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. 15, 1997
Filed:
Nov. 20, 1995
Applicant:
Inventor:
Reece Robert Clark, Redwood City, CA (US);
Assignee:
Midland Manufacturing Corp., Skokie, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01C / ; G01F / ;
U.S. Cl.
CPC ...
356-509 ; 250577 ; 73293 ;
Abstract
The liquid level sensor includes a modulated laser diode and collimating optics for collimating the diode output to produce an optical measurement signal beam transmitted to the fluid boundary through a diffuser to diverge the beam. A detector detects reflections of the beam from the fluid boundary to produce an output signal which is amplified and inverted to drive the modulator. The frequency of the modulation, which depends on the distance to the fluid boundary, is measured and the distance is derived from that measurement.