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:
Sep. 23, 1986
Filed:
Jun. 25, 1985
Robert P Collette, Pavilion, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
A pair of crystal-controlled oscillators generate respective signals at specific frequencies that are useful in processing a video signal, such as in providing clock-driven signal delay or producing a subcarrier signal. The frequencies are used in such a way that they feed through into the frequency spectrum of the processed video signal. Though the frequencies are nominal multiples of each other they cannot be maintained invariant because of normal circuit conditions, such as ambient temperature variations and circuit aging. The frequencies therefore mix and a difference frequency develops in the processed video signal. By injecting a suitable harmonic of the lower frequency signal into the crystal oscillator generating the higher frequency signal, the higher frequency will lock to variations in the lower frequency. The difference frequency consequently disappears.