Speaker
CA 1322042 C · Owner: Takayama, Satoshi · Inventors: Serikawa, Mitsuhiko; Satoh, Katsuaki; Sato, Kazue
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A speaker which is thin but which is capable of providing high-fidelity reproduction and ensuring a suitable level of sound pressure even when it is brought close to a wall. A closed chamber is formed in the rear of a part of a diphragm mounted in an enclosure and an open chamber is formed in the rear of the other part of the diaphragm. The phase difference between sounds radiated from the front and rear surfaces of the diaphragm is increased as large as possible by using an acoustic duct for the sound radiated through the open cavity, thereby minimizing cancellation of sounds and improving the sound pressure level.
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 September 7, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 7, 2010.
- 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.