Patent ID: 6642505
Filing Date: 2003-11-04
Classification: A47K,G01S,G01V

Abstract:
A reflection-type optical sensor comprising:a housing having inner wall surfaces defining a light-projecting chamber and a light-receiving chamber; a light-emitting device disposed in the light-projecting chamber for emitting light; a light-projecting lens disposed in the light-projecting chamber for projecting the emitted light toward an object; a light-receiving lens disposed in the light-receiving chamber for focusing reflected light from the object; and a light-receiving device disposed in the light-receiving chamber for receiving focused light from the light-receiving lens and outputting a signal depending upon the level of the focused light and the position of the object; wherein the light-projecting chamber and the light-receiving chamber have wall surfaces that receive incident light and are reflective surfaces for promoting the reflection of light so that reflected light incident on the wall surfaces is reflected and not absorbed by the wall surfaces; and wherein the housing is mounted when in use to a seat, and the light-projecting lens projects light toward a location at which a person would be located if sitting in the seat, such that the reflected light is focused by the light-receiving lens onto the wall surface of the light-receiving chamber, which reflects the focused light onto the light-receiving device to enable accurate detection of whether or not a person is sitting in the seat.