Patent ID: 8360419

Claim:
A sheet feeding apparatus, comprising: a sheet feeding cassette, which is mounted in an apparatus main body, and has a cassette body configured to contain a sheet and a side regulation member which is movably disposed in the cassette body and is configured to contact and regulate an edge of the sheet with a front regulation surface; a sheet feeding portion configured to feed the sheet contained in the cassette body; and a size detecting portion, disposed on a side opposite to a side on which the sheet of the sheet feeding cassette is contained, configured to detect a size of the sheet contained in the cassette body, wherein the size detecting portion comprises: a size detecting lever, of which a distal end is in sliding contact with a back surface, parallel to the front regulation surface, of the side regulation member and a proximal end is supported by a pivotal shaft, the size detecting lever configured to pivot in association with a movement of the side regulation member to a regulation position according to the size of the sheet; a plurality of detection elements turned ON and OFF according to a pivotal position of the proximal end of the size detecting lever; and a protrusion which is protrudingly provided on the back surface of the side regulation member, the distal end of the size detecting lever being in sliding contact with the protrusion so that the size detecting lever is pivoted in a direction of separating away from the side regulation member according to a movement of the side regulation member toward the size detecting portion.