Electronic system with expanding apparatus for expanding function of electronic apparatus

An electronic system comprising:

• an electronic apparatus including a box-like body which has a rear surface provided with a first connector and an engaging portion arranged on a front end portion of the body;
• and
• an expanding apparatus for expanding the functions of the electronic apparatus;
• said expanding apparatus comprising:
• a body case having a bearing surface for bearing the electronic apparatus;
• a second connector provided on the body case to face the rear surface of the body of the electronic apparatus placed on the bearing surface and adapted to be releasably connected with the first connector when the body is moved to a predetermined connecting position on the bearing surface;
• expanding means arranged within the body case and connected to the second connector, for expanding the functions of the electronic apparatus;
• a fixing member arranged on the body case and movable between a projected position wherein the fixing member engages the engaging portion of the body of the electronic apparatus located at the connecting position so as to restrict the movement of the body and a retreated position wherein the fixing member is disengaged from the engaging portion of the body;
• urging means for urging the fixing member to the projected position;
• and
• a lock mechanism for locking the fixing member at the projected position,
• wherein said lock mechanism comprises a lock plate arranged in the body case and movable between a first position wherein the lock plate is engaged with the fixing member located at the projected position and a second position wherein the lock plate is separated from the fixing member, a lock key including a key cylinder which has a key hole open to the lateral side of the body case and rotatable between a locked position and an unlocked position, and an interlocking mechanism for moving the lock plate between the first and second positions in interlock with the rotation of the key cylinder.