| 摘要 |
A calculation circuit (6) compares a current focus evaluation value provided from a focus evaluation value generation circuit (5) with a focus evaluation value of one preceding field stored in a memory (50) to determine whether a CCD (2) is in-focus or not. The calculation circuit (6) provides a driving signal VD to a linear motor so that the CCD (2) moves toward the in-focus position. A position prediction circuit (31) predicts the position where the CCD (2) arrives after a predetermined time period according to the driving signal VD. A comparator circuit (33) compares a predicted result from the position prediction circuit (31) with the actual moved position of the CCD (2) detected by a position detection circuit (30) to provide a signal Dpr corresponding to an amount of load according to the comparison result. A correction value determination circuit (35) and a bias determination circuit (36) correct the level of driving signal VD in response to signal Dpr to supply a second corrected driving signal VD2 to a voice coil (20). <IMAGE> |
