A sheet conveying device includes a sheet detection unit and a position adjusting mechanism. The position adjusting mechanism is disposed on a downstream side of the sheet detection unit in a sheet conveying direction in the sheet conveying path, includes an adjusting roller pair, and performs skew correction and positional displacement correction of a sheet, while conveying the sheet. The sheet conveying path includes a first conveying roller pair disposed on an upstream side of the position adjusting mechanism in the sheet conveying direction, and a curved part disposed between the adjusting roller pair and the first conveying roller pair, which curves in an S shape so as to be convex in a front and back side direction of the sheet alternately at different positions in the sheet conveying direction. The adjusting roller pair nips and conveys the sheet together with the first conveying roller pair.

A sheet conveyance apparatus includes a cover unit, a base unit, a roller unit configured to be detachable from the cover unit, and comprising a roller configured to convey the sheet along a conveyance path and a holder comprising an arm portion configured to extend in a width direction orthogonal to a sheet conveyance direction, a cam configured to swing the holder by rotating, and a cover member configured to be openable and closable with respect to the cover unit and configured to cover at least a portion of the arm portion against the conveyance path in a closed state, the cover member being opened by being pressed by the arm portion in a case where the roller unit is detached from the cover unit.

Provided are: a sheet feed device that is capable of suppressing the occurrence of a sheet feeding fault by changing the pressing contact force of a retard roller against a feed roller; and an image formation device equipped with the same. This sheet feed unit (50) is provided with: a pickup roller (29); a feed roller (31); a retard roller (32); a holding member (40) that holds the retard roller (32); a first biasing member (42) that biases the holding member (40); and a pressing contact force changing mechanism (60) that changes the pressing contact force of the retard roller (32) against the feed roller (31). The pressing contact force changing mechanism (60) has: a rotary shaft (61) disposed parallel to the axial direction of the retard roller (32); a cam member (70) that rotates with the rotary shaft (61); and a movable member (80) that contacts the cam member (70), moves in the axial direction in conjunction with the rotation of the cam member (70), and changes the biasing force generated by the first biasing member (42).

A sheet conveyer, including a body with a conveyer path, a first roller, a second roller, a roller holder supporting the second roller rotatably, an urging member urging the roller holder, and a guide member, is provided. The guide member is supported rotatably by the body at a position on a side opposite to the first roller across the second roller is pivotable between a closed position and an open position. The roller holder is movable between a first position, where the second roller contacts the first roller, and a second position, where the second roller is separated from the first roller and in which the roller holder contacts the guide member located at the open position. The roller holder located at the second position is restricted by the guide member from moving farther from the first position. The urging member urges the roller holder toward the first position.

A recording medium feeder includes: a first cassette and a second cassette that are disposed side by side in a cross direction and can be pulled out in the same pull-out direction; a housing that houses the first cassette and the second cassette; a transport unit that is disposed above the second cassette in the housing and transports a recording medium sent from the first cassette; and a feeding unit that is disposed in the housing and feeds a recording medium stored in the first cassette toward the transport unit, wherein the transport unit can be pulled out in the same direction as the first cassette and the second cassette, the feeding unit includes a first roller and a second roller that sandwich and transport a recording medium, and the first roller or the second roller releases the sandwiching when the first cassette is pulled out.

A sheet conveyance apparatus includes a cover unit, a base unit, a roller unit configured to be detachable from the cover unit, and comprising a roller configured to convey the sheet along a conveyance path and a holder comprising an arm portion configured to extend in a width direction orthogonal to a sheet conveyance direction, a cam configured to swing the holder by rotating, and a cover member configured to be openable and closable with respect to the cover unit and configured to cover at least a portion of the arm portion against the conveyance path in a closed state, the cover member being opened by being pressed by the arm portion in a case where the roller unit is detached from the cover unit.

A measuring device, includes a physical property value detector and a push contact member that pushes to bring a sheet material in contact with the physical property value detector; and further includes a first processor that stops conveyance of the sheet material, pushes to bring the sheet material in contact with the physical property value detector, and detects a physical property value of the sheet material; a second processor that, after having detected the physical property value, cancels the pushing by the push contact member, separates the sheet material from the physical property value detector, and starts conveyance of the sheet material; and a physical property value specifier that specifies the physical property value on a basis of physical property values of a plurality of positions within a surface of the sheet material detected by executing the first processing and the second processing repeatedly.

A medium conveying apparatus includes an imaging unit provided to be movable in a direction perpendicular to a conveying surface for conveying a medium, to image the medium, a roller pair provided on an upstream side of the imaging unit in a medium conveying direction, the roller pair including a first roller provided to be movable in a direction perpendicular to the conveying surface, and a second roller facing the first roller, and a conveyance guide provided on a rotation shaft of the first roller, to move in conjunction with a movement of the first roller. The conveyance guide includes a guide surface extending at least from a downstream end portion of a nip portion of the roller pair to an upstream end portion of the imaging unit in the medium conveying direction and being flush with a lower surface of the imaging unit.

A medium conveyor apparatus includes a main body, a first roller that is rotatably supported by the main body, and that receives a rotating force from a driving source, a bearing that is translationally movably supported by the main body, a second roller that is rotatably supported by the bearing, and that presses a medium against the first roller, and a rotation communicator that communicates a rotation from the driving source to the second roller, without communicating a rotation from the second roller to the driving source.

A sheet transport system for moving a sheet in a transport direction while adjusting a position of the sheet in a lateral direction normal to the transport direction to a target position, includes first and second pinch roller sets spaced apart from one another in the transport direction, each pinch roller set including two pairs of pinch rollers spaced apart from one another in the lateral direction, each pair forming a nip for pinching and driving the sheet with an individually controllable speed; a detection system for detecting a position of the sheet in the lateral direction while the sheet is pinched by the first pinch roller set; and a control system configured for carrying out the following actions: by controlling the speeds of the pinch rollers of the first pinch roller set before the sheet has reached the second pinch roller set, rotating the sheet by a first rotation angle for adjusting a given reference point on a leading part of the sheet to its target position; and when the sheet has left the first pinch roller set and while the reference point travels along a path segment that is symmetric with respect to the second pinch roller set, rotating, by controlling the speeds of the pinch rollers of the second pinch roller set, the sheet by a second rotation angle for aligning a leading edge of the sheet in the lateral direction.