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:
Mar. 23, 2004
Filed:
Apr. 14, 2000
Jun Ichihara, Kyoto, JP;
Hisayoshi Kitajima, Kyoto, JP;
Tetsuhiro Tanabe, Kyoto, JP;
Ken Nakahara, Kyoto, JP;
Haruo Tanaka, Kyoto, JP;
Rohm Co. Ltd., Kyoto, JP;
Abstract
A light source device for a laser beam printer in which a semiconductor laser is driven with a pulse current having a minimum pulse width at the ON time on the order of milliseconds or less is provided, wherein the semiconductor laser is formed so that either the rate of change at the rise portion of the pulse current becomes ±8% or less or the semiconductor laser is excited in a multiple mode in the vicinity of the threshold value of the oscillation, and the semiconductor laser oscillates in a single mode at a current separated from the threshold value, by adjusting of at least one of the width w of a stripe groove ( ) of the current block layer, the composition of clad layers ( ), the distance d between the current block layer ( ) and the active layer ( ), the composition of the current block layer ( ) and the formation of a light absorption layer into the current block layer ( ). As a consequence, in the case where the light source device for the laser beam printer is driven with a short drive pulse on the order of several hundred micro seconds, the light source device becomes such that a transient phenomenon is not generated at the time of the rise of the pulse and a stable light output can be obtained.