Docking unit and electronic apparatus system

1. A docking unit comprising:

a docking portion capable of docking of an electronic apparatus in which a mounting surface of an extension unit is detachably mounted on a back surface of a portable information apparatus;

a holding portion holding the portable information apparatus at a predetermined position in a docking direction when the electronic apparatus is docked with the docking portion; and

a forcibly moving portion forcibly moving the extension unit in the docking direction when the electronic apparatus is docked with the docking portion to thereby separate the extension unit from the portable information apparatus held with the holding portion to form a gap between the back surface of the portable information apparatus and the mounting surface of the extension unit.

2. The docking unit according to claim 1 , further comprising:

an air supply fan; and

an air supply path causing air supplied from the air supply fan to flow into the gap between the back surface of the portable information apparatus and the mounting surface of the extension unit.

3. The docking unit according to claim 2 , further comprising:

a power transmission device capable of supplying power to a battery unit of the extension unit docked with the docking portion; and

another air supply path circulating the air supplied from the air supply fan to the power transmission device.

4. The docking unit according to claim 1 , wherein:

a mounting magnet is on the mounting surface of the extension unit; and

a sticking target material to which the mounting magnet can be stuck is on the back surface of the portable information apparatus;

the docking portion has a concave shape into which the electronic apparatus can be inserted along the docking direction; and

the forcibly moving portion has an attracting magnet on a bottom surface of the docking portion and attracts the mounting magnet from a side of the back surface of the extension unit.

5. The docking unit according to claim 4 , wherein:

the forcibly moving portion has a repulsion magnet on a side surface of the docking portion and generates repulsion force to the mounting magnet.

6. The docking unit according to claim 1 , further comprising:

an extrusion mechanism for pressing and moving the extension unit docked with the docking portion in a direction opposite to the docking direction.

7. The docking unit according to claim 6 , wherein:

the extrusion mechanism moves the extension unit over a distance equal to or larger than a distance of the gap.

8. An electronic apparatus system, comprising:

a docking unit having:

a docking portion capable of docking of an electronic apparatus in which a mounting surface of an extension unit is detachably mounted on a back surface of a portable information apparatus;

a holding portion holding the portable information apparatus at a predetermined position in a docking direction when the electronic apparatus is docked with the docking portion; and

a forcibly moving portion forcibly moving the extension unit in the docking direction when the electronic apparatus is docked with the docking portion to thereby separate the extension unit from the portable information apparatus held with the holding portion to form a gap between the back surface of the portable information apparatus and the mounting surface of the extension unit,

the portable information apparatus, and

the extension unit.