Patent ID: 8897499

Claim:
A position detection system comprising: an imaging unit for capturing a projected image of an object; an electromagnetic wave emission unit to emit an electromagnetic wave to the imaging unit, wherein the electromagnetic wave emission unit comprises a first electromagnetic wave emission unit and a second electromagnetic wave emission unit placed in a different location from the first electromagnetic wave emission unit; a control unit to control emission of the electromagnetic wave by the electromagnetic wave emission unit; and a position determination unit, which: obtains a first projected image of the object based on an image captured during emission of the electromagnetic wave by the first electromagnetic wave emission unit and not by the second electromagnetic wave emission unit, and obtains a second projected image of the object based on an image captured during emission of the electromagnetic wave by the second electromagnetic wave emission unit and not by the first electromagnetic wave emission unit, determines a spatial position of the object based on estimating a first straight line connecting the first electromagnetic wave emission unit and a first point of the first projected image of the object, estimating a second straight line connecting the second electromagnetic wave emission unit and a second point of the second projected image of the object, and determining an intersection of the first straight line and the second straight line as the spatial position of the object, wherein the second point of the second projected image corresponds to the first point of the first projected image, and determines whether the object is a finger or a fist by determining whether a proximity between a pattern in the first projected image and a pattern in the second projected image is greater than a threshold proximity.