Image processing apparatus

摘要

The present invention provides an image processing apparatus capable of forming a sharp image of a detection mark formed in a plane. The image processing apparatus comprises a camera unit (1) comprising a lens system (12) and a photodetecting device (13) inclined at a predetermined angle to the optical axis (L') of the lens system. The camera unit (1) is disposed with the optical axis (L') of the lens system (12) inclined at a predetermined angle to a perpendicular line (L) to the plane including the detection mark so that the difference in length between respective sections of light paths between diametrically opposite portions of the detection mark and the lens system is canceled by the difference in length between respective sections of the same light paths between the lens system and the photodetecting device.