当光源来自焦点以产生平行光束或者平行光束以产生焦点的凹入的反射镜

当光源来自焦点以产生平行光束或者平行光束以产生焦点的凹入的反射镜的英文翻译

基本释义

• a concave reflector used to produce a parallel beam when the source is placed at its focus or to focus an incoming parallel beam