Patent Yard Sign in
Expired Canadian patentCanada

Color variation inducing device

CA 2063973 C · Owner: Tomatsu, Tsutomu · Inventors: Tomatsu, Tsutomu; Ono, Yoshiaki; Nakagawa, Tanehiro

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

A color variation inducing device is, positioned in contact with or in the proximity of or effects action through air blowing means on a thermally color-varying article provided with a thermally color-varying layer, thereby inducing color variation in the thermally color-varying layer. The device comprises an electrothermal converter device provided with a heat absorbing portion and a heat generating portion based on Peltier effect, a radiator connected to the heat generating side of the electrothermal converter device, and a casing for housing and supporting the electrothermal converter device, wherein the electrothermal converter device is rendered functionable under the application of a …

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 March 25, 1992 and granted April 20, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 25, 2012.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 25, 2014.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 25, 1992
GrantedApril 20, 1999
Term endedMarch 25, 2012
Patent numberCA 2063973 C
Classification (IPC)G02F1/23 +2 more

Timeline

Timeline From CIPO dates

1993199519971999200120032005200720092011Application filedMarch 25, 1992Patent grantedApril 20, 1999Term endedMarch 25, 2012

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.