Data communication apparatus
CA 2294532 A1 · Owner: Matsumoto, Wataru · Inventors: Matsumoto, Wataru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An on-hook/off-hook detector circuit (61) detects the voltage level of a telephone line (C) to determine whether the speech band is in on-hook or offhook state, and produces a state signal (81). TEQ (63) FEQ (66) and , constellation encoder gain scaling (67) perform adaptive equalization bit , distribution and gain distribution in time and frequency regions for data communication by using separate tables (75-80) depending on the state signal (81). Since the telephone is not used in on-hook state the transmission , subcarrier band for communication is shifted near or expanded into, the , speech band.
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 April 1, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 1, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 1, 2021.
- 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.