| 摘要 |
PURPOSE:To speedily perform focusing operation with accuracy by providing an arithmetic means which finds the defocusing quantity of a photographic lens and distance to an object from the detection output of a photodetecting means for focus detection and focus distance information on the lens. CONSTITUTION:When a camera user touches a shutter button for focusing, a fixed data circuit 110 inputs specific data (d), (f), B, and A determined by the constitution of an optical system for focus detection to a control arithmetic circuit 104, and a readout circuit RD outputs a power source and a readout signal to a lens information output circuit LID to read out the contents of a ROM, thereby inputting the focus information F to a register 116 and a conversion coefficient K to a register 117. Those data are used to calculate the object distance S and also find the current defocusing quantity DELTAL and defocusing direction (positive or negative), which are outputted to a multiplying circuit 114 and a display comparing circuit 111. Then, the focusing operation is completed when the defocusing quantity DELTAL outputted by the control arithmetic circuit 104 becomes smaller than focus data stored in a focusing width data circuit 112. |
