Continuous spectral recording spectrophotometer

Claim 1

IN A SPECTROPHOTOMETER OF THE TYPE HAVING A MONOCHROMATOR INCLUDING A CYCLICALLY OSCILLATING GRATING, A GRATING CAM HAVING WORKING AND NON-WORKING SURFACES MOUNTED ON A SHAFT, AND A CAM FOLLOWER AND LINKAGE MECHANISM FOR OSCILLATING THE GRATING IN RESPONSE TO ROTATION OF THE SHAFT AND THE GRATING CAM; A RECORDER INCLUDING A CHART, A CHART DRIVE MECHANISM, A PEN FOR MAKING A RECORD ON SAID CHART AND A PEN MOTOR FOR DRIVING SAID PEN; A MOTOR, SAID MOTOR BEING COUPLED TO SAID SHAFT AND SAID CHART DRIVE MECHANISM FOR DRIVING SAID SHAFT AND SAID CHART DRIVE MECHANISM; AND A RADIATION DETECTOR RESPONSIVE TO RADIATION PASSING THROUGH SAID MONOCHROMATOR FOR CONTROLLING SAID PEN MOTOR, THE IMPROVEMENT COMPRISING: A DISC MOUNTED ON SIAD SHAFT FOR ROTATION THEREWITH AND WITH SAID CAM; A SOURCE OF RADIATION POSITIONED ADJACENT SAID DISC; A RADIATION DETECTOR POSITIONED ADJACENT SAID DISC; PATTERN MEANS MOUNTED ON SAID DISC COOPERATING WITH SAID SOURCE AND SAID DETECTOR TO PRODUCE AN OUTPUT SIGNAL, SAID PATTERN MEANS CORRESPONDING TO SAID NON-WORKING SURFACES OF SAID CAM AS SAID DISC, CAM AND SHAFT ROTATE; AND MEANS COUPLED TO SAID DETECTOR AND RESPONSIVE TO SAID OUTPUT SIGNAL TO DECOUPLE SAID MOTOR FROM SAID CHART DRIVE MECHANISM AND TO DEACTIVATE SAID PEN MOTOR.