US Patent 7256713 Absolute angle detecting device

An absolute angle detecting device is provided. The absolute angle detecting device is composed of a first detecting element group that outputs a Gray code string for angle detection that detects a rotating angle in one sector of the multi-rotation body at required resolution, a second detecting element group and a third detecting element group that outputs a first and a second Gray code strings for sector identification. A rotating angle within one rotation (360 degrees) is detected by the Gray code for angle detection while setting one rotation of the multi-rotation body to one sector.