Enhanced privacy feature for telephone systems
CA 2030439 C · Owner: Jones, William Cumley · Inventors: Kalbow, Wayne Ronald; Larsen, Eric Tom; Mazur, Elizabeth Mary
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to apparatus and a method for use in conjunction with a service wherein a called telephone customer receives a display of the number of a calling telephone customer. In conjunction with this service customers areoffered a class of service and/or an option to dial a privacy request wherein their telephone number will not be displayed to the called telephone customer. In accordance with this invention, the customers are offered a class of service wherein they will receive calls only from telephone customers willing to have their telephone number displayed. If a call is made from a caller who does not wish to have his number displayed to a called customer who will not …
Read the whole patent
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 November 21, 1990 and granted September 13, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 21, 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.