Patent ID: 7644921

Claim:
An image forming apparatus comprising: a conveying device configured to convey a recording medium; a support shaft which is configured to be movably supported between a medium sensing position near a conveyance path along which the conveying device conveys the recording medium and a retracting position away from the medium sensing position, wherein the support shaft is biased to the medium sensing position; a medium sensing member connected to the support shaft and configured to rotate between a standby position wherein a portion of the medium sensing member is in the conveyance path and a detection position wherein the portion of the medium sensing member is removed from the conveyance path by the recording medium passing along the conveyance path when the support shaft is in the medium sensing position; and a rotation detection device configured to detect a rotational displacement of the medium sensing member, wherein at least a first end portion of the support shaft is supported by and laterally movable within a shaft hole and the support shaft is movable between the medium sensing position and the retracting position.