Image forming apparatus having a plurality of sensors for detecting whether the fed sheet is an OHP or plain paper sheet

摘要

An image forming apparatus of the invention includes: a sheet- type determining device which determines whether the fed sheet is of plain paper or of OHP film; a first timer which sets up the arrival timing of the sheet for the high-speed mode; a second timer which sets up the arrival timing of the sheet for the low-speed mode; a selecting device which selects the first timer when the type of the sheet determined by the sheet-type determining device is plain paper and selects the second timer in the case of OHP film; and a warning device which, if in either of the modes, the sheet does not reach a predetermined site within the predetermined arrival time, determines that the sheet has jammed and informs the user of the point of jamming.