Color detection apparatus for multiple color printing

Claim 1

A DENSITY MONITOR FOR COLORED INKS APPLIED TO A WEB, SAID MONITOR PROVIDING BIDIRECTIONAL SCALAR INDICATIONS OF VARIATION FROM NORMALLY DESIRED DENSITY OF EACH OF A PLURALITY OF INKS AS THEY ARE BEING APPLIED TO THE WEB, SAID MONITOR HAVING MEANS RESPONSIVE TO THE AMOUNT OF LIGHT ABSORPTION OF EACH OF SAID INKS, COMPRISING: MEANS FOR DEFINING A DISCRETELY ILLUMINATED PORTION OF SAID INK APPLIED WEB AND FOR RECEIVING THEREFROM DISCRETE SPECTRUM COMPONENTS OF THE LIGHT REFLECTED FROM SAID WEB IN PROPORTION TO THE DENSITY OF THE APPLIED INKS; SAID RECEIVING MEANS HAVING MEANS FOR SEPARATELY RESPONDING TO REPRESENTATIVE WAVELENGTHS OF EACH OF SAID SPECTRUM COMPONENTS AND FOR TRANSDUCING INTO ELECTRICAL SIGNALS THE QUANTUM OF EACH SPECTRUM COMPONENT IN A MANNER WHICH IS PRIMARILY INDICATIVE OF THE DENSITY OF ITS ASSOCIATED APPLIED INK; PRIMARILY SUBSTRACTIVE SUPPRESSION MATRIX MEANS COUPLED TO SAID RESPONDING MEANS FOR RECEIVING ALL OF SAID ELECTRICAL SIGNALS, OPERATING UPON THEM IN A PRIMARILY SUBTRACTIVE CORRECTIVE MODE, AND REMOVING FROM EACH SAID SIGNAL THE INFLUENCE OF THE INKS ASSOCIATED WITH THE OTHER OF SAID SIGNALS; SAID MATRIX MEANS HAVING A PLURALITY OF DISCRETE OUTPUTS EACH OF WHICH RECEIVES FROM SAID MATRIX MEANS ENERGIZATIONS SEPARATELY MANIFESTING THE DENSITY OF EACH OF SAID INKS; AND A PLURALITY OF BIDIRECTIONAL SCALER GENERATING AND INDICATING MEANS EACH RESPECTIVELY COUPLED TO ONE OF SAID PLURALITY OF MATRIX OUTPUTS; EACH SAID BIDIRECTIONAL SCALAR MEANS HAVING MEANS FOR GENERATING A SIGNAL CHARACTERISTIC OF THE DESIRED DENSITY OF ITS ASSOCIATED INK AND COACTING THIS CHARACTERTERISTIC SIGNAL WITH SAID MATRIX OUTPUT ENERGIZATIONS TO PROVIDE DYNAMIC BIDIRECTIONAL INDICATIONS OF THE DENSITY OF THE THEN BEING APPLIED INK AS COMPARED WITH ITS DESIRED DENSITY.