DEVICE FOR PHOTOMETERING IMAGES WITH EXPRESSED MAXIMUM OF SPATIAL DISTRIBUTION OF ILLUMINATION INTENSITY Russian patent published in 1997 - IPC

FIELD: optical instrumentation, photometry of spatially dispersed light fields with wide range of change of illumination intensity, in particular, diffraction patterns and images of spectra of radiation sources of type of filament lamps. SUBSTANCE: device includes photodiode image detector 1, analog-to-digital converter 2, calculator 3, clock pulse generator 4, former 5 of controlling pulses, first and second programmable interval timers 6, 7. At start of operation of photometering device calculator 3 programs operation of programmable timers 6, 7 to function under mode of frequency divider and program delay of initiating pulse, sets former 5 into mode of monotone or change of accumulation time switched over in center of reading interval and uses it for formation of line pulse of signal erasure. After calculated delay time equal to time of accumulation in first element of photodiode image detector 1 programmable interval timer 7 forms line reading pulse which initiates reading of signal in photodiode image detector 1 and its input through analog-to-digital converter 2 into calculator 3. Owing to difference of frequencies of erasure and reading clock pulses time of accumulation of signal can grow monotonously while photometering images with monotonously decreasing spatial change of illumination intensity or can first decrease for elements of first half of photodiode detector 1 and then rise in same degree for elements of second half while photometering images with expressed maximum in center of photodiode image detector 1. Difference of frequencies is provided by choice of frequency division ratio in programmable interval timer 6 and change of collection mode - by change of type of controlling signal fed from output of calculator 3 to corresponding input of. former 5 of controlling pulses. Illumination intensity of element of photodiode image detector 1 is calculated in relative units by division of value of signal of given element by time of its accumulation. EFFECT: enhanced operational reliability.