Abstract: A device for detecting edges of sheet-shaped print materials (1), especially of transparencies, that are moved along a transport path through a sheet-processing machine has a beam transmitter (31) and a beam receiver (32), whereby beam transmitter (31) and beam receiver (32) are mounted on different sides of the transport path in such a way that the beam path forms an acute angle to the surface of the sheet-shaped print material (1). Electronics (36) evaluate the beam received at the beam receiver (32), whereby the beam receiver (32) is at a lesser distance to the transport path in comparison to the beam transmitter (31).

Abstract: A device for detecting edges of sheet-shaped print materials (1), especially of transparencies, that are moved along a transport path through a sheet-processing machine has a beam transmitter (31) and a beam receiver (32), whereby beam transmitter (31) and beam receiver (32) are mounted on different sides of the transport path in such a way that the beam path forms an acute angle to the surface of the sheet-shaped print material (1). Electronics (36) evaluate the beam received at the beam receiver (32), whereby the beam receiver (32) is at a lesser distance to the transport path in comparison to the beam transmitter (31).

Abstract: A light-emitting diode is energized by converting a mechanical energy by means of a piezoelectric element into electrical charges which are transformed in a transformer into current pulses sufficient for activating the light-emitting diode. The component parts of a device of this invention include a rotation-symmetrical housing enclosing a striking member which is spring-biased against an opening in the housing, a piezoelectric element cooperating with the striking member and having two opposite electrodes connected to a primary winding of a pulse transformer. The secondary winding of the transformer is connected to the leads of the light-emitting diode. The piezoelectric element is pressed against the compression spring of the striking member by a connection spring leading to a terminal of the primary winding. All component parts are aligned along the center axis of the housing.