Patent ID: 9541496
Date: 2017-01-10
CPC Classifications: G01J,G01N,G08B

Claim:
1. A freshness estimation method comprising: emitting, with at least one light source, light having all or part of a wavelength band from 315 nm to 450 nm, and irradiating an eye of a fish with the light; detecting, with a light sensor, an intensity of light reflected from the eye of the fish; calculating, with a processor, an absorbance spectrum based on the intensity of light detected by the light sensor; calculating, with the processor, an absorbance difference by subtracting an absorbance in a certain wavelength in a wavelength band from 315 nm to 380 nm from a peak value of absorbance in a wavelength band from 410 nm to 430 nm; determining, with the processor, whether the calculated absorbance difference is smaller than a predetermined threshold; and outputting an indication, via at least one of a visual output device or sound output device, when the calculated absorbance difference is smaller than the predetermined threshold, thereby indicating that the fish is fresh.