The new PZD (Piezo Drive) piezoelectric drive marks another Tamron first in its autofocus SLR lenses, an internal standing wave ultrasonic motor system. Innovations to reduce parts and simplify operation also contributed to the lens’s reduced size and weight. Lighter and smaller than other autofocus drives, the piezoelectric drive uses a standing wave, instead of the traditional traveling wave, to turn and extend the piezoelectric element. Thus the entire element moves in a standing wave pattern, moving the metal tip (the contact surface) in an elliptic motion. The friction of this movement moves the rotor for a smooth, precise autofocus.
|A Video Showing the Operating Principles of the PZD|