A device includes at least one photoconductor configured for exhibiting an electrical resistance Rphoto dependent on an illumination of a light-sensitive region of the at least one photoconductor and at least one photoconductor readout circuit. The photoconductor readout circuit is configured for determining a differential voltage related to changes of the electrical resistance Rphoto of the photoconductor. The photoconductor readout circuit includes at least one bias voltage source configured for applying at least one periodically modulated bias voltage to the photoconductor such that the electric output changes its polarity at least once. The device further includes at least one electrical circuit configured to balance the differential voltage at a given illumination level.