| 摘要 |
PURPOSE:To detect a direction by detecting the direction of the magnetic flux of geomagnetism and by transducing the same into an electric signal. CONSTITUTION:A rotary-body supporting mechanism 70 is provided for a mobile body such as a vehicle in such a manner that it moves together with the mobile body, while a rotary body 88 sensing the geomagnetism and indicating constantly the prescribed direction is supported rotatably by the rotary-body supporting mechanism 70. The rotary body 88 is formed of opaque material and a piercing groove 102 as an opening part is formed in the circumferential side surface of the body 88 in the vertical direction thereof. And the part of the piercing groove 102 alone can pass a light from a luminous element 74 to the outside of the rotary body 88 and the light from the luminous element 74 is led to one of light-receiving elements 76 arranged around the rotary body 88. |
