Patent ID: 8427443

Claim:
A coordinate locating device for locating an object intruding an area monitored by a display apparatus, comprising: a light source configured to emit light, wherein the light source comprises a light emitting device; at least one reflector configured to reflect the light from the light source, each of the at least one reflector being a diffusive reflector configured to diffusively reflect the light from the light source; and a single detector configured to detect the light reflected by the at least one reflector and to detect at least two a shadows appearing on said reflector, a first shadow being caused by an object intruding an area monitored by the display apparatus and blocking the light from the light source and a second shadow being caused by the object intruding an area monitored by the display apparatus and blocking the diffused light from the diffusive reflector, wherein the light source and the single detector are disposed at different positions on the same edge of the coordinate locating device.