Printer

1. A printer for printing on a roll medium including a supply shaft and a medium wound around the supply shaft, the printer comprising:

a medium supplier including a shaft support, to which the supply shaft of the roll medium is detachably attached, and that rotatably supports the roll medium;

a medium temporary placement support that is located below the shaft support of the medium supplier, and that receives and supports the roll medium prior to the roll medium being attached to the medium supplier; and

a conveyor that conveys the medium in a conveyance direction that is perpendicular or substantially perpendicular to an axial direction of the supply shaft, the medium being unwound from the supply shaft; wherein

the medium temporary placement support includes at least one support bar that extends in the axial direction, and a placement seat supported by the at least one support bar;

the placement seat includes a placement surface on which the roll medium is placed and that extends in the conveyance direction, and a curved portion that includes a convex curve in an upstream end portion of the placement surface in the conveyance direction; and

an upstream portion of the placement seat in the conveyance direction has a different shape than a downstream portion of the placement seat in the conveyance direction.

2. The printer according to claim 1 , wherein

the placement seat includes a corner portion in a downstream end portion of the placement surface in the conveyance direction; and

in the conveyance direction, a height of the corner portion from the at least one support bar is greater than a height of the upstream portion of the placement seat from the at least one support bar.

3. The printer according to claim 1 , wherein when seen in the axial direction of the supply shaft, the upstream end portion of the placement seat in the conveyance direction is located on a downstream side in the conveyance direction of an upstream end portion of the at least one support bar in the conveyance direction.

4. The printer according to claim 1 , wherein

the at least one support bar includes a plurality of support bars, each of which extends parallel or substantially parallel to the supply shaft;

the plurality of support bars includes an upstream support bar located on an upstream side of at least one other support bar of the plurality of support bars in the conveyance direction;

an outer circumferential surface of the upstream support bar has a circular or substantially circular shape; and

when seen in the axial direction of the supply shaft, a curvature of the convex curve of the curved portion of the placement seat is equal to or smaller than a curvature of the upstream support bar.

5. The printer according to claim 4 , wherein when seen in the axial direction of the supply shaft, the placement seat is located on a downstream side in the conveyance direction of a tangent line that contacts an upstream side of an outer circumferential surface of the supply shaft and an upstream side of an outer circumferential surface of the upstream support bar.

6. The printer according to claim 4 , wherein the upstream portion of the placement seat includes a concave curve that contacts the upstream support bar.

7. The printer according to claim 6 , wherein a curvature of the concave curve is equal or substantially equal to a curvature of the upstream support bar.

8. The printer according to claim 1 , wherein

the at least one support bar includes a plurality of support bars, each of which extends parallel or substantially parallel to the supply shaft;

the plurality of support bars includes an upstream support bar that is located on an upstream side of at least one other support bar of the plurality of support bars in the conveyance direction;

an outer circumferential surface of the upstream support bar has a circular or substantially circular shape; and

the plurality of support bars includes a downstream support bar that is located on a downstream side of the upstream support bar in the conveyance direction;

the placement seat includes a through hole having a diameter equal to or larger than an outer diameter of the downstream support bar and that extends through the placement seat in the axial direction; and

the downstream support bar extends through the through hole.

9. The printer according to claim 8 , wherein

the placement seat is rotatably supported by the downstream support bar; and

when the placement seat is rotated about the downstream support bar and is not supported by the upstream support bar, the placement seat extends downward from the downstream support bar in a state in which an upstream end surface is located below the through hole.

10. The printer according to claim 1 , further comprising:

a second placement seat including a second placement surface on which the roll medium is placed and that extends in the conveyance direction.

11. A printer for printing on a roll medium including a supply shaft and a medium wound around the supply shaft, the printer comprising:

a medium supplier including a shaft support, to which the supply shaft of the roll medium is detachably attached, and that rotatably supports the roll medium;

a medium temporary placement support that is located below the shaft support of the medium supplier, and that receives and supports the roll medium prior to the roll medium being attached to the medium supplier;

a conveyor that conveys the medium in a conveyance direction that is perpendicular or substantially perpendicular to an axial direction of the supply shaft, the medium being unwound from the supply shaft;

a platen located on a downstream side of the medium supplier in the conveyance direction and on which the medium is placed during printing; and

a cutting head that cuts the medium placed on the platen; wherein

the medium temporary placement support includes at least one support bar that extends in the axial direction, and a placement seat supported by the at least one support bar; and

the placement seat includes a placement surface on which the roll medium is placed and that extends in the conveyance direction, and a curved portion that includes a convex curve in an upstream end portion of the placement surface in the conveyance direction.