Patent ID: 8573588

Claim:
A medium feeding cassette for storing a medium, said medium feeding cassette comprising: a cassette main body; a cassette extension member mounted to said cassette main body and provided so as to align the medium and extend from said cassette main body at an upstream side of said cassette main body in a feeding direction of said medium, said cassette extension member being movable with respect to said cassette main body; a locking mechanism configured to lock said cassette extension member in a predetermined position with respect to said cassette main body according to a size of said medium, said locking mechanism comprising a first locking portion and a second locking portion that engage each other so as to lock said cassette extension member in said predetermined position, said first locking portion comprises a convex portion and said second locking portion comprises concave portions, wherein said concave portions comprise a first concave portion that holds said cassette extension member at an extending position where said cassette extension member protrudes from said cassette main body, and a second concave portion that holds said cassette extension member at a retracting position where said cassette extension member is retracted from said extending position, the locking mechanism includes a flat portion disposed between the first concave portion and the second concave portion; a first releasing mechanism that releases locking of said cassette extension member by said locking mechanism; and a second releasing mechanism that releases locking of said cassette extension member by said locking mechanism, said second releasing mechanism being operable independently from said first releasing mechanism, wherein said convex portion moves in a direction to release locking of said cassette extension member when a force is applied to any portion of said cassette extension member in a direction to retract said cassette extension member into said cassette main body.