Printer

摘要

A duplex printer with a small, compact conveyance path has a medium supply path and a medium inverting path that merge into a middle conveyance path at a junction. The middle conveyance path goes to a path switching unit connecting a main conveyance path and the inverting path. A flap, which is a path switching member, is disposed in the path switching unit. A middle conveyance roller pair, having a middle conveyance roller and a nipping portion, conveys the medium (e.g. paper) through the middle conveyance path. The portion of the middle conveyance path from at least the junction to the nipping portion is a conveyance path portion defined by the roller surface of the middle conveyance roller. The paper fed to the middle conveyance path is guided by the middle conveyance roller from the junction to the nipping portion of the middle conveyance roller pair.

主权项

1. A printer comprising:
a media supply path that conveys a medium to be printed upon; a first conveyance path that conveys the medium past a print position, the direction of conveying the medium to the printing position for printing being the downstream direction of the first conveyance path; a looped inverting path that reverses the front and back sides of the medium; a junction where the downstream end of the media supply path and the downstream end of the inverting path merge; a second conveyance path extending from the junction to a path switching unit where the upstream end of the first conveyance path and the upstream end of the inverting path merge; and a conveyance roller pair that conveys the medium from the junction toward the path switching unit, the conveyance roller pair having a drive roller and a nipping portion; wherein the medium is guided by a conveyance roller from the junction to the media nipping portion of the conveyance roller pair, said conveyance roller being the drive roller of the conveyance roller pair;wherein:
the upstream end of the first conveyance path has a conveyance guide surface that faces the conveyance roller and guides media conveyed by the conveyance roller pair; the conveyance roller has an outside roller surface that rotates away from the conveyance guide surface in the downstream direction of the first conveyance path; and the path switching unit includes a path switching member having a first member surface on a side facing away from the conveyance roller and a second member surface opposite the first member surface on a side facing the conveyance roller, a first switching-member guide surface being formed on the first member surface and a second switching-member guide surface being formed on the second member surface; the path switching member being movably switchable between a first switching position and a second switching position, wherein the first switching position guides media, that is conveyed from the first conveyance path to the path switching unit, to the inverting path, and the second switching position guides media, that is conveyed from the second conveyance path to the path switching unit, to the first conveyance path, said path switching member being biased toward said first switching position in a resting state and requiring a pushing force to be moved to said second switching position; in said first switching position, the second switching-member guide surface being proximate to the conveyance roller and the distal end of the second switching-member guide surface, that is closest to the first conveyance path, facing the outside roller surface of the conveyance roller; when medium is conveyed to the path switching unit by the conveyance roller pair, the medium pushes on the second switching-member guide surface and pushes the path switching member to said second switching position; and in the second switching position, the second switching-member guide surface being moved away from the conveyance roller, and the distal end of the first switching-member guide surface, that is closest to the first conveyance path, being at a position moved away from the conveyance guide surface of the first conveyance path.