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:
Aug. 02, 1994
Filed:
Mar. 17, 1993
Karen L Herczeg, Rochester, NY (US);
David M Mcvay, Rochester, NY (US);
Daniel J Phelps, Rochester, NY (US);
Kimberley C Bell, Webster, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
Providing thermal compensation for laser diodes used in intensity modulated applications by using active feedback. A PIN diode serves as a laser light output sensor for the closed loop feedback system. The input from the PIN diode is convened into a voltage and then fed into a feedback amplifier. The PIN diode current is slightly dependent upon the temperature due to transmission effects of materials within the laser diode assembly. A temperature voltage signal generated by a semiconductor temperature sensor may be used as a second input to the feedback amplifier. The output of this amplifier is sampled at periodic intervals such as once a scan line, by a sample and hold amplifier. The output of the sample and hold amplifier is added to a data dependent modulated current reference in a summing amplifier. The output of the summing amplifier is the resultant sensor and provides an input reference to the laser driver integrated circuit.