纯激光光源的投影产品是显示技术发展的未来趋势之一。为了使用多个激光二极管作为光源实现大功率的均匀照明,设计了一种激光照明系统,在基于自由曲面阵列的匀光系统前增加两个透镜和圆形光棒以进一步提高目标面均匀度。激光阵列经准直后会聚到圆棒中传输,再经过透镜准直出射,通过自由曲面阵列后经场镜会聚到目标面上,形成均匀的照明区域。借助软件仿真模拟后发现:引入圆棒混光后,目标面均匀度从77.59%提高到90.99%。此外,还对自由曲面阵列单元的形状进行了研究,结果表明,相比于正方形的结构单元,选取与目标面长宽比一致的自由曲面单元可以得到更好的均匀度。

The projection products of pure laser sources are one of the future trends in the development of display technology. In order to use multiple laser diodes as the light source to achieve high power uniform illumination, a laser illumination system is designed in this paper. Two lenses and a round rod are added before the uniform illumination system based on the freeform surface array to further improve the uniformity of target surface. The laser array is collimated and then converged into a round rod for transmission. After being collimated by the lens, it passes through the freeform surface array and is converged on the target surface by the field lens to form a uniform illumination area. With the help of software simulation, it is found that the uniformity of the target surface increased from 77.59% to 90.99% after mixing the light with the round rod. In addition, the shape of the freeform array unit is studied. The experimental results show that, compared with the square structure unit, the freeform surface unit with the same aspect ratio as the target surface can get better uniformity.