Patent ID: 8633462

Claim:
A movement detection device configured to detect a movement of an object in a space range, the movement detection device comprising: a light source; a light guiding element; a first light sensing element, a second light sensing element and a third light sensing element, the first light sensing element and the second light sensing element having no offset therebetween along a first direction and having an offset therebetween along a second direction, the first light sensing element and the second light sensing element respectively having an offset along the first direction and the second direction with respect to the third light sensing element such that the object, when moving in the space range, reflects the light from the light source sequentially to the first, second and third light sensing elements through the light guiding element, wherein the first direction is perpendicular to the second direction; and a processing unit configured to identify the movement of the object along the first direction and the second direction according to a sequence in which the first, second and third light sensing elements detect the light reflected by the object.