Patent ID: 7568692

Claim:
A sheet feeder provided in an image forming apparatus, the image forming apparatus including at least one main frame mounted by screws in the image forming apparatus and defining a cassette accommodating space, the cassette accommodating space having a cassette insertion opening that opens to areas outside the image forming apparatus, the sheet feeder comprising: a sheet cassette in which sheets used for image formation are stacked, the sheet cassette being detachably insertable through the cassette insertion opening and into the cassette accommodating space along an inserting direction of the sheet cassette, a lifting mechanism mounted to the sheet cassette for movement with the sheet cassette relative to the main frame, the lifting mechanism being configured to receive a driving force from a location external of the sheet cassette for lifting the sheets stacked in the sheet cassette inserted into the cassette accommodating space up to a sheet feedable position, and a driving unit mounted on the main frame at a position for permitting insertion and removal of the sheet cassette into and out of the cassette accommodating space independent of the driving unit, the driving unit including a driving source and at least one gear driven by the driving source for giving a power to the lifting mechanism for lifting up the sheets by the lifting mechanism, wherein the driving source and the at least one gear of the driving unit are mounted on an inner part of the main frame facing the cassette accommodating space at such a position near the cassette insertion opening so that the at least one gear of the driving unit can be detached to the outside of the image forming apparatus through the cassette insertion opening with the sheet cassette detached from the cassette accommodating space, and wherein the driving source and the at least one gear of the driving unit are mounted at a position to be visually confirmed from outside of the image forming apparatus through the cassette insertion opening with the sheet cassette detached from the cassette accommodating space.