Patent ID: 8754852

Claim:
A non-contact type coordinate input system installed in a front surface of a display device, the system comprising: a light guide plate receiving incident light emitted from a light illuminating device, and comprising a transparent layer having a flat and continuous surface and a phosphor coated on the surface of the transparent layer or doped within the transparent layer; a plurality of optical sensors attached to one or both of edges in a transverse direction and to one or both of edges in a longitudinal direction of the light guide plate and detecting light emitted from the phosphor excited by the light emitted from the light illuminating device; and a calculation unit connected to the optical sensors, calculating a coordinate set with respect to a location of the excited phosphor using a light-receiving amount of the individual optical sensors, and delivering the calculated coordinate set to the display device or a computer system connected thereto, wherein the phosphor is selected from materials that react with infrared rays, and wherein the transparent layer has a haze of 10% or less and a transmittance of 80% or greater in an absorption-emission wavelength region of the phosphor.