An angle detection mechanism to detect a rotation angle of a rotation body includes a first detection unit to cause a first output value to constantly change in response to an angle change of the rotation body in the entire region of a specific rotation range and to set a change quantity of the first output value relative to the angle change in a first rotation region of the specific rotation range to be greater than a change quantity in a non-first rotation region, and a second detection unit to cause a second output value to constantly change in response to an angle change and to set a change quantity of the second output value in a second rotation region including a rotation region different from the first rotation region to be greater than a change quantity in a non-second rotation region.