A METHOD FOR INPUTTING COORDINATE CONTACTLESSLY USING A LIGHT GUIDE PLATE FOR SYSTEM INPUTTING COORDINATE CONTACTLESSLY

摘要

A method for inputting coordinate contactlessly using a light guide plate for a system inputting coordinate contactlessly is provided to make the light guide plate for a non-contact type coordinate input system eliminate inconvenience of a conventional contact-type coordinate input system inputting coordinates through direct contact, and to reduce use of sensors and optical loss as much as possible. A method for inputting coordinate contactlessly using a light guide plate for a system inputting coordinate contactlessly comprises the following several steps. Incident light is illuminated to a point of the light guide plate. Light emitted from the phosphor receiving the incident light having reached the light guide plate to reach optical sensors attached to at least two locations on the light guide panel is allowed. The intensity of light reaching the optical sensors to output a signal corresponding to the intensity of light is detected. A distance between each of the optical sensors and an incident point of light is calculated by substituting the output signal to a predetermined regression expression representing a relation between intensity of light and a distance. A point coincident to a locus of points is obtained where a ratio of distances from the respective optical sensors to the incident point of light or a ratio of distances between two optical sensors is constant. A coordinate set of the point is determined as a coordinate set at the incident point of light.