Calculator having merged key codes
CA 1052007 A · Owner: Hewlett-Packard Company · Inventors: Stockwell, Richard K.; Osborne, Thomas E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A hand-held programmable, electronic calculator is capable of performing a larger number of functions than the number of keys on its keyboard and has one or more prefix keys to allow one function key to initiate more than one function. Each key generates a unique key code when it is depressed, and the calculator may be programmed by storing a series of the key codes in a memory. Memory space can be saved by generating unique merged codes to represent the combination of a prefix key and a function key and storing, this single merged code rather than the two key codes.
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 April 3, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 3, 1996.
- 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.