Patent attributes
A printer having a cover opening and closing mechanism for opening and closing a cover to the roll paper compartment of the printer including a four-node parallel linkage mechanism and an urging member to prevent the four-node parallel linkage mechanism from locking into a fixed position when the cover is opened or closed. The four-node parallel linkage mechanism comprises right and left side panel portions of a rocker panel to which the cover is attached, right and left rocker arms located behind the rocker panel, and a parallel motion panel disposed horizontally connecting the top ends of the rocker panel and the rocker arms. A coil spring pulls up on the rocker arms when the cover opening and closing mechanism is swung down to the horizontal full open position, and a flexible strip between the rocker arms and parallel motion panel pushes up on the parallel motion panel. The parallel motion panel and the rocker arms are thus prevented from bending downward at the node where they join, and the parallel linkage mechanism is therefore prevented from locking.
