Patent ID: 8587846

Claim:
A detection device comprising: a detection section comprising an illumination unit that illuminates light toward a conveyance path along which a medium is conveyed, and a light-sensing unit that senses reflected light of the light illuminated from the illumination unit, the detection section detecting at least one of an image on the medium conveyed along the conveyance path or the medium; and a reference section comprising a reference member that is disposed at an opposite side of the conveyance path from the side thereof at which the illumination unit is disposed and that is provided to be rotatable with a rotation axis direction being a width direction of the medium, the reference member having a polygonal rod shape that includes a plurality of reflection faces that reflect the light illuminated by the illumination unit toward the detection section, and the reference member being configured such that any of the reflection faces may be caused to oppose the conveyance path by rotation of the reference member; wherein one of the reflection faces of the reference member comprises a test face comprising a position detection pattern, a focal point detection pattern and a depth detection pattern, wherein the detection section detects a position of the test face in the direction of rotation via the position detection pattern; wherein the detection section detects a focal point via the focal point detection pattern; and wherein the detection section detects an illumination depth of the light illuminated from the illumination unit via the depth detection portion.