Patent ID: 8348265

Claim:
An image forming apparatus comprising: a paper feeding unit operable for feeding a sheet; an image forming unit operable for forming a toner image on the sheet; a skew correcting roller pair which the conveyed sheet contacts such that at least a portion of the sheet bends; a rotary member pair operable for conveying the sheet to the skew correcting roller pair; a first sensor disposed upstream of the skew correcting roller pair in the sheet conveying direction in which the sheet is conveyed, the first sensor comprising: a first transmitting unit operable for transmitting a sending signal; and a first receiving unit positioned opposite the first transmitting unit having an interval therebetween such that a conveying path through which the sheet is conveyed is disposed therebetween and which is configured to output an output voltage representative of the sending signal received by the first receiving unit; a first signal processing unit configured to process the output voltage of the first receiving unit and configured to output a first reception level signal indicating a reception level of the sending signal received by the first receiving unit from the sending signal transmitted by the first transmitting unit; and a control unit configured to: control sheet conveyance in the image forming apparatus; receive the first reception level signal; and evaluate, based on at least the first reception level signal, bending of the sheet contacting the skew correcting roller pair; wherein the skew correcting roller pair is rotated after the sheet is sufficiently bent.