Patent ID: 9635244
Date: 2017-04-25
CPC Classifications: G02B,G03B,H02K,H04N

Claim:
1. An image pickup apparatus comprising: a lens holding frame configured to hold a lens and to be movable in a direction along an optical axis of the lens; a fixed frame at which the lens holding frame is arranged so as to be movable in the direction along the optical axis of the lens; a plurality of driving magnets arranged at the fixed frame such that an N-pole and an S-pole are alternately reversed along the optical axis of the lens; a plurality of driving coils arranged at the lens holding frame so as to be opposed respectively to the plurality of driving magnets, the plurality of driving coils being located at positions where cycles of magnetic poles of the plurality of driving magnets are shifted in the direction along the optical axis; a plurality of first detection portions mounted to the lens holding frame and configured to detect a position of the lens holding frame with respect to the fixed frame by detecting a change of a magnetic force of the plurality of driving magnets; a second detection portion configured to detect the position of the lens holding frame with respect to the fixed frame; a third detection portion configured to detect an absolute position of the lens holding frame with respect to the fixed frame; and a memory that stores mapping data in which data related to a state set based on output from the first detection portions and data set based on an output from the second detection portion and related to a switching position of the state are stored, wherein the lens holding frame is driven based on the output from the first detection portions at a time of initial driving, and when it is detected the third detection portion detects that the lens holding frame reaches a reference position with respect to the fixed frame, an output signal from the second detection portion at the time of the detection is set as the reference position, and the lens holding frame is driven based on a current value calculated from the mapping data stored in the memory and the output signal from the second detection portion.