Compensation for Target Surface Reflectance of the Proximity Sensor Using LD Power Variation Caused by Returned Light

Abstract

The proximity sensor using the power variation of a laser diode caused by the returned light from the target has the serious problem that the variation of the output originates from the changes of the reflectance of the surfaces and the fluctuation of the laser power itself. A compensation method for the reflectance of the target is proposed in this paper. This method uses the angular distributions of the reflectance of the targets. The stability control can be performed in the case of a fixed target, then, the results in this paper make the practical application of this sensor possible.