Abstract: A connector receptacle (20) is constituted by a contact (2) to which a data signal is serially communicated through a connector plug and a physical layer basic circuit (5) provided inside the connector receptacle (20) and adapted to perform specified processings so that the data signal is parallel communicated between the basic circuit and a link layer circuit for the communication. As a result, the distance between the contact (2) and the physical layer basic circuit (5) is short. Therefore, it is not necessary to pay so much attention as in conventional cases in designing a pattern layout (7) so as to prevent influence on the EMI and transmission characteristics, and it is easy to design the layout of the pattern constituting the transmission line for the data.

Abstract: A security system, including a cable having a groove formed in the inside thereof to accommodate therein an optical fiber with an excessive length, a plurality of supports having mandrels to support the optical cable so as to provide a fence, a light transmitter to inject light into one end of the optical cable and a light receiver to detect the light projecting out of the other end of the optical cable so that any transmission loss through the optical cable due to an intrusion of the fence may be measured. The cable is formed so that when tension is applied to the optical cable, a transmission loss is detected. The resulting system has a threshold capability which distinguishes valid from false intrusions.

Abstract: An optically scanning displacement sensor is arranged to compute by means of a triangulation an inverse function from a first measured distance signal proportional to output position signals from a position detecting means which receiving reflected light from an object to be detected, and the first measured distance signal is multiplied at a linearity correcting means by a signal of a sum of the inverse function and a constant so as to compute a second measured distance signal, whereby a two-dimensional position detection can be realized with the least required memory capacity and the minimum adjusting process.

Abstract: There is provided a photoelectric switch in which a beam reflected by an object to be detected is received in a trigonometric manner so that any failure in the distance measurement of the object can be prevented with employment of ordinary amplification circuit for received-light signals without enlarging the figure of the dynamic range of the circuit. In the switch, a circuit for comparing the ratio of the received-light signals to a predetermined operational level includes means for setting the nearest limit point for a set range of a detecting area to be farther than an intersection of the projected light beam with a line connecting centers of light-receiving lens and received-light detecting element so that the detection of the object can be made even when the dynamic range of the amplification circuit is saturated, whereby the presence of the object in the detecting area can be always discriminated even upon the dynamic range saturation of the amplification circuit.