| 摘要 |
PURPOSE:To correct dispersion in characteristics of distance measurement data and to accurately measure a distance by providing a position detecting means which detects the position of a focusing lens and making the characteristics of distance measurement data coincident with the characteristics of the output signal of the position detecting means to the subject distance. CONSTITUTION:A potentiometer is used as a focus sensor which detects the position of the focusing lens from the rotation of a motor 16. When the motor 16 rotates, the focus sensor 18 varies in resistance value. The variation in resistance value is converted into a voltage signal, which is outputted to an A/D converter 11 and converted into 8-bit data and outputted as a focus sensor value F to a microcomputer 7. The extension quantity of the lens 13 and the distance measurement data obtained from a PSD 5, on the other hand, are in the opposite relation from the distance, so the characteristics of the distance measurement data are converted and made coincident with the characteristics of a focus sensor value F, and then the motor 16 is controlled so that the converted distance measurement data is coincident with the focus sensor value F at all times, thereby accurately putting the focus lens 13 in focus. |
