初中阶段在演示凸透镜对光线有会聚作用的实验时 ,常利用太阳光或手电筒光通过凸透镜 ,然后在透镜的另一侧的白纸上找到一亮斑 ,这就说明凸透镜对光线有会聚作用 .尽管演示的效果和说服力都很好 ,但本人认为还缺乏可观性和生动性 .下面介绍一简易演示装置 .器材 :一块泡沫塑料? At the junior high school stage, when demonstrating that the convex lens converges on light, it often uses sun light or flashlight light to pass through the convex lens, and then finds a bright spot on the white paper on the other side of the lens. This shows that the convex lens converges on the light. Although the demonstration is very effective and persuasive, I believe that there is still lack of observability and vividness. Here is a brief demonstration device. Equipment: a piece of foam plastic?