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. 19, 1993
Filed:
Dec. 11, 1991
Hideaki Yamakawa, Tokyo, JP;
Hiroyuki Ibe, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A wide-dynamic range light receiver according to the present invention is constructed such that a non-linear impedance element is connected in series to a light-receiving element, and a resistor and a capacitor are connected in series between a connection node of the light-receiving element and the non-linear impedance element and an input terminal of a low-noise amplifier. The impedance of the non-linear impedance element increases as the output of the light-receiving element approaches a minimum reception light level, and the non-linear impedance element is finally set in the non-conductive state. Thus, at the minimum reception light level, the output current of the light-receiving element is supplied, with little loss, to the low-noise amplifier via the pure resistor and the capacitor. In addition, the impedance of the non-linear impedance element decreases exponentially in accordance with the increase in the input of the light-receiving element. Consequently, the output current of the light-receiving element begins to flow into the non-linear impedance element from a certain point, and the current to the low-noise amplifier is limited.