Head driving device configured to move a head member relative to tape as a recording medium and configured to stably hold the head member

A head driving device configured to move a head member relative to tape as a recording medium, the head driving device comprising:

• a base member including a first frame portion and a second frame portion;
• a head supporting member supporting the head member;
• a first beam member arranged between the first frame portion and the head supporting member and including a first base portion connected to the first frame portion and a first head side hinge portion connected to the head supporting member;
• a second beam member arranged on a side opposite to the first beam member with the head supporting member interposed therebetween, the second beam member including a second base portion connected to the second frame portion and a second head side hinge portion connected to the head supporting member;
• a first piezoelectric unit arranged on the first beam member and comprising piezoelectric elements configured to move the head supporting member in a direction along a surface of the tape when applied with a voltage;
• a second piezoelectric unit arranged on the second beam member and comprising piezoelectric elements configured to move the head supporting member in the direction along the surface of the tape when applied with a voltage;
• and
• a reinforcement member allowing the head supporting member to move in the direction along the surface and controlling the head supporting member from moving in a thickness direction of the head member.