A liquid ejection apparatus, including: a conveyor; and an ejector to eject a liquid; wherein each of an upstream roller pair, a first downstream roller pair, and a second downstream roller pair of the conveyor includes upper and lower rollers to respectively contact front and back surfaces of a recording medium, at least one of the upper and lower rollers being configured to give a conveyance force to the recording medium, wherein a rotation speed of the second downstream roller pair is higher than that of the first downstream roller pair, and the conveyance force of the first downstream roller pair is larger than that of the second downstream roller pair, and wherein the conveyance force of the second downstream roller pair is largest at a position thereof in the first direction which is nearest to the central position of the second downstream roller pair.

A medium transporting device includes a driving roller that transports a medium and that is driven to rotate, a driven roller that nips the medium between the driving roller and the driven roller and rotates in accordance with the rotation of the driving roller, a rotary shaft of the driven roller, a first pressing member that presses the rotary shaft in a direction in which the driven roller comes into contact with the driving roller, a second pressing member that presses the rotary shaft in a direction in which the driven roller comes into contact with the driving roller, and a spacer member that is integrally provided with a first spacer interposed between the rotary shaft and the first pressing member and a second spacer interposed between the rotary shaft and the second pressing member.

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 sheet feeding apparatus includes a stacking part, a feeding part, a separation part, an abutment part comprising an abutment area, the abutment part being configured to move between a first position and a second position, a transmission part comprising a rotary member and configured to transmit driving power from a driving source to the feeding part via the rotary member, the rotary member being configured to be stopped every one rotation, and a moving part configured to move the abutment part in response to rotation of the rotary member such that (1) the abutment part positions at the first position in a case where the rotary member is stopped, and (2) the abutment part moves from the first position to the second position and from the second position to the first position while the rotary member makes one rotation.

A paper thickness detecting device that detects a paper thickness in accordance with a detection signal of a displacement sensor, includes: a pair of paper thickness detecting rollers including a first roller and a second roller that pinch a paper conveyed via a pair of conveyance rollers; and the displacement sensor that detects a displacement amount of the pair of paper thickness detecting rollers at the time when the paper passes through the pair of paper thickness detecting rollers, wherein the paper thickness is detected on the basis of the displacement amount of the pair of paper thickness detecting rollers that follows to rotate with respect to the paper conveyed via the pair of conveyance rollers.

A transport roller, adapted to be used in a transport apparatus that transports a medium, includes a shaft, and a wheel group. The wheel group includes a plurality of toothed wheels arrayed in a direction in which the shaft extends, the plurality of toothed wheels being held by a holder which is held by the shaft. A plurality of teeth portions are provided on a peripheral surface of the wheel group, the plurality of teeth portions being disposed to be shifted in position from each other in a circumferential direction of the wheel group when the wheel group is viewed from the direction in which the shaft extends.

A sheet feed apparatus includes a sheet separation unit, and the sheet separation unit includes a separation roller that is provided so as to be brought into contact to an outer peripheral surface of a sheet feed roller, and separates a sheet fed by the sheet feed roller into one. The sheet separation unit comprises a hook for rotatably supporting the sheet separation unit in a main body casing of the sheet feed apparatus and an engaging claw that makes the sheet separation unit engage with the main body casing. Therefore, the sheet separation unit is held in the main body casing detachably.

An image processing device includes first and second feeding units. The first feeding unit feeds a sheet toward the second feeding unit in a sheet feeding direction via a sheet feeding path. The device further includes an image processing portion. The first feeding unit is in the path upstream of the processing portion and includes a first shaft rotating in the feeding direction. The second feeding unit is in the path downstream of the processing portion, and the first and the second units feed and hold the sheet. The second feeding unit includes a second shaft rotating in the feeding direction. The device includes a first supporting member supporting first and second ends of the first shaft, a second supporting member supporting first and second ends of the second shaft, and a third supporting member supporting one shaft at a predetermined portion which is not either end of either shaft.

A sheet feeding apparatus is provided with a pick-up roller that contacts sheets loaded on a load tray to pick up, a paper feed roller that feeds a picked-up sheet, and a separation roller brought into press-contact with the paper feed roller to separate the sheet, where the sheets are separated from the pick-up roller, the separation roller is rotated in a sheet return direction different from a sheet feed direction, and subsequently, the paper feed roller is separated from the separation roller. It is possible to prevent damage to a sheet and sheet jam from occurring in pulling out the load tray loaded with sheets to the front side.

A paper thickness detecting device that detects a paper thickness in accordance with a detection signal of a displacement sensor, includes: a pair of paper thickness detecting rollers including a first roller and a second roller that pinch a paper conveyed via a pair of conveyance rollers; and the displacement sensor that detects a displacement amount of the pair of paper thickness detecting rollers at the time when the paper passes through the pair of paper thickness detecting rollers, wherein the paper thickness is detected on the basis of the displacement amount of the pair of paper thickness detecting rollers that follows to rotate with respect to the paper conveyed via the pair of conveyance rollers.