Identification system
CA 1264840 C · Owner: Milheiser, Thomas A. · Inventors: Milheiser, Thomas A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A passive integrated transponder (PIT) is attached to or embedded in an item to be identified. It is excited via an inductive coupling from an interrogator. The PIT responds to the interrogator via the inductive coupling with a signal constituted by a stream of data unique to the identified item. The signal is in the form of two different frequencies a shift, from one to the second representing a data "one" and a shift, from the second frequency to the first frequency representing a data "zero". The responsive signal is then detected and processed for utilization in a data storage or display device.
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
- Granted January 23, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 23, 2007.
- 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.