Sheet supply device and image forming apparatus

An image forming apparatus, comprising:

• a image forming unit that forms an image on a recording medium serving as a sheet;
• and
• a sheet supply device that comprises:
• a device main body;
• a storage cassette comprising a stacking portion capable of moving up and down and including a hole, on which a sheet is loaded, the storage cassette capable of being pulled out of the device main body;
• a lifting mechanism that lifts up the stacking portion by using driving power supplied from a driving source;
• a delivery unit that is disposed above the stacking portion and performs a delivering operation in a contact state with the sheet on the stacking portion lifted by the lifting mechanism, thereby delivering the sheet to a downstream side in a conveying direction;
• a control unit that controls the delivering operation of the delivery unit;
• and
• a detecting unit comprising a swing member, which contacts the sheet in a location different from a contact location of the delivery unit, and a detecting portion that detects whether the sheet is loaded at a predetermine detecting position above the stacking portion based on a position of the swing member;
• wherein, when the detecting unit detects that the sheet is loaded at the predetermined detecting position, the control unit starts the delivering operation of the delivery unit,
• wherein, when the detecting unit detects that no sheet is loaded at the predetermined detecting position, the swing member is inserted into the hole, and
• wherein the control unit determines whether the sheet is loaded at the predetermined stacking position based on whether the detecting unit detects whether the sheet is loaded on the stacking portion within a predetermined time after the lifting mechanism starts to lift the stacking portion.