The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 27, 1977
Filed:
Jun. 19, 1975
Francis H Hilbert, Addison, IL (US);
Theodore S Rzeszewski, Lombard, IL (US);
Matsushita Electric Company of America, Franklin Park, IL (US);
Abstract
A low level video auxiliary signal is transmitted in addition to the conventional composite black and white or color television signal. The auxiliary signal is in the form of redundant, opposite-polarity signal portions during pairs of time successive signal portions, such as horizontal lines or fields of the composite television signal. The auxiliary signal also may be transmitted in the form of a predetermined frequency with the auxiliary information on successive lines of the composite television signal being out of phase by one-half the period of the auxiliary signal frequency. When the composite signal is detected and displayed by the conventional circuitry in the receiver, the auxiliary information is visually cancelled in the image displayed on the cathode ray tube and the normal video information is displayed. Additional circuitry is employed in the receiver to effect cancellation of the conventional video information from the display and to reinforce successive portions of the auxiliary signal; so that the auxiliary signal is displayed on the cathode ray tube of the receiver when desired.