Patent ID: 8786577

Claim:
A coordinate recognition apparatus, comprising: a plurality of light-emitting devices arranged in an array along an X direction; a plurality of light-receiving devices arranged in an array parallel to the array of the light-emitting devices and configured to detect light emitted by the light-emitting devices; and a controller configured to selectively drive the light-emitting devices and the light-receiving devices and form a plurality of groups of light paths each including a plurality of light paths parallel to one another in a plane including the light-emitting devices and the light-receiving devices such that an angle of the light paths varies from group to group, identify a position p and a position I of each of the groups of light paths based on an output from each of the light-receiving devices, the position p being in the X direction of the light-receiving device corresponding to the light path that passes through a center of a region shielded by an object, the position I being in the X direction of the light-emitting device forming the same light path, and calculate coordinates of the center of the light shield region in the plane based on the identified positions p and I of each of the groups of light paths, wherein the controller obtains a regression line using the positions p and I of each of the groups of light paths as a sample, with respect to a PL plane formed by using a position P of each of the light-receiving devices in the X direction and a position L of the light-emitting devices in the X direction as axes, and calculates coordinates of the center based on the obtained regression line, and the controller calculates b/(1−a) using a gradient a and an intercept b of the regression line, sets the calculated result as a coordinate of the center in the X direction, calculates −ah/(1−a) using a distance h between the array of the light-emitting devices and the array of the light-receiving devices and the gradient a, and sets the calculated result as a coordinate of the center in a Y direction orthogonal to the X direction.