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:
Oct. 13, 2015
Filed:
Jan. 25, 2012
Hiroshi Koizumi, Kanagawa, JP;
Masafumi Nogawa, Kanagawa, JP;
Yusuke Ohtomo, Kanagawa, JP;
NIPPON TELEPHONE AND TELEGRAPH CORPORATION, Tokyo, JP;
Abstract
An optical signal detection circuit () includes an amplification circuit () that differentially amplifies an electrical signal (Tout) corresponding to the pulse train of an optical signal (Pin) and outputs a differential output signal (Aout), and a comparator () that compares the voltage value of the positive-phase signal of the differential output signal (Aout) with the voltage value of the negative-phase signal and outputs a pulsed comparison output signal (Cout) corresponding to the comparison result. The amplification circuit () includes a current addition circuit (E) that adjusts a DC load current to generate a positive-phase signal (Aout+) and a negative-phase signal (Aout−) of the differential output signal (Aout) in accordance with an adjusted voltage value from an external adjusted voltage source (Vadj) and adjusts the DC bias of the positive-phase signal (Aout+) and the DC bias of the negative-phase signal (Aout−).