Exposure control apparatus for photomicrography

Claim 1

AN APPARATUS FOR MEASURING AND AUTOMATICALLY CONTROLLING THE EXPOSURE TIME FOR PHOTOMICROGRAPHY, COMPRISING AN ELECTROMAGNETIC SHUTTER, WHICH IS OPENED AND CLOSED BY AN ELECTRIC TIMER, WHICH CONTAINS A RESISTANCECAPACITANCE ARRANGEMENT AND DETERMINES THE EXPOSURE TIME AND PERMITS OF A CONTROL OF N EXPOSURE TIMES GRADED ACCORDING TO A GEOMETRIC SERIES, AND A LIGHT DETECTOR, WHICH IS INCLUDED IN THE PATH OF RAYS AND IS EXPOSED TO AN ILLUMINATION INTENSITY WHICH IS PROPORTIONAL TO THAT WHICH WOULD FALL ON THE SENSITIZED LAYER, CHARACTERIZED IN THAT A COMPENSATING CIRCUIT IS PROVIDED, WHICH INCLUDES N COMPENSATING RESISTORS RI, WHERE I=1 TO N, AN AUXILIARY VOLTAGE SOURCE, AND THE LIGHT DETECTOR, SAID COMPENSATING RESISTORS ARE SO DIMENSIONED THAT THEITH COMPENSATING RESISTOR COMPENSATES THE CURRENT FLOWING THROUGH THE LIGHT DETECTOR SO THAT A ZERO SIGNAL IS INDICATED, THE TIMER INCLUDES A RESISTANCE-CAPACITANCE ARRANGEMENT WHICH IS ADJUSTABLE IN N TIME CONSTANT STEPS N(RC)I, WHERE I=1 TO N, AND SAID RESISTANCE-CAPACITANCE ARRANGEMENT IS COUPLED BY KNOWN MEANS TO THE COMPENSATING RESISTORS RI IN SUCH A MANNER THAT THE CONNECTION OF THE ITH COMPENSATING RESISTOR, INTO THE CIRCUIT SO AS TO OBTAIN A ZERO SIGNAL RESULTS IN THE TIMER IN A SYNCHRONOUS ADJUSTMENT OF THE RESISTANCE-CAPACITANCE ARRANGEMENT TO THE ITH STEP, WHICH HAS BEEN DETERMINED BY CALIBRATION SO THAT THE TIMER CONTROLS AN EXPOSURE TIME WHICH RESULTS IN A CORRECT EXPOSURE WHEN THE ILLUMINATION INTENSITY OF THE SENSITIZED LAYER CORRESPONDS TO THE ITH STAGE.

Claim 2

AN APPARATUS FOR MEASURING AND AUTOMATICALLY CONTROLLING THE EXPOSURE TIME FOR PHOTOMICROGRAPHY, COMPRISING AN ELECTROMAGNETIC SHUTTER, WHICH IS OPENED AND CLOSED BY AN ELECTRIC TIMER, WHICH CONTAINS A RESISTANCECAPACITANCE ARRANGEMENT AND DETERMINES THE EXPOSURE TIME AND PERMITS OF A CONTROL OF N EXPOSURE TIMES GRADED ACCORDING TO A GEOMETRIC SERIES, AND A LIGHT DETECTOR, WHICH IS INCLUDED IN THE PATH OF RAYS AND IS EXPOSED TO AN ILLUMINATION INTENSITY WHICH IS PROPORTIONAL TO THAT WHICH WOULD FALL ON THE SENSITIZED LAYER, CHARACTERIZED IN THAT A COMPENSATING CIRCUIT IS PROVIDED, WHICH INCLUDES N COMPENSATING RESISTORS RI, WHERE I=1 TO N, AN AUXILIARY VOLTAGE SOURCE, AND THE LIGHT DETECTOR, SAID COMPENSATING RESISTORS ARE SO DIMENSIONED THAT THEITH COMPENSATING RESISTOR COMPENSATES THE CURRENT FLOWING THROUGH THE LIGHT DETECTOR SO THAT A ZERO SIGNAL IS INDICATED, THE TIMER INCLUDES A RESISTANCE-CAPACITANCE ARRANGEMENT WHICH IS ADJUSTABLE IN N TIME CONSTANT STEPS N(RC)I, WHERE I=1 TO N, AND SAID RESISTANCE-CAPACITANCE ARRANGEMENT IS COUPLED BY KNOWN MEANS TO THE COMPENSATING RESISTORS RI IN SUCH A MANNER THAT THE CONNECTION OF THE ITH COMPENSATING RESISTOR, INTO THE CIRCUIT SO AS TO OBTAIN A ZERO SIGNAL RESULTS IN THE TIMER IN A SYNCHRONOUS ADJUSTMENT OF THE RESISTANCE-CAPACITANCE ARRANGEMENT TO THE ITH STEP, WHICH HAS BEEN DETERMINED BY CALIBRATION SO THAT THE TIMER CONTROLS AN EXPOSURE TIME WHICH RESULTS IN A CORRECT EXPOSURE WHEN THE ILLUMINATION INTENSITY OF THE SENSITIZED LAYER CORRESPONDS TO THE ITH STAGE.