Method for producing images with depth information and image sensor

A method for producing N images of a three-dimensional scene where each image of rank i, i=1 to N, represents points of a scene located at a respective distance from an image sensor, this method using a pulsed light source, the image sensor comprising pixels able to accumulate, in a respective charge storage node of each pixel, charge generated by light, the method comprising emitting N successive trains of light pulses from the light source and under control of a reference clock, and, iteratively for each pulse train of rank i from the N successive trains of light pulses:

• a) emitting the ith train of light pulses, the pulses being emitted at instants determined using the reference clock and at intervals determined using said reference clock;
• a1) integrating charge for each light pulse of the ith train in a short integration time slot of length Tint starting with a temporal offset t1 relative to the pulse, this temporal offset representing a journey time of the light pulse between the light source and the sensor after reflection from a point located at the respective ith distance (di) from the sensor, the temporal offset ti being the same for all the light pulses of the ith pulse train and the values of the temporal offsets ti for the N trains being different from one another in order to correspond to various distances relative to the sensor and being spaced apart from one another by a time increment larger than the integration time Tint;
• b1) transferring the charge integrated for each light pulse of the ith train to the charge storage node of each pixel, and accumulating this charge with the charge resulting from the preceding light pulses of the same train;
• and
• b) reading the charge contained in the charge storage node of each pixel after the end of the ith pulse train, resetting the charge storage node, and delivering a respective image of rank i representing the points of the scene located at the ith distance (di) from the sensor.