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:
Jul. 18, 2000
Filed:
Dec. 31, 1998
Rein S Teder, Bloomington, MN (US);
Libbey-Owens-Ford Co., Toledo, OH (US);
Abstract
A moisture sensor for detecting moisture on the surface of a transparent material. The moisture sensor includes one or more emitters for producing emitter signals which are influenced by moisture on the transparent material, and one or more detectors for receiving the emitter signals. The detector produces a detector output signal which is filtered and amplified in a pre-demodulation gain and filtering circuit to remove some of the unwanted signal components including noise from ambient light and EMI. Digital Signal Processing filtering is used after the moisture signal is demodulated to a dc signal to discern small signal changes due to moisture events in the presence of large amounts of the noise created by the pre-demodulation gain circuit. The DSP filtering includes a low pass filter stage and a band pass filter stage implemented by a microcomputer using First In First Out shift registers, summing elements and division elements.