Chopper with alternating reflective and absorptive segments for radiant energy measuring system and method of optimizing same

Claim 1

IN A RADIANT ENERGY MEASURING SYSTEM FOR DETERMINING A CHARACTERISTIC OF A BODY IN WHICH AN OPTICAL SYSTEM COLLECTS A SOLID ANGLE OF RADIATION EMANATING FROM SAID BODY INTO AN OPTICAL PATH AND DIRECTS SAID PATH UPON A DETECTOR MEANS RESPONSIVE TO SAID RADIATION AND IN WHICH SAID RADIATION IS MODULATED PRIOR TO RECEPTION BY SAID DETECTOR MEANS, A MODULATION MEANS COMPRISING: A ROTATING TOOTHED GEAR CHOOPER WHEEL HAVING ALTERNATING CIRCUMFERENTIAL TEETH AND SPACES, THE ROTATING AXIS OF SAID WHEEL BEING SUBSTANTIALLY PARALLEL TO SAID OPTICAL PATH AND BEING SPACED THEREFROM SO THAT THE OPTICAL PATH IS ALTERNATELY OBTURATED BY SAID TEETH, THE SURFACE OF SAID CHOPPER WHEEL FACING SAID DETECTOR HAVING REFLECTIVE AND ABSORPTIVE PORTIONS ARRANGED IN AN ALTERNATING PATTERN CORRESPONDING TO THAT OF SAID TEETH AND SPACES.

Claim 3

A METHOD FOR COMPENSATING FOR THE RESIDUAL SIGNAL GENERATED FROM INTERNAL SOURCES OF RADIANT ENERGY OF A RADIANT ENERGY MEASURING SYSTEM CONTAINED WITHIN AN ENCLOSURE HAVING AN OPTICAL SYSTEM FOR COLLECTING A SOLID ANGLE OF RADIATION EMANATING FROM AN EXTERNAL SOURCE OF RADIANT ENERGY INTO AN OPTICAL PATH AND FOR FILTERING SAID RADIATION AND FOR DIRECTING SAID RADIATION UPON A DETECTOR MEANS AND IN WHICH A ROTATING TOOTHED GEAR CHOPPER WHEEL HAVING ITS CIRCUMFERENTIAL TEETH AND SPACES ALTERNATELY BLOCK AND PASS THE OPTICAL PATH TO MODULATE SAID RADIATION, THE METHOD COMPRISING THE STEPS OF: OBSTRUCTING THE OPTICAL SYSTEM SO THAT NO EXTERNAL RADIATION IS ADMITTED INTO THE ENCLOSURE HOUSING THE RADIANT ENERGY MEASURING SYSTEM; TAKING A FIRST MEASUREMENT WITH A CHOPPER WHEEL HAVING A UNIFORMLY HIGHLY ABSORPTIVE SURFACE FACING THE DETECTOR TO DERIVE A FIRST SIGNAL; TAKING A SECOND MEASUREMENT WITH A CHOPPER WHEEL HAVING A UNIFORMLY HIGHLY REFLECTIVE SURFACE FACING THE DETECTOR TO DERIVE A SECOND SIGNAL; AND CONSTRUCTING A CHOPPER WHEEL HAVING A SURFACE FACING THE DETECTOR MEANS WHICH IS ABSORPTIVE WITH A REFLECTIVE PORTION IN EACH SPACE SECTOR IF THE AMPLITUDE OF THE SECOND SIGNAL EXCEEDS THE FIRST SIGNAL, AND WHICH IS REFLECTIVE WITH AN ABSORPTIVE PORTION IN EACH SPACE SECTOR IF THE AMPLITUDE OF THE FIRST SIGNAL EXCEEDS THE SECOND SIGNAL, AND IN WHICH THE SIZE AND LOCATION OF THE PORTION IN THE SPACE SECTOR IS SELECTED IN ACCORDANCE WITH THE RELATIVE AMPLITUDE OF THE FIRST AND SECOND SIGNAL.

Claim 4

A METHOD FOR COMPENSATING FOR THE RESIDUAL SIGNAL GENERATED FROM INTERNAL SOURCES OF RADIANT ENERGY OF A RADIANT ENERGY MEASURING SYSTEM CONTAINED WITHIN AN ENCLOSURE HAVING AN OPTICAL SYSTEM FOR COLLECTING A SOLID ANGLE OF RADIATION EMANATING FROM AN EXTERNAL SOURCE OF RADIANT ENERGY INTO AN OPTICAL PATH AND FOR FILTERING SAID RADIATION AND FOR DIRECTING SAID RADIATION UPON A DETECTOR MEANS AND IN WHICH A ROTATING TOOTHED GEAR CHOPPER WHEEL HAVING ITS CIRCUMFERENTIAL TEETH AND SPACES ALTERNATELY BLOCK AND PASS THE OPTICAL PATH TO MODULATE SAID RADIATION, THE METHOD COMPRISING THE STEPS OF: OBSTRUCTING THE OPTICAL SYSTEM SO THAT NO EXTERNAL RADIATION IS ADMITTED INTO THE ENCLOSURE HOUSING THE RADIANT ENERGY MEASURING SYSTEM; TAKING A FIRST MEASUREMENT WITH A CHOPPER WHEEL HAVING A UNIFORMLY HIGHLY ABSORPTIVE SURFACE FACING THE DETECTOR TO DERIVE A FIRST SIGNAL; TAKING A SECOND MEASUREMENT WITH A CHOPPER WHEEL HAVING A UNIFORMLY HIGHLY REFLECTIVE SURFACE FACING THE DETECTOR TO DERIVE A SECOND SIGNAL; AND CONSTRUCTING A CHOPPER WHEEL HAVING A SURFACE FACING THE DETECTOR MEANS WHICH IS ABSORPTIVE WITH A REFLECTIVE PORTION IN EACH SPACE SECTOR IF THE AMPLITUDE OF THE SECOND SIGNAL EXCEEDS THE FIRST SIGNAL, AND WHICH IS REFLECTIVE WITH AN ABSORPTIVE PORTION IN EACH SPACE SECTOR IF THE AMPLITUDE OF THE FIRST SIGNAL EXCEEDS THE SECOND SIGNAL, AND IN WHICH THE SIZE AND LOCATION OF THE PORTION IN THE SPACE SECTOR IS SELECTED IN ACCORDANCE WITH THE RELATIVE AMPLITUDE OF THE FIRST AND SECOND SIGNAL.