The transmitter aims at the target and emits a beam of light from a semiconductor light source, a light-emitting diode (LED), a laser diode and an infrared emitter. The beam emits continuously, or varies the pulse width. The receiver consists of two photoelectric tubes, three photoelectric tubes and photocells. In front of the receiver, optical elements such as lens and aperture are installed. Behind it is a detection circuit that filters out the effective signal and applies it.

In addition, there are emission plate and optical fiber in the structure of the photoelectric switch.

The triangular reflector is a solid launcher. It is composed of a small triangular cone reflecting material, which can make the beam accurately return from the reflecting plate and has practical significance. It can vary the emission Angle from 0 to 25 with respect to the optical axis, so that the beam is almost from the root emission line, after reflection, or from this reflection ray back.