{
  "patent_number": "US 3819921",
  "country": "US",
  "title": "How Texas Instruments Invented the Handheld Electronic Calculator",
  "original_title": "Miniature electronic calculator",
  "summary": "This 1972 patent describes the architecture for the first truly portable, battery-powered electronic calculator that could fit in a pocket.",
  "what_it_does": "The patent details a system that shrinks bulky desktop calculator components into a handheld device. It uses an integrated semiconductor circuit array—a single chip—to handle memory storage, arithmetic operations like addition and division, and control signaling. The design stacks the keyboard, the circuit array, and the display in parallel planes to minimize the device's footprint. This allows the calculator to process multi-digit numbers and display results on a small screen or via a thermal printer while running on battery power.",
  "what_it_does_not_cover": [
    "Does not cover non-electronic or mechanical calculators (e.g., slide rules or abacuses).",
    "Does not cover calculators that require external power sources or wall outlets.",
    "Does not cover computing devices that lack a physical keyboard input mechanism.",
    "Does not cover general-purpose computers or microprocessors not specifically configured for arithmetic calculation."
  ],
  "filed": "1972-12-21",
  "granted": "1974-06-25",
  "expires": "1992-12-21",
  "status": "expired",
  "holder": "Texas Instruments Inc",
  "holder_url": "https://patentbrief.org/company/texas-instruments-inc",
  "inventors": [
    {
      "name": "J Kilby",
      "url": "https://patentbrief.org/inventor/j-kilby"
    },
    {
      "name": "J Merryman",
      "url": "https://patentbrief.org/inventor/j-merryman"
    },
    {
      "name": "Tassel J Van",
      "url": "https://patentbrief.org/inventor/tassel-j-van"
    }
  ],
  "times_cited": 18,
  "tags": [
    "consumer_electronics",
    "semiconductors",
    "mechanical"
  ],
  "abstract": "Binary-coded decimal electronic calculator capable of adding, subtracting, multiplying and dividing with some degree of automatic decimal point placement to provide a visual display of answers of up to 12 decimal digits. The decimal digits are serially displayed at a speed compatible with the calculator operations. The parts of the calculator are so adapted electrically and mechanically in relation to each other to result in a minature portable battery operated calculator of extremely small dimensions for example the outside case dimensions of 4 1/4 inches by 6 1/8 inches by 1 3/4 inches and very low weight of about 45 ounces, having a calculating capability only before obtainable in calculators of much larger size and weight while retaining mechanical and operational simplicity. Some significant aspects of the calculator are the primary electronics embodied in an integrated semiconductor circuit array located in substantially one plane for performing the arithmetic calculations and generating the control signals, a keyboard input arrangement located in substantially one plane parallel to the integrated semiconductor circuit array for producing unique electrical signals corresponding to number and command entries and a visual display using a semiconductor array, as for a thermal printer for printout.",
  "url": "https://patentbrief.org/patent/us/3819921/barcode-upc-scanner",
  "markdown_url": "https://patentbrief.org/patent/us/3819921/barcode-upc-scanner/md",
  "google_patents_url": "https://patents.google.com/patent/US3819921",
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}