| 摘要 |
An image forming apparatus having: a slit plate (102) in which a plurality of slits of different widths are provided, the slit plate (102) being movable in an amount proportional to an amount of movement of a elevating plate (68); a sensor unit (104) disposed such that the slits pass between a luminous element and a light-sensitive element, the sensor unit outputting (104) a detection signal that indicates whether light emitted by the luminous element is in a transmitted state or not; and a control unit (106) that stores positions of the elevating plate (68) corresponding to ratios of neighboring slit widths, and identifies a position of the elevating plate corresponding to a slit width ratio derived from a detection signal outputted by the sensor unit (104), thereby deriving a remaining quantity of sheets on the elevating plate (68). |
