Expansion device for expanding functions of compact electronic apparatus

An electronic system comprising:

• an electronic apparatus having a battery mount portion and an engaging portion provided in the battery mount portion;
• an expanding apparatus for expanding functions of the electronic apparatus, the expanding apparatus having a fitting portion;
• and
• a battery pack for supplying electric power to the electronic apparatus and expanding apparatus and for mechanically coupling the electronic apparatus and expanding apparatus, the battery pack including a first portion removably fitted in the battery mount portion, a second portion removably fitted to the fitting portion, and a lock mechanism for locking the first portion of the battery pack in the battery mount portion,
• the locking mechanism including:
• a lock member movable between an engaging position wherein the lock member engages the engaging portion of the first electronic apparatus so as to lock the first portion in the battery mount portion and a disengaging position wherein the lock member disengages from the engaging portion to allow the first portion of the battery pack to be removed from the battery mount portion,
• an operating member connected to the lock member, for moving the lock member between the engaging and disengaging positions, the operating member being movable between a lock position wherein the operating member moves the lock member to the engaging position, a release position wherein the operating member moves the lock member to the disengaging position, and an unlock position, and
• a holding mechanism for holding the operating member in the release position when the operating member is moved from the lock position to the release position and for releasing the hold of the operating member when the operating member is moved from the release position to the unlock position.