Method for measuring film thickness
CA 1313757 C · Owner: Ariki, Masayuki · Inventors: Tokumaru, Makoto; Nakano, Hideki; Nagao, Toshishige
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for measuring a film thickness comprising the steps of feeding a sheet to be measured by a rotatry shaft while intimately contacting, providing a light shield in parallel to the center of rotation of the rotary shaft at a predetermined distance from the rotary shaft surface to define a gap therebetween, scanning the gap with a laser beam by a reflective mirror, and measuring the time during which the laser beam passes through the gap to determine the film thickness of the sheet to be measured. A different-diameter portion is provided at the end portion of the rotary shaft calculating a difference between the time during which the laser beam passes through the gap on the …
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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
- Granted February 23, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 23, 2010.
- 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.