Recently published Samsung patent application US20110198481 talks about speeding up a ToF imager based on in-phase/out-of-phase light pulses measurement. The sensor includes a detection portion and a transfer portion separating the signal between two floating diffusions:
The detection portion is a pinned photodiode, while the transfer part consists of photogate, transfer gates Tx1 and Tx2 and floating diffusions FD1 and FD2 separately accumulating in-phase and out-of-phase signals. The photodiode is made has few different doping areas to create a potential stairs and speed the charge transfer to the photogate:
The detection portion is a pinned photodiode, while the transfer part consists of photogate, transfer gates Tx1 and Tx2 and floating diffusions FD1 and FD2 separately accumulating in-phase and out-of-phase signals. The photodiode is made has few different doping areas to create a potential stairs and speed the charge transfer to the photogate:
