Patent ID: 6992709

Claim:
An apparatus for determining a type of an illuminant comprising: a spectrum diffraction unit; a sensor coupled to said spectrum diffraction unit; and, an illuminant discrimination unit coupled to said sensor to receive a set of analog signals representative of a set of spectral components, respectively, in said illuminant and to determine said type, wherein said illuminant discrimination unit includes a set of analog signal scaling and negating units to receive the set of signals, respectively, from said sensor, wherein each analog signal scaling and negating unit is coupled to receive a control signal and selectively applies scaling and/or negating upon its respective analog signal based on the control signal, the analog signal scaling and negating units coupled to a comparison bus, an analog comparison unit coupled to said comparison bus to generate a set of binary comparison results, and a set of illuminant condition log units coupled to said comparison unit to store the set of comparison results and to evaluate a final decision as to illuminant type based on whether predefined illuminant discrimination conditions are met.