Motion detection device and detecting method thereof

A motion detection device, comprising:

• a first pixel;
• a second pixel and third pixel, adjacent to the first pixel at two sides of the first pixel;
• and
• a comparator, coupled to the first pixel without via any switch, coupled to the second pixel via a second switch and coupled to the third pixel via a third switch, and the comparator configured to
• output a first comparison result indicating a signal difference between the first and second pixels as a first reference difference,
• output a second comparison result indicating a signal difference between the first and third pixels as a second reference difference,
• output a third comparison result indicating a signal difference between the first and second pixels as a first current difference, and
• output a fourth comparison result indicating a signal difference between the first and third pixels as a second current difference, wherein
• the first comparison result is obtained by exposing the first pixel and the second pixel using different shutter times,
• the second comparison result is obtained by exposing the first pixel and the third pixel using different shutter times,
• the third comparison result is obtained by exposing the first pixel and the second pixel using a same shutter time, and
• the fourth comparison result is obtained by exposing the first pixel and the third pixel using the same shutter time.

An operating method of a motion detection device, the motion detection device comprising a pixel array, multiple comparators respectively coupled to a pair of pixel columns of the pixel array, multiple flip flops each coupled to one comparator, and multiple logic check circuits each coupled to one flip flop and one corresponding comparator coupled to the one flip flop, the operating method comprising:

• generating a reference image in which one pixel column among the pair of pixel columns is exposed by a first shutter time and the other one pixel column among the pair of pixel columns is exposed by a second shutter time, different from the first shutter time;
• comparing light signals in the reference image at the one pixel column among the pair of pixel columns with light signals in the reference image at the other one pixel column among the pair of pixel columns by the multiple comparators to generate a reference feature position map;
• generating a current image in which the one pixel column among the pair of pixel columns is exposed by the first shutter time and the other one pixel column among the pair of pixel columns is exposed by the first shutter time;
• comparing light signals in the current image at the one pixel column among the pair of pixel columns with light signals in the current image at the other one pixel column among the pair of pixel columns by the multiple comparators to generate a current feature position map;
• and
• processing the reference feature position map and the current feature position map by the multiple flip flops and the multiple logic check circuits to detect a motion.