| 摘要 |
A hill-climbing scheme of an automatic focusing process performed in a digital video camera obtains a moving speed Vj and an AGC gain Gj of a compensator lens every time an AF evaluation value AFj is detected corresponding to the position of the compensator lens. Adjustment factors α and &bgr; are computed with the moving speed Vj and the AGC gain Gj as parameters, where 0<α<1 and 0<&bgr;<1. The adjustment factor α is set to increase with an increase of the moving speed Vj, while the adjustment factor &bgr; is set to increase with a decrease of the AGC gain Gj. The automatic focusing process determines an in-focus position, based on the result of comparison between each detected AF evaluation value AFj and a threshold value TH. The threshold value TH is computed by multiplying a maximum value AFmax of the AF evaluation value AFj detected in the course of the hill-climbing scheme by the computed adjustment factors α and &bgr;. This arrangement attains the effective focusing technique of adequately determining the in-focus position according to various imaging conditions. |
