Example implementations relate to media stacking mechanisms. In some examples, a printing device can include a stacking mechanism that includes a tamper to tamp print media positioned within the stacking mechanism, and a controller comprising instructions to: tamp a first sheet of print media received at the stacking mechanism a first distance based on a first size of the first sheet of print media, tamp a second sheet of print media received at the stacking mechanism a second distance based on the second size of the second sheet of print media, wherein the second sheet of print media is positioned over the first sheet of print media, and tamp a third sheet of print media received at the stacking mechanism the second distance when the third sheet of print media is the first size, wherein the third sheet of print media is positioned over the second sheet of print media.

A hold down finger for a finisher process tray contacts the top sheet of paper on a paper tray to prevent subsequently printed pages from disturbing pages disposed on the paper tray. The hold down finger includes gears that move a portion of the hold down finger that contacts the top sheet of paper from a retracted position to a forward hold down position along a substantially elliptical path. After each sheet is printed and placed on top of other pages in the paper tray, the paper tray lowers and the hold down finger continues along the substantially elliptical path back to the retracted position. A rack gear associated with the paper tray engages a cylindrical gear of the hold down finger to return the hold down finger to the retracted position if the paper tray is forced upwards while the hold down finger is in the forward position.

A hold down finger for a finisher process tray contacts the top sheet of paper on a paper tray to prevent subsequently printed pages from disturbing pages disposed on the paper tray. The hold down finger includes gears that move a portion of the hold down finger that contacts the top sheet of paper from a retracted position to a forward hold down position along a substantially elliptical path. After each sheet is printed and placed on top of other pages in the paper tray, the paper tray lowers and the hold down finger continues along the substantially elliptical path back to the retracted position. A rack gear associated with the paper tray engages a cylindrical gear of the hold down finger to return the hold down finger to the retracted position if the paper tray is forced upwards while the hold down finger is in the forward position.

A medium passage switching mechanism disposed on a casing of an image forming device, includes a medium tray, a guiding component and a resilient component. An entrance passage, a first exit passage and a second exit passage are formed inside the casing. The medium tray is pivoted to the casing and can pivot between a first position and a second position. The guiding component is pivoted to the casing and can pivot between a third position and a fourth position. The resilient component abuts against the guiding component and the casing. When the medium tray pivots between the first position and the second position, the guiding component can be driven by cooperation of the resilient component and the medium tray to pivot between the third position and the fourth position for guiding a medium to enter into the first exit passage or the second exit passage from the entrance passage.

A medium passage switching mechanism disposed on a casing of an image forming device, includes a medium tray, a guiding component and a resilient component. An entrance passage, a first exit passage and a second exit passage are formed inside the casing. The medium tray is pivoted to the casing and can pivot between a first position and a second position. The guiding component is pivoted to the casing and can pivot between a third position and a fourth position. The resilient component abuts against the guiding component and the casing. When the medium tray pivots between the first position and the second position, the guiding component can be driven by cooperation of the resilient component and the medium tray to pivot between the third position and the fourth position for guiding a medium to enter into the first exit passage or the second exit passage from the entrance passage.

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 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 printing device includes a holder including: a first movable portion including a first support portion; a second movable portion including a second support portion; a pinion; a spring; an adjustment screw; a handle rotatable with the adjustment screw; and a stopper threadingly engaged with the adjustment screw. The first movable portion is movable in a first direction and a second direction opposite the first direction. The second movable portion is movable in the first direction and the second direction in accordance with movement of the first movable portion in the second direction and the first direction. The handle is positioned outside of a region defined between the first and second support portions positioned remotest from each other in the first direction. The stopper is in abutment with one of the first and second movable portions to restrict movements of the first and second movable portions.

A printing device includes a holder including: a first movable portion including a first support portion; a second movable portion including a second support portion; a pinion; a spring; an adjustment screw; a handle rotatable with the adjustment screw; and a stopper threadingly engaged with the adjustment screw. The first movable portion is movable in a first direction and a second direction opposite the first direction. The second movable portion is movable in the first direction and the second direction in accordance with movement of the first movable portion in the second direction and the first direction. The handle is positioned outside of a region defined between the first and second support portions positioned remotest from each other in the first direction. The stopper is in abutment with one of the first and second movable portions to restrict movements of the first and second movable portions.

A hold down finger for a finisher process tray contacts the top sheet of paper on a paper tray to prevent subsequently printed pages from disturbing pages disposed on the paper tray. The hold down finger includes gears that move a portion of the hold down finger that contacts the top sheet of paper from a retracted position to a forward hold down position along a substantially elliptical path. After each sheet is printed and placed on top of other pages in the paper tray, the paper tray lowers and the hold down finger continues along the substantially elliptical path back to the retracted position. A rack gear associated with the paper tray engages a cylindrical gear of the hold down finger to return the hold down finger to the retracted position if the paper tray is forced upwards while the hold down finger is in the forward position.