LIGHT-DETECTING DEVICE AND METHOD FOR CONVERTING OPTICAL RADIATION ON SWITCHED CONDUCTIVITY DIODES

摘要

A light-detecting device and method for converting optical radiation on switched conductivity diodes. The device comprises one or more photosensitive cells connected to address and signal lines, each cell comprising the following elements connected in series: a photodetector, an initial charge input circuit, a charge converter for converting the charge generated by the photodetector signal in addition to the initial charge into photodetector output voltage, a comparator which converts the difference between the photodetector output voltage and reference voltage into a digital cell signal, a reading circuit for reading the digital cell signal through the address lines and the signal lines, a circuit for generating digital codes of the cell signal, a random access memory for storing the digital codes, a reading circuit for reading the digital codes of the cell signals on one or more outputs of the light-detecting device.

主权项

1. A method for analogue-to-digital conversion of optical radiation on a switched conductivity diode comprising:
converting the optical radiation into photocurrent; integrating the photocurrent over an exposure time into an electric charge which changes an initial charge input before exposure; converting a resultant charge into signal voltage; comparing a signal voltage with a reference voltage and switching a comparator as a result of the comparison; generating binary signals modulated on switching time relative to initial time, generating digital codes based on the binary signals; and storing the digital codes and successively sending the digital codes to outputs;
where in order to input the initial charge into a switched conductivity diode, voltage corresponding to the initial charge is applied in a forward direction at a variation rate which causes injection of minority carriers, which does not exceed a level of triggering the switching diode into the conducting state, and the corresponding sampling voltage is applied as the reference voltage at a variation rate sufficiently high to cause injection of minority carriers, needed for triggering upon reaching voltage corresponding to the resultant charge, with given accuracy.