Phototransistor array having uniform current response and method of manufacture
CA 1077604 A · Owner: De La Moneda, Francisco H. · Inventors: Debar, David E.; De La Moneda, Francisco H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Variations of current gain from element to element in a phototransistor array are eliminated by covering the array with an opaque mask and etching openings in the mask over each phototransistor based upon an area reduction factor (ARF). The area reduction factor for an opening is equal to (Im/Ix)1-n where n is a constant definitive of the change in beta of a phototransistor in the array over a given range of collector currents; Im is the minimum collector current measured for the array and Ix is the collector current for the phototransistor beneath the opening. Based upon the ARF's the openings etched in the mask or, cover initiate uniform current form each phototransistor element when …
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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 May 13, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 13, 1997.
- 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.