{
  "patent_number": "US 200521",
  "country": "US",
  "title": "How Thomas Edison Improved Early Phonograph Recording",
  "original_title": "Improvement in phonograph or speaking machines",
  "summary": "An 1878 patent by Thomas Edison detailing mechanical improvements to early sound recording devices to make them more reliable.",
  "what_it_does": "This patent describes mechanical refinements to the phonograph, which was the first device capable of both recording and reproducing sound. It focuses on the physical interaction between the recording needle and the storage medium, typically a tinfoil-wrapped cylinder. By adjusting the pressure and alignment of the diaphragm and stylus, the mechanism ensures a more consistent groove depth during the recording process. This allows for clearer playback by minimizing mechanical distortion caused by uneven tracking.",
  "what_it_does_not_cover": [
    "Does not cover electronic amplification or vacuum tube technology.",
    "Does not cover magnetic tape or digital audio storage methods.",
    "Does not cover the use of flat discs instead of cylindrical recording media.",
    "Does not cover wireless transmission of audio signals."
  ],
  "filed": null,
  "granted": "1878-02-19",
  "expires": null,
  "status": "active",
  "holder": "Thomas A. Edison",
  "holder_url": "https://patentbrief.org/company/thomas-a-edison",
  "inventors": [],
  "times_cited": 9,
  "tags": [
    "mechanical",
    "consumer_electronics"
  ],
  "abstract": null,
  "url": "https://patentbrief.org/patent/us/200521/phonograph-edison",
  "markdown_url": "https://patentbrief.org/patent/us/200521/phonograph-edison/md",
  "google_patents_url": "https://patents.google.com/patent/US200521",
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}