Patent ID: 7459697

Claim:
A system for detecting intensity of fluorescence generated from a substance that is excited by light, comprising: a single light source emitting light having one wavelength; a fluorometer, comprising: n (n is an integer of not less than 2) narrow-band-pass filters for transmitting light in different limited wavelength regions of the fluorescence, and n light-receiving portions having one-to-one correspondence with the n narrow-band-pass filters, wherein the n narrow-band-pass filters are arranged to each have a different incident angle of light, wherein the n narrow-band-pass filters share a similar transmittance configuration; wherein an intensity P 1 of fluorescence transmitted though a first narrow-band-pass filter is detected by a first light-receiving portion, and wherein fluorescence reflected from an (n−1)-th narrow-band-pass filter is allowed to enter an n-th narrow-band-pass filter, and an intensity Pn of fluorescence transmitted through the n-th narrow-band-pass filter is detected by an n-th light-receiving portion, and wherein a relative ratio or a difference between the intensities P 1 , P 2 . . . , Pn of the fluorescence detected respectively by the n light-receiving portions is determined to detect a wavelength width of a spectrum of the fluorescence.