Rotation key device for a portable terminal

In an apparatus for inputting data by use of keys in a portable terminal, a rotation key device comprising:

• a base plate attached, at a lower surface thereof, to an upper surface of a first printed circuit board (PCB) mounted in a body of the portable terminal, the base plate being substantially centrally provided at an upper surface thereof with a plurality of coupling protrusions;
• a second PCB attached, at a lower surface thereof, to the upper surface of the base plate while allowing the coupling protrusions to extend therethrough, the second PCB being provided at the lower surface thereof with a plurality of dome switches, and at an upper surface thereof with a plurality of contact surfaces for receiving an electrical contact signal at either a rotated position or a fixed position of a contact terminal and sensing the rotated position of the contact terminal according to the rotation direction of the contact terminal;
• a ring-shaped washer attached to the upper surface of the second PCB;
• a rotation key supported by an upper surface of the ring-shaped washer so that the rotation key is rotatable in forward and reverse directions by an external force applied thereto;
• a contact plate coupled to an upper surface of the rotation key to rotate along with the rotation key, the contact plate having a plurality of contact terminals each adapted to come into contact with one of the contact surfaces of the second PCB and to generate an electrical contact signal at a rotation contact or a fixed contact of the rotation key;
• and
• a fixed button coupled with a center portion of the upper surface of the second PCB.