Patent ID: 8648998

Claim:
A method for measuring time of flight of radiation, the method comprising: emitting modulated radiation in response to a first modulation signal, projecting the modulated radiation onto a scene, receiving radiation, the received radiation comprising at least modulated radiation reflected by the scene, converting the received radiation into a radiation induced electrical signal, mixing the radiation induced electrical signal with a second modulation signal, thus generating a mixed signal, integrating the mixed signal, thus generating an integrated signal, injecting charge into the integrated signal when the integrated signal exceeds a threshold value, applying changes to the first and/or second modulation signal at one or more moments in time, measuring the integrated signal at one or more moments in time, thus obtaining at least one TOF pair difference signal, the measuring including using a single detector node and associated capacitor, to obtain a TOF pair difference signal, obtaining a corrected TOF pair difference signal by subtracting a value substantially equal to one or more times a voltage corresponding to the amplitude of the injected charge from the TOF pair difference whenever this difference is larger than half of the value substantially equal to one or more times the voltage corresponding to the amplitude of the injected charge and adding a value substantially equal to one or more times a voltage corresponding to the amplitude of the injected charge to the TOF pair difference whenever this difference is lower than minus half of the value substantially equal to one or more times the voltage corresponding to the amplitude of the injected charge, and using one or more corrected TOF pair difference signals to determine time of flight of radiation.