Mobile phone protection shell integrated with ultrathin magnifying lens

Abstract

The invention relates to the technical field of mobile phone accessories, in particular to a mobile phone protective shell integrated with an ultra-thin magnifier, which comprises a protective shell body and a magnifier connected with the protective shell body, and is characterized in that the protective shell body is provided with a storage part for flush storage of the magnifier; the magnifying lens is a Fresnel lens made of optical plastic, the thickness of the magnifying lens ranges from 0.4 mm to 0.8 mm, a plurality of optical centers are arranged on one face of the Fresnel lens, a plurality of annular refracting faces are concentrically arranged with the optical centers as the circle centers respectively, and the annular refracting faces are provided with aspheric curved surface sections. The Fresnel lens has the advantages of being ultrathin, good in imaging quality, low in manufacturing cost and the like, the Fresnel lens is integrated on the mobile phone protection shell, the requirement for portable use in a specific scene is met, the original shape of the mobile phone protection shell is maintained, extra size is not increased, and the original light and thin hand feeling and attractiveness of a mobile phone are maintained.

Description

Technical Field

[0001] This invention relates to the field of mobile phone accessories technology, and in particular to a mobile phone protective case that integrates an ultra-thin magnifying glass. Background Technology

[0002] Modern mobile phones mostly feature large screens and narrow bezels, with displays made of glass that are easily broken or damaged. Phone cases significantly reduce the chances of damage from bumps or drops, making them almost an essential accessory. Meanwhile, magnifying glasses, as a functional tool for certain groups, greatly facilitate their needs. For example, they help the elderly or those with poor eyesight to magnify small text, patterns, or objects; they help children observe and learn about insect behavior while playing outdoors; and they allow photography enthusiasts to use magnifying glasses in conjunction with their phone's camera for macro photography.

[0003] Currently, there are several technical solutions that combine a magnifying glass with a phone case, achieving a unified function. For example, Chinese patent document CN201820467108.5 discloses a phone case with a sliding magnifying lens. This case uses a sliding rail and a sliding plate on the case to slide the magnifying lens to the camera area for electronic magnification and observation using the phone's camera. However, the core purpose of the magnifying glass in this patent is to be integrated with the camera for electronic imaging and observation through the phone screen, rather than using the magnifying glass as an independent, direct visual optical tool. Therefore, it is somewhat cumbersome to use in scenarios where using a phone is unnecessary or inconvenient (such as quickly viewing documents or medicine labels). In addition, there are products on the market that use magnetic or snap-on methods to attach independent magnifying lenses to phone cases, catering to scenarios where the magnifying lens can be used alone or in conjunction with a camera. However, since the magnifying lenses in these products are usually traditional glass or resin convex lenses, they have a certain thickness and weight. Attaching the magnifying lens externally to the phone case increases the case's size, compromising its aesthetics and affecting the phone's grip. For example, Chinese patent document CN202421987652.4 exhibits these problems. Simply making the lens thinner results in insufficient magnification or poor image formation.

[0004] Therefore, it is necessary to develop a mobile phone case that can combine a magnifying glass with a mobile phone case in an ultra-thin form, and that allows the magnifying glass to be used conveniently as a standalone tool. Summary of the Invention

[0005] The present invention aims to solve the problem in the prior art where the magnifying glass contained in traditional mobile phone cases is too thick and heavy, affecting the size, appearance, and grip of the mobile phone.

[0006] To solve the above-mentioned technical problems, the present invention provides a mobile phone protective case with an integrated ultra-thin magnifying glass, including a protective case body and a magnifying glass connected to the protective case body, wherein the protective case body is provided with a storage component for flush storage of the magnifying glass;

[0007] The magnifying glass is a Fresnel lens made of optical plastic with a thickness of 0.4 mm to 0.8 mm. One side of the Fresnel lens has several optical centers, and several annular refractive surfaces are concentrically arranged with the optical centers as the center. The annular refractive surfaces have a curved cross-section in the shape of an aspherical surface.

[0008] Furthermore, the properties of the aspherical curved surface on the annular refractive surface satisfy the following formula:

[0009] Where x is the coordinate variable of a point on the surface, z is the surface vector height, c is the curvature of the surface vertex, k is the surface constant, which is the core parameter for defining the surface type, and αi represents the higher-order coefficient, i = 1, 2, 3...n.

[0010] Furthermore, the optical plastic is PMMA or PC, and the Fresnel lens is integrally molded from the PMMA or PC material using an injection molding process.

[0011] Furthermore, the storage component includes a sliding groove on the back of the protective shell body and a sliding strip on the edge of the Fresnel lens. The sliding strip and the sliding groove can slide together to store the Fresnel lens in the sliding groove.

[0012] Furthermore, the sliding bar is provided with a limiting member that can be interference-fitted with the inner wall of the sliding groove, which is used to secure the Fresnel lens in the sliding groove when it is stored.

[0013] Furthermore, the limiting element is a protruding rubber particle disposed on the sliding strip.

[0014] Furthermore, the protective case body includes a bottom case for accommodating the mobile phone and a top cover that can be flipped to cover the mobile phone screen, and the storage component is disposed on the top cover.

[0015] Furthermore, the storage component includes a magnetic frame disposed on the edge of the Fresnel lens and a magnetic frame disposed on the top cover. The Fresnel lens is stored on the top cover by the mutual attraction between the magnetic frames.

[0016] Furthermore, in the above technical solutions, the magnification of the Fresnel lens is 1.5 to 10 times.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. The magnifying glass is made with an ultra-thin Fresnel lens, which is much thinner than a traditional convex lens. This allows the magnifying glass to be integrated into the phone case in an ultra-thin manner. When stored, it is flush or nearly flush with the case surface without increasing the size of the phone case, maintaining the original slim and lightweight feel of the phone. Furthermore, the magnifying glass can be used independently without the restriction of the phone case. It is not only convenient for relevant users to quickly read small print, patterns, and other materials, but it can also be used for outdoor observation, starting fires in the wild, and other scenarios, enhancing the practical value of the product.

[0019] 2. Compared to conventional magnifying glasses that are simply made thinner and then combined with a phone case, resulting in a clear central area but poor edge sharpness and image distortion due to excessive distortion, this invention uses an aspherical design on the Fresnel lens. This ensures that each annular refractive surface of the Fresnel lens is aspherical, greatly improving the imaging quality of the magnifying glass and reducing image distortion. When combined with a phone case, it offers convenience, thinness, and excellent performance. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.

[0021] Figure 1 This is a schematic diagram of the overall structure of the Fresnel lens in this invention;

[0022] Figure 2 This is a cross-sectional view of the Fresnel lens and an enlarged schematic diagram of the curved surface cross-section of its aspherical surface in this invention;

[0023] Figure 3 This is a schematic diagram of the overall structure of the single-back-cover type mobile phone protective case corresponding to the present invention;

[0024] Figure 4 This is a schematic diagram of the overall structure of the flip-type mobile phone protective case corresponding to the present invention;

[0025] Figure 5 This is a schematic diagram of the Fresnel lens integrating multiple magnifications of the present invention.

[0026] Figure 6A This is a simplified optical path diagram of a Fresnel lens with a magnification of 2.5x in this invention;

[0027] Figure 6B for Figure 6A The corresponding spherical aberration diagram;

[0028] Figure 6C for Figure 6A Corresponding field curvature and distortion diagram;

[0029] Figure 6D for Figure 6A The corresponding lateral aberration map;

[0030] Figure 6E for Figure 6A The corresponding horizontal color difference diagram.

[0031] In the attached diagram: 1. Protective shell body; 2. Fresnel lens; 21. Ring refractive surface; 3. Bottom shell; 4. Top cover; 5. Sliding groove; 6. Sliding strip; 7. Limiting component; 8. Magnetic frame. Detailed Implementation

[0032] The technical solution of the present invention will now be described with reference to the accompanying drawings. However, the described embodiments are only some embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," etc., which indicate the direction or positional relationship, are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0034] In the description of this invention, unless otherwise explicitly specified and limited, the terms "set", "install", "connect", and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to an electrical connection or a mechanical connection; they can refer to an indirect connection through an intermediate medium, or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention in conjunction with the specific circumstances.

[0035] The accompanying drawings show various structural schematic diagrams according to embodiments disclosed in the present invention. These drawings are not drawn to scale, and some details may be enlarged or omitted for illustrative purposes.

[0036] like Figures 1-5 As shown, embodiments of the present invention are as follows:

[0037] A mobile phone case with an integrated ultra-thin magnifying glass includes a case body 1 and a magnifying glass disposed on the case body 1. The magnifying glass can be flush-mounted on the case body 1 or taken out separately for direct use. The magnifying glass is integrally molded from optical plastics such as PMMA (polymethyl methacrylate) or PC (polycarbonate) through an injection molding process and is made using the Fresnel imaging principle.

[0038] Because PMMA or PC materials possess excellent light transmittance and are lightweight, drop-resistant, and impact-resistant, they can be used to create Fresnel lenses 2 that can be combined with phone cases. This provides both a magnifying glass function and, along with the phone case itself, protects the phone. Furthermore, the optical plastic injection molding process for producing Fresnel lenses 2 is inexpensive and suitable for mass production alongside phone cases.

[0039] like Figure 1 As shown, the Fresnel imaging principle involves an optical center on one side of the Fresnel lens 2, and several annular refractive surfaces 21 concentrically arranged around this optical center. Each annular refractive surface 21 is an independent annular refractive prism centered on the optical center. The collective function of the annular refractive surfaces 21 is to converge incident parallel beams from one side to a common focal point. Figure 2 As shown, in order to further improve the imaging quality, each annular refractive surface 21 in this invention has a cross-section with an aspherical curved surface in the radial direction with the optical center as the center.

[0040] Based on the above technical solution, in specific implementation, it is only necessary to manufacture several concentric annular refractive surfaces 21 of different numbers or arrangements on the lens lens pressed from the optical plastic to set different magnifications of the magnifying glass, without having to adjust the magnification by increasing or decreasing the thickness of the lens. Furthermore, by designing the annular refractive surface 21 as an aspherical surface in its radial cross-section, the optical properties of the aspherical surface are utilized to further achieve ultra-thin magnification of the magnifying glass, improving its integration with the phone case. Therefore, for the Fresnel lens lens integrated with the phone case in this invention, its thickness can be set in the ultra-thin range of 0.4mm to 0.8mm. This satisfies the magnification function of removing the lens from the phone case, and also ensures that when the ultra-thin Fresnel lens 2 is housed within the body 1 of the phone case, it is essentially flush with the body 1, with almost no additional increase in the volume of the phone case, thus not affecting the feel of the phone case.

[0041] Furthermore, considering that conventional magnifying glasses mainly achieve magnification by increasing or decreasing lens thickness, there may be a situation where the central area is clear but the edge sharpness is poor, and the image distortion is prone to occur due to excessive lens distortion. However, the aspherical design of the annular refractive surface 21 in the radial section allows the lens to focus better, improves the quality of the observed image, effectively corrects aberrations, enhances optical performance, and greatly improves imaging quality and reduces image distortion.

[0042] Furthermore, the surface properties of the aspherical surface satisfy the following formula:

[0043]

[0044] Where x is the coordinate variable of a point on the surface, z is the surface vector height corresponding to x, c is the curvature of the surface vertex, k is the surface constant, which is the core parameter for defining the surface type, and αi represents the higher-order coefficients (i = 1, 2, 3...n). Introducing these coefficients allows for more precise adjustments to the surface, thereby further optimizing the imaging quality.

[0045] Combining the above formula, taking a Fresnel lens 2 with a magnification of 2.5x as an example, in the design process of this embodiment, in order to further obtain an ultra-thin lens that can realize magnification function and also has better lens imaging quality, the parameters in the above formula are globally optimized with the help of professional optical design software. A specific optimal parameter combination is solved for each ring, resulting in c = 0.204 and k = -0.614572. Substituting the parameters into the formula, and according to the x-coordinate variables of each point on the surface, the specific z values ​​of the Fresnel lens 2 with a magnification of 2.5x are obtained, thereby determining the cross-sectional design form of the aspherical surface.

[0046] In addition, such as Figures 6A-6E The figures shown are the optical analysis diagrams obtained in the design scenario of this embodiment. Figure 6A The simplified optical path diagram visually demonstrates the propagation trajectory of incident parallel light rays after passing through the refractive surfaces 21 of each ring of the Fresnel magnifier, clearly presenting the entire process of light rays from incident to convergence, and verifying the rationality of the optical path design with a magnification of 2.5 times. Figure 6B The spherical aberration diagram shows that the lens surface aberration value of this embodiment is extremely small, indicating that through parameter optimization, the spherical aberration of traditional lenses is effectively offset, ensuring the basic sharpness of the image. Figure 6C The field curvature and distortion diagrams show that the field curvature value of the lens in this embodiment is close to 0 and the distortion percentage is extremely low, which solves the defects of traditional magnifying glasses. Figure 6D The lateral aberration diagram shows that light rays incident at different angles can accurately converge at the corresponding positions on the imaging plane without significant offset, thus improving the sharpness of local details. Figure 6E The lateral color difference diagram shows that the lateral offset of light of different wavelengths is extremely small, indicating that the lens effectively controls the color separation phenomenon, ensures the color consistency of the image, and avoids visual blurring or color distortion caused by color difference.

[0047] Through the above image analysis, the 2.5x Fresnel lens 2 of this embodiment can achieve imaging quality comparable to or even surpassing some traditional thick glass convex lenses while maintaining an ultra-thin shape. When the Fresnel lens 2 is integrated into a mobile phone case, it ensures imaging quality while perfectly meeting the mobile phone case's demand for extreme thinness.

[0048] Specifically, in the implementation of mobile phone protective case products, such as Figure 3As shown, for a single-back-cover type mobile phone case, the Fresnel lens 2 is fitted onto the back of the case body 1 and can be slid out from the side or bottom of the case body 1 for use. Specifically, the storage component includes a sliding groove 5 on the back of the case body 1 and a sliding strip 6 on the edge of the Fresnel lens 2. The sliding strip 6 and the sliding groove 5 can slide together. When in use, the Fresnel lens 2 can be slid out from the back of the phone for independent use.

[0049] Furthermore, the sliding bar 6 is also provided with a limiting element 7, such as a protruding rubber particle or an elastic buckle. The limiting element 7 can be interference-fitted with the inner wall of the sliding groove 5 to secure the Fresnel lens 2 in the sliding groove 5 and prevent the Fresnel lens 2 from easily sliding off the protective shell body when the magnifying glass is not in use.

[0050] like Figure 4 As shown, for a flip phone case, the case body 1 includes a bottom shell 3 for accommodating the phone and a top cover 4 that can be flipped to cover the phone screen. The Fresnel lens 2 is disposed on the entire or part of the top cover 4. It can be an integrated setting or a detachable setting. When in use, simply flip open the top cover 4 of the phone to flip out the magnifying lens for independent use.

[0051] Furthermore, for flip-type mobile phone cases, the edges of the Fresnel lens 2 and the top cover 4 are respectively provided with matching magnetic frames 8. The Fresnel lens 2 can be placed on the top cover 4 by the mutual attraction between the magnetic frames 8, making it convenient to remove and use at any time.

[0052] Furthermore, since the Fresnel lens 2 primarily utilizes the different textures formed by several concentric annular refractive surfaces 21 on the lens to achieve different magnifications, therefore, as Figure 5 As shown, several optical centers can be set in different areas of the same lens made of PMMA or PC optical plastic. Using embossing or micro-engraving techniques, annular refractive surfaces 21 of varying numbers or arrangements, centered on each optical center, can be directly manufactured in this area, allowing different areas of the same lens to have different magnifications. While maintaining a lens thickness of 0.4mm to 0.8mm, magnifications of 1.5x to 10x can be achieved. Integrating such multi-magnification lenses into mobile phone cases can meet the needs of different scenarios requiring different magnifications.

[0053] Furthermore, a coating that enhances hardness and light transmittance can be applied to the lens to improve the product's durability.

[0054] This invention has many applications, including but not limited to the following described scenarios:

[0055] 1. When you need to quickly read other small images, texts, or other materials, you can quickly remove the Fresnel lens by sliding or flipping it, so that the optical center of the magnifying glass is aligned with the object to be read.

[0056] 2. When using your phone for macro photography, slide or flip the Fresnel lens to remove it and place it in front of the phone's camera, making sure the optical center of the magnifying glass is aligned with the camera lens. In this case, the magnifying glass acts as a front-facing macro accessory, significantly reducing the minimum focusing distance of the phone's camera and producing clearer, more detailed macro images than digital magnification. This is suitable for simple photography of insects, jewelry, textile textures, etc.

[0057] 3. When engaging in outdoor activities, the Fresnel lens can be removed from its protective case or its angle adjusted directly on the case to focus sunlight through the magnifying glass into a bright focal point, which can then be directed onto flammable materials such as hay or sawdust. Due to the focusing effect of the Fresnel lens, fire can be started quickly, meeting emergency needs.

[0058] It should be noted that the above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Those skilled in the art can understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A mobile phone protective case integrating an ultra-thin magnifying glass, characterized in that, include: The protective case body and the magnifying glass connected to the protective case body, wherein the protective case body is provided with a storage component for flush storage of the magnifying glass; The magnifying glass is a Fresnel lens made of optical plastic with a thickness of 0.4 mm to 0.8 mm. One side of the Fresnel lens has several optical centers, and several annular refractive surfaces are concentrically arranged with the optical centers as the center. The annular refractive surfaces have a curved cross-section in the shape of an aspherical surface.

2. The mobile phone protective case with an integrated ultra-thin magnifying glass according to claim 1, characterized in that, The properties of the aspherical surface on the annular refractive surface satisfy the following formula: Where x is the coordinate variable of a point on the surface, z is the surface vector height, c is the curvature of the surface vertex, k is the surface constant, which is the core parameter for defining the surface type, and αi represents the higher-order coefficient, i = 1, 2, 3...n.

3. The mobile phone protective case integrating an ultra-thin magnifying glass according to claim 1, characterized in that, The optical plastic is PMMA or PC, and the Fresnel lens is integrally molded from the PMMA or PC material using an injection molding process.

4. The mobile phone protective case with an integrated ultra-thin magnifying glass according to claim 1, characterized in that, The storage component includes a sliding groove on the back of the protective shell and a sliding strip on the edge of the Fresnel lens. The sliding strip and the sliding groove can slide together to store the Fresnel lens in the sliding groove.

5. The mobile phone protective case with an integrated ultra-thin magnifying glass according to claim 4, characterized in that, The sliding bar is provided with a limiting member that can be interference-fitted with the inner wall of the sliding groove, which is used to secure the Fresnel lens in the sliding groove when it is stored.

6. The mobile phone protective case integrating an ultra-thin magnifying glass according to claim 5, characterized in that, The limiting element is a protruding rubber particle set on the sliding bar.

7. The mobile phone protective case with an integrated ultra-thin magnifying glass according to claim 1, characterized in that, The protective case body includes a bottom case for accommodating the mobile phone and a top cover that can be flipped to cover the mobile phone screen, and the storage component is disposed on the top cover.

8. The mobile phone protective case with an integrated ultra-thin magnifying glass according to claim 7, characterized in that, The storage component includes a magnetic frame set on the edge of the Fresnel lens and a magnetic frame set on the top cover. The Fresnel lens is stored on the top cover by the mutual attraction between the magnetic frames.

9. The mobile phone protective case with an integrated ultra-thin magnifying lens according to any one of claims 1-8, characterized in that, The Fresnel lens has a magnification of 1.5x to 10x.

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