Patent ID: 6566790
Filing Date: 2003-05-20
Classification: G02B,H02N

Abstract:
A driving apparatus of an impact type piezoelectric actuator for moving an object in a direction parallel to expansion and contraction of a piezoelectric device comprising:a first driver for driving the piezoelectric device by a first driving mode in which polarity of a driving voltage applied to the piezoelectric device is alternately switched; a second driver for driving the piezoelectric device by a second driving mode in which application of the driving voltage to the piezoelectric device and grounding of the piezoelectric device are alternately switched; an electric power supply for applying the driving voltage to the piezoelectric device; a driving condition sensor for sensing a driving condition with respect to a moving speed of the object; a discriminator for discriminating whether or not the driving condition shows the moving speed of the object equal to or faster than a predetermined speed; and a controller alternatively controlling the first driver, when the driving condition shows the moving speed of the object to be slower than the predetermined moving speed, and the second driver, when the driving condition shows the moving speed of the object to be equal to or faster than the predetermined moving speed.