<p>A first shaft member is installed to extend in a first direction. A second shaft member is installed to extend in the first direction. A carriage main body is disposed between the first and second shaft members. A first slide member slides the carriage main body along the first direction on the first shaft member while contacting part of the periphery of the first shaft member. A second slide member slides the carriage main body along the first direction on the second shaft member while contacting part of the periphery of the second shaft member.</p>
