Patent ID: 7619205

Claim:
An image forming apparatus comprising: a main body including an image forming unit configured to form an image on a sheet transported through a sheet transport path, a detection unit including first and second photo sensors disposed in the main body and configured to detect movement of moving objects relating to an image forming process, and a control unit configured to control an operation of the moving objects based on a detection result in the detection unit, wherein the first photo sensor includes a first photo coupler having a first light emitting element and a first light receiving element arranged and disposed to be spaced from each other by a first interval, and a first prism coupled to the first photo coupler, the first prism having a first optical path to guide a light from the first light emitting element to the first light receiving element, and provided with a first slit that is wider than the first interval in the first optical path, through which a first object to be detected can pass, and wherein the second photo sensor includes a second photo coupler having a second light emitting element and a second light receiving element arranged and disposed to be spaced from each other by the first interval, and a second prism coupled to the second photo coupler, the second prism having a second optical path to guide a light from the second light emitting element to the second light receiving element, and provided with a second slit that is equal to or narrower than the first interval in the second optical path, through which a second object to be detected can pass.