Reflection-type optical sensor with reflecting wall surfaces

摘要

A holder (1) is molded from white polycarbonate resin and has a light-projecting portion (11) and a light-receiving portion (12). A light-projecting lens (3) and a light-emitting device (2) are mounted in a light-projecting chamber (11a) formed in the light-projecting portion (11). A light-receiving lens (4) and a light-receiving device (5) are mounted in a light-receiving chamber (12a) formed in the light-receiving portion (12). Those of the wall surfaces of the light-projecting chamber (11a) and the light-receiving chamber (12a) which are illuminated with light are reflecting surfaces (11b) and (12b) that promote reflection of light. The reflecting surfaces can be smooth surfaces, surfaces painted in white, inner surfaces of auxiliary members fabricated as separate parts from aluminum, or the like. Thus a misjudgment is prevented in judging whether the distance to an object to be detected is great or small. Application as a sitting sensor for a toilet seat device that can function also as a bidet. For closing a water ejection nozzle. Splitted receiver (5) for remote and near. <IMAGE>