A sheet feeding apparatus includes a sheet presence/absence detection sensor configured to detect presence or absence of a sheet on a stacking device, a sheet surface detection sensor configured to detect that a stacking tray is raised to enable a sheet to be fed, a separation cam, and a control unit. The control unit is configured to determine that the mounting state of a feeding holder to a holder support unit is defective when the sheet surface detection sensor detects that the sheet can be fed when the sheet presence/absence detection sensor detects absence of a sheet before sheet feeding processing by a pickup roller.

A sheet conveying apparatus includes: a casing provided with a first conveying path and a second conveying path; a first feeding tray provided in the casing and having a first supporting surface that supports a sheet; a supporting member that supports the first feeding tray from below in the casing; a first feeding section provided above the first supporting surface; a first guide member having a first guide surface to guide the sheet fed from the first feeding tray; a second feeding tray provided below the supporting member in the casing and having a second supporting surface that supports a different sheet; a second feeding section provided above the second supporting surface; a second guide member having a second guide surface to guide the different sheet fed from the second feeding tray; and a frame made of metal and being installed on a lower surface of the supporting member.

A sheet storage device includes a case, a lift plate, and a lift attachment. The lift attachment is fixed, in a detachable manner, to a central portion of the lift plate in a width direction. The lift attachment supports a lower surface of the sheets stacked on the lift plate at a position higher than the upper surface of the lift plate. The lift attachment includes a base portion and a pair of arm portions. The pair of arm portions are respectively formed to extend from an end portion of the base portion that is on a downstream side in the sheet feed direction, to opposite directions in the width direction.

The image forming apparatus includes a sheet storing unit insertably and pullably attached to the frame unit, an image forming unit, and a frame unit. The frame unit includes two frame members parallel to each other with a predetermined distance therebetween and are connected and fixed to each other. The two frame members respectively include engaged portions. The sheet storing unit includes engaging portions respectively engageable with the engaged portions in a state where the sheet storing unit is inserted in the frame unit. In a state where the engaging portions respectively engage with the engaged portions, the engaging portions that respectively engage with the engaged portions and a portion between the two engaging portions of the sheet storing unit serve as strengthening members to regulate deformation of the two frame members by at least a predetermined amount.

There is provided a conveyance unit including a conveyance roller; a nip member movable between a contact position and a separation position; a tray movable between an installation position and a pull-out position; and a lever. The lever is configured to have a first state, a second state and a third state. The lever in the first state can make contact with the tray moving between the installation position and the pull-out position. The lever pivots from the first state to the second state when the tray moves from the installation position to the pull-out position, and the lever pivots from the first state to the third state when the tray moves from the pull-out position to the installation position. The conveyance unit further includes an interlocking mechanism.

A sheet feeding device (4) includes a placing plate (34) on which a sheet is placed; a pickup roller (71) which feeds the sheet to a conveying path (25); a lift member (36) which is turned around a rotating shaft (46) to elevate the placing plate (34) and to make an downstream side end portion of an uppermost sheet in a conveying direction come into contact with the pickup roller (71); a drive unit (37) which rotates the rotating shaft (46); a variable resistor (54) which changes an electric resistance value depending on a rotating angle of the rotating shaft (46); and a control part (77) which calculates the rotating angle of the rotating shaft (46) using the electric resistance value measured by the variable resistor (54) and detects an amount of the sheets based on the calculated rotating angle.

An image forming apparatus includes an accommodation unit, feeding, conveying, and separating members, and detecting, control, image forming, and regulating units. The conveying member conveys a fed recording material. The separating member forms a nip and separates recording materials. The detecting unit detects that the recording material has been fed to the nip. The feeding member starts feeding an accommodated recording material and, where a recording material is fed to the nip, causes the feeding to be finished. An image is formed on a fed recording material. The regulating unit regulates an end on an upstream side. The control unit measures a period from a recording material feeding to detection that a recording material is fed to the nip. Based on the measured period, information is output indicating that a position of the regulating unit is deviated from a position according to a size of the accommodated recording materials.

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.

A sheet positioning member is provided on a sheet placing surface in such a way as to be movable in a predetermined first direction. The sheet positioning member includes a moving body, an abutting portion, an operation member, and a cam portion. The moving body moves in the first direction on the sheet placing surface. The abutting portion has an abutting surface that abuts on the side end portion when the sheet positioning member positions the sheet. The operation member is supported by the moving body so as to be pivotable around a support shaft that extends in the first direction, on a side of a back surface of the abutting portion. The cam portion displaces the abutting portion toward the side end portion by being pressed by the operation member in response to a pivoting operation of the operation member.

A sheet feeding device includes an upper sheet container, a lower sheet container, and a sheet detector. The lower sheet container disposed below the removable upper sheet container is configured to contain a sheet. The sheet detector is configured to detect the sheet in the lower sheet container and includes a sheet contact member disposed above the lower sheet container. The sheet contact member is contactable to the upper sheet container and the sheet in the lower sheet container. Either the upper sheet container or the sheet contact member has a sloped face inclined downward from downstream toward upstream in a container insertion direction, on at least one of a downstream side in the container insertion direction of a lower portion of the upper sheet container and an upstream side in the container insertion direction of an upper portion of the sheet contact member.