US Patent 8000029 Lens position detecting device and lens position detecting method

A lens position detecting device includes a lens, a lens driver for moving the lens in the optical axis direction, a lens drive command unit for outputting a drive command to the lens driver, a position detector for detecting that the lens is located at a predetermined position, and a first reference position detector that moves the lens to a first position upon starting a detecting operation, receives an output signal from the position detector while moving the lens in one direction along the optical axis direction from the first position, and detects a reference position of the lens based on the output signal.