数字微镜器件(DMD)具有较高的刷新速率和衍射效率，是理想的动态计算全息图加载器件。采用发光二极管(LED)作为光源来代替激光可以有效减少由激光的时间和空间相干性带来的散斑噪声。提出了一种以LED为光源、以DMD为计算全息图承载器的全息显示系统。研究了DMD进行全息显示的调制特性，分析了LED作为再现光源导致像质变差的原因，并用数值仿真的方法验证了LED的相干性和准直度对DMD全息显示系统再现像像质的影响。根据仿真分析结果，采用滤色片和空间滤波器来提高LED的相干性，同时采用非球面准直透镜来改善光的利用效率，最终得到了较好的显示效果。

Digital micro-mirror device (DMD) has the advantages of high refresh rate and high diffraction efficiency, and it is an ideal dynamic computer-generated hologram loader. Light-emitting diode (LED) is chosen as light source to replace the laser, since it can effectively reduce the speckle noise caused by both temporal and spatial coherence of laser. A holographic display system using LED as light source and DMD as computer-generated hologram loader is proposed in this paper. The modulation characteristics of DMD as a hologram display device are studied and the reason why worse image quality caused by LED chosen as represention light source is analyzed. The impact of coherence and collimation of LED on reconstruction image quality is analyzed. Numerical simulation results verify the above analysis. According to the results, a color filter and a spatial filter are used to improve the coherence of LED and an aspheric collimation lens is used to improve the optical efficiency. The experimental results show that the system has good display quality.