SIGNAL TRANSMITTER OF ROTARY PART

摘要

PURPOSE:To improve the reliability of signal transmission between a rotary part and a fixed body by using light for signal transmission and electromagnetic induction for power supply. CONSTITUTION:The rotary part 2 such as the steering wheel of a motorcar fitted to a shaft 1 has a cylindrical yoke 4 of a ferromagnetic material incorporating a coil 9 and a fixed part 3 has a cylindrical yoke 5 of a ferromagnetic material incorporating a facing coil 8 matched with the yoke 4. In the yoke 4, an annular member 6 having an annular groove 14 is fixed and a light emitting element 13 is fitted facing a part of the groove 14. At the position opposed to the light emitting element 13, an annular member 7 having a photodetecting element 12 is fitted inside of the yoke 5 while opposing to the annular member 6. The annular members 6 and 7 allow the groove 14 to serve as an optical transmission line and the signal transmission between the light emitting element 13 and photodetecting element 12 is performed. The power supply to the device on the rotary body side 2 is performed by the electromagnetic induction between the coils 8 and 9 through the yokes 4 and 5.