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:
Aug. 22, 1989
Filed:
Apr. 19, 1988
Mark L Larson, Grand Haven, MI (US);
Karl H Hanft, Holland, MI (US);
Desmond J O'Farrell, Holland, MI (US);
Donnelly Corporation, Holland, MI (US);
Abstract
The specification discloses a modulated optical moisture sensor control circuit for a vehicle windshield wiper. The control system includes a first detector providing a signal indicative of moisture on the windshield and a second detector providing a reference signal indicative of system variables, such as ambient light. The control system includes improved circuitry for separating the steady-state portion of each detector signal due to ambient light from the modulated infrared IR signal. The system further includes a sensitivity adjustment accessible by the vehicle operator to alter the sensitivity of the circuit to at least one of the two variable detector signals. Additionally, the control system cooperates with a conventional off/intermittent/on wiper switch so that the wiper is responsive to the moisture sensor only when the conventional switch is in the intermittent position and a second manually actuated switch indicates preferred operation in the moisture sensor mode.