Abstract: An automotive engine control system is provided for an automobile having a variable rotation speed engine which has a plurality of spark plugs served by respective spark plugs. The system includes an optical rotary encoder having a rotatable pulse scale having a row of code pattern with specific light-permeable or light-deflection slits each for outputting a reference position signal and other light-permeable or light-reflection slits each adapted to reduce the amount of light for outputting an angular signal, both of the optical signals being photoelectronically converted and the waveform of the resultant electric signals being shaped based on threshold voltages into electric pulse signals indicative of a reference angle of 0.degree.

Abstract: A photointerruptor for use in an optical transmission-type rotary encoder comprising a rotatable pulse scale having a code pattern and a light-emitting optical fiber and a light-receiving optical fiber secured to a housing with their end faces being opposed to each other on both sides of the code pattern. The housing has a housing main body a pair of optical fiber opposing members for previously inserting the top ends of the respective optical fibers and a housing main body having fitting recesses for holding the optical fiber opposing members with the end faces of the optical fibers being opposed to each other at a predetermined distance on both sides of the code pattern. The housing main body may be constituted by a pair of optical fiber opposing members engageable with each other.

Abstract: An optical encoder comprising a photointerruptor having light-emitting and light-receiving optical fibers and a rotatable pulse scale disposed in an optical path between both of the opposed end faces of the optical fibers so as to shut the optical path intermittently, thereby generating optical pulses in accordance with an angle of rotation of the pulse scale, in which the light-receiving optical fiber has a larger diameter and a greater numerical aperture NA than those of the light-emitting fiber. The light-emitting optical fiber may be replaced with a light-emitting device. Further, a reflector may be interposed in the optical path. Optical pulse signals indicative of an angle of rotation can be detected effectively and it is possible to facilitate the assembling or wiring operation and reduce the production cost.

Abstract: A photointerruptor for use in a light transmission type rotary encoder comprising a photointerruptor main body having a plurality pair of light emitting and light receiving optical fibers resin-molded therein, each pair of the optical fibers being disposed such that their end faces are opposed on both sides of each code pattern formed circumferentially on a pulse scale, the light emitting optical fibers joined by way of an optical branching device into a light input end and the light receiving optical fibers being extended in parallel with each other through the photointerruptor and, an adaptor integrally formed to the photointerruptor main body and through which the light input end of the light emitting optical fibers and the light emitting ends of the light receiving optical fibers are extended and arranged such that they are collectively connected with core wires of a multi-cored transmission optical fiber cable by way of a light connector respectively.