{
  "patent_number": "US 7812828",
  "country": "US",
  "title": "How Touchscreens Use Math to Recognize Your Fingers",
  "original_title": "Ellipse fitting for multi-touch surfaces",
  "summary": "Apple's patent on using mathematical ellipses to track and identify individual fingers and palms on a touch-sensitive surface.",
  "what_it_does": "This patent describes a method for a touchscreen to interpret raw electrical data as distinct physical objects. It takes a 'proximity image'—a grid of data from electrodes—and groups nearby pixels together to represent a touch. The system then mathematically fits an ellipse to these pixel groups to estimate the shape, size, and orientation of the finger or palm. By tracking these ellipses over time, the device can distinguish between a thumb and a fingertip or detect if a hand is resting on the screen.",
  "what_it_does_not_cover": [
    "Does not cover touch detection methods that do not use ellipse fitting (e.g., simple centroid or bounding box tracking).",
    "Does not cover hardware that lacks a proximity-sensing electrode grid.",
    "Does not cover software gestures that are not derived from the calculated ellipse parameters."
  ],
  "filed": "2007-02-22",
  "granted": "2010-10-12",
  "expires": "2027-02-22",
  "status": "active",
  "holder": "Apple Inc",
  "holder_url": "https://patentbrief.org/company/apple-inc",
  "inventors": [
    {
      "name": "Wayne Westerman",
      "url": "https://patentbrief.org/inventor/wayne-westerman"
    },
    {
      "name": "John G. Elias",
      "url": "https://patentbrief.org/inventor/john-g-elias"
    }
  ],
  "times_cited": 93,
  "tags": [
    "consumer_electronics",
    "software"
  ],
  "abstract": "Apparatus and methods are disclosed for simultaneously tracking multiple finger and palm contacts as hands approach, touch, and slide across a proximity-sensing, multi-touch surface. Identification and classification of intuitive hand configurations and motions enables unprecedented integration of typing, resting, pointing, scrolling, 3D manipulation, and handwriting into a versatile, ergonomic computer input device.",
  "url": "https://patentbrief.org/patent/us/7812828/ellipse-fitting-for-multi-touch-surfaces",
  "markdown_url": "https://patentbrief.org/patent/us/7812828/ellipse-fitting-for-multi-touch-surfaces/md",
  "google_patents_url": "https://patents.google.com/patent/US7812828",
  "relatedPatents": [
    {
      "patentNumber": "6323846",
      "countryCode": "US",
      "title": "How a Multi-Touch Screen Detects Multiple Fingers and Palms",
      "url": "https://patentbrief.org/patent/us/6323846/aqua-user-interface"
    },
    {
      "patentNumber": "7663607",
      "countryCode": "US",
      "title": "How Multi-Touch Screens Track Multiple Fingers at Once",
      "url": "https://patentbrief.org/patent/us/7663607/multipoint-touchscreen"
    },
    {
      "patentNumber": "7812826",
      "countryCode": "US",
      "title": "How Multi-Touch Gestures Like Pinch-to-Zoom Work on Smartphones",
      "url": "https://patentbrief.org/patent/us/7812826/iphone-software-keyboard"
    },
    {
      "patentNumber": "10564770",
      "countryCode": "US",
      "title": "How Touchscreens Predict Where Your Finger Will Land Before You Touch",
      "url": "https://patentbrief.org/patent/us/10564770/airpods-wireless-earbuds"
    },
    {
      "patentNumber": "5825352",
      "countryCode": "US",
      "title": "Logitech's Method for Using Two Fingers on a Touchpad",
      "url": "https://patentbrief.org/patent/us/5825352/apple-pinch-to-zoom"
    }
  ]
}