Patent ID: 6980420

Claim:
A portable electronic device comprising: an expansion base module having front and rear ends and two opposite sides that extend between said front and rear ends in a longitudinal direction; a hinge mechanism mounted slidably on said expansion base module and slidable relative to said expansion base module in said longitudinal direction between said front and rear ends of said expansion base module; a docking unit pivoted to said hinge mechanism and defining a docking groove, said docking unit including a docking connector; a system module including a panel having two opposite sides that respectively have two opposing end portions inserted into and detachably retained in said docking groove, said system module further including a system connector that is mounted on said panel and that mates with said docking connector; and a lock unit that includes a pair of latches; wherein said docking unit includes a crossbar that extends between said opposite sides of said expansion base module in a transverse direction, said crossbar having two opposite ends that are respectively disposed adjacent to said opposite sides of said expansion base module, said docking unit further including a pair of side arms that extend transversely and respectively from said opposite ends of said crossbar and that respectively define two opposite retaining grooves which open toward said system module and which cooperatively define said docking groove: wherein said end portions of said opposite sides of said panel are respectively formed with two opposing locking holes that are respectively disposed within said retaining grooves, said latches of said lock unit respectively extending in said retaining grooves and being operable to move between a locking position, in which said latches respectively and releasably engage said locking holes and an unlocking position, in which said latches respectively disengage from said locking holes; and wherein said crossbar is hollow and defines an inner space therein, said crossbar having a front wall that is formed with an elongated slot which extends in said transverse direction and which is in spatial communication with said inner space, said lock unit further including an operating lever that is mounted movably in said inner space and that is connected to said latches, and a knob that protrudes outwardly of said inner space from said operating lever through said slot so as to permit sliding movement of said operating lever in said transverse direction between a first position, in which said latches are disposed at said locking position, and a second position, in which one of said latches is disposed at said unlocking position.