A sheet feeding device includes a sheet stacking unit, a long sheet stacking unit, a first guide, a first detector, and a closing unit. The sheet stacking unit is movable up and down. Sheets are stacked on the sheet stacking unit. The long sheet stacking unit is detachably mounted on the sheet stacking unit. Long sheets are stacked on the long sheet stacking unit. The first guide is movable along a feeding direction through a groove. The first guide is deformable into a shape that does not interfere with the long sheet stacking unit. The first guide guides a rear end portion of the sheets in the feeding direction. The first detector is provided in the first guide. The first detector detects the sheets stacked on the sheet stacking unit. The closing unit is detachably attached to the groove in the sheet stacking unit. The closing unit closes the groove.

An image forming apparatus includes a unit group including a specific unit having a specific component that performs an operation necessary for notification of paper remaining on a mounting surface; and a processor configured to control supply of power to the unit group at a return from a sleep state based on a return event, in which the processor is configured to in a case where there is no paper on the mounting surface at a transition to the sleep state, perform first control to supply power to a specified power supply destination corresponding to the return event at the return from the sleep state, and in a case where there is a paper on the mounting surface at the transition to the sleep state, perform second control to supply power to the specific unit at the return from the sleep state even in a case where the specific unit is not included in the specified power supply destination of the unit group.

A feeding device includes a loading portion, a lifting mechanism, a conveying unit, a sheet detector, a near-end detector, and process circuitry. The loading portion stacks a plurality of sheets. The lifting mechanism lifts the loading portion. The conveying unit conveys the sheets on the loading portion. The sheet detector detects presence or absence of the sheets on the loading portion at a specified height position. The sheet count detector detects a number of sheets conveyed by the conveying unit. The near-end detector detects a near-end state in which a stack height of the sheets on the loading portion is a specified value or less. The process circuitry controls the lifting mechanism based on a detection result of the sheet detector before the near-end state is detected, and controls the lifting mechanism based on a detection result of the sheet count detector after the near-end state is detected.

A paper feed device includes: a sensor unit that includes a coil substrate and a conductive plate which is opposite the coil substrate, that outputs an output value corresponding to a position of the conductive plate; a first cursor link mechanism which moves the first conductive plate according to the position of the first cursor in the longitudinal direction of the first coil substrate; a storage unit which stores first sheet size data; and a control unit which recognizes the magnitude of the first output value of the sensor unit and which recognizes, based on the recognized magnitude of the first output value and the first sheet size data, the size of the set sheets.

A sensor can sense a weight of items in an area. A sensor can sense a height of items in the area. An available capacity of the area can be determined based on the sensed weight and height.

A detector includes a first member that makes contact with an upper surface of a paper sheet stored in a sheet feeding cassette, and a second member that supports the first member such that it is capable changing postures, while also movably supporting the first member in an up-and-down direction to coincide with the upper surface of a paper sheet stored in the sheet feeding cassette. The first member has a guide portion that makes contact with the sheet feeding cassette and/or a paper sheet stored in the sheet feeding cassette. The first member changes postures with respect to the second member as a result of the guide portion making contact with the sheet feeding cassette and/or a paper sheet stored in the sheet feeding cassette.

Provided is an image-forming device that improves convenience for a user. The image-forming device includes a plurality of power-supply stages, remaining paper amount detection sensors, and a system control unit. A remaining paper amount detection sensor detects the remaining paper amount in a paper-supply stage. When the remaining paper amount that is detected by the remaining paper amount detection sensor is less than a fixed value, the system control unit sets the paper-supply stage having a paper amount that is less than the fixed value as a FAX use only paper-supply stage.

An image forming apparatus includes a medium storing part storing mediums, a sheet feeding part feeding the medium from the medium storing part, an image forming part forming an image to the medium, a residual quantity detecting part, a storage part, and a residual medium estimating part. The residual quantity detecting part detects a residual quantity of the mediums stored in the medium storing part as a relative residual quantity with regard to a maximum storing quantity of the mediums in the medium storing part. The storage part stores maximum storing number of the mediums corresponding to the maximum storing quantity of the medium storing part. The residual medium estimating part calculates number of estimated residuals of the mediums stored in the medium storing part on the basis of the relative residual quantity detected by the residual quantity detecting part and the maximum storing number stored in the storage part.

A feeding device includes a feeding device body of which a downstream end portion in a feeding direction, in which a material to be fed is fed, is mounted on a mounting portion, and that is openable and closable between a closed position where an upstream end portion is positioned above the downstream end portion and an open position where the upstream end portion is positioned on a side of the downstream end portion, a stacked portion that is provided on the feeding device body and on which the material to be fed is stacked in the open position, a detection unit that has a detection member hanging down to a downstream end portion of the stacked portion in the open position, moves to a downstream side in the feeding direction as the detection member is pressed by a downstream end portion of the material to be fed stacked on the stacked portion, and detects a stack of the materials to be fed on the stacked portion, and a restriction unit that restricts movement of the detection member to the downstream side in the feeding direction in the closed position.

An image forming system includes a first feeding portion configured to feed a recording sheet, a second feeding portion configured to feed an inserting sheet from one of a plurality of supporting portions, and a controller configured to execute a determination process of determining whether or not there is a supporting portion usable as a new feeding source other than a supporting portion serving as a current feeding source of an inserting sheet. The controller is capable of switching between first control and second control in which a feeding process of a recording sheet is executed respectively in a first mode and a second mode in a case where it has been determined in the determination process that there is no supporting portion usable as the new feeding source.