| 摘要 |
PURPOSE:To realize the auto/manual switch for an auto-focus camera, by connecting a distance ring to an auto-focus drive mechanism via a rotary member to ensure the control of distance at all times with a manual operation. CONSTITUTION:When a distance measuring system 19 measures a long distance, the electric conduction is secured to an electromagnet 17. While an electromagnet 1 receives the electric conduction in the case of a short distance. An iron piece is absorbed to such electromagnet, and the 2nd rotary member 8 is turned round a shaft 5. Accordingly the 1st rotary member 4 turns backward to turn a distance ring 1 to a prescribed position via a pin 2. When an intermediate distance is measured, both magnets 17 and 18 receive no electric conduction. Such free rotation attains not only the automatic focusing but an optional manual control of distance. |
