为了提高航空遥感器的地面分辨率，改善图像清晰度，本文分析了遥感器离焦原因，根据推扫式航空遥感器光学系统的特点和结构形式，设计了一种使用凸轮和直线导轨的调焦机构来补偿CCD感光面的离焦量。设计中采用偏心的内、外曲线凸轮，以保证CCD探测器的位置稳定性。对机构的误差分析和精度实验表明: 该调焦机构的误差不大于遥感器的半焦深0.04 mm，满足使用要求。提出的像面调焦方法适用于装机空间小，焦距较短的遥感器。

To get higher accuracy ground sampled distances and to improve the imaging resolution for aerial remote sensing instruments, this paper analyzes the reasons that a remote sensing instrument is out of focus. Based on the characteristics and structures of the optical system for a push-scan aerial remote sensing instrument, it designs an image plane focusing structure to compensate the motion error of the focusing structure. In design, an eccentric cam with inner and outer curves is used to ensure the position stabilization of the CCD sensor when the remote sensing instrument is imaging. The motion error is tested to verify the validity of the simulation result. The test shows that the error is less than 0.04 mm, which meets using demands. The focusing method of moving focal plane proposed is suitable for aerial remote sensing instruments whose focal length is shorter and size is smaller.