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. 01, 2010
Filed:
Jun. 16, 2006
Hiroaki Kyogoku, Hyogo-ken, JP;
Hiroaki Kyogoku, Hyogo-ken, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A laser driving circuit configured to drive a semiconductor laser diode, which is less susceptible to noise interference and capable of achieving the control of laser light intensity with high accuracy. Respective circuit components in the laser driving circuit such as an amplifier circuit, a sample hold circuit, a voltage-to-current converter, and a switching circuit are all integrated into an integrated circuit. A capacitor included in the sample hold circuit is further provided as built-in in the integrated circuit, which is previously attached externally. In addition, by changing the resistance of a resistor which is externally connected between the bias current setting terminal of the amplifier circuit and the ground potential by way of a terminal of the integrated circuit, the current outputting capability of the amplifier circuit can be variably adjusted through the adjustment of the charging time of the capacitor. As a result, the response speed of a feedback control loop for controlling the light intensity of laser diode can be increased with less noise interference and high accuracy.