{
  "patent_number": "US 4723129",
  "country": "US",
  "title": "How Canon's Bubble Jet Printers Make Ink Droplets",
  "original_title": "Bubble jet recording method and apparatus in which a heating element generates bubbles in a liquid flow path to project droplets",
  "summary": "Canon's 1988 patent on bubble jet printing uses a tiny heater to instantly vaporize ink, creating a bubble that pushes out a droplet of ink from the printer head.",
  "what_it_does": "This patent describes how bubble jet printers work. Imagine a tiny tube, called a liquid flow path, with ink inside. At one end is an opening, the orifice, where ink droplets come out. Near this opening, but not too close, is a heating element. When the printer needs to make a dot, it sends a signal to this heater. The heater instantly gets super hot, boiling the ink right next to it. This creates a bubble. The bubble expands and pushes the ink in front of it out of the orifice, forming a droplet. Once the bubble pops, the heater cools down, and more ink flows in to fill the path, ready for the next droplet. The key is heating the ink *really* fast and only in a small spot, so it's a violent bubble, not just gentle simmering.",
  "what_it_does_not_cover": [
    "Printing methods that use continuous streams of ink droplets.",
    "Printing methods that rely on mechanical pressure or vibration to eject ink.",
    "Printing methods where the heating element heats the entire ink chamber uniformly.",
    "Printing methods that do not involve the formation and collapse of a vapor bubble in the ink.",
    "Inkjet printers that use piezoelectric crystals to eject ink."
  ],
  "filed": "1986-02-06",
  "granted": "1988-02-02",
  "expires": "2006-02-06",
  "status": "expired",
  "holder": "Canon Inc",
  "holder_url": "https://patentbrief.org/company/canon-inc",
  "inventors": [
    {
      "name": "Shigeru Ohno",
      "url": "https://patentbrief.org/inventor/shigeru-ohno"
    },
    {
      "name": "Yasushi Sato",
      "url": "https://patentbrief.org/inventor/yasushi-sato"
    },
    {
      "name": "Ichiro Endo",
      "url": "https://patentbrief.org/inventor/ichiro-endo"
    },
    {
      "name": "Takashi Nakagiri",
      "url": "https://patentbrief.org/inventor/takashi-nakagiri"
    },
    {
      "name": "Seiji Saito",
      "url": "https://patentbrief.org/inventor/seiji-saito"
    }
  ],
  "times_cited": 1806,
  "tags": [
    "consumer_electronics",
    "semiconductors",
    "mechanical"
  ],
  "abstract": "A liquid jet recording process comprises the step of providing a continuous passageway defining a path through which liquid can flow. The passageway has an inlet thereto and an outlet orifice therefrom and further defines a thermal chamber portion located directly in the path intermediate the inlet and the outlet orifice and spaced upstream from the outlet orifice. Liquid is supplied to the passageway to fill it and an input signal is generated each time it is desired to produce a liquid droplet. The liquid in the thermal chamber portion is heated in response to each input signal and heating is sufficient instantaneously to cause a change of state of the liquid in the thermal portion chamber sufficient to produce a force acting on liquid filling the passageway between the thermal chamber portion and the orifice that overcomes the surface tension of liquid at the orifice and thereby projects a droplet of liquid from the orifice. After projection of the droplet of liquid and with attenuation of the change of state and the force produced thereby, the liquid chamber portion is replenished with liquid. Apparatus for performing the liquid jet recording process is also disclosed.",
  "url": "https://patentbrief.org/patent/us/4723129/inkjet-bubble-jet-printing",
  "markdown_url": "https://patentbrief.org/patent/us/4723129/inkjet-bubble-jet-printing/md",
  "google_patents_url": "https://patents.google.com/patent/US4723129",
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    {
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      "countryCode": "US",
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}