PAPER FEEDING APPARATUS DETECTING RECORDING PAPER PRESENCE/ABSENCE, PAPER FEED CASSETTE ATTACHING/DETACHING, AND LIFT PLATE REACHING RISING STOP POSITION, AND IMAGE FORMING APPARATUS EQUIPPED WITH THE SAME

摘要

Provided is a paper feeding apparatus that commonalizes mechanisms for detecting paper feed cassette attaching/detaching, recording paper presence/absence, and lift plate reaching rising stop position. When paper feed cassette is removed, a contact piece has first inclination, a light shielding piece has first position, and a first sensor and a second sensor are OFF. When paper feed cassette having no recording paper is inserted, contact piece has second inclination by an opening edge part; light shielding piece has second position; and a first sensor is OFF, a second sensor being ON. When recording paper is on lift plate, contact piece has third inclination by recording paper, light shielding piece having third position, and first sensor and second sensor being ON. When lift plate is raised to rising stop position, contact piece has fourth inclination, light shielding piece having fourth position, first sensor being ON and second sensor being OFF.

主权项

1. A paper feeding apparatus, including an attachable and detachable cassette having a lift plate, a paper being placed thereon, and a raising part to raise the lift plate, comprising:
a contact piece, being inclined by said lift plate; a light shielding member, being turned in accordance with the inclination of the contact piece; and an optical sensor part, detecting a position of the light shielding member, an opening being formed in said lift plate, said optical sensor part distinguishably detecting said light shielding member having reached a first position, upon said cassette having been removed, thereby said contact piece having had a first inclination; said light shielding member having reached a second position, upon said contact piece having been contacted with an opening edge part formed in said lift plate, thereby having had a second inclination; said light shielding member having reached a third position, upon said contact piece having been contacted with the uppermost layer of the paper placed on said lift plate positioned in the lowest position, thereby having had a third inclination; and said light shielding member having reached a fourth position, upon said raising part having been driven to raise said lift plate to a rising stop position to feed said paper, thereby said contact piece having had a fourth inclination.