A folding playpen or play yard frame and/or a locking hinge mechanism for a folding playpen or play yard frame of the type having tubular rails for supporting sides and a floor of the playpen or play yard. The locking hinge mechanism includes a housing and a lock assembly movably mounted to the housing. The lock assembly is pivotally attached to proximal portions of the tubular rails for locking and unlocking the rails relative to the housing. The lock assembly and housing are configured and adapted to require the locking hinge assembly to be lifted to effect limited relative motion between the housing and the proximal portions of the tubular rails prior to unlocking the lock assembly and permitting greater relative motion between the housing and proximal portions of the tubular rails. This provides greater safety against the hinge accidentally being folded or being folded by a child.