Patent ID: 6995358

Claim:
A reflective sensor used to detect presence or absence of a subject to be detected at a detecting position, the reflective sensor comprising: a sensor portion having a light-emitting element for emitting light toward the detecting position, and a light-receiving element for receiving light emitted from the light-emitting element and reflected on the subject to be detected present at the detecting position and generating an electrical signal corresponding to a quantity of received light; and a filter, disposed between the sensor portion and the detecting position and made of a light-transmitting material capable of transmitting light heading to the detecting position from the light-emitting element and light heading to the light-receiving element from the subject to be detected at the detecting position, for preventing intrusion of dust into the sensor portion, wherein a surface of the filter on a side of the sensor portion is formed into a tapered shape having a first inclined plane opposing the light-emitting element, a second inclined plane opposing the light-receiving element, and a ridge portion formed where the first and second inclined planes meet, the ridge portion extending in a space between the light-emitting element and the light-receiving element.