Image forming apparatus
CA 2017561 C · Owner: Nagase, Yukio · Inventors: Itoh, Masahiro; Kemmochi, Kazuhisa; Sakemi, Yuji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An image forming apparatus wherein a laser beam produced by a laser source is imaged through an imaging optical system on an image bearing member as a beam spot. The beam spot scans the image bearing member in a main scan direction. The laser source is rendered on and off to form an image with picture elements. The laser driving pulse width per picture element is changed in accordance with the image density of the image to be formed, so that the tone gradation of the image is provided on the image bearing member in accordance with the pulse width. The size of the spot measured in the main scan direction (1/e2 diameter) is not more than 0.7 times of the size of the picture element measured …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed May 25, 1990 and granted July 9, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 25, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 25, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.