A transport unit includes a glue belt, a pressurizing roller, a roller driving unit, and a control unit. The glue belt includes an adhesive layer. The pressurizing roller presses a medium against the adhesive layer while reciprocating in a Y direction. The roller driving unit generates a driving force for the pressurizing roller to reciprocate. The control unit controls the roller driving unit. The pressurizing roller is separated from the adhesive layer along with reciprocation. The control unit is capable of detecting a load of the roller driving unit, and determines whether the magnitude of the adhesive force of the adhesive layer is less than a target value, based on the load.

A transport device includes a transporting belt having an endless shape and configured to transport a medium, a first roller including a first circumferential surface brought into contact with the transporting belt, the first roller being a roller around which the transporting belt is wound, a second roller including a second circumferential surface brought into contact with the transporting belt, the second roller being a roller around which the transporting belt is wound, a pressing section including a bearing unit including a contact portion brought into contact with the first circumferential surface, the pressing section being configured to press the first circumferential surface on an inner side of the transporting belt, and a support portion disposed on an inner side of the transporting belt and configured to support the pressing section.

An optical media sensor includes a guide wall, a light emitter, a light receiver and a blower. The guide wall has an opening. The light emitter emits light to a medium sheet through the opening. The light receiver detects an amount of light travelling from the medium sheet. The blower generates a wind pressure that presses the medium sheet against the guide wall when detecting the amount of light.

A sheet feeding device includes a sheet accommodating portion for accommodating a sheet, a feeding roller for feeding the sheet by rotation thereof in a state in which the feeding roller contacts an uppermost sheet accommodated in the sheet accommodating portion, a detecting portion for detecting a surface property of the sheet accommodated in the sheet accommodating portion, a changing means for changing contact pressure of the feeding roller to the uppermost sheet, and a controller for controlling the changing means so as to change the contact pressure on the basis of a result of the surface property of the sheet detected by the detecting portion.

A sheet container includes a sheet loader, a pair of sheet regulators, a pressing member, and a pressing force adjusting device. The sheet loader is movable in a vertical direction and configured to load a sheet. The pair of sheet regulators is configured to regulate a position in a width direction of the sheet loaded on the sheet loader. The pressing member is disposed on at least one of the pair of sheet regulators and configured to press a lateral end face of the sheet, toward another one of the pair of sheet regulators in the width direction of the sheet. The pressing force adjusting device is configured to adjust pressing force generated by the pressing member to the sheet while maintaining a state in which the pressing member applies the pressing force to the sheet.

A sheet container includes a sheet loader, a pair of sheet regulators, a pressing member, and a pressing force adjusting device. The sheet loader is movable in a vertical direction and configured to load a sheet. The pair of sheet regulators is configured to regulate a position in a width direction of the sheet loaded on the sheet loader. The pressing member is disposed on at least one of the pair of sheet regulators and configured to press a lateral end face of the sheet, toward another one of the pair of sheet regulators in the width direction of the sheet. The pressing force adjusting device is configured to adjust pressing force generated by the pressing member to the sheet while maintaining a state in which the pressing member applies the pressing force to the sheet.

An image forming apparatus that has a transfer device that includes an intermediate transfer belt that is tensioned by a plurality of support rollers, a secondary transfer roller that faces one of the support rollers via the intermediate transfer belt, a cam that adjust a pressing force that presses the intermediate transfer belt by the secondary transfer roller, a motor that drives the cam, and a conveyor that conveys a recording medium to a transfer nip formed between the intermediate transfer belt and the secondary transfer roller is provided with a controller that controls an operation of the motor. The controller executes first control of operating the motor with a constant torque and stopping the motor when a rotation angular speed of the motor is less than or equal to a first threshold and second control of operating the motor at a predetermined timing to adjust a transfer nip amount.

A sheet feeding device includes a tray to store a stack of sheets, and a sheet elevation mechanism provided at the bottom of the tray to lift the stack of sheets until a top sheet of the stack of sheets reaches a predetermined height position. A paper feed roller is disposed above the tray to come in contact with the top sheet having reached the predetermined height position and rotated by a motor to deliver the top sheet from the tray. Additionally, the sheet feed device includes a controller to control the sheet elevation mechanism based on a drive torque of the motor to adjust the height position of the stack of sheets, after delivery of the first sheet from the tray by the paper feed roller and upon delivery of a second sheet by the paper feed roller. The frictional force to be produced between the second sheet and the paper feed roller is substantially equal to the frictional force produced between the first sheet and the paper feed roller during delivery of the first sheet.

A sheet feeding device includes a tray to store a stack of sheets, and a sheet elevation mechanism provided at the bottom of the tray to lift the stack of sheets until a top sheet of the stack of sheets reaches a predetermined height position. A paper feed roller is disposed above the tray to come in contact with the top sheet having reached the predetermined height position and rotated by a motor to deliver the top sheet from the tray. Additionally, the sheet feed device includes a controller to control the sheet elevation mechanism based on a drive torque of the motor to adjust the height position of the stack of sheets, after delivery of the first sheet from the tray by the paper feed roller and upon delivery of a second sheet by the paper feed roller. The frictional force to be produced between the second sheet and the paper feed roller is substantially equal to the frictional force produced between the first sheet and the paper feed roller during delivery of the first sheet.

A medium transport device includes a guide configured to guide a medium on which an image is recorded, and curved along a transport direction of the medium, and an actuator configured to actuate the guide between a contact position where the guide is in contact with the medium and a separation position where the guide is separated from the medium. The guide is configured to move to the contact position until a leading edge of the medium in the transport direction passes along the guide, and move to the separation position after the leading edge of the medium in the transport direction has passed along the guide.