Abstract: A focus control apparatus controls a step motor and a piezoelectric material into order to control a focal distance between an electronic imaging device and a lens unit. The focus control apparatus has an image calculating unit for processing an image signal taken by the electronic imaging device into a resolution value, a displacement controlling unit receiving the resolution value in order to determine an optimal focal distance between the electronic imaging device and the lens unit and output a displacement controlling signal, a step motor controller and a piezoelectric material controller. The displacement controlling signal is supplied to the step motor controller or the piezoelectric material controller to control optimally the distance between an electronic imaging device and a lens unit.

Abstract: A piezoelectric focusing apparatus and method for the same are proposed to quickly adjust a distance between a lens unit and an electronic imaging device. An expanding table associated with increased voltage and a shrinkage table associated with decreased voltage for the piezoelectric material is constructed. A bi-directional deformation table is then established by associating voltages on the expanding table and the shrinkage table corresponding to the same deformation. A voltage is supplied to the piezoelectric material according to the bi-directional deformation table for generating a desired deformation and controlling a focusing distance between the lens unit and the electronic imaging device.

Abstract: A focus control apparatus controls a step motor and a piezoelectric material into order to control a focal distance between an electronic imaging device and a lens unit. The focus control apparatus has an image calculating unit for processing an image signal taken by the electronic imaging device into a resolution value, a displacement controlling unit receiving the resolution value in order to determine an optimal focal distance between the electronic imaging device and the lens unit and output a displacement controlling signal, a step motor controller and a piezoelectric material controller. The displacement controlling signal is supplied to the step motor controller or the piezoelectric material controller to control optimally the distance between an electronic imaging device and a lens unit.