PURPOSE: To obtain an input tool without limiting a coordinate input designating range by providing a light recursive reflection type input device and a laser beam source part and executing a coordinate input by the angular scan of a laser beam based on the principle of triangle measurement.
CONSTITUTION: A central axis is provided for designating coordinates to be inputted, and a cylindrical recursive reflection surface is provided while surrounding this central axis. For example, a light source unit 4 emits an incident beam while executing the angular scan from a specified point P1 along a coordinate surface 2, and generates a detection pulse by receiving the recursively reflected beam by an input device 1. For this detected pulse, the central position of pulse width is coincident with a time point for the incident beam to pass through a central axis Po of the input device 1. A calculation part 6 determines amplitudes θ1 and θ2, which are formed by an optical path connecting specified points P1 and P2 and the central axis Po of the input device 1 and a reference line, by electrically processing the detection pulses to be generated at light source units 4 and 5, and calculates the coordinates designated by the input device 1 according to the principle of the triangle measurement by using the angle values θ1 and θ2 and a set distance L between two points. Thus, the coordinate input device can be obtained to be adopted for a two-dimensional coordinate surface equipped with arbitrary areas.
SAITO NORIO
HIROSE TOSHIYUKI
