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:
Apr. 12, 2011
Filed:
Jun. 16, 2008
John J. Cooley, Cambridge, MA (US);
Steven B. Leeb, Belmont, MA (US);
Al-thaddeus Avestruz, Waltham, MA (US);
Leslie K. Norford, Lexington, MA (US);
John J. Cooley, Cambridge, MA (US);
Steven B. Leeb, Belmont, MA (US);
Al-Thaddeus Avestruz, Waltham, MA (US);
Leslie K. Norford, Lexington, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A fluorescent lamp sensor system is provided. The fluorescent lamp sensor system includes a plurality of bulbs and a plurality of electrodes coupled to the bulbs. A balanced differential circuit measures changes in electric fields produced by the bulbs in front of the electrodes. The balanced differential circuit includes a symmetric current source associated with alternating the surface potential of the bulbs. A current mode detection circuit detects the current associated with the capacitive effects of the balanced differential circuit. A synchronous detection circuit isolates the capacitive effects of the symmetrical current source from stray signals that differ in either frequency or phase.