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. 08, 1994
Filed:
Sep. 14, 1992
Shigeo Ogino, Toyokawa, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
Disclosed is a driving apparatus of a laser diode, comprising a light detection circuit serial-connected with a pin diode detecting the intensity of the emission of light from the laser diode, the light detection circuit producing a signal depending on the intensity of the emission detected by the pin diode, a modulation circuit serial-connected with the laser diode, the output current of the modulation circuit varying depending on the difference between an input signal and the signal outputted from the light detection circuit, and a constant voltage drop device disposed in the series circuit including the laser diode and the modulation circuit, the constant voltage drop device causing a voltage drop of a certain degree regardless of the strength of a current flowing thereto. A Zener diode having Zener voltage equivalent to the dropped constant voltage or having at least one diode which generates forward voltage drop equivalent to the dropped constant voltage or the like is used as the above constant voltage drop device, the device being disposed, for example, between the laser diode and the modulation circuit.