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:
Jan. 13, 1998
Filed:
May. 13, 1996
Alan John Lowne, Victor, NY (US);
Johnson & Johnson Clinical Diagnostics, Inc., Rochester, NY (US);
Abstract
A reflective wetting or spot detecting system incorporates a light emitting diode and a solid state photo sensor arranged on the same side of a medium being analyzed. The sensor is carried at one end of an elongated housing with a linear channel extending through. The channel is oriented on a line that is normal to the medium being analyzed. The channel functions as a lensless, passive focuser of reflected radiant energy. The source of radiant energy is located at an acute angle with respect to the medium. A conditioning circuit is coupled to the output of the sensor. The conditioning circuitry includes a current-to-voltage converter, a signal reducing stage, an amplifying stage and a comparator. The signal reducing stage reduces the voltage signal, produced by the current voltage converter, a predetermined amount, thereby effectively providing the amplifier stage with a greater dynamic range than it would have otherwise had. The output from the amplifier stage charges a capacitor with first and second different time constants depending on whether a medium to be analyzed is present or not. Output from the comparator circuitry drives output amplifiers to provide a digital signal indicative of a wetting or spotting event.