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:
Jun. 30, 1992
Filed:
Jul. 02, 1991
Gopal K Srivastava, Arlington Heights, IL (US);
Zenith Electronics Corporation, Glenview, IL (US);
Abstract
An adaptive oscillator control system includes a phase locked loop together with a static phase error correction system and external scan system components. An oscillator range control includes a processor having a plurality of established oscillator frequency ranges which are identified by oscillator range code numbers. A first frequency approximation is provided based upon either an oscillator range code number or a known standard scan frequency. A frequency detector provides a second frequency approximation and a confidence circuit examines oscillator consistency and enables the phase locked loop. Thereafter, a lock detector responds to the occurence of frequency and phase lock by the phase lock loop to enable the static phase error corrector and deactivate the oscillator range control system. The lock detector upon detecting horizontal synchronization, for broadcast type video, increases the second frequency approximation range. The system changes oscillator frequency and tuning and adjusts external sweep components such as phase locked loop filter, horizontal yoke tuning, and drive signal applied to the horizontal output amplifier after lock.