A rolled medium supporting mechanism for supporting a rolled medium to be rotatable around a roll shaft, the rolled medium supporting mechanism comprising:
- a supporting member having a substantially cylindrical shape with a plurality of rectangular-shaped window portions provided therein and having pin attachment portions;
- a plurality of pins disposed in the pin attachment portions and extending in an axial direction from the supporting member;
- a flange member formed integrally and concentrically with the supporting member and having a circular dish-like shape and which makes abutting contact with an edge of the rolled medium, the flange member having a circular hole and a cutout portion formed in an end face center of the circular dish-like shape;
- an opening/closing member having a substantially circular dish-like shape having a first end face having a plurality of cam holes and a handle portion which enables a user to rotate the opening/closing member, a second end face of the opening/closing member having a shaft portion which extends through the circular hole of the flange member and which is disposed inside the supporting member;
- and
- a plurality of blade members arranged in the circumferential direction of the supporting member, each member of the plurality of blade members having a substantially rectangular shape in which a first edge thereof is supported by the plurality of pins extending from the pin attachment portions of the supporting member in the axial direction, an end facing the opening/closing member, the end having a plurality of cam pins formed therein which extend through the cam holes of the opening/closing member, while a second edge of the plurality of blade members is capable of moving in the circumferential direction from the supporting member from the rectangular-shaped window portions towards the outer circumference of an inner peripheral face of the flange member in order to make abutting contact with a inner peripheral face of the hollow shaft portion of the rolled medium as the handle portion of the opening/closing member is rotated by the user, causing the cam pins of the blade members to be guided from a first position in the cam holes to a second position;
- wherein the opening/closing member causes the blade members to move from a position where the expandable abutting members block the rectangular-shaped window portions of the supporting member are concentric with an outer surface of the supporting member by causing the second edge to move away from the supporting member a predetermined angle in accordance with an inner diameter of the hollow shaft portion of the rolled medium,
- wherein the cutout portion of the flange member prevents the blade members from interfering with each other as they are moved.