Yamada Hirotaka, Moriyasu Kengo, Sato Hiroto, Hatanaka Hidekazu
Opt Express. 2017 Dec 11;25(25):32132-32141. doi: 10.1364/OE.25.032132.
The speckle reduction for laser projectors has been vigorously studied because speckle causes a serious deterioration in image quality. Most speckle reduction methods can be categorized into wavelength diversity, angular diversity and polarization diversity, which are usually treated independently. In this paper, it is shown that the effect of wavelength diversity and angular diversity on speckle reduction is not independent, and that the effect of wavelength also depends on incidence and observation angles on screen. The speckle reduction effect by wavelength diversity is smaller when the angular diversity is larger. Also, the speckle reduction effect is investigated on various screens including matte and silver screens, and it is shown that the effect of wavelength diversity is larger on matte screen than on silver screen.
由于散斑会严重降低图像质量，激光投影仪的散斑减少问题已得到深入研究。大多数散斑减少方法可分为波长分集、角度分集和偏振分集，这些方法通常是独立处理的。本文表明，波长分集和角度分集对散斑减少的影响并非相互独立，而且波长的影响还取决于屏幕上的入射角和观察角。当角度分集较大时，波长分集对散斑减少的效果较小。此外，还研究了在包括磨砂屏和银屏在内的各种屏幕上的散斑减少效果，结果表明，波长分集在磨砂屏上的效果比在银屏上更大。
