where light beams reflected from an optical disc are applied. A focus error signal is generated by an astigmatism method by using independently these light reception areas and a tracking error signal is generated by a differential phase detection method by using one or both the light reception areas.
An optical detector comprising no laser source in a package of said optical detector, comprising:
Dependencies are inferred from the claim text.