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. 02, 1998
Filed:
May. 22, 1996
Hiroshi Oono, Tokyo, JP;
Masaaki Yokomizo, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A laser-diode driving circuit that ensures that the optical output of a laser diode will be stable within a wide temperature range. This circuit includes a reference voltage generator for generating a reference voltage, a control voltage generator for generating a control voltage, an amplifier for producing an amplified output signal corresponding to the difference between the reference voltage and the control voltage, and a driving current generator for generating a driving or operating current for driving a laser diode. The driving current generator is driven by the amplified output signal. The control voltage has a temperature dependence approximately the same as that required for keeping an optical output of the laser diode at a specified level independent of the ambient temperature change. Preferably, the control voltage generator contains a p-n junction diode for producing a temperature-dependent voltage, and a thermistor for compensating the temperature-dependent voltage to thereby produce said control voltage having an exponential characteristic with respect to the ambient temperature.