Patent ID: 8537218

Claim:
A distance image sensor using time-of-flight method, comprising: a radiation source that generates radiation pulses to irradiate an object for measuring time-of-flight; an image generating unit including a controller that generates control signals indicating 1st to n-th imaging timings corresponding to 1st to n-th times-of-flight (n>1) different from each other, a pixel array of a plurality of pixels including a detection element for sensing incident radiation to generate electric charge, and a signal generator that generates 1st to n-th element image signals corresponding respectively to the 1st to n-th imaging timings responding to the control signals; and a processing unit that combines the 1st to n-th element image signals to generate an image signal including distance information concerning the object; wherein the detection element of each pixel generates 1st and 2nd electric charges respectively responding to an incident radiation that enters the detection element in 1st and 2nd imaging windows at each of the 1st to n-th imaging timings; each pixel provides 1st and 2nd element signals from the 1st and 2nd electric charges corresponding respectively to the 1st and 2nd imaging windows; the 1st imaging window, set immediately before an imaging time prescribed from a reference time, has a predetermined duration; the 2nd imaging window, set immediately after the imaging time, has a predetermined duration; the i-th element image signal (1≦i≦n) includes the 1st and 2nd element signals of each pixel at the i-th imaging timing; the radiation source provides 1st to n-th pulse trains as the radiation pulses to be irradiated to the object in each of the 1st to n-th frames arranged in order with respect to a time axis, the 1st to n-th pulses are shifted respectively by shift amounts different from each other from the start point of the 1st to n-th frames, in each of the 1st to n-th frames, the reference time is positioned at the start point of each frame, each of the 1st to n-th frames includes the 1st and 2nd imaging windows, the duration in each of the 1st to n-th pulses is smaller than the period of the 1st imaging window, and the duration in each of the 1st to n-th pulses is smaller than the period of the 2nd imaging window.