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:
Sep. 17, 1991
Filed:
Aug. 30, 1989
Shigeru Miyata, Nagoya, JP;
Yoshitaka Yamada, Nagoya, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
A liquid mixing ratio detecting sensor has cylindrical holder which is immersed in sulfuric acid solution. The holder is filled with silicone oil. A glass plate is placed within the holder. A light emitting diode emits light beams which enter the glass plate through its vertical side, and totally reflect from a boundary between the glass plate and the sulfuric acid solution. The light beams coming out from the glass plate is reflected by a reflection plate to enter into the glass plate through its vertical side, and totally reflected from a reference boundary between the glass plate and the silicone oil when a refractive index of the sulfuric acid solution is greater than that of silicone oil. On the other hand, the light beams entered into the glass plate refracts at the reference boundary to fall on a photo diode when the refractive index of the sulfuric acid solution decreases to be smaller than that of silicone oil.