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:
Aug. 04, 1987
Filed:
Nov. 27, 1984
Kurt J Johannes, Hamburg, DE;
U.S. Philips Corporation, New York, NY (US);
Abstract
A circuit for detecting the vertical blanking period in a picture signal, having a pulse interval detector and a subsequent pulse shaping stage. A composite synchronizing signal, which contains pulses in a predetermined sequence, is applied to the pulse interval detector. The pulse interval detector supplies an output signal change when the interval between the pulses falls short of a predetermined time threshold. The output signal is applied to the pulse shaping stage which, in response thereto, produces a vertical synchronizing signal. With such a circuit arrangement, a vertical synchronizing signal is obtained substantially without delay with respect to the composite synchronizing signal, while at the same time, the circuit design effort and cost are reduced, because of the fact that the pulse interval detector constitutes the time threshold with a predetermined multiple of a period of a periodical clock signal and that the pulse shaping stage forms the vertical synchronizing signal at the occurrence of given pulses in the sequence of pulses of the composite synchronizing signal after the occurrence of the change in the output signal.