Angle detection apparatus, rotation amount specification unit, and rotary driving unit

An angle detection apparatus comprising:

• a rotating body;
• another rotating body;
• a transmission mechanism that causes the other rotating body to rotate by reducing a speed of a rotation of the rotating body;
• an angle detector that detects a rotational angle of the rotating body;
• another angle detector that detects a rotational angle of the other rotating body;
• and
• a processor that specifies a number of revolutions of the rotating body, wherein
• the processor specifies the number of revolutions while dynamically varying a specification condition for specifying the number of revolutions according to a numerical value decided according to the detected rotational angle of the rotating body and a reduction ratio of the transmission mechanism, and the detected rotational angle of the other rotating body,
• wherein
• the processor performs
• a shift process of shifting the specification condition for specifying the number of revolutions by a predetermined shift quantity at a time,
• a determination process of determining whether or not a detection result from the other angle detector satisfies a specification condition shifted by the shift process,
• an update process of repeating the shift process and the determination process while also updating a loop counter value until a predetermined condition is satisfied, and
• a process of specifying the number of revolutions according to the loop counter value when the detection result from the other angle detector has satisfied the specification condition shifted by the shift process.