Patent ID: 7050044

Claim:
A PDA that comprises: a body comprising a processor, a monitor and a connection groove, the processor processes and stores the data of the body, the monitor displays the data of the body, the connection groove is installed at one end of the body and connected to the processor; an expansion back case, sliding on the body and comprising a cover panel and a connection port, the cover panel is installed at one end of the expansion back case, the connection port is located under the cover panel, the connection port is coupled to the connection groove and the cover panel covers the connection port and the connection groove when the body and the expansion back case are connected; and a fastening unit for securing and releasing the body and the expansion back case, the fastening unit including two groove regions and two corresponding fasteners, the groove regions being located on two opposing sides of the body and extending to the end of the body at which the connection goove is located, the fasteners being installed on the cover panel and arranged and configured to cooperate with the respective groove region to secure the body to the expansion back case when the body and the expansion back case are connected.