Patent ID: 7620307

Claim:
An image pickup apparatus configured to return a movable portion to a reset position, the apparatus comprising: relative phase detecting means for detecting an amount of change in a relative phase associated with movement of the movable portion; origin point position detecting means for detecting that the position of a reference part corresponding to an origin point of the movable portion passes through the origin point; relative position deriving means for deriving information on a relative position of the movable portion based on a counter value and phase resolution position information; relative detection position retaining means for retaining a relative detection position of the movable portion based on the information on the relative position obtained at the time of the detection by the origin point position detecting means; calculating means for calculating an absolute detection phase based on the relative detection position of the movable portion and for generating a drive signal based on the absolute detection phase; and driving means for moving the movable portion to the reset position based on the drive signal, the relative phase detecting means operable to output a plurality of signals which are out of phase, in which a difference in phase depends on a position of the movable portion; and said relative position deriving means including (i) means for creating phase regions by dividing a unit cycle by a predetermined number in accordance with a relationship between phases of the signals and for creating phase information based on a state of each phase in an individual phase region, (ii) means for performing a counting operation based on an increase or decrease in the phase information so as to obtain the counter value, and (iii) means for receiving the phase information and the signals and for generating the phase resolution position information therefrom.