Abstract: A photoconductor read out circuit includes a biasing signal generator connected to apply an alternating current biasing signal to a first terminal of the photoconductor. An input capacitance connected to a second terminal of the photoconductor stores charge applied to that terminal. A charge transfer amplifier included in the read out circuit receives a demodulating signal and functions to transfer charge to a summing node in response to the charge stored by the input capacitance and in coordination with the demodulating signal. A charge collection arrangement included in the read out circuit selectively resets the summing node to a base charge level, and stores charge applied to the summing node between resets to the base charge level.