四、机械结构工作原理本文介绍主要的四个机构:自动调焦机构、自动卷片倒片机构、马达过载保护机构和输片定位机构。1.自动调焦机构图3是自动调焦机构示意图。图中所示状态为常态:互锁揿板1下端 M 处在拉簧3的作用下压下微动开关K_4,使 K_4接通卷片马达电路,起预置卷片作用;快门(?)杆6被快门顶杆5锁住快门上弦状态;调焦圈7在扭 Fourth, the working principle of mechanical structure This article describes the main four bodies: automatic focusing mechanism, automatic winding film rewinding institutions, motor overload protection agencies and film positioning mechanism. 1. Auto Focus Mechanism Figure 3 is a schematic diagram of auto focus mechanism. The state shown in the figure is normal: the lower end M of the interlocking plate 1 depresses the micro switch K_4 under the action of the extension spring 3 to make the K_4 turn on the winding motor circuit, The lever 6 is locked by the shutter plunger 5 in the shutter-up state; the focus ring 7 is twisted