Sheet size detector for sheet container

Claim 1

An image recording apparatus, comprising: a plurality of containers for storing sheets to be fed therefrom, the sheets stored in the containers of a given recording apparatus being in one of a plurality of sheet size groups, a plurality of sheet guides in each of said containers for biasing sheets toward a predetermined location, the positions of said sheet guides corresponding to the sheet size in each of said containers, respectively; means for determining positions of said sheet guides and outputting position data corresponding to size range increments including the size of sheets disposed in each of said plurality of containers; memory means for storing sheet size data for a plurality of sheet size groups including at least a first sheet size group and a second sheet size group, at least said first and second sheet size groups including sheet sizes within a single size range increment; first means for comparing outputted position data from any one of said containers with sheet size data stored in said memory means to determine if sheets in a selected one of said containers are included in either of said first group or said second group or are included in said single size range increment common to said first and second groups; second means for comparing position data of another container in said given recording apparatus with sheet size data stored in said memory means to determine if sheets in said other container are included in either of said first or second groups and excluded from said single size range increment when said outputted position data from said one container corresponds to a sheet size included in said single size range increment; and means for determining the sheet size of sheets in said one container based upon outputted position data from said sheet guide position determining means and the size group of sheets stored in said given recording apparatus as determined by said first means or said second means.