Patent ID: 8556408

Claim:
A medium press device for holding a medium conveyed in a conveyance direction over a platen in an ink jet printer, the medium press device comprising: a pair of press members for holding opposite side sections of a medium in a width direction thereof which is orthogonal to the conveyance direction, the press members being mounted to undergo movement in the width direction of the medium; and support tools for supporting the respective press members and permitting the press members to advance and retract in the width direction of the medium in accordance with positions of the side sections of the medium in the width direction, the support tools comprising: two groove portions arranged in parallel with the platen along a longitudinal direction of the platen, one of the groove portions being arranged at the upstream side of the platen with respect to the conveyance direction of the medium and the other of the groove portions being arranged at the downstream side of the platen with respect to the conveyance direction of the medium, slider blocks fixed to each press member, some of the slider blocks being slidable along the inside of the one groove portion and others of the slider blocks being slidable along the inside of the other groove portion, and plate springs respectively connected to the slider blocks that are fixed to each press member and that are slidable along the one groove portion and plate springs respectively connected to the slider blocks that are fixed to each press member and that are slidable along the other groove portion, each plate spring being elastically pressed against an inner wall of its corresponding groove portion so that a frictional force is produced between the plate spring and the inner wall of the groove portion; wherein the press members regulate movement of the medium in the width direction thereof.