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:
Mar. 14, 2000
Filed:
May. 08, 1998
Craig Thomas Johnson, San Diego, CA (US);
Joseph Scott McCoy, San Marcos, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A scanner includes a photodetector, and encoder and an exposure control. For each line of pixels detected by the photodetector, the exposure control starts the exposure time and then stops the exposure time after a specified amount of relative motion has been detected. Thus, variations in the amount of relative motion cause inversely proportional variations in the exposure time to ensure that exposure time for each line of pixels corresponds to the same displacement. The exposure control can compensate for unavoidable position and velocity errors encountered in a dc motor drive and thereby allows a dc motor drive to be used in low cost commercial scanning products.