Motion recognition method

A motion recognition method in which a light emitting element projects light and a light receiving element detects the light reflected by a reflective body to recognize a motion of the reflective body, the motion recognition method comprising:

• a light detecting step of detecting light reflected by the reflective body to measure a luminous intensity of the light by the light receiving element;
• a first coordinate setting step of setting a planar coordinate (X1, Y1) of the reflective body in which the center of a light reception range of the light receiving element is taken as the origin thereof in a first position using the luminous intensity of the light by a data processing unit;
• a second coordinate setting step of setting a planar coordinate (X2, Y2) of the reflective body in which the center of a light reception range of the light receiving element is taken as the origin thereof in a second position using the luminous intensity of the light by a data processing unit;
• and
• a direction determining step of, when the reflective body moves from the first position to the second position, obtaining an angle (θ) between a line segment connecting the origin and the planar coordinate (X1, Y1) in the first position and a line segment connecting the planar coordinate (X1, Y1) in the first position and the planar coordinate (X2, Y2) in the second position and determining that the reflective body moves in a direction passing through a ½ point of the angle (θ) in the first position by the data processing unit.