Ultrasonic transducer
CA 2092929 A1 · Owner: Ngk Insulators, Ltd. · Inventors: Ishida, Yoshihiko; Tani, Makoto; Asai, Yuji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A phase-insensitive ultrasonic transducer has a zinc oxide single crystal as a piezoelectric semiconducting acoustoelectric element providing high, sensitivity and operable over a range of wavelengths of the ultrasonic waves. The electrical conductivity of said zinc oxide single crystal may be selected in the range 10-8 to 10-2 .OMEGA.-1.cm-1. The single crystal can have an attenuation rate for ultrasonic waves of 10 MHz of at least 0.8 cm-1.
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 March 30, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 30, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 30, 2015.
- 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.