一、认识透镜顾名思义,所谓透镜,是指透明的镜子,通常是用玻璃磨成.它的一个侧面或者两个侧面是球面的一部分,如图1所示.根据其厚薄不同的特点,可将其分为凸透镜和凹透镜两类.图中A、B、C的中间比边缘厚,叫凸透镜;D、E、F的中间比边缘薄,叫凹透镜. First, to understand the lens As the name suggests, the so-called lens, refers to a transparent mirror, usually ground into glass. Its one side or both sides is a part of the sphere, as shown in Figure 1. According to its different thickness characteristics, can be It is divided into two types: convex lens and concave lens. In the figure, the middle of A, B, C is thicker than the edge, which is called convex lens; the middle of D, E, F is thinner than the edge and called concave lens.