{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9697862","patent":{"patent_number":"US-9697862","title":"Disk-shaped glass substrate, magnetic-disk glass substrate, method for manufacturing magnetic-disk glass substrate, and magnetic disk","assignee":null,"inventors":[],"filing_date":"2014-06-27T00:00:00.000Z","publication_date":"2017-07-04T00:00:00.000Z","cpc_codes":["G11B","G11B","G11B","G11B"],"num_claims":20,"abstract":"A disk-shaped glass substrate for a magnetic-disk glass substrate includes an outer circumference having a roundness of 1.3 μm or less. A first reference circle is obtained with a least squares method from a first outline corresponding to a shape of a lap around the outer circumference. A second reference circle is obtained with a least squares method from a second outline obtained by performing low-pass filtering using a period in which the number of peaks per lap is 150 as a cut-off value on the first outline. A ratio of the second peak count value defined by the number of peaks of the second outline that project outward in a radial direction from the second reference circle to the first peak count value defined by the number of peaks of the first outline that project outward in a radial direction from the first reference circle is 0.2 or less."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Disk-shaped glass substrate, magnetic-disk glass substrate, method for manufacturing magnetic-disk glass substrate, and magnetic disk","description":"A disk-shaped glass substrate for a magnetic-disk glass substrate includes an outer circumference having a roundness of 1.3 μm or less. A first reference circle is obtained with a least squares method","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9697862","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-9697862","citation_suggestion":"Patentable. \"Disk-shaped glass substrate, magnetic-disk glass substrate, method for manufacturing magnetic-disk glass substrate, and magnetic disk\" (US-9697862). https://patentable.app/patents/US-9697862","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9697862","json":"https://patentable.app/api/llm-context/US-9697862","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T15:06:36.510Z"}