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:
Dec. 28, 1976
Filed:
Mar. 21, 1975
Raymond T Hebert, Saratoga, CA (US);
John P Ekstrand, Palo Alto, CA (US);
Spectra-Physics, Inc., Mountain View, CA (US);
Abstract
Method and apparatus for processing input binary encoded analog signals to precisely determine the time occurrence of positive-going and negative-going transitions. Such digital signals result, for example, when bar codes (e.g. Universal Product Codes) are optically scanned. Transitions are determined by detecting the zero crossings, at selected gating times, of the second derivative of the input signals. The selected gating times occur whenever the first derivatives of the input signals exceed a threshold level. The threshold level is determined in one embodiment by peak-to-peak detecting the input signals and adding this value to a rectified noise measurement signal.