Patent ID: 7059597

Claim:
A sheet supply apparatus for supplying a sheet, comprising: a sheet supply tray for stacking the sheet; an auxiliary tray movably attached to the sheet supply tray to move between a support position where the auxiliary tray supports a portion of the sheet stacked on the sheet supply tray and a storage position where the sheet supply tray overlaps the auxiliary tray; sheet supply means situated adjacent to the sheet supply tray for supplying the sheet stacked on the sheet supply tray; sheet detection means mounted on the auxiliary tray and having detection positions changed by a movement of the auxiliary tray, said sheet detecting means detecting presence or absence of the sheet stacked on the auxiliary tray; tray position detection means for detecting a position of the auxiliary tray between the support position and the storage position; and identifying means electrically connected to the sheet detection means and the tray position detection means for identifying a length of the sheet in a sheet supply direction based on detection results of the sheet detection means and the tray position detection means.