Telecentric lens has parallel chief ray with its optical axis and is ideal for co-axial lighting.
远心镜头拥有与它的光轴平行的主光线，同轴照明是非常理想的。
2
Ray traces of the injecting electron-cyclotron wave into an equilibrium mirror plasma from different locations and with various angles are given by using a parallel plane-stratified-model.
本文利用平行平板模型，给出了在不同位置、以不同角度入射到平衡的磁镜等离子体中电子回旋波的传播轨迹；
3
The fractures in all the specimens were clearly visible when the X-ray beam was parallel to the plane of osteotomy.