Patent ID: 8169607

Claim:
An optical characteristic measurement device, comprising: a housing; a spectrometer arranged in said housing; a cut-off portion for cutting off light entering said spectrometer from outside of said housing; a photodetector arranged in said housing, for receiving light split by said spectrometer; and a processing unit for outputting a result of detection by said photodetector, said photodetector having a detection surface greater than a light incident surface receiving light from said spectrometer, and said processing unit being operative to obtain a first spectrum detected in a first detection area corresponding to said light incident surface receiving light from said spectrometer and a first signal intensity detected in a second detection area different from said light incident surface receiving light from said spectrometer while said light entering said housing is cut off, calculate a first correction spectrum by subtracting a first correction value calculated based on said first signal intensity from each component value of said first spectrum, obtain a second spectrum detected in said first detection area and a second signal intensity detected in said second detection area while said cut-off portion is opened, calculate a second correction spectrum by subtracting a second correction value calculated based on said second signal intensity from each component value of said second spectrum, and calculate an output spectrum representing a measurement result by subtracting each component value of said first correction spectrum from a corresponding component value of said second correction spectrum.