Patent ID: 8847882

Claim:
An apparatus for recognizing the position of an indicating object, comprising: a first reflecting means ( 200 ) that is installed along left, right, and bottom edges of a screen ( 50 ) to again retro-reflect a laser beam irradiated from an object-sensing means ( 100 ) to the object sensing means ( 100 ); an object sensing means ( 100 ) formed as two pairs that is disposed on the upper left and right of the screen ( 50 ) at a predetermined distance to irradiate a laser beam to the first reflecting means ( 200 ), receive the laser beam retro-reflected from the first reflecting means ( 200 ), and analyze a change in light amount of the reflected laser beam over time so as to sense position coordinates of an indicating object on a planar surface of the screen ( 50 ); and a fixing means ( 300 ) including a housing ( 310 ) having a hollow bar shape to accommodate the object sensing means ( 100 ) therein and a fixing member ( 330 ) fixing the housing ( 310 ) to the upper portion of the screen ( 50 ) by fixedly being installed to the upper portion of the screen ( 50 ) so as to be combined with the housing ( 310 ), such that the object sensing means ( 100 ) is be easily installed on the upper portion of the screen, wherein the object sensing means ( 110 ) includes: a laser beam irradiating means ( 110 ) installed so as to face the screen ( 50 ) surface to irradiate the laser beam to the screen ( 50 ); a scan means ( 130 ) including a 45° squared prism shaped mirror ( 131 ) that is installed in an optical axis direction of the laser beam irradiating means ( 110 ) to receive the laser beam irradiated from the laser beam irradiating means ( 110 ) and make the propagation direction of the laser beam parallel with the screen ( 50 ) and a synchronization signal detector ( 135 ) that is disposed on the upper portion of the 45° squared prism shaped mirror ( 131 ) in the optical axis direction to receive the laser beam when the laser beam is irradiated to the upper portion of the screen ( 50 ) by rotating the 45° squared prism shaped mirror ( 131 ), thereby scanning a position angle of the indicating object; a refracting means ( 150 ) installed between the laser beam irradiating means ( 110 ) and the scan means ( 130 ) to transmit the laser beam irradiated from the laser beam means ( 110 ), irradiated the transmitted laser beam to the scan means ( 130 ), and refract the laser beam returned to the scan means ( 130 ) via the first reflecting means ( 200 ) from the scan means( 130 ) at an angel of 90° ;and a detecting means ( 170 ) installed on a side of the refracting means ( 150 ) to condense the laser beam returned by sequentially transmitting the scan means ( 130 ) and the refracting means ( 150 ) via the first reflecting means ( 200 ), thereby detecting whether the indicating object is touched to the screen ( 50 ).