Low-distortion large-target-surface video conference lens and electronic device

Abstract

The application discloses a kind of low distortion, big target surface video conference lens and electronic equipment.The lens is sequentially from object side to image side first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens;First lens has negative refractive power, the object side surface of this lens is convex, the image side surface of this lens is concave;Second lens has positive refractive power, the object side surface of this lens is convex, the image side surface of this lens is concave, etc.The application is directed to the problem that existing video conference lens cannot consider small size, big target surface, big CRA, high definition, low distortion and small field curvature video conference lens, and proposes an innovative optical design.Through glass-plastic hybrid design, the number of glass lenses is reduced, and a 1 / 1.56 inch target surface sensor is matched to realize a small size, big target surface, big CRA, high definition, low distortion and small field curvature video conference lens.

Description

Technical Field

[0001] This invention relates to the field of video conferencing lens technology, and more particularly to a low-distortion, large-area video conferencing lens and electronic device. Background Technology

[0002] With the rapid development of the internet, the convenience and speed of online office work, such as online meetings, online education, and live streaming, have become increasingly apparent. These services offer advantages such as real-time multi-party communication that breaks through time and space limitations, accelerated decision-making processes, and adaptability to various hybrid office scenarios. As the eyes of online work, video conferencing lenses capture and image data to meet the needs of virtual reality communication during meetings. Their performance directly affects the clarity, smoothness, and stability of video services. With the continuous improvement of technical specifications for video conferencing systems, lenses are required to have larger image planes, lower distortion and field curvature, while also placing higher demands on lens size and image quality.

[0003] Currently available video conferencing lenses still cannot simultaneously achieve high image quality, large sensor size, and small volume, and cannot meet the application requirements of some scenarios, such as the inability of the field-of-view CRA to match the non-linear CRA curve of high-end sensors, and insufficient lens field curvature. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a low-distortion, large-area video conferencing lens and electronic device. This lens can at least solve one of the technical shortcomings mentioned in the background art.

[0005] According to one aspect of the present invention, a low-distortion, large-area video conferencing lens is provided, comprising, from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens;

[0006] The first lens has negative refractive power, the object side of the lens is convex, and the image side of the lens is concave.

[0007] The second lens has positive refractive power, and the object-side surface of the lens is convex, while the image-side surface of the lens is concave.

[0008] The third lens has negative refractive power, and its object-side surface is convex while its image-side surface is concave.

[0009] The fourth lens has positive refractive power, the object side of the lens is convex, and the image side of the lens is concave.

[0010] The fifth lens has positive refractive power, and the object-side surface of the lens is convex, as is the image-side surface of the lens.

[0011] The sixth lens has negative refractive power. The object side of the lens is concave, and the image side of the lens is also concave.

[0012] The seventh lens has positive refractive power, the object side of the lens is concave, and the image side of the lens is convex.

[0013] The eighth lens has negative refractive power, and the object-side surface of the lens is concave, as is the image-side surface of the lens.

[0014] The first, second, third, fourth, fifth, and sixth lenses are glass lenses; the seventh, eighth, and ninth lenses are plastic lenses.

[0015] In the above technical solution, this invention addresses the problem that existing video conferencing lenses cannot simultaneously achieve small size, large sensor surface area, large CRA, high definition, low distortion, and low field curvature, and proposes an innovative optical design. Through a glass-plastic hybrid design, the number of glass lenses used is reduced, and combined with a 1 / 1.56-inch sensor surface area, a video conferencing lens with small size, large sensor surface area, large CRA, high definition, low distortion, and low field curvature is achieved, significantly improving image quality. Specifically:

[0016] (1) By combining lenses with different diopter powers, the light is gently deflected to the optical axis by compressing the field of view and expanding the beam, which reduces the tolerance sensitivity and effectively reduces the outer diameter of the subsequent lenses. This balances the characteristics of a large field of view and a small volume, effectively shortens the total length of the lens, reduces the lens cost, and maintains the system's large image plane and high image quality performance.

[0017] (2) By using a front group of four elements and a rear group of four elements, image quality is improved and system distortion is reduced. The combination of glass spherical lenses and plastic aspherical lenses achieves both a large image area and a small volume, while effectively reducing the number of lenses and the outer diameter.

[0018] (3) By combining glass-plastic hybrid design, optimized optical path and target surface adaptability, this invention reduces lens cost, shortens the total length of the lens and reduces lens weight, while ensuring good imaging quality of the system, providing technical support for the miniaturization and high performance of video conferencing lenses.

[0019] In some embodiments, an aperture stop is provided between the fourth lens and the fifth lens, and the seventh lens is a plastic aspherical lens made of high refractive index material.

[0020] In the above technical solution, the present invention further improves the performance of the video conferencing lens by optimizing the structural design of the optical system. Specifically, an aperture stop is provided between the fourth lens and the fifth lens, and the seventh lens is a plastic aspherical lens made of a high refractive index material.

[0021] (1) The aperture stop is positioned between the fourth and fifth lenses. This design effectively controls the incident angle and path of light, optimizing the distribution of light in the optical system. By adjusting the distance between the lenses and the aperture stop, astigmatism can be corrected, especially excelling in correcting coma, distortion, and transverse aberration. This choice of aperture stop position not only improves image quality but also provides greater optimization space for the design of subsequent lenses.

[0022] (2) The seventh lens is a plastic aspherical lens made of high-refractive-index material. High-refractive-index material can effectively correct spherical aberration and coma in the optical system, especially under conditions of large field of view and large aperture, which can significantly improve the sharpness and consistency of the image. The design of the aspherical lens can achieve complex light correction functions within a small lens size, thereby reducing the lens spacing and effectively shortening the overall length of the optical system. The combination of high-refractive-index material and aspherical design can further reduce the tolerance sensitivity of the system while ensuring image quality, and improve production consistency and reliability.

[0023] (3) By optimizing the aperture position and applying aspherical lenses made of high-refractive-index glass, the lens spacing and light path are reduced, significantly lowering the overall size of the lens and meeting the development needs of miniaturization and lightweight video conferencing lenses. It effectively corrects spherical aberration, coma, astigmatism, distortion, and transverse aberration, ensuring high resolution and large target surface compatibility of the imaging system. The combined design of high-refractive-index materials and aspherical lenses reduces reliance on complex lens groups while improving production efficiency and yield.

[0024] In some embodiments, the lens satisfies the following condition:

[0025] 1.63 <nd1<1.80,45<vd1<62;

[0026] 1.80 <nd2<1.95,16<vd2<40;

[0027] 1.75 <nd3<1.85,23<vd3<30;

[0028] 1.58 <nd4<1.75,50<vd4<70;

[0029] 1.50 <nd5<1.55,55<vd5<58;

[0030] 1.63 <nd6<1.67,19<vd6<24;

[0031] 1.98 <nd7<2.12,16<vd7<29;

[0032] 1.65 <nd8<1.68,19<vd8<21;

[0033] In the formula, nd1 to nd9 are the refractive indices of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens, respectively, and vd1 to vd9 are the dispersion coefficients of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens, respectively.

[0034] In the above technical solution, the rational combination of the refractive index and dispersion coefficient of each lens ensures that the optical system achieves high resolution and high contrast imaging effects across the entire field of view, meeting the requirements for high-definition image quality. By optimizing lens materials and structural design, the number and size of lenses are reduced, effectively shortening the overall length of the optical system and reducing lens weight, thus meeting the trend of miniaturization and lightweighting in video conferencing lenses. The rational combination of high-Abbe number and low-Abbe number materials reduces reliance on expensive optical materials, while improving production efficiency and yield, and lowering overall production costs.

[0035] In some embodiments, the third and fourth lenses are designed as cemented doublet lenses, and the image-side surface of the fourth lens is concave.

[0036] In the above technical solution, the cemented doublet lens, by rationally combining materials with different refractive indices and dispersion coefficients, can effectively correct axial and transverse chromatic aberration, ensuring color consistency and sharpness in the image. The cemented doublet design optimizes the light convergence path, reduces spherical aberration and astigmatism, and improves image uniformity and contrast. The cemented design reduces air gaps between lenses, decreasing light reflection and scattering at the interface, thus improving system stability and reliability. Furthermore, setting the fourth and fifth lenses to positive refractive power helps converge light, ensuring that incident beams from each field of view are accurately deflected and converged onto the imaging plane after passing through the optical system, improving image sharpness and resolution. Positive refractive lenses effectively suppress aberrations such as spherical aberration, chromatic aberration, field curvature, and astigmatism, ensuring high-resolution and high-contrast imaging across the entire field of view. The synergistic effect of the cemented doublet lens and the positive refractive lens ensures high-resolution and high-contrast imaging across the entire field of view, meeting the requirements for high-definition imaging. By optimizing the lens combination and structural design, the overall number and size of lenses are reduced, effectively shortening the overall length of the optical system and reducing the weight of the lens, thus meeting the development needs of miniaturization and lightweighting of video conferencing lenses.

[0037] In summary, this invention solves the technical challenges of existing video conferencing lenses in terms of chromatic aberration correction, image quality optimization, and miniaturization by designing the third and fourth lenses as cemented doublet lenses and setting the fourth and fifth lenses to positive optical diopter. It has significant innovation and practicality.

[0038] In some embodiments, the lens satisfies the following condition:

[0039] nd7>1.98

[0040] In the formula, nd7 represents the refraction of the seventh lens.

[0041] In the aforementioned technical solutions, high-refractive-index materials can effectively correct spherical aberration, coma, and chromatic aberration in optical systems, especially under conditions of large aperture and wide field of view, significantly improving image sharpness and consistency. High-refractive-index materials allow for thinner lens designs while achieving complex light correction functions within a smaller lens spacing, thereby effectively shortening the overall length of the optical system and meeting the miniaturization needs of drone lenses. Combined with the design of the aperture stop positioned between the fifth and sixth lenses, the application of high-refractive-index materials further enhances the performance of the optical system.

[0042] In some embodiments, the lens satisfies the following condition:

[0043] nd6 <nd8<nd7;vd7<vd6

[0044] In the formula, nd6, nd7, and nd8 are the refractive indices of the sixth, seventh, and eighth lenses, respectively, and vd6 and vd7 are the dispersion coefficients of the sixth and seventh lenses, respectively.

[0045] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the seventh lens are glass spherical lenses, and the fifth lens, the sixth lens, and the eighth lens are plastic aspherical lenses.

[0046] In the above technical solution, aspherical lenses are used in the fifth, sixth, and eighth lenses of the rear group. By increasing the order of even-order aspherical lenses, the utilization efficiency of each lens is improved, thereby reducing the number of lenses used, effectively reducing the size of the lens, and also effectively controlling edge distortion. At the same time, the special shape of the last plastic aspherical lens ensures a non-linear relationship between image height and CRA, matching the CRA curve of high-end sensors.

[0047] By using aspherical lenses in the fifth lens, the sixth lens, and the eighth lens, the present invention can significantly improve the performance of the optical system. Aspherical lenses can effectively correct aberration phenomena such as spherical aberration, coma, astigmatism, and distortion. Especially under the conditions of a large field angle and a large aperture, the clarity and consistency of imaging are significantly improved. The application of aspherical lenses effectively corrects various aberrations, ensuring that the optical system achieves high-resolution and high-contrast imaging effects within the entire field of view, meeting the requirements for high-definition imaging. By increasing the order of the even aspherical surface, each aspherical lens can承担 more optical functions, thus reducing the number of lenses used and making the optical system more compact, meeting the development trend of miniaturization and lightweight of video conferencing lenses. Aspherical lenses can effectively control the deflection of light in the edge region, reduce edge distortion, and improve the uniformity and overall quality of imaging. Glass lenses have the characteristics of high refractive index and low dispersion, which are suitable for correcting chromatic aberration and improving imaging quality; plastic lenses have the advantages of lightweight and low cost, and are suitable for aspherical design to further optimize aberration correction. The combined design of glass and plastic lenses reduces the total number and size of lenses, effectively shortens the total length of the optical system, and at the same time reduces the weight of the lens. The use of plastic aspherical lenses reduces the dependence on expensive glass materials, improves production efficiency and yield rate, and reduces the overall production cost.

[0048] In some embodiments, the lens satisfies the following conditional formula:

[0049] 3 < TTL / f < 4;

[0050] In the formula, TTL is the total optical length of the lens, and f is the focal length of the lens.

[0051] In the above technical solution, by reasonably controlling the ratio of the total optical length (TTL) to the focal length (f), the best balance between the volume and imaging quality of the optical system is ensured. Specifically: when the ratio of the total optical length to the focal length satisfies 3 < TTL / f < 4, the optical system can ensure excellent imaging quality while maintaining a small volume. This design precisely controls the compactness of the optical system, avoiding the degradation of imaging quality caused by too small volume and the不理想 miniaturization caused by too large volume. When TTL / F < 3, the volume of the optical system is likely to be too small, and the imaging quality is reduced; when 3 < TTL / F < 4, the volume of the optical system can be controlled, taking into account small volume while ensuring imaging quality; when TTL / F > 4, the possibility of the optical lens being too large increases, the miniaturization of the lens is不理想, the manufacturing cost and portability problems increase, and at the same time, it may lead to redundancy of optical performance.

[0052] The video conferencing lens of this application has a TTL of <25mm, an effective lens diameter of <φ18.3mm, an F-number of <6.3mm, and a small size; the MTF is greater than 0.3 across the entire field of view at a frequency of 250lp / mm, resulting in good image quality; the target surface height is >10.3mm, which can be matched with a 1 / 1.56” sensor, providing a large target surface; the chromatic aberration along the vertical axis is within the Airy disk radius, and the chromatic aberration along each wavelength is small, so the image will not be affected by blue-violet fringing; the F-Tan (Theta) distortion is <5%, and the TV distortion is <4%, so the image of this system will not be affected by distortion.

[0053] In some embodiments,

[0054] According to another aspect of the invention, an electronic device is provided, comprising the aforementioned low-distortion, large-area video conferencing lens; and an image sensor configured to receive an image formed by the low-distortion, large-area video conferencing lens.

[0055] In the above technical solution, the advantages of this electronic device rely on a low-distortion, large-area video conferencing lens, which will not be elaborated here. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is a schematic diagram of the structure of Example 1 of the low-distortion, large-area video conferencing lens of the present invention;

[0058] Figure 2 This is an MTF curve diagram of an example of a low-distortion, large-area video conferencing lens of the present invention;

[0059] Figure 3 This is a Through Focus curve diagram for Example 1 of the low-distortion, large-area video conferencing lens of the present invention;

[0060] Figure 4 This is a chromatic aberration curve of the lateral axis of an example of a low-distortion, large-area video conferencing lens of the present invention;

[0061] Figure 5 This is an axial chromatic aberration curve of an example 1 of the low-distortion, large-area video conferencing lens of the present invention;

[0062] Figure 6 This is a field curvature and distortion curve diagram of an example of the low-distortion, large-area video conferencing lens of the present invention;

[0063] Figure 7 This is a structural schematic diagram of Example 2 of the low-distortion, large-area video conferencing lens of the present invention;

[0064] Figure 8 This is an example 2 MTF curve of the low-distortion, large-area video conferencing lens of the present invention;

[0065] Figure 9 This is a Through Focus curve diagram for an example of the low-distortion, large-area video conferencing lens of the present invention;

[0066] Figure 10 This is a chromatic aberration curve of the lateral axis of the low-distortion, large-area video conferencing lens of the present invention, Example 2.

[0067] Figure 11 This is an example of the low-distortion, large-area video conferencing lens of the present invention, showing the axial chromatic aberration curve.

[0068] Figure 12 This is a field curvature and distortion curve diagram of an example of the low-distortion, large-area video conferencing lens of the present invention;

[0069] Figure 13 This is a structural schematic diagram of Example 3 of the low-distortion, large-area video conferencing lens of the present invention;

[0070] Figure 14 This is a 3MTF curve of an example of the low-distortion, large-area video conferencing lens of the present invention;

[0071] Figure 15 This is a Through Focus curve diagram for an example of the low-distortion, large-area video conferencing lens of the present invention.

[0072] Figure 16 This is a chromatic aberration curve of the 3rd example of the low-distortion, large-area video conferencing lens of the present invention.

[0073] Figure 17 This is an example of the low-distortion, large-area video conferencing lens of the present invention, showing the axial chromatic aberration curve.

[0074] Figure 18 This is a three-field curvature and distortion curve diagram of the low-distortion, large-area video conferencing lens of the present invention;

[0075] Figure 19 This is a structural schematic diagram of Example 4 of the low-distortion, large-area video conferencing lens of the present invention;

[0076] Figure 20 This is a 4MTF curve of an example of the low-distortion, large-area video conferencing lens of the present invention;

[0077] Figure 21This is a Through Focus curve diagram for example 4 of the low-distortion, large-area video conferencing lens of the present invention;

[0078] Figure 22 This is a chromatic aberration curve diagram of the 4th example of the low-distortion, large-area video conferencing lens of the present invention.

[0079] Figure 23 This is an example of the low-distortion, large-area video conferencing lens of the present invention, shown in axial chromatic aberration curve 4.

[0080] Figure 24 This is a 4-field curve and distortion curve diagram of the low-distortion, large-area video conferencing lens of the present invention;

[0081] Figure 25 This is a schematic diagram of the structure of Example 5 of the low-distortion, large-area video conferencing lens of the present invention;

[0082] Figure 26 This is a 5MTF curve of an example of the low-distortion, large-area video conferencing lens of the present invention;

[0083] Figure 27 Example 5 of the low-distortion, large-area video conferencing lens of this invention: Through Focus curve;

[0084] Figure 28 This is a chromatic aberration curve diagram of the 5th example of the low-distortion, large-area video conferencing lens of the present invention.

[0085] Figure 29 This is an example 5 of the low-distortion, large-area video conferencing lens of the present invention, showing the axial chromatic aberration curve.

[0086] Figure 30 This is a graph showing the distortion curves of five fields in an example of the low-distortion, large-area video conferencing lens of the present invention.

[0087] Figure 31 This is a schematic diagram of the structure of Example 6 of the electronic device of the present invention. Detailed Implementation

[0088] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the invention. Similarly, the following embodiments are only some, not all, embodiments of the present invention, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0089] The purpose of this invention is to provide a low-distortion, large-area video conferencing lens and electronic device with high optical performance. Embodiments according to the invention will now be described in detail with reference to the accompanying drawings.

[0090] Figure 1 , Figure 7 , Figure 13 , Figure 19 , Figure 25 These are cross-sectional views of low-distortion, large-aperture video conferencing lenses (optical systems) according to Examples 1 to 5. The low-distortion, large-aperture video conferencing lenses of each example are used in video conferencing cameras including interchangeable-lens or non-interchangeable-lens models. In each cross-sectional view, the left side is the object-side OBJ and the right side is the image-side IMA. In each cross-sectional view, Li represents the i-th lens, ST represents the aperture stop (fixed aperture stop or visible aperture stop), and G1 represents the protective glass & filter. IMA represents the image plane, and when the low-distortion, large-aperture video conferencing lenses 1 to 5 of each example are used in interchangeable-lens or non-interchangeable-lens video conferencing cameras, a solid-state imaging element (photoelectric conversion element), such as a CMOS image sensor or a CCD image sensor, is arranged on the image plane IMA.

[0091] Based on the low-distortion, large-area video conferencing lenses of each example, from the object side to the image side, the lenses are in the following order: first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, and eighth lens L8.

[0092] The first lens L1 has negative refractive power, and the object side of the lens is convex and the image side is concave.

[0093] The second lens L2 has positive refractive power, and the object side of the lens is convex and the image side is concave.

[0094] The third lens L3 has negative refractive power. The object side of this lens is convex and the image side is concave.

[0095] The fourth lens L4 has positive refractive power. The object side of the lens is convex and the image side is concave.

[0096] The fifth lens L5 has positive refractive power, and the object side and image side of the lens are both convex.

[0097] The sixth lens L6 has negative refractive power. The object side and the image side of this lens are both concave.

[0098] The seventh lens L7 has positive refractive power. The object side of the lens is concave and the image side is convex.

[0099] The eighth lens L8 has negative refractive power. The object side of the lens is concave, and the image side of the lens is concave. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the seventh lens L7 are glass spherical lenses, while the fifth lens L5, the sixth lens L6, and the eighth lens L8 are plastic aspherical lenses.

[0100] The third lens L3 and the fourth lens L4 are designed as cemented doublet lenses, and the image side of the fourth lens L4 is set to be concave.

[0101] The low-distortion, large-area video conferencing lenses in each example can meet at least one of the following setup conditions 1) to 4):

[0102] 1) 1.63 <nd1<1.80,45<vd1<62;1.80<nd2<1.95,16<vd2<40;1.75<nd3<1.85,23<vd3<30;1.58<nd4<1.75,50<vd4<70;1.50<nd5<1.55,55<vd5<58;1.63<nd6<1.67,19<vd6<24;1.98<nd7<2.12,16<vd7<29;

[0103] 1.65 <nd8<1.68,19<vd8<21;

[0104] 2) nd7 > 1.98;

[0105] 3)nd6 <nd8<nd7;vd7<vd6;

[0106] 4)3 <TTL / f<4。

[0107] In the above conditional expressions, f is the focal length of the lens; nd1 to nd9 are the refractive indices of the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses, respectively; vd1 to vd9 are the dispersion coefficients of the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses, respectively; and TTL is the total length of the lens's optical system.

[0108] A detailed description of low-distortion, large-area video conferencing lenses based on various examples is now provided.

[0109] Please refer to the optical structure of Example 1. Figure 1 The specific parameters of Example 1 are shown in Tables 1 and 2 below. In Example 1, the lens focal length f' = 6.23 mm, the effective diameter of the first lens element is 17.003 mm, and the target surface height is 10.350 mm.

[0110] Table 1 Example 1 Parameter Table

[0111]

[0112] Table 2 Example 1 Aspherical Surface Parameter Table

[0113]

[0114]

[0115] Figure 2 The MTF curve for Example 1 shows that the MTF across the entire field of view is greater than 0.3 at 250 lp / mm and greater than 0.6 at 125 lp / mm. Figure 3 The Through Focus curve for Example 1 shows that the defocusing amount is small across the entire field of view, and the field curves for each field of view are all less than 3µm with low astigmatism. Figure 4 The image shows the vertical chromatic aberration curve for Example 1, where the lens's vertical chromatic aberration correction is less than 1.7µm. Figure 5 The axial color difference curve for Example 1 shows that the axial color difference is small in the 435nm-650nm range, and the blue-purple edge phenomenon is minimal. Figure 6 The field curvature and distortion curves for Example 1 show that the field curvature curves for each wavelength overlap, indicating good lens chromatic aberration correction; distortion is <5%, TV distortion is <4%, and the image quality is not affected by distortion.

[0116] Please refer to the optical structure of Example 2. Figure 7 The specific parameters for Example 2 are shown in Tables 3 and 4 below. In Example 2, the focal length f' = 6.24 mm, the effective diameter of the first lens is 16.969 mm, and the target height is 10.321 mm.

[0117] Table 3 Example 2 Parameter Table

[0118]

[0119]

[0120] Table 4 Example 2 Aspherical Surface Parameter Table

[0121]

[0122] Figure 8 The MTF curve for Example 2 shows that the MTF across the entire field of view is greater than 0.3 at 250 lp / mm and greater than 0.6 at 125 lp / mm. Figure 9 Example 2 shows the Through Focus curves. The full field of view curves show a small defocusing amount, and the field curves for each field of view are all less than 3µm with small astigmatism. Figure 10 The image shows the vertical chromatic aberration curve for Example 2, where the lens's vertical chromatic aberration correction is less than 1.7µm. Figure 11 The axial color difference curve for Example 2 shows that the axial color difference is small in the 435nm-650nm range, and the blue-purple edge phenomenon is minimal. Figure 12 The field curvature and distortion curves for Example 2 show that the field curvature curves for each wavelength overlap, indicating good lens chromatic aberration correction; distortion is <5%, and TV distortion is <4%, meaning the image quality is not affected by distortion.

[0123] Please refer to the optical structure of Example 3. Figure 13 The specific parameters of Example 3 are shown in Tables 5 and 6 below. In Example 3, the lens focal length f' = 6.24 mm, the effective diameter of the first lens element is 16.031 mm, and the target surface height is 10.330 mm.

[0124] Table 5 Example 3 Parameter Table

[0125]

[0126]

[0127] Table 6 Example 3 Aspherical Surface Parameter Table

[0128]

[0129] Figure 14 The MTF curve for Example 3 shows that the MTF across the entire field of view is greater than 0.3 at 250 lp / mm and greater than 0.6 at 125 lp / mm. Figure 15 Example 3 shows the Through Focus curves. The full field of view curves show a small defocusing amount, and the field curves for each field of view are all less than 3µm with small astigmatism. Figure 16 The image shows the vertical chromatic aberration curve for Example 3, where the lens's vertical chromatic aberration correction is less than 1.7µm. Figure 17 The axial color difference curve for Example 3 shows that the axial color difference is small in the 435nm-650nm range, and the blue-purple edge phenomenon is minimal. Figure 18 The field curvature and distortion curves for Example 3 show that the field curvature curves for each wavelength overlap, indicating good lens chromatic aberration correction; distortion is <5%, and TV distortion is <4%, meaning the image quality is not affected by distortion.

[0130] Please refer to the optical structure of Example 4. Figure 19 The specific parameters for Example 4 are shown in Tables 7 and 8 below. In Example 4, the lens focal length f' = 6.24 mm, the effective diameter of the first lens element is 18.268 mm, and the target surface height is 10.369 mm.

[0131] Table 7 Example 4 Parameter Table

[0132]

[0133]

[0134] Table 8 Example 4 Aspherical Surface Parameter Table

[0135]

[0136] Figure 20 The MTF curve for Example 3 shows that the MTF across the entire field of view is greater than 0.3 at 250 lp / mm and greater than 0.6 at 125 lp / mm. Figure 21Example 3 shows the Through Focus curves. The full field of view curves show a small defocusing amount, and the field curves for each field of view are all less than 3µm with small astigmatism. Figure 22 The image shows the vertical chromatic aberration curve for Example 3, where the lens's vertical chromatic aberration correction is less than 1.7µm. Figure 23 The axial color difference curve for Example 3 shows that the axial color difference is small in the 435nm-650nm range, and the blue-purple edge phenomenon is minimal. Figure 24 The field curvature and distortion curves for Example 3 show that the field curvature curves for each wavelength overlap, indicating good lens chromatic aberration correction; distortion is <5%, and TV distortion is <4%, meaning the image quality is not affected by distortion.

[0137] Please refer to the optical structure of Example 5. Figure 25 The specific parameters of Example 5 are shown in Tables 9 and 10 below. In Example 5, the lens focal length f' = 6.24 mm, the effective diameter of the first lens element is 18.047 mm, and the target surface height is 10.351 mm.

[0138] Table 9 Example 5 Parameter Table

[0139]

[0140]

[0141] Table 10 Example 5 Aspherical Surface Parameter Table

[0142]

[0143] Figure 26 The MTF curve for Example 5 shows that the MTF across the entire field of view is greater than 0.3 at 250 lp / mm and greater than 0.6 at 125 lp / mm. Figure 27 Example 5 shows the Through Focus curves. The full field of view curves show a small amount of defocus, and the field curves for each field of view are all less than 3µm with small astigmatism. Figure 28 The image shows the vertical chromatic aberration curve for Example 5, where the lens's vertical chromatic aberration correction is less than 1.7µm. Figure 29 The axial color difference curve for Example 5 shows a small axial color difference between 435nm and 650nm, with minimal blue-purple edge phenomenon. Figure 30 Example 5 shows the field curvature and distortion curves. The field curvature curves of each wavelength overlap, indicating good lens chromatic aberration correction. The distortion is less than 5%, and the TV distortion is less than 4%, so the image will not be affected by distortion.

[0144] Based on Examples 1 to 5, this invention offers the following advantages: Optimized lens effective diameter and system size: By limiting the effective lens diameter to less than φ18.3mm, this invention significantly reduces the physical size of the lens while ensuring the performance of the optical system. This design makes the lens more compact, meeting the miniaturization and lightweight requirements of video conferencing. A focal length F of less than 6.3mm enables wide-angle imaging, covering a wider area, making it particularly suitable for video conferencing applications. The lens utilizes a glass-plastic hybrid design, reducing the number of glass lenses used while leveraging the lightweight properties of plastic lenses to significantly reduce the lens weight, improving the endurance and mobility of video conferencing. MTF performance: At a frequency of 250lp / mm, the modulation transfer function (MTF) value across the entire field of view is greater than 0.3, ensuring high imaging resolution and image sharpness. Target height matching: With a target height greater than 10.3mm, it can match a large 1 / 1.51-inch target sensor, ensuring the imaging surface covers the entire sensor, improving imaging integrity and quality. Through the above design, this invention achieves significant technical advancements in the following aspects:

[0145] Improved image quality: High resolution, wide field of view, and large aperture design ensure high image quality of the optical system in various environments, meeting the requirements for high-definition imaging.

[0146] System miniaturization and lightweighting: By optimizing lens materials and structural design, the number and size of lenses are reduced, effectively shortening the overall length of the optical system and reducing the weight of the lens, thus meeting the development trend of miniaturization and lightweighting of video conferencing lenses.

[0147] Reduced production costs: The hybrid glass-plastic design and reasonable combination of high Abbe number and low Abbe number materials reduce the dependence on expensive optical materials, while improving production efficiency and yield, thus reducing overall production costs.

[0148] Color reproduction and uniformity: By optimizing the light path and correcting aberrations, color consistency and uniformity of the image are ensured, thus improving the visual effect of the image.

[0149] In summary, this invention solves the technical challenges of existing video conferencing lenses in terms of chromatic aberration correction, image quality optimization, and miniaturization by precisely defining the refractive index and dispersion coefficient of each lens, combined with aspherical design and material optimization. It has significant innovation and practicality.

[0150] Example 6

[0151] For reference Figure 31 A description of an electronic device A according to Example 6 of the present invention will be given. Figure 31This is a schematic diagram of an electronic device (video conferencing camera) used in a camera optics system, based on any of the low-distortion, large-area video conferencing lenses in Examples 1 to 5.

[0152] exist Figure 31 In the figures, reference numeral A2 indicates the main body of the electronic device, and reference numeral A1 indicates any of the camera optical systems (interchangeable lenses) including the low-distortion, large-area video conferencing lenses according to Examples 1 to 6. Reference numeral A3 indicates an image sensor (photoelectric conversion element) such as a CMOS image sensor or a CCD image sensor, which is built into the camera body A2 and receives light (the optical image formed by the camera optical system 11) from the camera optical system A1 and performs photoelectric conversion.

[0153] By using a low-distortion, large-area video conferencing lens according to any one of Examples 1 to 6 in electronic devices such as digital still cameras, electronic devices with high optical performance can be obtained.

[0154] Each example can provide electronic devices with high optical performance.

[0155] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims will be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A low-distortion, large-area video conferencing lens, characterized in that, From the object side to the image side, the lenses are arranged in the following order: first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens. There are eight lenses with refractive power. The first lens has negative refractive power, the object side of the lens is convex, and the image side of the lens is concave. The second lens has positive refractive power, and the object-side surface of the lens is convex, while the image-side surface of the lens is concave. The third lens has negative refractive power, and its object-side surface is convex while its image-side surface is concave. The fourth lens has positive refractive power, the object side of the lens is convex, and the image side of the lens is concave. The fifth lens has positive refractive power, and the object-side surface of the lens is convex, as is the image-side surface of the lens. The sixth lens has negative refractive power. The object side of the lens is concave, and the image side of the lens is also concave. The seventh lens has positive refractive power, the object side of the lens is concave, and the image side of the lens is convex. The eighth lens has negative refractive power, and the object-side surface of the lens is concave, as is the image-side surface of the lens. The first, second, third, fourth, fifth, and sixth lenses are glass lenses; the seventh, eighth, and ninth lenses are plastic lenses. The third and fourth lenses are designed as cemented doublet lenses; The lens satisfies the following condition: 1.63 <nd1<1.80,45<vd1<62; 1.80 <nd2<1.95,16<vd2<40; 1.75 <nd3<1.85,23<vd3<30; 1.58 <nd4<1.75,50<vd4<70; 1.50 <nd5<1.55,55<vd5<58; 1.63 <nd6<1.67,19<vd6<24; 1.98 <nd7<2.12,16<vd7<29; 1.65 <nd8<1.68,19<vd8<21; In the formula, nd1 to nd9 are the refractive indices of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens, respectively, and vd1 to vd9 are the dispersion coefficients of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens, respectively. The lens satisfies the following condition: 3 <TTL / f<4; In the formula, TTL is the total optical length of the lens, and f is the focal length of the lens.

2. The low-distortion, large-area video conferencing lens as described in claim 1, characterized in that, An aperture stop is provided between the fourth lens and the fifth lens, and the seventh lens is a plastic aspherical lens made of high refractive index material.

3. The low-distortion, large-area video conferencing lens as described in claim 1, characterized in that, The lens satisfies the following condition: nd7>1.98 In the formula, nd7 is the refractive index of the seventh lens.

4. The low-distortion, large-area video conferencing lens as described in claim 1, characterized in that, The lens satisfies the following condition: nd6 <nd8<nd7;vd7<vd6 In the formula, nd6, nd7, and nd8 are the refractive indices of the sixth, seventh, and eighth lenses, respectively, and vd6 and vd7 are the dispersion coefficients of the sixth and seventh lenses, respectively.

5. A low-distortion, large-area video conferencing lens as described in claim 1, characterized in that, The first lens, the second lens, the third lens, the fourth lens, and the seventh lens are glass spherical lenses, while the fifth lens, the sixth lens, and the eighth lens are plastic aspherical lenses.

6. An electronic device, characterized in that, A low-distortion, large-area video conferencing lens according to any one of claims 1-5; and an image sensor configured to receive an image formed by the low-distortion, large-area video conferencing lens.

Images