Wide angle, breath-taking, full-frame camera lens

Abstract

The utility model relates to camera lens field especially wide -angle breathes full frame camera lens, including: first lens group, the second lens group with positive focal length, variable diaphragm, the third lens group with positive focal length and movable and the fourth lens group with negative focal length are arranged in proper order along the light direction, this lens structure is small and light, and the high performance of F1.8 maximum aperture is realized while the cost and appearance advantage are obtained, and the imaging is excellent at infinite and near range; the aspheric lens is used to the rear group and reduces aberration, and makes distortion less than 3%; through the calculation selection satisfies the mobile group of low breath effect, adjusts the light incidence position and length and positive and negative focal length proportion of mobile group, makes the angle of view change tend to be gentle when the system switches in the far and near shooting, greatly reduces the discomfort of video shooting, improves the photographic experience; the mobile group constitution is simplified, and the size and weight of mobile group are reduced significantly, and the motor load is small, and the focusing efficiency is effectively guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of camera lenses, and more particularly to a wide-angle full-frame camera lens with reduced breathing. Background Technology

[0002] With the rise of short videos on social media platforms, more and more netizens are sharing and exchanging information by shooting daily vlogs. For these users, owning a compact and lightweight automatic mirrorless camera lens is incredibly beneficial. Early mirrorless lenses on the market primarily focused on image quality, using large apertures, low distortion, and bokeh effects to meet customer needs. However, many early products failed to address the uncomfortable breathing camera shake that viewers experience during video recording. Lenses that not only offer excellent resolution, low distortion, large aperture, and a compact design, but also significantly reduce breathing camera shake during video recording, would undoubtedly be highly sought after by professionals and possess a strong competitive edge. Utility Model Content

[0003] The purpose of this invention is to provide a wide-angle, breathable full-frame camera lens to solve the aforementioned technical problems.

[0004] The technical solution of this utility model is implemented as follows:

[0005] A wide-angle, breath-free full-frame camera lens includes: a first lens group with negative optical power, a second lens group with positive optical power, a variable aperture, a third lens group with positive optical power, and a fourth lens group with negative optical power arranged sequentially along the light-gathering direction. The first lens group, the second lens group, and the fourth lens group are all fixed, while the third lens group is movable. Its movement from the image side to the object side achieves focusing from infinity to near.

[0006] Optionally, the first lens group consists of a first lens, a second lens, and a third lens arranged sequentially along the light-incident direction, wherein the first lens and the second lens are negative lenses bent toward the image side.

[0007] Optionally, the radii of curvature of both the first lens and the second lens satisfy the following condition:

[0008] (LnR2+LnR1) / (LnR2-LnR1) < -1.4;

[0009] Wherein, LnR1 is the radius of curvature of the side of the negative lens closest to the object, and LnR2 is the radius of curvature of the side of the negative lens closest to the image plane. This setting reduces the front aperture of the optical system by compressing the light beam height; by using two similarly shaped lenses to share the function, the distortion and astigmatism caused by the front ultra-concave lens are reduced.

[0010] Optionally, the third lens is a biconvex positive lens, and satisfies the following conditions:

[0011] PgF3+0.0017vd3 > 0.67;

[0012] F3 / FG1 < -1;

[0013] Wherein, PgF3 is the partial dispersion of the biconvex positive lens with respect to the g and F lines, vd3 is the Abbe number of the biconvex positive lens, F3 is the focal length of the biconvex positive lens, FG1 is the focal length of the first lens group, and the third lens corresponding to the above parameters belongs to a special anomalous dispersion material, which can effectively correct the second-order spectrum and better eliminate chromatic aberration.

[0014] Optionally, both the second and third lens groups are composed of multiple lenses arranged together, and each of the second and third lens groups has at least one lens that satisfies the following condition:

[0015] Vd > 70; where Vd is the Abbe number of the lens material, an ultra-low dispersion material that can reduce chromatic aberration.

[0016] Optionally, the focal length of the second lens group satisfies the following condition:

[0017] 1 < FG2 / f < 1.6; where FG2 is the focal length of the second lens group and f is the focal length of the optical system. The effect of eliminating breathing is achieved by designing a suitable focusing group position and focal length ratio.

[0018] Optionally, the second lens group consists of a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the light-incident direction;

[0019] The third lens group consists of an eighth lens, a ninth lens, and a tenth lens arranged sequentially along the light-gathering direction.

[0020] Optionally, the eighth and ninth lenses in the third lens group are a set of cemented doublet lenses, and the tenth lens is a biconvex positive lens, wherein the tenth lens satisfies the following condition:

[0021] Nd10 > 1.85; 1.5 < F10 / f < 2; nd10 is the refractive index of the tenth lens about the d line, F10 is the focal length of the tenth lens, and f is the focal length of the optical system. Using high refractive index materials reduces the light emission angle and better balances the imaging quality at far and near distances.

[0022] Optionally, the fourth lens group is composed of multiple lenses arranged together, including at least one aspherical negative lens bent towards the object side, and the aspherical negative lens satisfies the following condition:

[0023] |(LnR3+LnR4) / (LnR4-LnR3)| > 4.36;

[0024] Wherein, LnR3 is the radius of curvature of the aspherical negative lens on the object side, and LnR4 is the radius of curvature of the aspherical negative lens on the image side. By reducing off-axis aberrations and distortion, the imaging quality is improved.

[0025] Optionally, the fourth lens group satisfies the following condition:

[0026] -3 < FG4 / f < -2; where FG4 is the focal length of the fourth lens group and f is the focal length of the optical system, used to correct residual aberrations.

[0027] Optionally, the fourth lens group consists of an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens arranged sequentially along the light-gathering direction.

[0028] The beneficial effects of this utility model are:

[0029] The wide-angle, breath-free full-frame camera lens of this invention features a compact and lightweight structure, achieving high performance with a maximum aperture of F1.8 while maintaining cost and aesthetic advantages. It delivers excellent imaging at both infinity and close-up distances. The rear lens utilizes aspherical lenses to reduce aberrations and minimize distortion to less than 3%. By calculating and selecting a movement group that satisfies the low breathing effect, and adjusting the light incident position, length, and positive / negative power ratio of the movement group, the system achieves smoother angle changes during switching between near and far shooting, significantly reducing discomfort during video shooting and improving the photographic experience. The simplified movement group structure significantly reduces its size and weight, resulting in a lighter motor load and effectively ensuring focusing efficiency. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of the wide-angle, breath-free full-frame camera lens described in the embodiment;

[0032] Figure 2 A graph showing the spherical aberration curves for wide-angle full-frame camera lenses with reduced breathing effect;

[0033] Figure 3 Field curvature curve of a wide-angle full-frame camera lens;

[0034] Figure 4 This is a distortion curve diagram for a wide-angle, full-frame camera lens with reduced breathing effect.

[0035] Icon labels:

[0036] 1-First lens group; 11-First lens; 12-Second lens; 13-Third lens;

[0037] 2-Second lens group; 21-Fourth lens; 22-Fifth lens; 23-Sixth lens; 24-Seventh lens;

[0038] 3-Third lens group; 31-Eighth lens; 32-Ninth lens; 33-Tenth lens;

[0039] 4-Fourth lens group; 41-Eleventh lens; 42-Twelfth lens; 43-Thirteenth lens; 44-Fourteenth lens;

[0040] 5-Variable aperture; 6-Photosensitive element. Detailed Implementation

[0041] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0042] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0043] Example 1: As Figure 1 As shown, this embodiment provides a wide-angle, breath-free full-frame camera lens, including a first lens group 1 with negative optical power, a second lens group 2 with positive optical power, a variable aperture 5, a third lens group 3 with positive optical power, a fourth lens group 4 with negative optical power, and a photosensitive element 6 arranged sequentially along the light-gathering direction. The first lens group 1, second lens group 2, and fourth lens group 4 are fixed, while the third lens group 3 is movable, moving from the image side to the object side to achieve focusing from infinity to near. Both the second lens group 2 and the third lens group 3 are composed of multiple lenses arranged in a row. At least one lens in each of the second and third lens groups 3 satisfies the following conditions: Vd > 70, ultra-low dispersion material, which can reduce chromatic aberration; where Vd is the Abbe number of the lens material. The focal length of the second lens group 2 satisfies the following condition:

[0044] 1 < FG2 / f < 1.6; where FG2 is the focal length of the second lens group 2, and f is the focal length of the optical system. The effect of eliminating lens breathing is achieved by designing a suitable focusing group position and focal length ratio. The fourth lens group 4 is composed of multiple lenses arranged together, including at least one aspherical negative lens bent towards the object side. The aspherical negative lens satisfies the following condition: |(LnR3+LnR4) / (LnR4-LnR3)| > 4.36; where LnR3 is the radius of curvature of the aspherical negative lens on the object side, and LnR4 is the radius of curvature of the aspherical negative lens on the image plane side. The image quality is improved by reducing off-axis aberrations and distortion. The fourth lens group 4 satisfies the following condition: -3 < FG4 / f < -2; where FG4 is the focal length of the fourth lens group, and f is the focal length of the optical system. This is used to correct residual aberrations.

[0045] Specifically, such as Figure 1 As shown, the first lens group 1 consists of a first lens 11, a second lens 12, and a third lens 13 arranged sequentially along the light-incident direction. The first lens 11 and the second lens 12 are negative lenses curved towards the image side. The radii of curvature of both the first lens 11 and the second lens 12 satisfy the following condition: (LnR2+LnR1) / (LnR2-LnR1) < -1.4; where LnR1 is the radius of curvature of the negative lens on the object side, and LnR2 is the radius of curvature of the negative lens on the image side. This setting reduces the front aperture of the optical system by compressing the light beam height; using two similarly shaped lenses to share the load reduces distortion and astigmatism caused by the front ultra-concave lens. The third lens 13 is a biconvex positive lens and satisfies the following conditions: PgF3+0.0017vd3 > 0.67; F3 / FG1 < -1. Wherein, PgF3 is the partial dispersion of the biconvex positive lens about the g-line and F-line, vd3 is the Abbe number of the biconvex positive lens, F3 is the focal length of the biconvex positive lens, FG1 is the focal length of the first lens group 1, and the third lens 13 corresponding to the above parameters belongs to a special anomalous dispersion material, which can effectively correct the second-order spectrum and better eliminate chromatic aberration.

[0046] The second lens group 2 consists of a fourth lens 21, a fifth lens 22, a sixth lens 23 and a seventh lens 24 arranged sequentially along the light-incident direction;

[0047] The third lens group 3 consists of an eighth lens 31, a ninth lens 32, and a tenth lens 33 arranged sequentially along the light-incident direction. The eighth lens 31 and the ninth lens 32 in the third lens group 3 are a set of cemented doublet lenses, and the tenth lens 33 is a biconvex positive lens. The tenth lens 33 satisfies the following conditions: Nd10 > 1.85; 1.5 < F10 / f < 2; nd10 is the refractive index of the tenth lens 33 about the d-line, F10 is the focal length of the tenth lens 33, and f is the focal length of the optical system. The use of high refractive index material reduces the light exit angle and better balances the imaging quality at both near and far distances.

[0048] The fourth lens group 4 consists of an eleventh lens 41, a twelfth lens 42, a thirteenth lens 43, and a fourteenth lens 44 arranged sequentially along the light-gathering direction.

[0049] The wide-angle, breath-free full-frame camera lens described in this embodiment features a compact and lightweight structure, achieving high performance with a maximum aperture of F1.8 while maintaining cost and aesthetic advantages. It delivers excellent imaging at both infinity and close-up distances. The rear element uses aspherical lenses to reduce aberrations and minimize distortion to less than 3%. By calculating and selecting a movement group that satisfies the low breathing effect, and adjusting the light incident position, length, and positive / negative power ratio of the movement group, the angle of view changes during switching between near and far shooting become smoother, significantly reducing discomfort during video shooting and improving the photography experience. The simplified movement group structure significantly reduces its size and weight, resulting in a lighter motor load and effectively ensuring focusing efficiency.

[0050] In the specific implementation process, the radius of curvature, thickness, refractive index, and dispersion coefficient of each lens surface from the object side (the side of the photographed object) to the image side (the side of the image sensor or film) are shown in Table 1:

[0051] Table 1

[0052] Surface serial number Radius of curvature (mm) Thickness (mm) Refractive index Dispersion coefficient 1 Infinity 5 2 43.437 1.8 1.7283 28.319 3 17.702 8.340 4 76.141 1.3 1.5168 64.199 5 21.754 6.96 6 126.546 4.8 1.946 17.942 7 -126.546 5.58 8 -27.641 1.3 1.8061 33.287 9 34.963 7.7 1.623 58.121 10 -41.214 0.1 11 271.618 5.5 1.801 34.967 12 -44.603 0.1 13 63.667 6.9 1.497 81.605 14 -40.130 2.4 15 Infinity D1 16 -31.068 0.9 1.6034 38.011 17 21.686 6.9 1.49700 81.605 18 -39.569 0.1 19 128.849 4.5 2.0033 28.316 20 -54.156 D2 21 -48.239 0.9 1.6989 30.05 22 69.860 0.1 23 29.5 9.67 1.49700 81.605 24 -29.5 0.1 25 -53.036 0.9 1.8348 42.725 26 219.972 4.68 27 -37.258 2.050 1.8088 40.97 28 -53.927 13.18 29 Infinity 2 1.5168 64.199 30 Infinity 2

[0053] It should be noted that surface 1 in the above table is not shown in the illustration. Figure 1 middle;

[0054] Radius of curvature (mm): Indicates the degree of curvature of the lens surface. Positive values ​​represent convex surfaces, and negative values ​​represent concave surfaces.

[0055] Thickness (mm): refers to the distance between two adjacent surfaces, i.e., the thickness of the lens or air gap.

[0056] Refractive index: the ability of a material to bend light, used to calculate the change in direction of light as it passes through a lens.

[0057] Dispersion coefficient (Abbe number): A numerical value that describes the dispersion characteristics of a material. The larger the value, the smaller the color difference.

[0058] The aspherical coefficients of aspherical positive lenses are shown in Table 2:

[0059] Table 2

[0060] Surface serial number 27 28 k -33.093 4.584 A4 -1.022e-04 -9.525e-05 A6 -1.964e-07 1.425e-06 A8 8.485e-10 -1.645e-08 A10 -5.091e-13 9.338e-11 A12 2.060e-14 -1.871e-13

[0061] k: Conic constant, used to adjust the shape of aspherical surfaces.

[0062] A4, A6, A8, A10, A12: Higher-order aspherical coefficients, which affect the precise shape of the lens surface to optimize optical performance.

[0063] The specific values ​​of D1 and D2 in Table 1 at different focusing distances are shown in Table 3:

[0064] Table 3

[0065] Conjugate distance Infinity Most recently (0.2m) D1 9.21mm 5.92mm D2 1.25mm 4.54mm

[0066] Infinity: The dimensions of each distance when the lens is focused at infinity.

[0067] Closest (0.2m): The dimensions of each distance when the lens is focused at the closest working distance (e.g., 0.2 meters).

[0068] In summary, the key specifications of the wide-angle, breath-free full-frame camera lens of this embodiment are shown in Table 4:

[0069] Table 4

[0070] Focal length f 24.67mm Relative aperture FNO. 1.87 Field of view ω 82.9° Overall optical length 111.22mm

[0071] like Figure 2 The figure shows the spherical aberration curve of a wide-angle, breath-free full-frame camera lens according to this embodiment. The horizontal axis represents spherical aberration, and the vertical axis represents the normalized entrance pupil. As can be seen from the figure, the spherical aberration of the three different wavelengths of light converges to a very small range, allowing the lens to obtain a clear and transparent image.

[0072] like Figure 3 The figure shows the field curvature curve of a wide-angle, breath-free full-frame camera lens according to this embodiment. The horizontal axis represents field curvature, the vertical axis represents image height, the T-line represents the meridional direction, and the S-line represents the sagittal direction. As can be seen from the figure, the image can be imaged on the same plane across the entire frame, without any localized blurring. Furthermore, the small distance between the meridional and sagittal curves indicates uniform image formation in different directions.

[0073] like Figure 4The figure shows the distortion curve of a wide-angle, breath-free full-frame camera lens according to this embodiment, where the horizontal axis represents distortion and the vertical axis represents image height. As can be seen from the figure, the distortion is controlled below 3% across the full-frame range.

[0074] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A wide-angle, breath-free full-frame camera lens, characterized in that, include: A first lens group (1) with negative optical power, a second lens group (2) with positive optical power, a variable aperture (5), a third lens group (3) with positive optical power, and a fourth lens group (4) with negative optical power are arranged sequentially along the light-gathering direction. The first lens group (1), the second lens group (2), and the fourth lens group (4) are all fixed, while the third lens group (3) is movable. It moves from the image side to the object side to achieve focusing from infinity to near.

2. The wide-angle, breath-free full-frame camera lens according to claim 1, characterized in that, The first lens group (1) consists of a first lens (11), a second lens (12) and a third lens (13) arranged sequentially along the light-gathering direction, wherein the first lens (11) and the second lens (12) are negative lenses bent toward the image side.

3. A wide-angle, breath-free full-frame camera lens according to claim 2, characterized in that, The radii of curvature of both the first lens (11) and the second lens (12) satisfy the following condition: (LnR2+LnR1) / (LnR2-LnR1) < -1.4; Wherein, LnR1 is the radius of curvature of the side of the negative lens closest to the object, and LnR2 is the radius of curvature of the side of the negative lens closest to the image plane.

4. A wide-angle, breath-free full-frame camera lens according to claim 2, characterized in that, The third lens (13) is a biconvex positive lens and satisfies the following conditions: PgF3+0.0017vd3 > 0.67; F3 / FG1 < -1; Wherein, PgF3 is the partial dispersion of the biconvex positive lens about the g-line and the F-line, vd3 is the Abbe number of the biconvex positive lens, F3 is the focal length of the biconvex positive lens, and FG1 is the focal length of the first lens group (1).

5. A wide-angle, breath-free full-frame camera lens according to claim 4, characterized in that, Both the second lens group (2) and the third lens group (3) are composed of multiple lenses arranged together, and each of the second lens group (2) and the third lens group (3) has at least one lens that satisfies the following condition: Vd > 70; where Vd is the Abbe number of the lens material.

6. A wide-angle, breath-free full-frame camera lens according to claim 5, characterized in that, The focal length of the second lens group (2) satisfies the following condition: 1 < FG2 / f < 1.6; where FG2 is the focal length of the second lens group (2) and f is the focal length of the optical system.

7. A wide-angle, breath-free full-frame camera lens according to claim 6, characterized in that, The second lens group (2) consists of a fourth lens (21), a fifth lens (22), a sixth lens (23) and a seventh lens (24) arranged sequentially along the light-gathering direction; The third lens group (3) consists of an eighth lens (31), a ninth lens (32) and a tenth lens (33) arranged sequentially along the light-gathering direction.

8. A wide-angle, breath-free full-frame camera lens according to claim 7, characterized in that, The eighth lens (31) and the ninth lens (32) in the third lens group (3) are a set of cemented doublet lenses, and the tenth lens (33) is a biconvex positive lens, and the tenth lens (33) satisfies the following conditions: Nd10 > 1.85; 1.5 < F10 / f < 2; nd10 is the refractive index of the tenth lens (33) about the d line, F10 is the focal length of the tenth lens (33), and f is the focal length of the optical system.

9. A wide-angle, breath-free full-frame camera lens according to claim 8, characterized in that, The fourth lens group (4) is composed of multiple lenses arranged together, including at least one aspherical negative lens bent towards the object side, and the aspherical negative lens satisfies the following condition: |(LnR3+LnR4) / (LnR4-LnR3)| > 4.36; Wherein, LnR3 is the radius of curvature of the aspherical negative lens on the object side, and LnR4 is the radius of curvature of the aspherical negative lens on the image side.

10. A wide-angle, breath-free full-frame camera lens according to claim 8, characterized in that, The fourth lens group (4) satisfies the following conditions: -3 < FG4 / f < -2; where FG4 is the focal length of the fourth lens group and f is the focal length of the optical system.

11. A wide-angle, breath-free full-frame camera lens according to claim 10, characterized in that, The fourth lens group (4) consists of an eleventh lens (41), a twelfth lens (42), a thirteenth lens (43) and a fourteenth lens (44) arranged sequentially along the light-gathering direction.

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