Patent ID: 7719695

Claim:
A sensor device, comprising a housing; a source of radiation; a reflective surface supported within the housing and positioned in a path of radiation from the source and having a contour that directs radiation reflected from the surface along a field, the reflective surface contour shaping the reflected radiation into the field so that the field has at least two sides that are parallel to each other as the reflected radiation leaves the reflective surface; and a sensing element positioned in a path of the field such that the reflected radiation can be incident on the sensing element, the sensing element detecting an amount of interruption of the field that otherwise irradiates the sensing element to provide information regarding at least a feature of an object in the field between the sensing element and the reflective surface that causes the interruption, wherein the sensing element is supported by the housing so that there is a viewing window through which the reflected radiation passes as the radiation moves from the reflective surface directly at the sensing element.