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:
Oct. 20, 2009
Filed:
Dec. 29, 2006
Dengpeng Chen, Singapore, SG;
Chi Boon Ong, Singapore, SG;
Chee Heng Wong, Singapore, SG;
Avago Technologies ECBU IP (Singapore) Pte. Ltd., Singapore, SG;
Abstract
A sensor for measuring the properties of light from a light source is disclosed. The sensor includes first and second photodetectors that are illuminated by the light. The first and second photodetectors generate first and second photodetector signals indicative of the first and second weighted averages of the intensity of light in a wavelength band between 400 nm and 700 nm. The first photodiode is more sensitive to light having wavelengths between 400 nm and 500 nm than the second photodetector. The sensor also includes a color temperature processing circuit that generates a first processed signal that is related to a ratio of the first and second signals. The color temperature processing circuit could include first and second logarithmic amplifiers that generate first and second logarithmic signals, respectively, from the first and second photodetector signals and a subtraction circuit that forms a signal indicative of the difference between the first and second logarithmic signals.