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. 01, 1983
Filed:
Oct. 02, 1980
Jack Beery, Fairport, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
The present invention is a programmed brake for controlling the deceleration of a scanning carriage. An encoder including an electro-optic sensor mounted on a moving carriage together with a stationary grating having a plurality of unevenly spaced apertures, provides velocity data of the rate of the relative movement of the sensor and grating during flyback or scan return. In particular, the sensor detects a plurality of light pulses through each of the apertures as the sensor moves relative to the grating. The light signals are conveyed to a counter and the count is compared to a reference number representing a deceleration profile or standard number of signals desired for each aperture. If the number of light signals is less than the standard, occurring if the carriage is overspeed, a transistor driver is pulsed to activate an electromagnetic brake connected to the scanning carriage. When the scanning carriage velocity has slowed sufficiently, the brake is inactivated.