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:
Nov. 14, 2006
Filed:
Mar. 28, 2005
Applicants:
Makoto Akiba, Koganei, JP;
Mikio Fujiwara, Koganei, JP;
Inventors:
Makoto Akiba, Koganei, JP;
Mikio Fujiwara, Koganei, JP;
Assignee:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03F 3/08 (2006.01); H03K 3/42 (2006.01);
U.S. Cl.
CPC ...
Abstract
A low-level light detector includes an avalanche photodiode (APD) to which is applied a bias voltage adjusted to produce a multiplication factor of not more than 30, and a capacitor for accumulating carriers produced by light in the APD and multiplied using the APD characteristics, the capacitor being connected to the avalanche photodiode. The detector detects the intensity of light impinging on the avalanche photodiode by periodically reading the capacitor voltage and obtaining time-based differences in the voltage, or by resetting the capacitor voltage to a predetermined voltage each time the capacitor voltage is read.