Computer trackball
CA 2188480 C · Owner: At&T Corp. · Inventors: Blonder, Greg E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A computer trackball comprises a transparent outer sphere inside of which is disposed a second inner sphere. The outer diameter of the inner sphere is a little bit smaller than the inner diameter of the outer sphere. Disposed on the outer surface of the inner sphere, at one "end" thereof is a logo or other graphical image. The inner sphere tends to maintain itself in a predetermined orientation ? e.g. with the graphical image pointing directly "up" relative to the keyboard or other housing in which the trackball is held ? notwithstanding rotation of the outer sphere by a user in the course of operating the trackball.
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 October 22, 1996 and granted May 30, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 22, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 22, 2018.
- 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.