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:
Dec. 16, 1986
Filed:
Jan. 16, 1984
Theodore S Rzeszewski, Lombard, IL (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A television system having a fully compatible high-definition signal receivable at conventional resolution by conventional TV receivers and which is transmitted to the TV receivers by one TV channel carrying the conventional signal and a second TV channel carrying the high-frequency luminance and chrominance information. The high-frequency chrominance information is time compressed and transmitted during the horizontal retrace interval of the second TV channel. The baseband signal containing the high-frequency luminance components is derived from the lower sideband output of a product modulator whose inputs are taken from an anti-alias filtered (camera) source of wideband luminance information and a local oscillator. The phase of the local oscillator is transmitted to the TV receivers by a tone burst signal gated into the vertical retrace interval of the second channel. The high-frequency chrominance information comprises Q' and I' segments which are transmitted at alternate horizontal retrace intervals. The television receivers comprise memories which alternately store the transmitted Q' and I' segments. The storage of the received segments is done at a higher rate than the accessing of these segments thus a time expansion operation is performed by the memories. In addition, since the segments are alternately transmitted, a storage mechanism is provided so that a segment received on a previous horizontal horizontal line's active time for displaying both Q' and I' information.