Image forming apparatus having detachable sheet cassette

An image forming apparatus for forming an image on a sheet comprising:

• a main body portion provided with an image forming section;
• a sheet cassette detachably provided to the main body portion for storing therein a stack of a plurality of cut sheets;
• sheet supplying means for supplying each one of the sheets from the sheet cassette;
• sheet feeding means for feeding the sheet supplied by the sheet supplying means to the image forming section, the sheet feeding means comprising a first sheet feed roller rotatably supported by the main body portion, and a second sheet feed roller supported by the sheet cassette at a position confrontable with the first sheet feed roller when the sheet cassette is fully attached to the main body portion;
• sheet guide means including first and second guide plates provided at the main body portion for defining a sheet feed passage ridging between the sheet feeding means and the image forming section, the first guide plate being pivotally movable in a state of detachment of the sheet cassette from the main body portion for providing an open space at the sheet feed passage;
• and
• biasing means provided in the sheet cassette for urging the second roller toward the first roller when the sheet cassette is attached to the main body portion.