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:
May. 28, 2002
Filed:
Dec. 16, 1998
Nippon Sheet Glass Co., Ltd., Osaka, JP;
Abstract
A rain sensor including light emitting means for guiding light into a window glass so as to undergo total internal reflection within the window glass, light receiving means for receiving the light which has undergone total internal reflection within the window glass, and means for detecting the amount of water drops adhered to or present upon the window glass so as to output a driving signal to a wiper driver apparatus a difference signal corresponding to a difference between a preset reference value and an output signal of an amplifier circuit of the light receiving means is fed back to the amplifier and an amplification factor of the amplifier circuit is adjusted so as to maintain the output signal thereof at a constant value irrespective of the operation condition of the wiper, when electrical power is applied to the rain sensor Furthermore, in a protecting method for the rain sensor a driving current fed to light emitting element is measured and converted into an ambient temperature, and a driving current supplied to the light emitting element by the driver circuit is stopped when the converted value is outside a preset temperature range, by turning a switch circuit to OFF.