{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-8493824","patent":{"patent_number":"US-8493824","title":"Optical head and optical disc device","assignee":null,"inventors":[],"filing_date":"2006-10-10T00:00:00.000Z","publication_date":"2013-07-23T00:00:00.000Z","cpc_codes":["G11B","G11B"],"num_claims":18,"abstract":"A tilt can be detected highly accurately by minimizing the tilt detection error. An optical head includes: an objective lens for converging a light beam from a light source onto an optical disc; a photodetector section receiving the beam, reflected from the disc, at divided areas on its photodetection plane and outputting light detection signals from those areas; and a tilt detecting section for detecting a relative tilt between the lens and disc based on the detection signals. The tilt detecting section generates a first push-pull signal PP1 based on the detection signals supplied from a first group of areas, which are arranged symmetrically to a virtual reference line drawn parallel to a disc radial direction and crossing an optical axis, also generates a second push-pull signal PP2 based on the detection signals supplied from a second group of areas, different from the first group and also arranged symmetrically to the reference line, changes coefficients k according to the location of the lens in a disc radial direction, and generates a tilt detection signal TLT by TLT=PP1−k×PP2. "},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Optical head and optical disc device","description":"A tilt can be detected highly accurately by minimizing the tilt detection error. An optical head includes: an objective lens for converging a light beam from a light source onto an optical disc; a pho","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-8493824","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-8493824","citation_suggestion":"Patentable. \"Optical head and optical disc device\" (US-8493824). https://patentable.app/patents/US-8493824","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-8493824","json":"https://patentable.app/api/llm-context/US-8493824","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-05-31T18:37:07.409Z"}