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:
Mar. 15, 1994
Filed:
Jul. 13, 1993
Lauren F Yazolino, Orinda, CA (US);
John L Goodell, Sunnyvale, CA (US);
Pacific Pay Video Limited, Mountain View, CA (US);
Abstract
A cable television system provides television signals in multiple predefined television signal formats. Each television has a multi-standard receiver for receiving television signals in those predefined television signal formats. Hidden behind each television, or elsewhere out of view of the user, is a converter coupling the respective television to a transmission cable. The only connection from the converter to the television is a cable connected to the television's cable or antenna input port. Each television includes a raster scan CRT and CRT control circuitry that controls the raster scan sweep pattern of the electron beams generated by the CRT. The CRT control circuitry includes a horizontal scan synchronization circuit that synchronizes each horizontal sweep of the CRT electron beams with a horizontal synchronization signal in the received television signal, and generates a distinctive transient voltage signal at the beginning of each horizontal sweep of the CRT electron beams. External to the converter box is a horizontal sweep pickup antenna suitable for positioning proximate the monitored television. Internal to the converter box is a filter that extracts the horizontal synchronization component of the television signal on the channel selected by the user. A synchronization signal comparator compares the extracted horizontal synchronization component of the selected television signal with the signals, if any, received from the antenna, and outputs a result signal indicating whether the television is both turned on and tuned so as to receive the selected television signal.