IMAGING DEVICE COMPRISING A CIRCUIT FOR ANALOG-DIGITAL CONVERSION BY MEANS OF THE INJECTION OF A QUANTITY OF CHARGES THAT VARIES AS A FUNCTION OF THE NUMBER OF PREVIOUS INJECTIONS

摘要

The invention belongs to the field of imaging devices comprising: a detector (11) that generates electric charges in response to incident photon radiation, and an analog-digital conversion circuit (12) forming means for reading the quantity of electric charges generated. The analog-to-digital conversion circuit (12) comprises: a comparator (122) which can switch depending on the comparison between a potential (Va) on an integration node (A) and a pre-determined threshold potential (Vthreshold); a counter (123) that is incremented with each switch of the comparator; a counter-charge injection circuit (124) which injects a quantity Qc of counter-charges at the integration node (A) with each switch of the comparator; and control means (125) which determine the quantity Qc of counter-charges injected. The analog-to-digital conversion circuit (12) is characterised in that the control means (125) determine the quantity Qc of counter-charges injected as a function of a value of the counter (123).