{
  "patent_number": "US 8619056",
  "country": "US",
  "title": "How Touchscreens Tell Real Touches From False Ghost Touches",
  "original_title": "Ghost resolution for a capacitive touch panel",
  "summary": "A method for capacitive touchscreens to distinguish between actual finger presses and false ghost signals that occur when multiple points are touched simultaneously.",
  "what_it_does": "When you touch a capacitive screen in two places, the grid of wires can sometimes create two extra 'ghost' points, making the device think you touched four spots. This patent describes a method to resolve this by charging the intersecting wires at each suspected point and measuring the resulting capacitance. By comparing the summed-up electrical values of these points, the system can mathematically determine which points are physically being touched and which are merely electrical artifacts. It then removes the false ghost points from the system's active list.",
  "what_it_does_not_cover": [
    "Does not cover touchscreens that use resistive technology rather than capacitive sensing.",
    "Does not cover software-level gesture recognition or palm rejection algorithms.",
    "Does not cover hardware designs that physically prevent ghosting through shielding or specialized grid layouts.",
    "Does not cover methods that rely solely on time-domain analysis without concurrent charging of traces."
  ],
  "filed": "2009-12-30",
  "granted": "2013-12-31",
  "expires": "2029-12-30",
  "status": "active",
  "holder": "Elan Microelectronics Corp",
  "holder_url": "https://patentbrief.org/company/elan-microelectronics-corp",
  "inventors": [
    {
      "name": "Min-Jhih Lin",
      "url": "https://patentbrief.org/inventor/min-jhih-lin"
    },
    {
      "name": "Po-Hao Kuo",
      "url": "https://patentbrief.org/inventor/po-hao-kuo"
    },
    {
      "name": "Yi-Hsin Tao",
      "url": "https://patentbrief.org/inventor/yi-hsin-tao"
    },
    {
      "name": "Hsin-Shieh Tsai",
      "url": "https://patentbrief.org/inventor/hsin-shieh-tsai"
    },
    {
      "name": "Chia-Hsing Lin",
      "url": "https://patentbrief.org/inventor/chia-hsing-lin"
    }
  ],
  "times_cited": 2,
  "tags": [
    "consumer_electronics",
    "semiconductors"
  ],
  "abstract": "Ghost resolution sensing methods are provided for capacitive touch panels. When ghost is detected involving two points on a capacitive touch panel, for each of the two points, the intersected traces at that one are concurrently charged to sense the capacitance value from either one of the intersected traces, and according thereto, a real point and a ghost point can be distinguished from each other. Alternatively, the intersected traces are crisscross driven by two synchronous and in phase signals or synchronous but out of phase signals, to sense the capacitance values at the two points. Preferably, intersectional calibration is performed in conjunction therewith, to recognize the real points.",
  "url": "https://patentbrief.org/patent/us/8619056/ghost-resolution-for-a-capacitive-touch-panel",
  "markdown_url": "https://patentbrief.org/patent/us/8619056/ghost-resolution-for-a-capacitive-touch-panel/md",
  "google_patents_url": "https://patents.google.com/patent/US8619056",
  "relatedPatents": [
    {
      "patentNumber": "7663607",
      "countryCode": "US",
      "title": "How Multi-Touch Screens Track Multiple Fingers at Once",
      "url": "https://patentbrief.org/patent/us/7663607/multipoint-touchscreen"
    },
    {
      "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": "8493330",
      "countryCode": "US",
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      "url": "https://patentbrief.org/patent/us/8493330/individual-channel-phase-delay-scheme"
    },
    {
      "patentNumber": "8125456",
      "countryCode": "US",
      "title": "How Touchscreens Save Battery by Sleeping Between Touches",
      "url": "https://patentbrief.org/patent/us/8125456/multi-touch-capacitive-scanning"
    },
    {
      "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"
    }
  ]
}