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:
Sep. 16, 1986
Mitsumo Kawano, Honjo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An automatic phase control (APC) circuit with improved reliability of phase control, in which a phase of a reference signal from a crystal oscillator is alternately switched between two phases by a switch. The APC circuit includes a phase locked loop (PLL) for stabilizing a phase of a signal, e.g., a playback color signal of a VTR, with the phase of the reference signal, which is changed alternnately in phase between the two phases. An irregular detection (ID) circuit monitors the irregularity of the PLL. When a first monitored output of the ID circuit appears successively over two horizontal cycles, a burst ID processing for the PLL is actuated. When a second monitored output of the ID circuit follows after the first monitored output, the alternation timing of the reference signal is forcibly shifted by the switch.