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. 21, 1989
Filed:
Sep. 19, 1986
Thomas Zalenski, Killingworth, CT (US);
Summagraphics Corporation, Fairfield, CT (US);
Abstract
A method and apparatus for calibrating an electro-optical mouse during the detection of light reflected from a surface with optically contrasting indicia. The voltage output from the light detector is compared with stepped ramped sequences of reference voltage signals representing a count, the ramped sequence being stopped in response to each transition of the comparator between a first state where the amplitude of one of the input signals is less than that of the other and a second state where the amplitude of the one of the input signals is equal to or greater than the other. A processor determines the highest and lowest numbers at which any of the ramped sequences are stopped; and calculates at least one threshold value in dependence on the difference between the highest and lowest numbers.