An FPC compartment in a left rim is slit-shaped. A left FPC positioning member supports a flexible printed circuit (FPC) in the FPC compartment such that a main surface of the FPC extends substantially horizontally. The FPC supported in the FPC compartment is twisted by substantially 90° at an entrance to a left hinge. The FPC extends around a hinge pin and is received in a left electronic-component compartment. The FPC is held in the left electronic-component compartment such that the main surface of the FPC extends substantially vertically. A left end piece located adjacent to the left hinge has a left cavity accommodating a left deformable bend of the FPC.
