Patent ID: 7733489

Claim:
A method of two-band mixing or three-band mixing on a visual device comprising: a. integrating one-band bandpass filter(s) of central wavelength 1 and one-band bandpass filter(s) of central wavelength 2 , or integrating one two-band bandpass filter of central wavelengths 1 and 2 in visual optical instruments for two-color mixing application, or b. integrating one-band bandpass filter(s) of central wavelength 1 , one-band bandpass filter(s) of central wavelength 2 , one-band bandpass filter(s) of central wavelength 3 , or integrating one three-band bandpass filter of central wavelengths 1 , 2 , and 3 in optical instruments for three-color mixing application, c. illuminating the surface of objects with sufficient illumination, d. determining the feasible wavelength set for two- or three-band mixing application in terms of color difference, or chromaticness difference, or uniform background criterion, e. identifying the targets or classifying the objects by operators or inspectors using two- or three-band mixing visual device.