Patent ID: 7635123

Claim:
An image forming apparatus, comprising: a bypass sheet supplier configured to supply a recording medium and including a bypass tray configured to load the recording medium, a lateral side fence configured to regulate the recording medium in a main scanning direction, and a sensor unit configured to detect whether a lateral edge of the recording medium extending in a sub-scanning direction contacts the lateral side fence; a control mechanism configured to issue one of a first warning and a first guidance indicating that the recording medium is not properly set on the bypass tray when the recording medium is not contacted by the lateral side fence; an image forming mechanism configured to form an image on the recording medium sent from the bypass sheet supplier according to image data; a carriage detector configured to detect whether or not the image forming mechanism is lifted up to a predetermined height in accordance with a thickness of the recording medium; a conveyer configured to convey the recording medium from the bypass tray to the image forming mechanism; a conveyer controller configured to determine whether there is no recording medium being conveyed by the conveyer; an output tray configured to receive the recording medium having the image formed by the image forming mechanism and conveyed from the image forming mechanism without being reversed; and an output tray detector configured to detect an event that the output tray is opened, wherein the bypass sheet supplier further includes a shutter disposed upstream of one of the conveyer and the image forming mechanism in a sheet conveyance direction and configured to regulate a foremost edge of the recording medium in the sub-scanning direction, and a shutter sensor disposed near an end contact portion of the shutter, the shutter being configured to contact the foremost edge of the recording medium and the shutter sensor being configured to detect whether the foremost edge of the recording medium contacts the shutter or not, wherein the control mechanism issues one of a second warning and a second guidance indicating that the recording medium is not properly set on the bypass tray when the foremost edge of the recording medium does not contact the shutter, wherein the control mechanism opens the shutter to convey the recording medium from the bypass tray to the image forming mechanism when the sensor unit detects an event that the lateral edge of the recording medium contacts the lateral side fence, the shutter sensor detects an event that the foremost edge of the recording medium contacts the shutter, the carriage detector detects an event that the image forming mechanism is lifted up to the predetermined height, the conveyor controller determines that there is no recording medium being conveyed, and the output tray detector detects an event that the output tray is opened.