| 摘要 |
PURPOSE:To obtain excellent automatic focusing in response to the state of an object with high accuracy by implementing automatic focusing of the object through the use of brightness information of a picked-up pattern so as to prevent malfunction. CONSTITUTION:An iris drive voltage is fed from an iris drive circuit 9 to a microcomputer 8 via an A/D converter circuit 6 and a pattern split integration circuit 7 to detect the state of the iris 2. Moreover, the output of an image pickup element 3 is integrated by an integration circuit 7 for each prescribed area via the A/D converter circuit 6 as luminance information as it is and characteristics such as an iris, gain and a gamma characteristic are corrected by a signal processing circuit 4. As a result, a threshold level to detect fluctuation in the focus information, a drive variable for the iris 2 and its drive speed or the like are varied in the automatic focus control using not only the focus information but also the brightness information and the iris drive information. |
