| 摘要 |
PURPOSE:To completely attain an automatic focal point matching function irrespective of the storage time of an image pickup element by controlling the phase of a reference frequency and the gain of a high frequency component and correctly detecting the phase and the amplitude of a reference frequency component included in the high frequency component by the reference frequency. CONSTITUTION:When the switching switch 15 of the storage time of the image pickup element is in a field storage mode, the reference frequency outputted from a reference frequency generator 9 is controlled in phase by a phase controller 13 so as to obtain the peak at the center (center of storage time) of a vertical scanning period as shown in a figure (a). Then, when the storage mode of the image pickup element is switched to an electronic shutter mode, the reference frequency is controlled so as to have the peak in the center of the storage time in the electronic shutter mode by the phase controller 13 as shown in a figure (b). At the time of the electronic shutter mode, the gain of the high frequency component is controlled by a gain control circuit 14 and the phase and the amplitude of the reference frequency component are correctly detected. |
