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:
Aug. 02, 2011
Filed:
Mar. 17, 2005
Seiichiro Mizuno, Hamamatsu, JP;
Haruhiro Funakoshi, Hamamatsu, JP;
Tetsuya Taka, Hamamatsu, JP;
Hamamatsu Photonics K.K., Hamamatsu-shi, Shizuoka, JP;
Abstract
A photodetector of a wide dynamic range of incident light amount detection and low temperature dependence is provided. A first signal processing unitincludes an integrating circuit, a first holding circuit, a comparing circuit, a second holding circuit, and a latching circuit. The integrating circuithas a variable capacitor unit that is selectively set to a capacitance value among a plurality of capacitance values, accumulates charges, output from the photodiode, into the variable capacitor unit over an accumulating period that is in accordance with the capacitance value set at the variable capacitor unit, and outputs a voltage Vthat is in accordance with the amount of the accumulated charges. The comparing circuitinputs the voltage Voutput from the integrating circuit, performs a quantitative comparison of the voltage Vwith a reference voltage V, outputs a compared signal Sexpressing the result of comparison, and, when the voltage Voutput from the integrating circuitat the end of an accumulating period is less than the reference voltage V, instructs the first holding circuitto hold the voltage.