Power supply system for electronic instrument

A power supply system for an electronic instrument, including a storage battery device, a storage battery charger and an alternative power source unit, said electronic instrument having a first terminal group, said storage battery charger being adapted to charging said storage battery device, either of said storage battery device after charging and said alternative power source unit being connected to said first terminal group, for supplying said electronic instrument with electric power;

• said storage battery device comprising:
• a second terminal group, connectable to said first terminal group, for supplying electric power externally;
• and
• a first outer wall being at least partially flat and fittable on said electronic instrument;
• said alternative power source unit comprising:
• a third terminal group, connectable to said first terminal group, for supplying electric power externally;
• a second outer wall being at least partially flat and fittable on said electronic instrument;
• and
• a detectable recess, formed in said second outer wall;
• said storage battery charger comprising:
• a fourth terminal group, connectable to said second terminal group, for supplying electric power externally;
• a receiving wall fitted on said first outer wall;
• a projected portion, disposed in a projected state to project from an inside to an outside of said receiving wall and in movable fashion between said projected state and a retracted state to retract to said inside of said receiving wall, said projected portion being pressed by said first outer wall and moved from said projected state to said retracted state, said projected portion in said projected state having a size equal to or smaller than a size of said detectable recess of said alternative power source unit, and being received in said detectable recess when said second outer wall is fitted on said receiving wall, to be left in said projected state;
• a terminal cover, disposed on said receiving wall in a covering position of covering said fourth terminal group and in movable fashion between said covering position and an uncovering position of uncovering said fourth terminal group, said terminal cover being pressed by said storage battery device and moved from said covering position to said uncovering position, said fourth terminal group being connected to said second terminal group, to allow loading of said storage battery device;
• and
• a lock device, associated with said projected portion and said terminal cover, for hindering said terminal cover from moving away from said covering position while said projected portion has said projected state, to avoid wrong loading of said alternative power source unit, said lock device allowing said terminal cover to move to said uncovering position when said projected portion has said retracted state.

In combination, at least first and second electronic instruments and at least first and second power source units which supply power to the electronic instruments, said first power source unit comprising:

• a first terminal group for supplying electronic power externally;
• and
• a first outer wall being that is at least partially flat;
• said second power source unit comprising:
• a second terminal group, formed similarly to said first terminal group, for supplying electric power externally;
• a second outer wall, formed similarly to said first outer wall;
• and
• a detectable recess formed in said second outer wall;
• said first electronic instrument comprising:
• a third terminal group, connectable to said first terminal group, and supplied with said electric power by said first power source unit;
• a first receiving wall fitted on said first outer wall;
• a first projected portion, disposed in a projected state to project from an inside to an outside of said first receiving wall and in movable fashion between said projected state and a retracted state to retract to said inside of said first receiving wall, said first projected portion being pressed by said first outer wall and moved from said projected state to said retracted state when said first power source unit is coupled to said first electronic instrument, said first projected portion in said projected state having a size equal to or smaller than a size of said detectable recess of said second power source unit, and being received in said detectable recess when said second outer wall is fitted on said first receiving wall, to be left in said projected state;
• a first terminal cover, disposed on said first receiving wall in a covering position of covering said third terminal group and in movable fashion between said covering position and an uncovering position of uncovering said third terminal group, said first terminal cover being pressed by said first power source unit and moved from said covering position to said uncovering position, said third terminal group being connected to said first terminal group, to allow coupling of said first power source unit to said first electronic instrument;
• and
• a first lock device, associated with said first projected portion and said first terminal cover, for hindering said first terminal cover from moving away from said covering position while said first projected portion has said projected state, to avoid coupling of said second power source unit to said first electronic device, said first lock device allowing said first terminal cover to move to said uncovering position when said first projected portion has said retracted state;
• said second electronic instrument comprising:
• a fourth terminal group, connectable to said second terminal group, and supplied with said electric power by said second power source unit;
• a second receiving wall fitted on said second outer wall;
• a second projected portion, disposed in a projected state to project from an inside to an outside of said second receiving wall and in movable fashion between said projected state and a retracted state to retract to said inside of said second receiving wall, said second projected portion in said projected state having a size larger than said detectable recess in said second power source unit, said second projected portion being pressed by said second outer wall and moved from said projected state to said retracted state when said second power source unit is coupled to said second electronic instrument;
• a second terminal cover, disposed on said second receiving wall in a covering position of covering said fourth terminal group and in movable fashion between said covering position and an uncovering position of uncovering said fourth terminal group, said second terminal cover being pressed by said second power source unit and moved from said covering position to said uncovering position, said fourth terminal group being connected to said second terminal group, to allow coupling of said second power source unit to said second electronic instrument;
• and
• a second lock device, associated with said second projected portion and said second terminal cover, for hindering said second terminal cover from moving away from said covering position while said second projected portion has said projected state, said second lock device allowing said second terminal cover to move to said uncovering position when said second projected portion has said retracted state.