Accessory for use with an overhead projector
CA 1254780 A · Owner: Levin, Wilfred · Inventors: Levin, Wilfred
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An accessory for use with an overhead projector comprises a platen which has a generally rectangular transparent central portion and an opaque peripheral portion bounding the central portion. In the region of peripheral portion the platen has two mutually orthogonal upstanding, ridges, each extending substantially the entire length of the corresponding side of the central portion and each being defined by a pair of opposed inner and outer ridge-defining surfaces. The inner ridge-defining surfaces of the two ridges serve to locate a plurality of superimposed transparencies in register with each other and with respect to the central portion. The outer ridge-defining surfaces of the two ridges …
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 May 30, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 30, 2006.
- 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.