US Patent 7502064 Using light pulses to implement auto-focus in a digital camera

A camera includes a light transmitter configured to transmit light pulses at a first rate, a light receiver configured to receive return signals corresponding to the light pulses transmitted by the light transmitter, and a sampler configured to sample electrical signals corresponding to the return signals received by the light receiver, wherein the sampler is configured to sample the electrical signals at a second rate that is lower than the first rate.