A sheet feeder includes: a first roller; a separation member; a shutter; a pressing portion; and a cam portion. The separation member contacts the first roller at a contact position. An axis of the shutter is positioned downstream of the separation member in a conveying direction. The shutter is movable between first and second positions. The shutter in the first position has a portion positioned upstream of the contact position in the conveying direction. The pressing portion is positioned upstream of the separation member and the shutter in the first position in the conveying direction. The pressing portion is movable between third and fourth positions. The pressing portion in the third position faces the first roller. The pressing portion in the fourth position is separated from the first roller farther than in the third position. The cam portion is positioned upstream of the pressing portion in the conveying direction.

In one example implementation, a printing device may comprise a number of media skewing rollers to skew a print medium to a predetermined angle with respect to a media feed path and a print engine to print an image on the skewed print medium, the print engine skewing a digital representation of the image based on the predetermined angle such that the image printed is aligned with the print medium. In another example implementation, a printing device may comprise a number of skewing rollers to skew a print medium to a predetermined angle with respect to a media path, a number of pinch rollers to receive the skewed print medium prior to printing, and a print engine skewed to the same predetermined angle as the skewed print medium.

A paper feeding device comprises a storage surface for a stack of papers and being adapted to be move vertically between a first, lower end position and a second, upper end position, and a feeding roll for feeding papers from their position on the storage surface and imparting an uppermost sheet of paper a horizontal displacement. A first mounting device comprises a first vertically movable, preferably pivotable housing adapted to mount or suspend a first end of the feeding roll, and a second mounting device comprises a second vertically movable, preferably pivotable housing adapted to mount or suspend a second end of the feeding roll opposite to the first end of the feeding roll. By providing the first and second housings pivotable independently of each other and an intermediate axle, the feeding roll adapts to a non-uniform stack of papers, improving the reliability of the feeding.

A medium transportation device includes a transportation driving roller that transports a medium; a roller unit including a separation roller as a driven roller that is rotated by rotation of the transportation driving roller and a shaft which penetrates a rotation center of the separation roller; a holder that detachably holds the roller unit; and a lock mechanism that switches between an unlocked state in which the roller unit is unlocked from the holder and a locked state in which the roller unit is locked to the holder.

A medium, of which skew is appropriately corrected, is fed from an intermediate unit to a post processing unit so as to suppress an adverse effect of the skew of the medium in the post processing unit.

A sheet separation mechanism comprises a separation roller set and a reverse roller set rotating in the same rotation direction. The reverse roller set presses sheets onto the separation roller set to stop one or multiple ones of the sheets close to the reverse roller set from passing through a nip between the separation and reverse roller sets, and allow the sheet directly contacting the separation roller set to pass through the nip. The reverse roller set comprises a shaft, and two reverse rollers and an annular member all mounted on the shaft, which rotates the reverse rollers. The annular member, disposed between the two reverse rollers, is rotatable relatively to the shaft and movable relatively to the shaft in a radial direction of the shaft. The annular member and the reverse rollers commonly press the sheets. A sheet-fed scanning apparatus using the sheet separation mechanism is also provided.

A conveyor includes: a first roller; a second roller opposed to the first roller; a roller holder including a roller supporter; a frame supporting the roller holder and having a first surface and second surface; and a moving member that is moved to move the roller supporter. The roller holder includes: a contact portion that is located upstream of the roller supporter in a conveying direction and contacts the second surface; a thin portion disposed between the roller supporter and the contact portion; and an engaging portion engaged with the moving member at a position located downstream of the thin portion in the conveying direction. The roller supporter is moved from a first position to a second position by bending of the thin portion, which bending is caused when the engaging portion is moved away from the second roller with movement of the moving member.

An image forming apparatus includes a print medium tray in which a print medium is loaded and a pickup roller which is configured to pick up the loaded print medium from the print medium tray. The pickup roller includes at least one first pickup block and at least one second pickup block configured to alternately come into contact with an upper portion of the loaded print medium. Using such a configuration, the pickup performance of the image forming apparatus may be improved.

A sheet conveying apparatus, including: a base body having a conveyor surface; a separating roller configured to rotate about a first rotation axis parallel to a width direction of the conveyor surface and to convey a sheet downstream in a conveyance direction orthogonal to the width direction; a separating piece opposed to the separating roller and configured to cooperate with the separating roller to separate sheets being conveyed one by one; an attachment member removably attached to the base body at a position at which the attachment member is opposed to the separating roller, so as to form a part of the conveyor surface; a holder holding the separating piece and supported by the attachment member so as to be movable toward and away from the separating roller; and a first urging member provided between the attachment member and the holder for urging the separating piece toward the separating roller.

A sheet separation mechanism comprises a separation roller set and a reverse roller set rotating in the same rotation direction. The reverse roller set presses sheets onto the separation roller set to stop one or multiple ones of the sheets close to the reverse roller set from passing through a nip between the separation and reverse roller sets, and allow the sheet directly contacting the separation roller set to pass through the nip. The reverse roller set comprises a shaft, and two reverse rollers and an annular member all mounted on the shaft, which rotates the reverse rollers. The annular member, disposed between the two reverse rollers, is rotatable relatively to the shaft and movable relatively to the shaft in a radial direction of the shaft. The annular member and the reverse rollers commonly press the sheets. A sheet-fed scanning apparatus using the sheet separation mechanism is also provided.