Patent ID: 6844563

Claim:
A fluorescence detecting device comprising: a semiconductor integrated circuit substrate including a first photodiode, a second photodiode, and a signal detecting circuit for detecting electric signals from the photodiodes; a fluorescence reaction vessel where a fluorescence reaction occurs; and a first optical filter and a second optical filter that have different light transmission spectral characteristics from each other, wherein the first optical filter is arranged above the first photodiode, the second optical filter is arranged above the second photodiode, and the fluorescence reaction vessel is formed above these optical filters, both of a fluorescence signal and an excitation light signal are detected by each of the first photodiode and the second photodiode, and a ratio between the fluorescence signal and the excitation light signal detected by the first photodiode and a ratio between the fluorescence signal and the excitation light signal detected by the second photodiode are different from each other according to the difference between the light transmission spectral characteristics of the optical filters, and the signal detecting circuit outputs a fluorescence signal from which influences of an excitation light are eliminated, the fluorescence signal being derived based on a difference between the ratio between the fluorescence signal and the excitation light signal detected by the first photodiode and the ratio between the fluorescence signal and the excitation light signal detected by the second photodiode.