Abstract: A high frequency oscillation type proximity switch prevents mutual interference when it is mounted adjacent to other proximity switches. The switch includes a comparator having a threshold value at a level higher than an object detection level of the oscillation output of the proximity switch. When an output is continuously obtained from the comparator, a beat is generated and the generation of mutual interference is detected. Then, the generation is externally displayed, and mutual interference is alarmed and prevented by changing the oscillation frequency.

Abstract: A reflection type photoelectric switch adapted to project light to an object to be detected and sense the object on the basis of reflected light therefrom, which comprises a split-type composite light receiving unit consisting of two light receiving segments, a differential amplifer receiving the outputs of the two light receiving segments, and a waveform shaping device for discriminating the differential amplification output of the differential amplifier with a predetermined level and generating a detection output for the object.

Abstract: There is provided a photoelectric switch comprising a photoelectric detection means, a circuit means disposed independently of the detection means, and cable means interconnecting the detection and circuit means, there being formed in the photoelectric detection means a parallel circuit comprised of a light emission photodiode and a display photodiode of opposite polarity thereto as connected in parallel-circuit relation, which parallel circuit is connected to a pulse oscillation circuit included in the circuit means with a couple of lines, whereby a pulse current of single polarity is applied from the pulse oscillation circuit to the parallel circuit to thereby actuate only the light emission photodiode, and there being disposed in the circuit means a display circuit which functions in response to a detection output obtained in the circuit means so that through the tow lines a pulse current of opposite polarity to the first-mentioned pulse current flows to the parallel circuit in a phase where the first-ment

Abstract: There is provided a photoelectric switch comprising a light projecting segment including a pulse oscillator and a light-emitting element adapted to give a pulse light emission in response to an output pulse of the pulse oscillator, a light reception segment including a light reception element adapted to yield a light reception signal on incidence of light, a gate circuit adapted to gate the light reception signal according to the output pulse of the pulse oscillator and an integration circuit for integrating outputs of the gate circuit, and a control circuit for varying the pulse frequency by controlling the pulse oscillator on generation of a light reception signal from the light reception element.

Abstract: A reflection-type photoelectric switching apparatus for providing an electric switching signal indicating existance information of an object to be detected thereby comprising a light projecting device for projecting a beam of light to the object, a light receiving photoelectric device arranged in side-by-side relation with the light projecting device for receiving a reflected light from the object, an optical axis adjusting means which is controllable from outside of housing of the apparatus for adjusting the optical axes of the light projecting and receiving devices, and optical members which allow both the light beam from the projecting device and the light beam to be incident on the receiving device to pass within a predetermined light path so that the two light beams will be crossed in a desired detection field, the distance from the apparatus to the desired detection field being continuously variable by the optical axis adjusting means.

Abstract: A photoelectric switch comprising a circuit block which is housed within a fluid-tight enclosure.The enclosure comprises a box-like housing having a first opening at one end, a second opening at another end and a cap means closing the first opening and fixed to the housing. The circuit block comprising a circuit board and a plurality of circuit elements, is placed in the enclosure through the first opening. A light-source element and a light-responsive element are positioned in the cap means and electrically connected to the circuit board.A conductor is electrically connected to the circuit board and extends out of the enclosure through the second opening.

Abstract: A photoelectric detector for detecting the presence of an object which comprises at least a light ray projecting element, for example, of a luminescent diode and a light ray receiving photoelectric element, for example, of a photo transistor. The two elements are respectively received in bores formed in a housing in such a manner that only the light rays emitted by the projecting elements is received by the receiving element with any lights due to irregular reflection prevented from reaching the receiving element so as to avoid erroneous functioning of the detector.