模拟摄像机自动聚焦原理及其电路设计

The Principle and Circuits of Analog Camera's Auto-focusing

设计了一种基于复合视频信号自动聚焦的模拟摄像机。该摄像机包括图像显示、字符显示、自动光圈、红外线遥控、步进电机控制、云台驱动和自动聚焦等几个模块。阐述了自动聚焦模块中的模拟滤波电路及聚焦搜索策略。模拟电路用来提取复合视频信号中反映图像清晰的量,即亮度信号的高频分量。聚焦搜索策略控制变焦电机到达图像最清晰点。

We designed a kind of auto-focus camera,which based on composite video signal.The camera includes the following modules: the image display,character shows,automatic iris,infrared remote control,stepper motor control,pan & tilt drive and autofocusing.In this paper,we mainly introduce the analog filter circuit and focus search strategy.Through the analog circuit to extract the brightness s highfrequency components from composite video signal.The focus search strategy control the focus motor to get the best po...