Provided is a paper feeding roll that prevents paper transportation failures over a long time. A paper feeding roll 10 is provided with an axial body 12 and an elastic layer 14 formed on an outer periphery of the axial body 12. The circumferential surface of the elastic layer 14 has a plurality of projections 16 forming surface unevenness. Each projection 16 of the plurality of projections 16 is shaped such that a position X of a distal-end part preceding in an opposite direction to a paper feeding direction precedes, in the opposite direction to the paper feeding direction, a position Y of a base-end part preceding in the opposite direction to the paper feeding direction.

A sheet feeding mechanism includes a feeding path, at least one card feeding roller mounted to the feeding path, at least one paper feeding roller coaxial with the at least one card feeding roller, at least one card idle roller contacting with the at least one card feeding roller, at least one paper idle roller contacting with the at least one paper feeding roller, at least one elastic unit connected to the feeding path, and a stroke limiting unit. The at least one elastic unit is fastened to the feeding path. The at least one elastic unit has a stretching stroke. The stroke limiting unit controllably shortens the stretching stroke.

A conveyance device includes a locking mechanism for an access cover. The locking mechanism includes a cooperating lever and a locking shaft attached to the cooperating lever. The locking shaft is slidable in an axial direction thereof between a locking position where the locking shaft engages in a locking groove of the access cover and a second unlocking position located lateral o the locking groove. When in the second unlocking position, the locking shaft engages with an engaged portion provided at part of a housing or at a fixed frame attached to the housing to constrain the cooperating lever against downward movement of a distal end of the cooperating lever. The locking mechanism further includes an operating member coupled to the locking shaft and including a holding portion capable of being held from outside the housing.

A one-way clutch includes: an outer member that has an inner periphery including an internal gear; an inner member that is rotatably disposed, and includes an engagement portion; and a planetary gear that is rotatable relative to the inner member, meshes with the internal gear, and is prevented from rotating by engaging with the engagement portion, wherein in a state in which the outer member and the inner member rotate together, the planetary gear engages with the engagement portion; in a state in which relative rotation between the outer member and the inner member is performed, the planetary gear disengages from the engagement portion; and in a state in which the planetary gear engages with the engagement portion, a top land of the internal gear abuts on a bottom land of the planetary gear.

A one-way clutch includes: an outer member that has an inner periphery including an internal gear; an inner member that is rotatably disposed, and includes an engagement portion; and a planetary gear that is rotatable relative to the inner member, meshes with the internal gear, and is prevented from rotating by engaging with the engagement portion, wherein in a state in which the outer member and the inner member rotate together, the planetary gear engages with the engagement portion; in a state in which relative rotation between the outer member and the inner member is performed, the planetary gear disengages from the engagement portion; and in a state in which the planetary gear engages with the engagement portion, a top land of the internal gear abuts on a bottom land of the planetary gear.

A sheet conveyance apparatus includes a first conveyance portion configured to convey a sheet, a second conveyance portion configured to convey the sheet, the second conveyance portion including an abutment portion configured to form a loop on the sheet by being abutted against a leading edge of a sheet conveyed by the first conveyance portion, a curved guide portion, which is curved, configured to guide the sheet conveyed by the first conveyance portion to the second conveyance portion, and a rotary member arranged downstream of the first conveyance portion and upstream of the second conveyance portion in a sheet conveyance direction, and configured to be driven to rotate by a surface of the sheet that is guided by the curved guide portion, the surface sliding against the curved guide portion.

A paper transmitting device including a feed wheel and a cleaning member is provided. The feed wheel is rotatably disposed for driving a document to move. The cleaning member is disposed on one side of the feed wheel, and has a fabric and porous structure and a woolen friction surface, so that the cleaning member contacts the feed wheel to clean the feed wheel.

A paper transmitting device including a feed wheel and a cleaning member is provided. The feed wheel is rotatably disposed for driving a document to move. The cleaning member is disposed on one side of the feed wheel, and has a fabric and porous structure and a woolen friction surface, so that the cleaning member contacts the feed wheel to clean the feed wheel.

A drive transmission device includes a chassis fixed to an apparatus main body and a driving roller that is driven by a driving source. A belt member transmits rotational force of the driving roller. A tension roller contacts the belt member to apply tension to the belt member. A support member supports the tension roller rotatably and is swingable about a rotational shaft of the chassis. A screw fixes the support member to the chassis at a predetermined position. A retaining member is able to be engaged with the chassis, in which the support member is arranged and fixed between a part of the retaining member and the chassis in an insertion direction of the screw.

A drive transmission device includes a chassis fixed to an apparatus main body and a driving roller that is driven by a driving source. A belt member transmits rotational force of the driving roller. A tension roller contacts the belt member to apply tension to the belt member. A support member supports the tension roller rotatably and is swingable about a rotational shaft of the chassis. A screw fixes the support member to the chassis at a predetermined position. A retaining member is able to be engaged with the chassis, in which the support member is arranged and fixed between a part of the retaining member and the chassis in an insertion direction of the screw.