US Patent 11525902 Time-of-flight ranging device suitable for indirect time-of-flight ranging

A time-of-flight ranging device suitable for indirect time-of-flight ranging is provided. The time-of-flight ranging device includes a light emitting module, a first sensing pixel, a second sensing pixel, a differential readout circuit, and a processing circuit. The light emitting module emits a light pulse to a sensing target, so that the sensing target reflects a reflected light pulse. The first sensing pixel generates a first sensing signal and a second sensing signal. The second sensing pixel generates a third sensing signal and a fourth sensing signal. The differential readout circuit generates first digital data according to the first sensing signal and the third sensing signal and generates second digital data according to the second sensing signal and the fourth sensing signal. The processing circuit calculates a distance between the time-of-flight ranging device and the sensing target according to the first digital data and the second digital data.