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. 11, 2006
Filed:
Apr. 23, 2002
Masazumi Marutani, Kawaski, JP;
Takuji Yamamoto, Kawasaki, JP;
Naoki Kuwata, Kawasaki, JP;
Katsuya Yamashita, Hachioji, JP;
Masazumi Marutani, Kawaski, JP;
Takuji Yamamoto, Kawasaki, JP;
Naoki Kuwata, Kawasaki, JP;
Katsuya Yamashita, Hachioji, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
According to a PLL circuit of the present invention, an output of a phase comparator is adjusted according to a space-to-mark transition-probability of an input signal so that an output of a voltage controlled oscillator has a predetermined frequency and phase. Therefore, even when a phase of a timing clock is set other than at, an output of the PLL circuit can be kept at the set phase, irrespective of the space-to-mark transition-probability. By using the PLL circuit as such in an optical communication apparatus and an optical communication system, a discrimination point can be kept almost fixed, and therefore, it is possible to lower an error rate.