针对液晶显示屏幕检测中光源照明均匀性较差的问题，基于非成像光学理论提出了一种大口径小角度的发光二极管(LED)照明光源设计方法。光源采用阵列式照明方式，对单颗LED 设计菲涅耳透镜实现小角度的准直照明；推导阵列均匀照度分布条件并利用TracePro 软件进行优化，确定阵列最优间距；最终通过在照明面上的光斑拼接叠加实现均匀矩形照明。照明光源由12×9个配光单元形成均匀方形阵列排布，每两个配光单元间距30 mm。仿真结果表明，光源的发光角度小于±10°，在距光源170 mm 的照明面上，平均照度大于45000 lx，非均匀性3.8%，均满足设计指标。该方法设计的阵列式光源无论平均照度还是照度均匀性均比现有光源有明显优势。

In order to increase the illuminance uniformity of the source used in the liquid crystal display(LCD) detection, based on nonimaging optics, a method of a light emitting diode (LED) source with large aperture and small view angle is proposed in this paper. The illumination system of this source is realized by array of LEDs and the lenses. For a single LED, Fresnel lens is designed to collimate the beam with small view anglethen, the optimal distance of the array is obtained by deducing the uniform illumination condition and optimizing it with TracePro. Finally, the uniform rectangular illumination is achieved through splicing superposition the spot on the illuminating surface. The illumination source consists of 12×9 optical units which are arranged in uniform rectangle, and the distance between every two optical units is 30 mm. The simulation results show that the viewing angle of the source is less than ±10°. At the target surface 170 mm away from the source, the average illuminance is greater than 45000 lx, and the nonuniformity is 3.8%. All of the indexes meet the design requirements. Comparing with the existed source, the arrayed source designed in this paper has obvious advantages whether on the average illuminance or the illuminance uniformity.