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:
Feb. 26, 1991
Filed:
Oct. 02, 1989
Neelam Gupta, Silver Spring, MD (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
An apparatus for detecting target objects which exhibit ratios of reflectance values that are substantially the same at two separated wavelengths when compared with background objects having reflectance values that are substantially different at the same two wavelengths has a two channel active optical sensor and logic circuitry. A first signal is transmitted at a wavelength lambda-1 which is different from a second signal which is transmitted at a wavelength lambda-2. The two signals are directed towards an object which reflects the signals therefrom. The reflected signals are received and a ratio is calculated. The ratio is compared with a predetermined threshold value to indicate when a target object has been identified.