{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-8483022","patent":{"patent_number":"US-8483022","title":"Optical head device and optical disc apparatus","assignee":null,"inventors":[],"filing_date":"2009-07-10T00:00:00.000Z","publication_date":"2013-07-09T00:00:00.000Z","cpc_codes":["G11B","G11B","G11B","G11B","G11B","G11B"],"num_claims":11,"abstract":"An optical head device and an optical disc apparatus of a simple structure capable of canceling an offset in a tracking error signal caused when an objective lens shifts; in the optical head device, a polarizing hologram 104 has first diffraction areas 112 and 113 including a whole of an area irradiated with overlap of a zeroth-order beam of reflection light from an optical disc 1 and positive/negative first-order beams of the reflection light, and a second diffraction area 111 including an area irradiated with the zeroth-order beam of the reflection light and not irradiated with the positive/negative first-order beams of the reflection light without including the first diffraction area; and a photodetector 109 has a first light receiving section 131 for receiving a first light beam which is a zeroth-order beam of diffraction light generated by the polarizing hologram 104, a second light receiving section for receiving a second light beam which is a positive first-order beam of the diffraction light generated by the second diffraction area, and a third light receiving section for receiving a third light beam which is a negative first-order beam of the diffraction light generated by the second diffraction area."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Optical head device and optical disc apparatus","description":"An optical head device and an optical disc apparatus of a simple structure capable of canceling an offset in a tracking error signal caused when an objective lens shifts; in the optical head device, a","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-8483022","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-8483022","citation_suggestion":"Patentable. \"Optical head device and optical disc apparatus\" (US-8483022). https://patentable.app/patents/US-8483022","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-8483022","json":"https://patentable.app/api/llm-context/US-8483022","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-05-30T14:58:41.870Z"}