Abstract: A system including at least one apparatus that measures thicknesses of objects. The apparatus includes a first emitter, a second emitter, a first receiver, and a second receiver. The first emitter and the second receiver are positioned diagonally opposed across a plane, and the second emitter and the first receiver are positioned diagonally opposed across the plane. The first receiver receives a first signal emitted by the first emitter after reflecting off of an object occupying the plane. The second receiver is positioned to receive a second signal emitted by the second emitter after reflecting off of the object. The apparatus includes a circuitry operable to determine the thickness of the object based on reflections of the first signal and the second signal.

Abstract: A photoelectric sensor includes an emitter that emits a plurality of light beams. Fractions thereof pass through transparent portions of a first body and a second body in series before intersecting an optically powered surface, which directs the fractions to a target focusing an image that passes through a perimeter of the first body in one direction and focusing an image that passes through a perimeter of the second body in a perpendicular direction. The emitter, first and second bodies, and the optically powered surface are positioned so as to form a light spot on the target within which the fractions of the plurality of light beams substantially overlap. The fractions of the plurality of light beams reflect off of the target and are received by a receiver, which detects changes in the light to determine whether a mark is present on the target.

Abstract: A coaxial photoelectric sensor may include both an optical emitter and optical receiver disposed on a printed circuit board. A total internal reflection optical component may be optically aligned with the optical emitter so as to reflect an illumination signal generated by the emitter. A reflective optical component may be optically aligned with the total internal reflection optical component so as reflect the illumination signal received from the total internal reflection optical component. A target reflector component may be optically aligned with the reflective optical component to coaxially reflect the illumination signal received from the reflective optical component. An optical detector may be configured to generate an electrical signal in response to receiving the illumination signal.

Abstract: A coaxial photoelectric sensor may include both an optical emitter and optical receiver disposed on a printed circuit board. A total internal reflection optical component may be optically aligned with the optical emitter so as to reflect an illumination signal generated by the emitter. A reflective optical component may be optically aligned with the total internal reflection optical component so as reflect the illumination signal received from the total internal reflection optical component. A target reflector component may be optically aligned with the reflective optical component to coaxially reflect the illumination signal received from the reflective optical component. An optical detector may be configured to generate an electrical signal in response to receiving the illumination signal.