Abstract: To provide a multi-optical axis photoelectric sensor and a multi-optical axis photoelectric sensor system, which enable function setting by an extremely simple operation, and further make it unnecessary to increase the size of a housing or to separately prepare a PC or a function setting tool. The multi-optical axis photoelectric sensor has: a columnar housing, from one end of which in the longitudinal direction an electric cord is pulled out, and at the other end of which in the longitudinal direction a plug-in type socket is provided, and a plug piece detachably attachable to the socket of the columnar housing. Particular information to serve as a function determining element on the columnar housing side is incorporated in the plug piece in a manner referenceable from a processing circuit on the columnar housing side via the socket. Further, the processing circuit on the columnar housing side is set so as to determine a function based upon particular information in the plug piece referenced via the socket.

Abstract: To provide a multi-optical axis photoelectric sensor and a multi-optical axis photoelectric sensor system, which enable function setting by an extremely simple operation, and further make it unnecessary to increase the size of a housing or to separately prepare a PC or a function setting tool. The multi-optical axis photoelectric sensor has: a columnar housing, from one end of which in the longitudinal direction an electric cord is pulled out, and at the other end of which in the longitudinal direction a plug-in type socket is provided, and a plug piece detachably attachable to the socket of the columnar housing. Particular information to serve as a function determining element on the columnar housing side is incorporated in the plug piece in a manner referenceable from a processing circuit on the columnar housing side via the socket. Further, the processing circuit on the columnar housing side is set so as to determine a function based upon particular information in the plug piece referenced via the socket.

Abstract: A reflective-type photoelectric switch projects emitted light from a light-emitting element toward a detection zone by a light-projecting optical system, and guides reflected light from an object to be detected in the detection zone to a light-receiving element by a light-receiving optical system. A special optical element is used in part of at least one of the two optical systems. The optical element functions to diverge light in a direction parallel to a plane containing the optic axes of the light-emitting and light-receiving elements, and condense light in a direction perpendicular to the same plane. As a result, it is possible to detect, with excellent sensitivity, both an object which is far from the switch and an object very near the switch.

Abstract: A light projecting circuit of a photoelectric switch includes a light projecting element (2), a driver circuit (1, 3) for driving the light projecting element by use of pulses, and a change-over switch (4) for increasing or for decreasing an amount of light emitted from the light projecting element. With this provision, in an operation to adjust optical axes, the change-over switch can be used to increase the amount of the emitted light. Consequently, the position of the projected light beam can be easily confirmed.