Variable-focus water lens

Abstract

The invention relates to a physical teaching aid, and particularly relates to a variable-focus water lens which comprises an orbit (namely a round lens frame), a crystalline lens (namely an elastic transparent film and water), a ciliary body (comprising a plastic straw, a valve core and an injector) and a metal rod. The variable-focus water lens is characterized in that the elastic transparent film is sheathed on the round lens frame for sealing so as to form a sealing cavity capable of containing the water; the bottom end of the round lens frame is connected with the metal rod; a small hole at the top end of the round lens frame is connected with the plastic straw; the part, extending out of the round lens frame, of the plastic straw is connected with the valve core; the other end of the valve core is connected with the injector; and the injector is used for injecting water into the elastic transparent film or sucking the water in the elastic transparent film, so that the convex degree of the elastic transparent film is changed, and then the focus of the water lens can continuously change according to experimental demands. The variable-focus water lens is simple and convenient in material selection, can show clear phenomena and vivid images, and is simple to operate and strong in practicability.

Description

Technical field: [0001] The invention relates to a teaching aid for physics teaching, in particular to a variable focus water lens. Background technique: [0002] At present, in physics teaching and medical physics teaching in medical colleges, when the teacher is teaching the section about "eyes and glasses", because the current textbooks in various versions use convex lenses to simulate the lens of the eye, when exploring the imaging of the eye In principle, to make images of objects with different distances and nears be formed on the light screen, it is necessary to use a convex lens with a different focal length. Due to equipment limitations, it is difficult to find a convex lens with a suitable focal length in actual operation. To make the image clear If it is formed on the light screen, it is necessary to change the distance between the convex lens and the light screen, which is not consistent with the actual adjustment of the eyes; when demonstrating the change of the...

AI Technical Summary

Problems solved by technology

[0002] At present, in physics teaching and medical physics teaching in medical colleges, when the teacher is teaching the section about "eyes and glasses", because the current textbooks in various versions use convex lenses to simulate the lens of the eye, when exploring the imaging of the eye In principle, to make images of objects with different distances and nears be formed on the light screen, it is necessary to use a convex lens with a different focal length. Due to equipment limitations, it is difficult to find a convex lens with a suitable focal length in actual operation. To make the image clear If it is formed on the light screen, it is necessary to change the distance between the convex lens and the light screen, which is not consistent with the actual adjustment of the eyes; when demonstrating the change of the focal length caused by the change of the shape of the lens in myopia and hyperopia, we can only use convex lenses with different focal lengths. Realization, the shape change of the lens cannot be demonstrated; it is also difficult to accurately form the image on the retina when exploring the correction of myopia and hyperopia

In short, the experiment was carried out according to the experimental equipment provided in the textbook. Since the convex lens used in the laboratory is made of glass, and the curvature of its convex surface is fixed, it is difficult for students to perceive the convexity of the lens and the contraction and relaxation of the muscle, and the operation is difficult. The effect is not obvious, which brings great difficulties to the actual teaching

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