光学成像检测设备的快速自动对焦是基于机器视觉快速缺陷检测的关键，为了解决检测过程中不同倍数物镜景深（0.5~91 μm）跨度大以及被检测物体振动给快速对焦造成的影响等问题，提出了基于激光三角法的显微镜离焦在线检测及补偿方法。该方法利用激光三角法进行离焦量和离焦方向的快速探测，使用由行程100 μm的压电陶瓷和行程25 mm直流电机构成的宏微双驱动结构协同控制完成大范围对焦任务。实验结果表明，构建的宏微结构对焦方式可以在0.4 s内实现高倍物镜±0.5 μm景深至低倍物镜±91 μm景深大范围的快速自动对焦，并实现被检测物体±3 μm振动范围的快速自动跟随对焦。该方法满足了新一代薄膜场效应晶体管液晶显示器（TFT-LCD）工业检测装备对自动化对焦范围、速度和精度的要求，同时可应用在平板显示器（FPD）检测、线路板检测、生物医学和自动机器装配等领域。

The fast automatic focusing equipment of optical imaging detection is one of the most important devices in rapid optical inspection based on machine vision. In order to limit the impact caused by multiple objectives, whose depths of fields(DOF) are from 0.5 μm to 91 μm, and vibration in rapid automatic focusing, a fast detection and compensation of microscope defocus method based on laser triangulation method is proposed. In this method, a macro institution into micro dual driven structure is proposed. It is constructed by the piezoelectric ceramics(PZT) with stroke of 100 μm and direct current(DC) motor with stroke of 25 mm. Based on the structure and laser triangulation, multiple objectives, defocus amount and direction are rapidly detected, cooperating with PZT and DC motor. Experimental results show that the macro-micro dual-drive focus mode can achieve a wide range of auto focusing within 0.4 s, from a low magnification objective (±91 μm) DOF to a higher magnification objective (±0.5 μm), and follow focus in the vibration range (±3 μm). This method meets requirements of the industrial thin film transistor-liquid crystal display(TFT-LCD) automation inspection equipment in broad automatic focusing range, speed and accuracy. It can also be applied in many other fields, such as flat panel display(FPD) inspection, printed circuit board inspection, biomedicine, automatic assembly machines and so on.