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:
May. 17, 1983
Filed:
Jun. 01, 1981
Masutomi Ohta, Yokohama, JP;
Minoru Sakai, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method of and an apparatus for securely and precisely extracting from a received television signal a start pulse signal which is a binary signal provided at the beginning of an information signal multiplexed in the vertical blanking period of the television signal is disclosed. A PLL circuit acting as a frequency multiplier is provided to obtain a multiplied-frequency signal synchronized with a horizontal synchronizing signal (separated from the television signal by a synchronizing separator circuit) and having a frequency N times equal to or higher than a horizontal synchronizing frequency, first and second extracting gate pulses are formed from the multiplied-frequency signal, the start pulse signal is extracted from the received television signal by the first extracting gate pulse, the extracted start pulse signal is made to pass through a filter resonating with the start pulse signal to remove a noise component, a waveform at a central portion of the filtered start pulse signal is extracted by the second extracting gate pulse, and the extracted waveform is produced as a start pulse for bit synchronization of the information signal.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile