Abstract: A photoelectric smoke detector has a circuit substrate coupled to an optical-system base as disposed in a circuit accommodating zone defined within a detector housing by the base together with a smoke supervisory zone, a light projecting element and an integrated circuit incorporating therein a light receiving element and smoke detecting means are mounted to the circuit substrate, and the optical-system base holds therein a light receiving lens which is capable of condensing scattered light from smoke particles onto the light receiving element in the integrated circuit on the circuit substrate. Effective reduction in the number of constituent parts is thereby attained, to promote reduction in manufacturing costs, and to effectively realize dimensional minimization.

Abstract: An optical sensor discriminating the presence of an object or detecting distance to an object which includes a light projecting element for projecting light to a detection area, a light receiving element for receiving light reflected from an object present in the detection area and an anamorphic light receiving lens for expanding a condensed light spot received on the light receiving element in a direction perpendicular to a direction of movement of the light spot on the light receiving element. The light receiving element outputs a detection signal which discriminates the presence of the object in the detection area. The light receiving element can be rectangular in shape and comprise two or more triangular shaped photodiodes which output detection signals that can be processed to determine a distance between the object and the light receiving element.

Abstract: An optical sensor comprises a sensor circuit having parts which are optically interconnected with each other through an optical interconnection board interposed therebetween. The interconnection between the sensor circuit parts is thereby simplified remarkably, so that the mass-producibility of the sensor can be increased to lower its manufacturing costs.

Abstract: An object detecting apparatus has a plurality of light emitters which are sequentially actuated for projecting sequential light beams. A first structure is provided for receiving beams not reflected off any external body. A second structure is provided for receiving any part of the light beams reflected from an object in the area. A reference phase signal corresponding to the projected light beams is generated. A detection phase signal corresponding to the received reflected beam is also generated. The light emitters corresponding to the reflected light beams are continuously activated. The detection area is restricted by inhibition of output from an alarm phase difference discriminating circuit to a circuit when a difference between the reference and detection phases is not within a predetermined range. Consequently, the detection area can be restricted to a desired range, and the alarm circuit can be retained non-operative unless the object remains continuously in the area.