Magnifier function: Magnifier is a simple visual optical device used to observe the tiny details of objects. It is a convergent lens, and its focal length is much smaller than the apparent distance of the eyes.
In order to see the tiny object or the details of the object clearly, it is necessary to move the object closer to the eye, which can increase the viewing angle and form a larger real image on the retina. But when the object is too close to the eye, it is not clear. In other words, to be good at observation, we should not only make the object have a large enough opening angle to the eyes, but also take a suitable distance.
Obviously, for the eyes, these two requirements are mutually restrictive. If you put a convex lens in front of your eyes, this problem can be solved. The convex lens is the simplest magnifying glass and a simple optical instrument to help the eyes observe tiny objects or details.
A magnifying glass for expanding data consists of a lens and a lens handle.
1, lens
A transparent or translucent object. Its refractive surface is two spheres, or a sphere and a plane. It feels smooth, not uneven. I usually have material around me. It is characterized by a thick center and a thin edge.
2, rearview mirror handle
The handle of the mirror is connected with the lens, and the shape is not limited. The most common is columnar.
Magnify the image of the object-the main function of the magnifying glass is to put the magnifying glass in front of the object at an appropriate distance, and watch the magnified image from the lens, paying attention to the fact that the object is not actually magnified.
Focus on fire-secondary function Under strong light, the focus part of the lens will be particularly bright, and the focus part will zoom or catch fire. Note that the magnifying glass cannot enlarge the angle. The combination of two magnifying glasses can increase the magnification of the object.
Baidu encyclopedia-magnifying glass