Amphibious magnifier
By setting a sealing ring around the magnifying glass to create a dry air space, the problem of poor magnification effect of optical magnifying glasses in water is solved, realizing the magnification function for both land and water use, and avoiding the influence of water vapor condensation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI BAOSHAN MIDDLE SCHOOL
- Filing Date
- 2025-12-17
- Publication Date
- 2026-07-24
AI Technical Summary
Existing optical magnifiers cannot effectively magnify in water because the difference in refractive index between air and water causes the refractive index of light in water to be close to 1, which significantly reduces the magnification effect.
Design an amphibious magnifying glass. By setting a sealing ring on the outer periphery of the magnifying glass body to form a sealed space, the lens is placed in dry air to avoid direct contact with water and maintain the magnification effect.
It achieves normal magnification in both water and air, overcomes the problem of magnifying glasses failing in water, expands the scope of application, and avoids the fogging problem caused by water vapor condensation.
Smart Images
Figure CN224553583U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of magnifying glasses, and in particular relates to an amphibious magnifying glass. Background Technology
[0002] With the rapid development of the marine economy, scientific research in the ocean and other waters is becoming increasingly frequent. This includes underwater observation and research of plants and animals, underwater archaeological observation, analysis of underwater shipwrecks or aircraft wrecks, underwater geological exploration, and other diving operations. On land, everyone knows that a magnifying glass is an essential tool for similar work. Workers carry magnifying glasses of different sizes for detailed observation and analysis of research objects when necessary. However, this essential tool is rarely seen being carried or used during the aforementioned diving operations.
[0003] Through research and experimentation, it has been confirmed that ordinary optical magnifying glasses cannot be used properly in water! This is because the refractive index of air and water is different, which means that optical magnifying glasses can hardly magnify effectively when the medium they are in contact with is water.
[0004] The reasons are as follows:
[0005] The refractive index of air is close to 1, while that of glass is 1.5. According to Snell's law of refraction:
[0006]
[0007] Here, A and B are the angle of incidence and the angle of refraction when light travels from air into the glass, respectively. A n B Let $\mathbf$ and $\mathbf$ be the refractive indices of air and glass, respectively. The ratio of their sine values is equal to the ratio of the refractive indices of glass and air. In other words, the greater the difference in refractive indices, the more pronounced the refraction effect. Thus, in a convex lens used as a magnifying glass, the refraction of light from the air is significant when it enters the lens, resulting in a noticeable magnification effect.
[0008] However, if the lens is placed in water, since the refractive index of water is 1.333, which is not much different from the refractive index of glass (1.5), the refractive effect is not very obvious. Specific numerical calculations can be used to compare the two cases:
[0009] 1. Air and Glass:
[0010]
[0011] 2. Water and glass:
[0012]
[0013] Here A w The angle of incidence of light from water to glass. Let be the refractive index of water. We can see that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is 1.5 when light travels from air to glass; however, the ratio is only 1.12 when light travels from water to glass, which is close to 1 (1 indicates no refraction). This means the change in the angle of light caused by refraction is not significant, and therefore the magnification effect is also not obvious. This can also be seen from the change in the focal length of the lens.
[0014] The magnification (M) of a convex lens is inversely proportional to its focal length (f); the shorter the focal length, the greater the magnification. This is expressed as:
[0015]
[0016] Here, E is the distance of distinct vision for the human eye, approximately 25cm. Common magnifications (M) for magnification are approximately 2 to 5 times, corresponding to focal lengths of 12.5cm to 5cm. Let's take a magnifying glass with a magnification of 5 times and a focal length of 5cm as an example to observe its behavior in water.
[0017] Parallel light rays, after passing through a lens with a focal length of 5cm, converge at a point 5cm on the opposite optical axis. This is due to the parallel light rays undergoing two refractions: one from air to glass, and the other from glass to air. The changes in angle caused by the two refractions are approximately the same. Figure 1 Let the distance from the incident point to the optical axis be h. Then the angle α at which the light ray is deflected can be expressed as:
[0018]
[0019] or
[0020]
[0021] In equations (2) and (3), the angle α is caused by the change in the angle of the parallel light rays. The greater the change in angle, the greater α. If the light rays do not change, then α = 0. According to equation (1), the greater the ratio of the refractive indices of the two media, the greater the change in angle. Corresponding to the two cases of glass and air and glass and water, since the refractive index of air is smaller in the former, that is, the ratio of the two media is larger, the angle of change of the light rays is larger. Thus, the focal length of the magnifying glass made from them is shorter, and the shorter the focal length, that is, the greater the magnification. From a similar analysis, it can be seen that for the latter, that is, the case of glass and water, the focal length of the lens in water will become longer, that is, the magnification will become smaller. The magnitude of the change can be inferred by the following formula:
[0022]
[0023] In equations (5) and (6), f airand f water The focal lengths of the same lens in air and water, respectively, n g and n m Let R1 and R2 be the refractive indices of the glass and the medium in which it is contained, i.e., the refractive index of water (the refractive index of air is taken as 1 here), respectively. R1 and R2 are the radii of curvature of the two surfaces of the lens, respectively. The convexity and concavity of the lens are indicated by positive and negative signs. Dividing the above equation by the following equation and eliminating identical factors, we get:
[0024]
[0025] We transform it and change the value n g =1.5 and n m Substituting 1.333 into the equation:
[0026]
[0027] This means the focal length has increased by about four times, so the original focal length of 5cm has become about 20cm. Since magnification is inversely proportional to focal length, the magnification of the magnifying glass in air is now only 1 / 4 of the original, or only 1.25 times. Calculations show that its magnification effect becomes very negligible in water.
[0028] So, what methods can be used to overcome the failure of this magnifying glass in water? Several methods readily come to mind:
[0029] Using a convex lens with a smaller radius of curvature is an option, but this method is not ideal. Lenses with too small a radius of curvature are shaped like glass spheres, which not only become bulky but also cause severe distortion, making them undesirable and impractical.
[0030] Special optical glass with a higher refractive index is used for fabrication. However, special materials with high refractive indices are not only expensive, but also offer limited magnification improvement, and some have poor isotropy.
[0031] This method employs a camera and display device. While theoretically feasible due to the electronic circuitry, it suffers from a complex structure, high water tightness requirements due to the electronic components, high cost, and inconvenience in portability. Its biggest drawback is its significant difference from the conventional use of a magnifying glass: a narrow field of view, difficulty in aiming at the observed object, and overall inconvenience. Utility Model Content
[0032] One object of this invention is to provide an amphibious magnifying glass, which offers at least the advantages described below.
[0033] Another objective of this invention is to provide an amphibious magnifying glass that can achieve almost the same magnification effect in water as it does in air, overcoming the problem that magnifying glasses cannot be used in water. Since it can also be used for observation in air like a regular magnifying glass, it can be conveniently used on both land and water without the need for replacement.
[0034] The technical solution of this utility model is as follows:
[0035] An amphibious magnifying glass, comprising a magnifying glass body and a sealing ring disposed on the outer periphery of the magnifying glass body;
[0036] in;
[0037] The front and rear contact surfaces of the magnifying glass body with the external media are both flat.
[0038] The magnifying glass body has a lens structure inside that has a magnifying effect.
[0039] Preferably, in the amphibious magnifying glass, there is dry air between the lens structure and the sealing ring.
[0040] Preferably, in the amphibious magnifying glass, the magnifying glass body includes a front plate glass and a rear plate glass arranged in parallel, and a convex lens located between the front plate glass and the rear plate glass.
[0041] Preferably, in the amphibious magnifying glass, the magnifying glass body includes a flat glass and a plano-convex lens, and the plano-convex lens has its flat side facing outward and parallel to the flat glass.
[0042] Preferably, in the amphibious magnifying glass, the magnifying glass body includes two plano-convex lenses arranged opposite each other, with the planar sides of the two plano-convex lenses facing outwards and the convex sides touching.
[0043] Preferably, in the amphibious magnifying glass, the convex lens and the plano-convex lens are Fresnel lenses.
[0044] This utility model has the following beneficial effects:
[0045] When a flat surface comes into contact with water, it does not cause any change in the shape of the image, allowing the magnifying glass to achieve the same normal magnification effect in water as it does in air.
[0046] The overall structure can be used not only in water but also in air, making it more widely applicable.
[0047] The space between the magnifying glass body and the sealing ring is dry air, so there will be no problem of water vapor condensation and fogging.
[0048] Other advantages, objectives and features of this invention will be apparent in part from the following description, and in part from the understanding of those skilled in the art through study and practice of the invention. Attached Figure Description
[0049] Figure 1 This is a schematic diagram of the converging optical path of the lens;
[0050] Figure 2 A schematic diagram of the structure of one embodiment of the amphibious magnifying glass provided by this utility model;
[0051] Figure 3 A schematic diagram of another embodiment of the amphibious magnifying glass provided by this utility model;
[0052] Figure 4 This is a schematic diagram of another embodiment of the amphibious magnifying glass provided by this utility model. Detailed Implementation
[0053] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.
[0054] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not imply the presence or addition of one or more other elements or combinations thereof.
[0055] Since lenses cannot effectively magnify underwater, this can be achieved by avoiding water and creating a sealed space to house the lens. Observations show that if a magnifying glass is placed outside a transparent, flat glass aquarium filled with water, it can still magnify the fish or other objects inside. Therefore, by placing the spherical part of the magnifying glass within a sealed space, we can maintain its magnifying performance.
[0056] However, underwater observation requires the person to be submerged, which seems different from observing a fish tank. But closer analysis reveals that underwater, a person wears a diving mask, and their eyes are still exposed to air. To create a similar optical environment, we simply place a similar flat glass fish tank behind a magnifying glass. By observing fish or other aquatic objects in another tank through this water-only fish tank and then through the magnifying glass, we can see the same normal magnification effect as in air. Wearing a flat diving mask underwater is like looking at a magnified underwater image through a glass container.
[0057] Therefore, this utility model provides an amphibious magnifying glass, which includes a magnifying glass body and a sealing ring that is sealed on the outer periphery of the magnifying glass body;
[0058] in;
[0059] The magnifying glass body may consist of multiple pieces, with its front and rear surfaces in contact with the external medium being flat, or an additional flat glass surface may be added.
[0060] The magnifying glass body has a lens structure inside that has a magnifying effect.
[0061] Example 1
[0062] like Figure 2 As shown, the magnifying glass body includes a front plate glass and a rear plate glass arranged in parallel, and a convex lens located between the front plate glass and the rear plate glass.
[0063] Two parallel flat glass plates are placed on either side of a convex lens. These are then sealed, placing the lens within an air medium. Since only the outer flat glass plate comes into contact with the water, no distortion occurs, much like observing a fish in a flat aquarium where the fish's shape remains unchanged. Experimental observations have confirmed its effectiveness and feasibility.
[0064] Example 2
[0065] like Figure 3 As shown, the magnifying glass body includes a flat glass plate and a plano-convex lens, with the plano-convex lens having its flat side facing outward and parallel to the flat glass plate.
[0066] Since Example 1 requires two flat glass plates on both sides of the convex lens, which is cumbersome, it can be simplified. A plano-convex lens (one side flat and the other convex, with the flat side facing outwards) can be used instead, requiring only one flat glass plate placed in front of the convex side. Because the flat surface in contact with water does not alter the image shape, the effect is the same as the first method, but one flat glass plate can be omitted.
[0067] Example 3
[0068] like Figure 4 As shown, the magnifying glass body includes two plano-convex lenses arranged opposite each other, with the planar sides of the two plano-convex lenses facing outwards and the convex sides touching.
[0069] By placing two plano-convex lenses parallel to each other with their convex sides facing inward and touching, and their flat sides facing outward, the same magnification effect can be achieved without using flat glass.
[0070] The convex lenses used above can also be replaced by Fresnel lenses, which would reduce the thickness.
[0071] All three embodiments described above provide almost identical magnification in water as they do in air, overcoming the problem that magnifying glasses cannot be used underwater. Furthermore, the amphibious magnifying glass provided by this invention also achieves magnification in air, thus enabling amphibious use.
[0072] Because the pressure increases significantly in deep water—exceeding 3 atmospheres at depths greater than 20 meters—the glass must withstand the water pressure. Therefore, the flat glass in Examples 1 and 2 needs to be thickened if necessary. However, Example 3, being entirely composed of plano-convex glass, has a larger average thickness, and the two convex surfaces contact each other at the center, resulting in stronger pressure resistance. If a Fresnel lens is used, the increased internal contact area will further enhance its pressure resistance.
[0073] When using a magnifying glass underwater, if the water temperature is low, water vapor will condense on the glass walls, causing fogging, similar to fogging inside swimming goggles, which severely affects observation. Therefore, when sealing flat glass or plano-convex lenses with the surface facing outwards, it is necessary to choose dry weather, or place them in a drying oven or desiccant for at least an hour before removing and sealing. Alternatively, seal one side completely first, then seal about 80% of the other side, place it in a desiccant for one to two hours, and finally quickly seal the remaining part completely. This will eliminate water vapor from the internal space, preventing fogging in the water.
[0074] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details.
Claims
1. An amphibious magnifying glass, characterized in that, Includes a magnifying glass body and a sealing ring that is sealed on the outer periphery of the magnifying glass body; in; The front and rear contact surfaces of the magnifying glass body with the external medium are both flat. The magnifying glass body has a lens structure inside that has a magnifying effect.
2. The amphibious magnifying glass as described in claim 1, characterized in that, There is dry air between the lens structure and the sealing ring.
3. The amphibious magnifying glass as described in claim 1, characterized in that, The magnifying glass body includes a front plate glass and a rear plate glass arranged in parallel, and a convex lens located between the front plate glass and the rear plate glass.
4. The amphibious magnifying glass as described in claim 1, characterized in that, The magnifying glass body includes a flat glass plate and a plano-convex lens, with the plano-convex lens having its flat side facing outward and parallel to the flat glass plate.
5. The amphibious magnifying glass as described in claim 1, characterized in that, The magnifying glass body includes two plano-convex lenses placed opposite each other, with the planar sides of the two plano-convex lenses facing outwards and the convex sides touching.
6. The amphibious magnifying glass as described in claim 4, characterized in that, The convex lens and the plano-convex lens are Fresnel lenses.