Time-of-flight sensor and control method thereof

A time-of-flight sensor, configured to operably capture a three-dimensional (3D) image of an object, the time-of-flight sensor comprising:

• a light source, which is configured to operably emit projection light pulses at the object according to a projection signal;
• an array of a plurality of pixel circuits, wherein each of the pixel circuits is configured to operably accumulate image charges in response to reflection light pulses which are light pulses of the projection light pulses reflected from the object, and store a first sum of a plurality of first portions of the image charges and a second sum of a plurality of second portions of the image charges according to the projection signal over a plurality of accumulation periods;
• and
• a processing circuit, which is coupled to the array of the pixel circuits, and includes:
• a first readout circuit, which is configured to operably calculate the first sum of the first portions of the image charges;
• and
• a second readout circuit, which is configured to operably calculate the second sum of the second portions of the image charges;
• wherein the first readout circuit and the second readout circuit simultaneously calculate the first sum of the first portions of the image charges and the second sum of the second portions of the image charges to generate a distance information signal of the 3D image of the object;
• wherein in each of the accumulation periods, the first portion of the image charges are accumulated in the pixel circuit during a first time period, and the second portion of the image charges are accumulated in the pixel circuit during a second time period, wherein the first time period and the second time period are both within said each accumulation period and the second time period is directly following the first time period;
• wherein a delay time between the projection light pulses and the reflection light pulses is proportional to a product of an ON time period and a division of the second sum of a sum of the first sum and the second sum.