Patent Yard Sign in
Expired Canadian patentCanada

Automatic contrast reduction circuit for a teletext or monitor operation

CA 1214864 A · Owner: Rca Corporation · Inventors: Sendelweck, Gene K.

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

In a TV receiver responsive to either conventional television video signals or an auxiliary video signal representative of alphanumeric text or graphic information, to prevent undesired "blooming" of the display due to high kinescope beam currents when the alphanumeric text or graphics are displayed on the screen of a kinescope, means are provided for reducing at least one amplitude characteristic of the auxiliary video signal, such as its peak-to-peak signal level (contrast) so as to reduce the kinescope beam current whenever the alphanumeric text or graphics are displayed.

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 December 2, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 2, 2003.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 25, 1984
GrantedDecember 2, 1986
Term endedDecember 2, 2003
Patent numberCA 1214864 A
Classification (IPC)H04N5/59 +2 more

Timeline

Timeline From CIPO dates

1985198719891991199319951997199920012003Application filedSep 25, 1984Patent grantedDec 2, 1986Term endedDec 2, 2003

Sources & verification

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