{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9817218","patent":{"patent_number":"US-9817218","title":"Zoom lens and imaging apparatus","assignee":null,"inventors":[],"filing_date":"2015-02-24T00:00:00.000Z","publication_date":"2017-11-14T00:00:00.000Z","cpc_codes":["H04N"],"num_claims":11,"abstract":"A zoom lens includes, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power, the fourth lens group having at least two positive lenses, the zoom lens satisfying a conditional expression (a) of −2.0<f3/f4<−0.35where f3 indicates a focal length of the third lens group and f4 indicates a focal length of the fourth lens group."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Zoom lens and imaging apparatus","description":"A zoom lens includes, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a positive ","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9817218","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-9817218","citation_suggestion":"Patentable. \"Zoom lens and imaging apparatus\" (US-9817218). https://patentable.app/patents/US-9817218","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9817218","json":"https://patentable.app/api/llm-context/US-9817218","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T13:18:00.119Z"}