Patent ID: 8355071
Filing Date: 2013-01-15
Classification: G02B,H04N

Abstract:
1. An optical system comprising: an operation unit which upon being operated changes the position of an optical member; a first sensing unit which detects the operated position of the operation unit; a driving unit which drives the optical member; a second sensing unit which detects the position of the optical member; a control unit which calculates a target position of the optical member on the basis of the operated position detected by the first sensing unit and controls the driving unit to drive the optical member to the target position such that the second sensing unit detects the position of the optical member to be the target position; and a storage unit which stores the operated position of the operation unit and the position of the optical member before power supply to the optical system terminates, wherein: when power supply to the optical system terminates and then the power supply restarts, the control unit compares the stored operated position and the operated position detected by the first sensing unit upon restart; if the stored operated position and the operated position detected after the power supply restarts are different, the driving unit is controlled such that the optical member is positioned at the target position calculated on the basis of the operated position after the power supply restarts, and if the stored operated position and the operated position detected after the power supply restarts are the same, the driving unit is controlled such that the optical member is positioned at the stored position of the optical member.