There is provided a photoelectric switch that prevents erroneous detection at the time of detecting a label pasted on a workpiece, a component assembled to a workpiece, a register mark printed on a sheet-like member, or the like, to improve detection accuracy. The photoelectric switch includes: a first light projecting unit; a second light projecting unit a light receiving unit for receiving a reflected light from the first detection area to generate a first light reception signal, and receiving a reflected light from the second detection area to generate a second light reception signal; a casing accommodating the first light projecting unit, the second light projecting unit, and the light receiving unit; and a detection signal generating unit for generating a detection signal based on at least one of the specific wavelength components of the first light reception signal and the second light reception signal.

An optical keypad for use in hazardous areas and which can ensure safe and reliable detection of keystrokes through an at least 8 mm thick glass window, as is required for electronics equipment located in hazardous explosive areas (In accordance with ATEX Directive 94/9/EC and similar requirements) is obtained by providing a system in which at least 6 LEDs are lit in a pseudo-random sequence, modulated by a pseudo-random frequency and the interval between the lighting of each of the LEDs is change randomly to avoid interference between collocated keypads and light from other sources, such as daylight and artificial light.

An actuation device for a public transport vehicle to avoid transmission of bacteria during the actuation. The device can be actuated by a predefined contactless actuation gesture, the device having a sensor unit that measures without contact and an evaluation unit, which is connected to the sensor unit. The sensor unit can generate a sensor signal transmit the sensor signal to the evaluation unit when an object, in particular a finger or a hand of a person, performs, within a detection space of the sensor unit, a movement at a distance from the actuation device, the signal being dependent on the movement sequence of the movement. The evaluation unit can check whether the movement is a predefined contactless actuation gesture, by which the actuation device can be actuated. If the movement is such an actuation gesture, a control signal is generated for a device of the vehicle.

A retrographic sensor includes a transparent structure, a transparent elastomeric pad, and an at least partially reflective layer. One or more excitation light sources emit light toward a side surface of the transparent structure. The side surface may include a fluorescent layer, where the light from the one or more excitation light sources excites fluorescent emissions from the fluorescent layer. The fluorescent emissions may illuminate the at least partially reflective layer.