| 摘要 |
PURPOSE:To always stably perform auto-focusing by detecting the focal length of a photographic zoom lens and setting the size of a distance measuring area to a preliminarily determined value based on the detection output. CONSTITUTION:A zoom lens 7 incorporating a focusing lens part 8, a diaphragm 12, etc., is used to obtain an object image, and this image is made incident on an image pickup element 13 driven by a driving circuit 14 to output a video signal. This signal is branched into two, and one is sent to a vide signal processing circuit 15 and a generated video signal is outputted as a monitor video signal through an adder 27, and the other is inputted to an AF signal processing circuit 16 and an AF control circuit 17 connected to this circuit 16 is used to drive the lens 6. A digital pattern 21 obtained by the lens 7 is applied to the adder 27 through a pattern control circuit 22, a ROM23, a distance measuring area prescribing timing generating circuit 24, and a distance measuring area display frame generating circuit 25 and is joined with said monitor signal. Thus, the size of the visual field of distance measuring is set. |
