Patent ID: 8586907

Claim:
A method comprising: generating a photocurrent representative of radiation incident on a photodetector of a pixel during a time period; accumulating on a capacitor a charge at least partially from the photocurrent; producing a first output signal of the pixel representing the charge accumulated on the capacitor; and producing a second output signal of the pixel indicative of an amount of time required for the charge accumulated on the capacitor to reach a reference level, wherein the second output signal is produced using an RS flip-flop circuit, wherein the first output signal is an analog signal, wherein the second output signal is a digital signal, wherein the method further comprises modifying the first output signal at an end of the time period using the second output signal to produce a resulting signal representing an amount of the radiation incident on the photodetector, wherein producing the second output signal comprises comparing, at one or more times during the time period, the charge accumulated on the capacitor to the reference level; and (a) responsive to the charge accumulated on the capacitor being less than the reference level, generating a first digital value; and (b) responsive to the charge accumulated on the capacitor exceeding the reference level, generating a second digital value.