Patent ID: 8503044

Claim:
An angle detection device, comprising: a horizontal axis rotator including: a rotating shaft supported by a case member inside the case member in a rotating shaft direction parallel to a horizontal plane of the case member; a center of gravity at a position different from a position of the rotating shaft; and a diagonal line formed on an outer circumferential surface of the horizontal axis rotator, the outer circumferential surface being a circumferential surface formed along a circumferential direction around a rotation axis of the horizontal axis rotator, the diagonal line intersecting with a width direction that is a direction orthogonal to the circumferential direction around the rotation axis if the outer circumferential surface is spread into a plane along the circumferential direction around the rotation axis; and an imaging sensor including an imaging element group that is a plurality of imaging elements arrayed in at least one line in an array direction that is a direction in which the plurality of imaging elements are arrayed, the array direction being parallel to the rotating shaft direction, the imaging sensor being fixed to the case member opposite to the outer circumferential surface inside the case member, wherein the imaging element group intersects with the diagonal line if the outer circumferential surface is viewed from the imaging sensor toward the rotating shaft, and an intersection position that is a position of the intersection changes according to rotation of the case member around the rotation axis when viewed from the rotating shaft.