Patent ID: 7063225

Claim:
An opening-closing mechanism for rotating a door member between a closed position for closing an opening portion of a box-shape base member and an open position for opening the opening portion, comprising: a first fixed internal gear portion to be disposed on the box-shape base member, a second fixed gear portion to be disposed on the box-shape base member and located inside the first fixed internal gear portion, and a pair of arm portions to be fixed to the door member, one of said arm portions having a circular arc shape gear portion engaging the first fixed internal gear portion, and a rotary gear disposed at a center of the circular arc shape gear portion and engaging the second fixed gear portion, said one of the arm portions being supported to be vertically movable through the engagements between the first fixed internal gear portion and the circular arc gear portion and between the second fixed gear portion and the rotary gear to allow the door member to be moved through the one of the arm portions along a path corresponding to the first fixed internal gear portion.