Investigation on cutting ratio for round brilliant cut diamond
- 经济学院－已发表论文 
利用MATLAB软件模拟钻石内部的光路,选取平行等距的光源分别从冠部及亭部照射钻石,重点研究光源从垂直入射至倾斜入射下不同的切工比例对钻石亮度及火彩的影响,从光线返回值、暗区比值和加权平均色散角等方面分析探讨了影响圆形明亮琢型钻石亮度及火彩的各种因素,给出了达到最佳加工效果的各种因素间搭配关系。模拟分析认为:亭角在39.0°~41.0°范围内较为合适,具有最大光线返回值及较小的暗区比值。通过加权平均色散角计算分析,当亭角的大小一定时,存在唯一大小的冠角使加权平均色散角出现明显的峰值,从而获得能够出现最佳火彩效果的亭角与冠角的组合。当钻石的台宽比大于最小台宽比(A_(min))时,台宽比对亮度无影响;在A_(min)~100%范围内,台宽比越小,加权平均色散角的权数越大,火彩效果越好。The optical path in diamond is simulated by the technique of MATLAB,and a series of parallel and equidistant lights are selected. The crown and pavilion of the diamond are illuminated respectively. This paper focuses on the influence of different cutting ratios on diamond intensity and fire,under vertical incident light changing to oblique incidence light. Various factors,such as light returning values,dark region values and weighted average dispersion angles,which have impact on the intensity and fire of round brilliant cut diamond,are analyzed and discussed,and the relationship of various factors to achieve the best processing effect is given.The simulation analysis shows that the pavilion angle is more suitable in the range of 39. 0° to 41. 0°,and has maximum light return and smaller dark area ratio. The calculation and analysis results of the weighted average dispersion angle shows that when the size of the pavilion angle is determined,only a crown angle makes the curve of weighted average dispersion angle appear obvious peak,and the combination of pavilion angle and crown angle which can appear the best fire color is also obtained. When table percentage of diamond is larger than the minimum table percentage( A_(min)),the table percentage has no effect on the brilliance. In the range of A_(min)to 100%,when the table percentage is smaller,the weight of weighted average dispersion angle is bigger,and the fire is better.