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:
Apr. 02, 1985
Filed:
Jul. 15, 1982
Charles B Ackerman, Paradise Valley, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A sensing system and method for detecting changes in the level of a liquid surface utilizing a source of essentially monochromatic illumination of narrow beam width for directing an incident beam toward a liquid surface at an oblique angle thereto, and thereby providing a reflected beam therefrom. A beam expander is interposed between the illumination source and the liquid source for increasing the narrow beam width of the incident beam to a beam width substantially greater than the wavelength of disturbances in the liquid surface. A converging lens is mounted transverse to and intercepts a portion of the reflected beam from the liquid surface for focusing that portion of the reflected beam to a centrum. A beam detector is positioned adjacent to the centrum for providing an indication of changes in the level of the liquid surface by detecting corresponding changes in a relative position of the centrum. An optical filter can be used to intercept the reflected beam to allow only the frequency of the monochromatic illumination source to pass therethrough in a Czochralski furnace.