Method and apparatus for compensating for shutter speed variations
CA 2028640 C · Owner: Farrington, David L. · Inventors: Farrington, David L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An exposure control system for a photographic camera employing a scanning type shutter that includes a pair of cooperating shutter blade elements automatically compensates for exposure altering variations in shutter blade element speed that may occur from one exposure interval to another. The exposure control system includes an encoder to provide information on the actual position of the shutter blade elements as a function of time during an exposure cycle. The encoder generates a series of pulses representative of relative blade element position as the blades are moved during the exposure cycle. The time between these pulses is measured and directly converted into a signal representative …
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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 October 26, 1990 and granted January 16, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 26, 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.