Patent ID: 8159585

Claim:
A method for reading out a photo-sensitive region, the method comprising: providing at least one photo-sensitive region; providing at least one transfer gate associated with the photo-sensitive region; providing a charge-to-voltage conversion region electrically connected to the transfer gate; providing a reset mechanism that resets the charge-to-voltage conversion region; resetting the charge-to-voltage conversion region with the transfer gate off; after resetting the charge-to-voltage conversion region, measuring a first sample of the charge-to-voltage conversion region; after measuring the first sample, turning on the transfer gate to transfer charge from the photo-sensitive region to the charge-to-voltage conversion region; after transferring the charge from the photo-sensitive region, measuring two samples V TGon1 and V TGoff1 charge-to voltage conversion region, wherein V TGon1 is measured with the transfer gate on and V TGoff1 is measured with the transfer gate off; after measuring the two samples V TGon1 and V TGoff1 , resetting the charge-to-voltage conversion region a second time; after resetting the charge-to-voltage conversion region the second time, measuring two samples V TGon2 and V TGoff2 of the charge-to-voltage conversion region, wherein V TGon2 is measured with the transfer gate on and V TGoff2 is measured with the transfer gate off; determining a high conversion gain measurement using an equation (V TGoff1 −the first sample); and determining a low conversion gain measurement using an equation (V TGon1 −the first sample)−(V TGon2 −V TGoff2 ).