Piezoelectric actuator, piezoelectric actuator device, lens barrel, optical device and manufacturing method thereof

A piezoelectric actuator comprising:

• a first piezoelectric element pre-polarized along a first direction and displaceable along a direction substantially perpendicular to said first direction;
• a second piezoelectric element pre-polarized along a direction substantially parallel to said first direction and displaceable along a direction substantially parallel to said first direction;
• a third piezoelectric element provided in the same row along said first direction opposite to said first piezoelectric element with respect to said second piezoelectric element, wherein:
• said third piezoelectric element is pre-polarized along the first direction and displaceable along a direction substantially perpendicular to said first direction;
• a supporting portion to support said third piezoelectric element;
• a relative moving member clamped by displacement of said first piezoelectric element and relatively moved to said supporting portion by displacement of said second piezoelectric element;
• an electrode configured to apply a voltage to said first piezoelectric element and said second piezoelectric element and arranged between said first piezoelectric element and said second piezoelectric element;
• and
• a positioning portion configured to position said relative moving member at a radial direction and attached to said supporting portion, wherein
• said first piezoelectric element is associated with one end of said second piezoelectric element and said supporting portion is associated with an other end of said second piezoelectric element through contact with said third piezoelectric elements so that said first piezoelectric element, said second piezoelectric element, said third piezoelectric element and said supporting portion are located in this sequence along said first direction, said relative moving member is movably positioned by said positioning portion at a position detached from said first piezoelectric element toward said first direction.