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:
Jan. 10, 2012
Filed:
Feb. 20, 2009
Hirotaka Nakamura, Makuhari, JP;
Shunji Kimura, Makuhari, JP;
Kazutaka Hara, Makuhari, JP;
Koji Kitahara, Yokohama, JP;
Hirotaka Nakamura, Makuhari, JP;
Shunji Kimura, Makuhari, JP;
Kazutaka Hara, Makuhari, JP;
Koji Kitahara, Yokohama, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
NTT Electronics Corporation, Kanagawa, JP;
Abstract
A modulation method according to the invention is applied to a modulation device in which a light source is driven by a differential signal while a modulation circuit and the light source are capacitively coupled. In the modulation method of the invention, when an average potential fluctuates at an input terminal of the light source, a potential fluctuation is externally provided using a control circuit such that a normal phase side and a reverse phase side become equal to each other in a time constant of the fluctuation in average potential, and transient states of the average potentials at the normal phase side and reverse phase side are equalized and cancel each other as in-phase components of a signal input to the light source, which allows an optical signal to be normally transmitted from the light source. The optical signal can normally be transmitted from the light source even before the average potentials at a normal phase input terminal and a reverse phase input terminal of the light source are stabilized.