| 摘要 |
PURPOSE:To quickly detect a change in an object even at the time of photographing a wall or the like having no pattern and to restart focusing operation by detecting the brightness difference of a brightness signal in an area set up in a picture, at the time of generating a prescribed change in the brightness difference after ending focusing operation, restarting the focusing operation. CONSTITUTION:Digital integration values V1, V1' corresponding to one field of a high band component more than 200kHz which is the cut-off frequency of an HPF out of brightness signals in the 1st and 2nd areas A, B are respectively outputted from integration circuits 59, 50g as the 1st and 2nd focus evaluating values Va, Vb. The evaluation value V1 and data W1 stored in the 4th memory 82 are inputted to a subtractor 84 by a variation detection circuit 81. A subtraction value (V1-W1) is outputted to the succeeding selection circuit 86 as a variation W1 of the value V1 from time immediately after the end of the focusing operation. The selection circuit 86 selects the variation Wk in accordance with an area switching signal Sa outputted from a focus motor control circuit 100 and outputs the selected value to the circuit 100. |
