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:
Jun. 14, 1988
Filed:
Jun. 30, 1986
Ronald W Froelich, Covina, CA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A circuit for correcting the write power of a laser raster output scanner as it scans across the write drum. During calibration, a piece of glass reflects part of the beam into a photo multiplier tube, the output of which is converted into a digital signal. This is compared to a reference signal. The difference for each segment of the scan is stored in RAM and also is converted back to an analog signal to modulate an acousto-optic modulator in the laser optics to correct the write power. After the system has settled to a point where the write power at the drum does not vary across the scan, the glass may be removed and the system operates using the corrections stored in RAM.