US Patent 7590361 Image forming apparatus and control method therefor

An image forming apparatus includes a position detection circuit which detects the registration error amount between a recording medium conveyance unit and an image forming unit positioned by a positioning mechanism, on the basis of reading of a reference pattern arranged on either unit, and a controller which calculates a correction amount on the basis of the detected registration error amount and controls the operation timings of the image forming unit and recording medium conveyance unit in accordance with the correction amount.