Patent ID: 7411744

Claim:
An obstacle-detectable mobile device, comprising: a frame body capable of traveling on a surface; a control circuit mounted to said frame body for controlling traveling manner and direction of said frame body and configured to avoid obstacles obstructing the mobile device; and a detection system mounted to said frame body and electrically connected with said control system, said detection system having an optical emitter, an optical receiver, and a reflector, said optical emitter emitting the light toward the surface at a given angle to define a projection area on the surface, said reflector facing said projection area, the light emitted to the projection area being reflected to said reflector to define a reflection area on said reflector, the reflection area being variably located on said reflector subject to a height that the surface is positioned, said optical receiver facing said reflector to define a receiving area on said reflector, the receiving area never overlapping the surface; wherein the reflection area is overlapped with said receiving area when said optical emitter is spaced from the surface at a given distance; wherein the reflection area is not overlapped with the receiving area when said optical emitter is farther than the given distance from the surface; wherein said optical receiver being enabled to receive the light from said optical emitter is dependent on whether or not the receiving area is overlapped with the reflection area; and wherein the detection system of the mobile device is configured to reject ambient light pollution and avoid misdetection of obstacles.