Coil device, and wireless power transmitter and wireless power receiver having the same

A wireless power transmitter, comprising:

• a case having a reception space and varying a charging area upon a user's selection;
• a coil part, having, in the reception space of the case, a coil body formed of a wound conductor having a predetermined length, wherein a gap between turns of the wound conductor of the coil body varies as the charging area of the case varies such that the coil part wirelessly transmits power;
• and
• a power supplying unit supplying power to the coil part.

A wireless power receiver, comprising:

• a case having a reception space and varying a charging area upon a user's selection;
• a coil part, having, in the reception space of the case, a coil body formed of a wound conductor having a predetermined length, wherein a gap between turns of the wound conductor of the coil body varies as the charging area of the case varies such that the coil part wirelessly receives power;
• and
• a connection unit transmitting the power received in the coil part to an external device.