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.

Date of Patent:
Sep. 02, 1980

Filed:

Oct. 25, 1978
Applicant:
Inventors:

Richard A Shroyer, Rochester, NY (US);

William A Martin, Fairport, NY (US);

Assignee:

Eastman Kodak Company, Rochester, NY (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J / ; G01J / ; G03B / ;
U.S. Cl.
CPC ...
356218 ; 356226 ; 354 / ; 250226 ;
Abstract

A method and apparatus for discriminating among various types of illuminants, such as fluorescent light, incandescent light and natural daylight. Such apparatus includes a photoelectric circuit for producing a signal having an amplitude which varies with intensity variations of the illuminant, a bandpass filter circuit having a bandpass centered at the fundamental frequency of the intensity variations of an illuminant energized by an alternating current source, a high-pass filter circuit that passes frequencies higher than such fundamental frequency, a pair of peak detectors for detecting the peak value of signals passed by the first and second filter circuits, and logic circuitry responsive to the outputs of the peak detectors for providing logic outputs indicative of the type of illuminant.


Find Patent Forward Citations

Loading…