| 摘要 |
PURPOSE:To improve a switching function and to execute automatic focusing whose practical application field is wide, by providing the first switching means for switching an AF means to an operating state and a non-operating state, and the second switching means for switching from one set state to the other state. CONSTITUTION:When a changeover switch SW1 is set to the (b) side, an automatic focusing device (AF) becomes a non-operative state, but by depressing a push-switch SW2, the AF can be operated. The SW2 is a monostable type switch, and therefore, when external force is removed, it is immediately reset to have a function before the operation. When the SW1 is connected to the (a) side, the AF usually becomes a non-operating state, but by depressing the SW2, the AF can be operated temporarily. Also, the same switching circuit can be constituted of a bistable type switch SW1, a monostable type push-switch SW2 and a logical circuit IC. |
