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:
Apr. 29, 2003
Filed:
Jun. 29, 2001
Shin Nagata, Tokyo, JP;
Sanyo Denki Co., Ltd., Tokyo, JP;
Abstract
A variation in optical output of a semiconductor luminous device outputting an optical signal to an optical fiber which is caused due to a variation in ambient temperature and an end of a life thereof capable of being compensated for without measuring the optical output. An output variation quantity H (Ta) of the semiconductor luminous device due to the ambient temperature Ta is operated in a step S In a step S an output reduction quantity ST of the semiconductor luminous device obtaining by accumulating an output reduction ST thereof per unit time due to a deterioration of the device is provided. In a step S it is judged that a life of the device reaches an end when the output reduction ST exceeds a reference value ST When the former fails to exceed the latter, a variation quantity IH(Ta) of a drive current command value due to the ambient temperature Ta and a current reduction quantity IST(ST, dST) determined due to a deterioration of the device are operated in a step S A drive current Id for driving the semiconductor luminous device is determined on the basis of a sum Is of the current command value Ic, the current variation quantity and the current reduction quantity. An output of the device is compensated for by repeating steps S to S