Colorimeter employing tristimulus values

Claim 1

A COLORIMETER FOR DETERMINING THE COLOR OF A SAMPLE COMPRISING IN COMBINATION: OPTICAL MEANS TO TRANSMIT LIGHT FROM SAID SAMPLE; CHOPPING MEANS TO CHOP SEPARATE PORTIONS OF SAID LIGHT, EACH PORTION BEING CHOPPED AT A SEPARATE FREQUENCY; MEANS IN OPTICAL ALIGNMENT WITH SAID CHOPPING MEANS TO FORM AN INDIVIDUAL SPECTRUM FROM EACH OF SAID SEPARATE PORTIONS OF THE CHOPPED LIGHT; MASKING MEANS IN OPTICAL ALIGNMENT WITH SAID SPECTRUM FORMING MEANS FOR TRANSMITTING ONLY SELECTED DIFFERENT PORTIONS OF SAID INDIVIDUAL SPECTRA; DETECTING MEANS IN OPTICAL ALIGNMENT WITH SAID MASKING MEANS FOR CONVERTING SAID TRANSMITTED PORTIONS OF SAID INDIVIDUAL SPECTRA TO ELECTRICAL SIGNALS, WHICH SIGNALS ALTERNATE AT THE FREQUENCIES OF SAID CHOPPING MEANS; ELECTRICAL FILTERING MEANS ELECTRICALLY CONNECTED TO SAID DETECTING MEANS FOR ISOLATING FROM EACH OTHER SAID ELECTRICAL SIGNALS ALTERNATING AT THE FREQUENCIES OF SAID CHOPPING MEANS; AND COMPUTING MEANS ELECTRICALLY CONNECTED TO SAID ELECTRICAL FILTERING MEANS FOR CONVERTING SAID SIGNALS INTO ELECTRICAL OUTPUTS VARYING IN MAGNITUDE AS A FUNCTION OF THE COLOR OF SAID SAMPLE.