large aperture lens

Abstract

The present application relates to a large aperture lens, comprising: first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, ninth lens, tenth lens, eleventh lens and twelfth lens arranged in turn along the direction of optical axis from object side to image side, the optical power of the first lens and the second lens is negative, the optical power of the third lens, the seventh lens and the eleventh lens is positive; the image side surface of the first lens is concave, the third lens is double convex lens, the object side surface of the seventh lens and the eleventh lens is convex, the image side surface of the twelfth lens is convex; the large aperture lens contains a three cemented lens group, the focal length Fb of the three cemented lens group and the system focal length F of the large aperture lens satisfy: 4≤|Fb / F|≤9. The maximum aperture of the lens is F0.7, 5M pixels are considered, and F0.7 / F1.6 two aperture grades are switched arbitrarily.

Description

Technical Field

[0001] This invention relates to the field of imaging optical system technology, and more particularly to a large aperture lens. Background Technology

[0002] With the rapid development of technology, the requirements for optical lenses are becoming increasingly stringent. Currently available lenses can achieve a maximum aperture of around F1.0, and their imaging performance is adequate for common low-light environments. However, their light transmission capability remains unsatisfactory for scenes with extremely low ambient light. To meet the demands for higher pixel counts and more powerful low-light imaging effects, research into imaging lenses with larger apertures and higher resolution has become a new hot topic. Currently, a few lenses can achieve an aperture of F0.8, but they are enormous, with a total lens length exceeding 120mm, and their applications are typically in the infrared field. For security monitoring, such lenses are not practically useful. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a low-cost, large-aperture lens that can operate normally in temperatures ranging from -40℃ to +80℃, achieves a maximum aperture of F0.7, while also supporting 5M pixels, and can switch between F0.7 and F1.6 at will to meet the needs of different scenarios.

[0004] To achieve the above-mentioned objective, the present invention provides a large-aperture lens, comprising: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens arranged sequentially along the optical axis from the object side to the image side.

[0005] The first and second lenses have negative optical power, while the third, seventh, and eleventh lenses have positive optical power.

[0006] The first lens has a concave image-side surface, the third lens is a biconvex lens, the seventh and eleventh lenses have convex object-side surfaces, and the twelfth lens has a convex image-side surface.

[0007] According to one aspect of the invention, the large aperture lens further includes a thirteenth lens located on the image side of the twelfth lens.

[0008] According to one aspect of the invention, the thirteenth lens is a convex-concave lens along the optical axis from the object side to the image side.

[0009] According to one aspect of the invention, the large aperture lens further includes an aperture stop located between the third lens and the fourth lens, between the fourth lens and the fifth lens, or between the sixth lens and the seventh lens.

[0010] According to one aspect of the invention, the center distance D1 between the aperture stop and the lens adjacent to the image side of the aperture stop and the center distance D between the two lenses adjacent to the aperture stop satisfy the relationship: 0≤D1 / D≤0.5.

[0011] According to one aspect of the invention, the large aperture lens comprises a cemented doublet lens group and a cemented triplet lens group.

[0012] According to one aspect of the invention, the focal length Fa of the cemented doublet lens group and the effective focal length F of the large aperture lens satisfy the following relationship: 11≤|Fa / F|≤28.

[0013] According to one aspect of the invention, the focal length Fb of the triplex lens group and the effective focal length F of the large aperture lens satisfy the relationship: 4≤|Fb / F|≤9.

[0014] According to one aspect of the invention, the difference Vd2 between the Abbe values ​​of the two lenses that are cemented together to form the doublet lens group satisfies the following relationship: 30 ≤ |Vd2| ≤ 40.

[0015] According to one aspect of the invention, the difference Vd3 between the maximum and minimum Abbe numbers of the three lenses that make up the cemented triplet lens group satisfies the following relationship: 15 ≤ |Vd3| ≤ 50.

[0016] According to one aspect of the invention, the large aperture lens comprises at least seven lenses with positive optical power and four lenses with negative optical power.

[0017] According to one aspect of the invention, the large aperture lens comprises at least five plastic aspherical lenses.

[0018] According to one aspect of the invention, the radius of curvature R1 of the object side of the third lens and the radius of curvature R2 of the image side of the third lens satisfy the relationship: 0.1≤(R1+R2) / (R1-R2)≤0.6.

[0019] According to one aspect of the invention, in the large aperture lens, the combined focal length FG1 of the front lens group consisting of the first three lenses from the object side and the effective focal length F of the large aperture lens satisfy the relationship: -5≤FG1 / F≤-2.

[0020] According to one aspect of the invention, the combined focal length FG2 of the rear lens group consisting of the last three lenses from the object side and the effective focal length F of the large aperture lens satisfy the relationship: 2≤FG2 / F≤9.

[0021] According to one aspect of the present invention, the total optical length (TTL) of the large aperture lens and the entrance pupil diameter (ENPD) of the large aperture lens satisfy the following relationship: 7 ≤ TTL / ENPD ≤ 10.

[0022] According to one aspect of the invention, the half-image height IH of the large aperture lens and the total optical length TTL of the large aperture lens satisfy the following relationship: 11≤|TTL / IH|≤17.

[0023] According to the present invention, an optical architecture consisting of twelve or thirteen lenses is adopted, and the positive and negative optical powers, the different shapes, surface types, and materials of the object side and image side of each lens are reasonably distributed. This enables the lens to have a large aperture, high resolution, and excellent image quality. The maximum aperture is FNO=0.7, and the resolution reaches the 5M pixel requirement, that is, it ensures extremely high resolution even at a large aperture.

[0024] According to one aspect of the present invention, the hybrid optimized design of plastic aspherical lenses and glass spherical lenses overcomes the difficulty of focus drift caused by the large expansion coefficient of plastic aspherical lenses in high and low temperature environments, enabling the lens to maintain focus within a temperature range of -40℃ to 80℃. Furthermore, the successful application of this hybrid lens design, combining glass and plastic materials, to large-aperture lenses with the aforementioned imaging performance effectively reduces costs. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0026] Figure 1 A schematic diagram illustrating the optical system structure of the large-aperture lens according to Embodiment 1 of the present invention;

[0027] Figure 2 This schematic diagram illustrates the optical system structure of the large-aperture lens in Embodiment 2 of the present invention.

[0028] Figure 3 This schematic diagram illustrates the optical system structure of the large-aperture lens according to Embodiment 3 of the present invention.

[0029] Figure 4This diagram illustrates the optical system structure of the large-aperture lens in Embodiment 4 of the present invention. Specific Implementation

[0030] The description of the embodiments in this specification should be taken in conjunction with the accompanying drawings, which should form part of the complete specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and may be indicated in a simplified or convenient manner. Furthermore, parts of the various structures in the drawings will be described separately; it is worth noting that elements not shown in the figures or not described in words are in a form known to those skilled in the art.

[0031] The description of the embodiments herein, including any references to directions and orientations, is for ease of description only and should not be construed as limiting the scope of the invention. The following description of preferred embodiments involves combinations of features, which may exist independently or in combination; the invention is not particularly limited to the preferred embodiments. The scope of the invention is defined by the claims.

[0032] like Figures 1 to 4 As shown in the figure, an embodiment of the present invention discloses a large-aperture lens, comprising: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, and a twelfth lens L12 arranged sequentially along the optical axis from the object side to the image side. The first lens L1 and the second lens L2 both have negative optical power, while the third lens L3, the seventh lens L7, and the eleventh lens L11 all have positive optical power.

[0033] Furthermore, the large-aperture lens comprises at least seven lenses with positive optical power and four lenses with negative optical power. The large-aperture lens also comprises at least five plastic aspherical lenses.

[0034] Regarding the lens shape, the image-side surface of the first lens L1 is concave, the third lens L3 is a biconvex lens, the object-side surfaces of the seventh lens L7 and the eleventh lens L11 are convex, and the image-side surface of the twelfth lens L12 is convex.

[0035] In one embodiment of the present invention, such as Figure 1 , Figure 2 or Figure 4 As shown, the large-aperture lens, in addition to the twelve lenses in the above embodiment, also includes a thirteenth lens L13. The thirteenth lens L13 is located on the image side of the twelfth lens L12 and is adjacent to the twelfth lens L12. Regarding the shape of this lens, the object side of the thirteenth lens L13 is convex, and its image side is concave.

[0036] Furthermore, the large-aperture lens comprises at least seven lenses with positive optical power and four lenses with negative optical power. The large-aperture lens also comprises at least five plastic aspherical lenses.

[0037] In one embodiment of the present invention, the large aperture lens further includes an aperture stop (STOP), which is located between the third lens L3 and the fourth lens L4, such as... Figure 4 As shown. Or the stop stop is located between the fourth lens L4 and the fifth lens L5, as shown. Figure 3 As shown. Or it may be located between the sixth lens L6 and the seventh lens L7, such as... Figure 1 or Figure 2 As shown.

[0038] In one embodiment of the present invention, the center distance D1 between the stop and the lens adjacent to the image side of the stop and the center distance D between the two lenses adjacent to the stop satisfy the relationship: 0 ≤ D1 / D ≤ 0.5. For example, as shown... Figure 1 As shown, the center distance D1 between the aperture stop STOP and the seventh lens L7 and the center distance D between the sixth lens L6 and the seventh lens L7 satisfy the relationship: 0≤D1 / D≤0.5. This design allows the lens to have sufficient space to achieve arbitrary switching between the variable apertures F / 1.6 and F / 0.7.

[0039] According to the above-described scheme of the present invention, an optical architecture consisting of twelve or thirteen lenses is adopted. By rationally distributing the positive and negative optical powers of each lens, the different shapes, surface types, and materials of the object-side and image-side surfaces, the lens can achieve beneficial effects such as a large aperture, high resolution, and excellent image quality. The maximum aperture is FNO = 0.7, while the resolution meets the 5M les requirement (5M pixel requirement), ensuring extremely high resolution even at a large aperture. The hybrid optimized design of plastic aspherical lenses and glass spherical lenses overcomes the difficulty of focus drift caused by the large expansion coefficient of plastic aspherical lenses in high and low temperature environments, enabling the lens to maintain focus within a temperature range of -40℃ to 80℃. Furthermore, the successful application of the hybrid lens design of glass and plastic materials to a large-aperture lens with the above-mentioned imaging performance effectively reduces its cost.

[0040] In one embodiment of the present invention, the large-aperture lens includes a cemented doublet lens group and a cemented triplet lens group. Preferably, the focal length Fa of the cemented doublet lens group and the effective focal length F of the large-aperture lens satisfy the relationship: 11 ≤ |Fa / F| ≤ 28. By using cemented lenses and rationally configuring the cemented doublet and cemented triplet lens groups, chromatic aberration of the lens can be minimized or even eliminated. Simultaneously, optimizing the focal length range of the cemented doublet lens group and its relationship with the lens focal length reduces light energy reflection loss, improves illumination, and further improves image quality and the sharpness of the lens image.

[0041] Preferably, the focal length Fb of the cemented triplet lens group and the effective focal length F of the large-aperture lens satisfy the relationship: 4≤|Fb / F|≤9. By optimizing the focal length range of the cemented triplet lens group and its relationship with the lens focal length, the large aperture of the lens optical system is further ensured, and the total optical length (TTL) of the optical system is shortened while increasing the amount of light entering the lens, so that the total optical length (TTL) meets the size performance requirement of TTL≤64.5mm.

[0042] Preferably, the difference Vd2 between the Abbe values ​​of the two lenses that make up the cemented doublet lens group satisfies the relationship: 30≤|Vd2|≤40, which can eliminate chromatic aberration that occurs during lens imaging as much as possible, thereby improving the lens's resolving power.

[0043] Preferably, the difference Vd3 between the maximum and minimum Abbe numbers of the three lenses that make up the cemented triplet lens group satisfies the relationship: 15≤|Vd3|≤50, which can eliminate chromatic aberration as much as possible during lens imaging, thereby improving the lens's resolving power.

[0044] In one embodiment of the present invention, the radius of curvature R1 of the object side of the third lens L3 and the radius of curvature R2 of the image side of the third lens L3 satisfy the relationship: 0.1≤(R1+R2) / (R1-R2)≤0.6. By controlling the radius of curvature of the third lens L3, spherical aberration of the lens imaging can be improved, the sensitivity of the central field of view can be reduced, and thus the imaging resolution can be improved.

[0045] In one embodiment of the present invention, in the optical architecture of the large-aperture lens with twelve or thirteen lenses, starting from the object side, the combined focal length FG1 of the front lens group G1 composed of the first three lenses and the effective focal length F of the large-aperture lens satisfy the relationship: -5≤FG1 / F≤-2. Whether for an optical architecture composed of twelve or thirteen lenses, the front lens group G1 includes a first lens L1, a second lens L2, and a third lens L3. This allows for a reasonable distribution of the optical power of the front lens group G1 in the lens, avoiding excessive concentration of optical power, which is beneficial for improving the image quality of the lens, reducing the lens sensitivity, and ensuring good imaging performance of the lens under both high and low temperatures.

[0046] In one embodiment of the present invention, in the optical architecture of the large-aperture lens with twelve or thirteen lenses, starting from the object side, the combined focal length FG2 of the rear lens group G2 composed of the last three lenses and the effective focal length F of the large-aperture lens satisfy the relationship: 2≤FG2 / F≤9. For an optical architecture composed of twelve lenses, the rear lens group G2 includes a tenth lens L10, an eleventh lens L11, and a twelfth lens L12. For an optical architecture composed of thirteen lenses, the rear lens group G2 includes an eleventh lens L11, a twelfth lens L12, and a thirteenth lens L13. This arrangement can control the direction of light, smoothly transition the light from the front to the rear, increase the amount of light transmitted, and avoid the occurrence of vignetting. It also helps to improve the aberration of edge rays, enhance the image quality of the optical imaging lens, and reduce tolerance sensitivity.

[0047] In one embodiment of the present invention, the total optical length (TTL) of the large aperture lens and the entrance pupil diameter (ENPD) of the large aperture lens satisfy the relationship: 7≤TTL / ENPD≤10. This is beneficial for controlling the total optical length (TTL) of the lens within a suitable range, i.e., TTL≤64.5mm, and also helps to avoid problems or defects such as insufficient light transmission caused by an excessively small entrance pupil diameter (ENPD).

[0048] In one embodiment of the present invention, the half-image height IH of the large aperture lens and the total optical length TTL of the large aperture lens satisfy the relationship: 12≤|TTL / IH|≤17, which ensures lens miniaturization while ensuring good imaging quality of the optical imaging lens.

[0049] In summary, the large-aperture lens of this invention offers the advantages of maintaining extremely high resolution at large apertures, low cost, and high imaging performance without blurring within a temperature range of -40℃ to 80℃. Specifically, it has a maximum aperture of FNO = 0.7, achieves a resolution of 5M pixels, has a total optical length TTL ≤ 64.5mm, and provides sufficient space to allow for arbitrary switching between two aperture stops: F / 1.6 and F / 0.7.

[0050] The large aperture lens of the present invention will be specifically described below with reference to four embodiments, accompanying drawings, and tables. In the following embodiments, the aperture stop (including the object side and the image side) is referred to as one surface, the cemented surface of the cemented lens group is referred to as one surface, the parallel plate CG and the filter IR are both referred to as two surfaces, and the image plane IMA is referred to as one surface.

[0051] The parameters for each embodiment that conforms to the above relationship are shown in Table 1 below:

[0052] Relationship Example 1 Example 2 Example 3 Example 4 11≤|Fa / F|≤28 13.27 12.15 11.65 27.43 4≤|Fb / F|≤9 5.13 4.5 7.63 8.27 30≤|Vd2|≤40 30.9 30.9 33 30.9 15≤|Vd3|≤50 48.6 48.6 44.8 19.7 0.1 ≤ (R1 + R2) / (R1 - R2) ≤ 0.6 0.52 0.50 0.13 0.58 -5≤FG1 / F≤-2 -3.18 -3.24 -2.45 -4.68 2≤FG2 / F≤9 7.61 8.90 2.69 3.71 0≤D1 / D≤0.5 0.15 0.05 0.42 0.34 7≤TTL / ENPD≤10 7.62 7.36 7.95 9.36 12≤|TTL / IH|≤17 16.36 12.43 13.62 14.56

[0053] Table 1

[0054] In an embodiment of the present invention, the aspherical lens of the large aperture lens satisfies the following formula:

[0055]

[0056] In the above formula, z is the axial distance from the vertex to the surface at a position perpendicular to the optical axis at a height h; c represents the curvature at the vertex of the aspherical surface; k is the conic coefficient; A4, A6, A8, A 10 A 12 A 14 A 16 ...represent aspheric coefficients of the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders, respectively.

[0057] Example 1

[0058] See Figure 1 The parameters of the large aperture lens in this embodiment are as follows:

[0059] Image height IH = 6.6mm; Aperture FNO = 0.7 / FNO = 1.6;

[0060] In this embodiment, the fourth lens L4, the sixth lens L6, the eighth lens L8, the tenth lens L10, and the thirteenth lens L13 all have positive optical power, while the fifth lens L5, the ninth lens L9, and the twelfth lens L12 all have negative optical power. Regarding the shape of each lens, along the optical axis from the object side to the image side, the first lens L1 is a plano-concave lens, the second lens L2 and the twelfth lens L12 are concave-convex lenses, the third lens L3, the fourth lens L4, the sixth lens L6, the eighth lens L8, and the tenth lens L10 are convex-convex lenses, the fifth lens L5 and the ninth lens L9 are concave-concave lenses, and the seventh lens L7, the eleventh lens L11, and the thirteenth lens L13 are convex-concave lenses.

[0061] Among them, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are cemented together to form a triplet lens group, and the ninth lens L9 and the tenth lens L10 are cemented together to form a doublet lens group.

[0062] The relevant parameters of each lens in the large aperture lens of this embodiment include: surface type, radius of curvature (R value), thickness, refractive index of the material and Abbe number, as shown in Table 2 below.

[0063]

[0064]

[0065] Table 2

[0066] The aspherical coefficients of each aspherical lens in the large aperture lens of this embodiment include: the quadratic surface constant K, the fourth-order aspherical coefficient A4, the sixth-order aspherical coefficient A6, the eighth-order aspherical coefficient A8, and the tenth-order aspherical coefficient A1. 10 12th order aspherical coefficient A 12 Fourteenth-order aspherical coefficient A 14 and the sixteenth-order aspherical coefficient A 16 As shown in Table 3 below.

[0067]

[0068] Table 3

[0069] Combination Figure 1 As shown in Tables 1 to 3 above, the large-aperture lens of this embodiment ensures extremely high resolution at large apertures, low cost, and high imaging performance without blurring within a temperature range of -40℃ to 80℃. Specifically, the maximum aperture FNO = 0.7, while achieving a resolution of 5M pixels, the total optical length TTL ≤ 64.5mm, and there is sufficient space to allow arbitrary switching between two aperture stops: F / 1.6 and F / 0.7.

[0070] Example 2

[0071] See Figure 2 The parameters of the large aperture lens in this embodiment are as follows:

[0072] Image height IH = 8.8mm; Aperture FNO = 0.7 / FNO = 1.6;

[0073] In this embodiment, the fourth lens L4, the sixth lens L6, the eighth lens L8, the tenth lens L10, and the thirteenth lens L13 all have positive optical power, while the fifth lens L5, the ninth lens L9, and the twelfth lens L12 all have negative optical power. Regarding the shape of each lens, along the optical axis from the object side to the image side, the first lens L1, the seventh lens L7, the eleventh lens L11, and the thirteenth lens L13 are convex-concave lenses; the second lens L2 and the twelfth lens L12 are concave-convex lenses; the third lens L3, the fourth lens L4, the sixth lens L6, the eighth lens L8, and the tenth lens L10 are convex-convex lenses; and the fifth lens L5 and the ninth lens L9 are concave-concave lenses.

[0074] Among them, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are cemented together to form a triplet lens group, and the ninth lens L9 and the tenth lens L10 are cemented together to form a doublet lens group.

[0075] The relevant parameters of each lens in the large aperture lens of this embodiment include: surface type, radius of curvature (R value), thickness, refractive index of the material and Abbe number, as shown in Table 4 below.

[0076]

[0077]

[0078] Table 4

[0079] The aspherical coefficients of each aspherical lens in the large aperture lens of this embodiment include: the quadratic surface constant K, the fourth-order aspherical coefficient A4, the sixth-order aspherical coefficient A6, the eighth-order aspherical coefficient A8, and the tenth-order aspherical coefficient A1. 10 12th order aspherical coefficient A 12 Fourteenth-order aspherical coefficient A 14 and the sixteenth-order aspherical coefficient A 16 As shown in Table 5 below.

[0080]

[0081]

[0082] Table 5

[0083] Combination Figure 2As shown in Tables 1, 4, and 5 above, the large-aperture lens of this embodiment possesses the advantages of maintaining extremely high resolution at a large aperture, low cost, and high imaging performance without blurring within a temperature range of -40℃ to 80℃. Specifically, it has a maximum aperture of FNO = 0.7, a resolution of 5M pixels, an optical total length TTL ≤ 64.5mm, and sufficient space to allow for arbitrary switching between two aperture stops: F / 1.6 and F / 0.7.

[0084] Example 3

[0085] See Figure 3 The parameters of the large aperture lens in this embodiment are as follows:

[0086] Image height IH = 8.8mm; Aperture FNO = 0.7 / FNO = 1.6;

[0087] In this embodiment, the fourth lens L4, the fifth lens L5, the ninth lens L9, the tenth lens L10, and the twelfth lens L12 all have positive optical power, while the sixth lens L6 and the eighth lens L8 both have negative optical power. Regarding the shape of each lens, along the optical axis from the object side to the image side, the first lens L1 and the twelfth lens L12 are convex-concave lenses, the second lens L2, the sixth lens L6, and the eighth lens L8 are concave-concave lenses, the third lens L3, the fifth lens L5, the seventh lens L7, the ninth lens L9, and the eleventh lens L11 are convex-convex lenses, and the fourth lens L4 and the tenth lens L10 are concave-convex lenses.

[0088] Among them, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are cemented together to form a triplet lens group, and the second lens L2 and the third lens L3 are cemented together to form a doublet lens group.

[0089] The relevant parameters of each lens in the large aperture lens of this embodiment include: surface type, radius of curvature (R value), thickness, refractive index of the material and Abbe number, as shown in Table 6 below.

[0090]

[0091]

[0092] Table 6

[0093] The aspherical coefficients of each aspherical lens in the large aperture lens of this embodiment include: the quadratic surface constant K, the fourth-order aspherical coefficient A4, the sixth-order aspherical coefficient A6, the eighth-order aspherical coefficient A8, and the tenth-order aspherical coefficient A1. 10 12th order aspherical coefficient A 12 Fourteenth-order aspherical coefficient A 14 and the sixteenth-order aspherical coefficient A 16 As shown in Table 7 below.

[0094]

[0095] Table 7

[0096] Combination Figure 3 As shown in Tables 1, 6, and 7 above, the large-aperture lens of this embodiment possesses the advantages of maintaining extremely high resolution at a large aperture, low cost, and high imaging performance without blurring within a temperature range of -40℃ to 80℃. Specifically, it has a maximum aperture of FNO = 0.7, a resolution of 5M pixels, an optical total length TTL ≤ 64.5mm, and sufficient space to allow for arbitrary switching between two aperture stops: F / 1.6 and F / 0.7.

[0097] Example 4

[0098] See Figure 4 The parameters of the large aperture lens in this embodiment are as follows:

[0099] Image height IH = 8.8mm; Aperture FNO = 0.7 / FNO = 1.6;

[0100] In this embodiment, the fourth lens L4, the fifth lens L5, the ninth lens L9, and the twelfth lens L12 all have negative optical power, while the sixth lens L6, the eighth lens L8, the tenth lens L10, and the thirteenth lens L13 all have positive optical power. Regarding the shape of each lens, along the optical axis from the object side to the image side, the first lens L1, the fourth lens L4, the fifth lens L5, the seventh lens L7, the eleventh lens L11, and the thirteenth lens L13 are convex-concave lenses; the second lens L2 and the twelfth lens L12 are concave-convex lenses; the third lens L3, the sixth lens L6, the eighth lens L8, and the tenth lens L10 are convex-convex lenses; and the ninth lens L9 is a concave-concave lens.

[0101] Among them, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are cemented together to form a triplet lens group, and the ninth lens L9 and the tenth lens L10 are cemented together to form a doublet lens group.

[0102] The relevant parameters of each lens in the large aperture lens of this embodiment include: surface type, radius of curvature (R value), thickness, refractive index of the material and Abbe number, as shown in Table 8 below.

[0103]

[0104]

[0105] Table 8

[0106] The aspherical coefficients of each aspherical lens in the large aperture lens of this embodiment include: the quadratic surface constant K, the fourth-order aspherical coefficient A4, the sixth-order aspherical coefficient A6, the eighth-order aspherical coefficient A8, and the tenth-order aspherical coefficient A1. 10 12th order aspherical coefficient A 12 Fourteenth-order aspherical coefficient A 14 and the sixteenth-order aspherical coefficient A 16 As shown in Table 9 below.

[0107]

[0108]

[0109] Table 9

[0110] Combination Figure 4 As shown in Tables 1, 8, and 9 above, the large-aperture lens of this embodiment possesses the advantages of maintaining extremely high resolution at a large aperture, low cost, and high imaging performance without blurring within a temperature range of -40℃ to 80℃. Specifically, it has a maximum aperture of FNO = 0.7, a resolution of 5M pixels, an optical total length TTL ≤ 64.5mm, and sufficient space to allow for arbitrary switching between two aperture stops: F / 1.6 and F / 0.7.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A large aperture lens, characterized in that, include: The first lens (L1), second lens (L2), third lens (L3), fourth lens (L4), fifth lens (L5), sixth lens (L6), seventh lens (L7), eighth lens (L8), ninth lens (L9), tenth lens (L10), eleventh lens (L11), and twelfth lens (L12) are arranged sequentially along the optical axis from the object side to the image side. The first lens (L1) and the second lens (L2) have negative optical power, while the third lens (L3), the seventh lens (L7), and the eleventh lens (L11) have positive optical power. The image-side surface of the first lens (L1) is concave, the third lens (L3) is a biconvex lens, the object-side surfaces of the seventh lens (L7) and the eleventh lens (L11) are convex, and the image-side surface of the twelfth lens (L12) is convex. The large aperture lens includes a cemented triplet lens group, wherein the fourth lens (L4), the fifth lens (L5), and the sixth lens (L6) are cemented together to form the cemented triplet lens group, or The seventh lens (L7), the eighth lens (L8), and the ninth lens (L9) are cemented together to form a three-cemented lens group; The focal length Fb of the triplex lens group and the effective focal length F of the large aperture lens satisfy the following relationship: 4≤|Fb / F|≤9.

2. The large aperture lens according to claim 1, characterized in that, The difference Vd3 between the maximum and minimum Abbe numbers of the three lenses forming the cemented lens group satisfies the following relationship: 15 ≤ |Vd3| ≤ 50.

3. The large aperture lens according to claim 1, characterized in that, The large aperture lens also includes a thirteenth lens (L13), which is located on the image side of the twelfth lens (L12).

4. The large aperture lens according to claim 3, characterized in that, Along the optical axis from the object side to the image side, the thirteenth lens (L13) is a convex-concave lens.

5. The large aperture lens according to claim 1, characterized in that, The large aperture lens also includes a stop, which is located between the third lens (L3) and the fourth lens (L4), between the fourth lens (L4) and the fifth lens (L5), or between the sixth lens (L6) and the seventh lens (L7).

6. The large aperture lens according to claim 5, characterized in that, The center distance D1 between the stop and the lens adjacent to the image side of the stop and the center distance D between the two lenses adjacent to the stop satisfy the following relationship: 0≤D1 / D≤0.

5.

7. The large aperture lens according to claim 1, characterized in that, The large aperture lens includes a cemented doublet lens group, wherein the ninth lens (L9) and the tenth lens (L10) are cemented together to form the cemented doublet lens group, or The second lens (L2) and the third lens (L3) are cemented together to form a cemented doublet lens group.

8. The large aperture lens according to claim 7, characterized in that, The focal length Fa of the doublet lens group and the effective focal length F of the large aperture lens satisfy the following relationship: 11≤|Fa / F|≤28.

9. The large aperture lens according to claim 7, characterized in that, The difference Vd2 between the Abbe values ​​of the two lenses forming the cemented doublet lens group satisfies the following relationship: 30 ≤ |Vd2| ≤ 40.

10. The large aperture lens according to any one of claims 1 to 9, characterized in that, The large aperture lens comprises at least seven lenses with positive optical power and four lenses with negative optical power.

11. The large aperture lens according to any one of claims 1 to 9, characterized in that, The large aperture lens contains at least five plastic aspherical lenses.

12. The large aperture lens according to any one of claims 1 to 9, characterized in that, The radius of curvature R1 of the object side of the third lens (L3) and the radius of curvature R2 of the image side of the third lens (L3) satisfy the following relationship: 0.1≤(R1+R2) / (R1-R2)≤0.

6.

13. The large aperture lens according to any one of claims 1 to 9, characterized in that, In the large aperture lens, the combined focal length FG1 of the front lens group (G1) consisting of the first three lenses, starting from the object side, and the effective focal length F of the large aperture lens satisfy the following relationship: -5≤FG1 / F≤-2.

14. The large aperture lens according to any one of claims 1 to 9, characterized in that, In the large aperture lens, the combined focal length FG2 of the rear lens group (G2) consisting of the last three lenses from the object side and the effective focal length F of the large aperture lens satisfy the following relationship: 2≤FG2 / F≤9.

15. The large aperture lens according to any one of claims 1 to 9, characterized in that, The total optical length (TTL) of the large aperture lens and the entrance pupil diameter (ENPD) of the large aperture lens satisfy the following relationship: 7 ≤ TTL / ENPD ≤ 10.

16. The large aperture lens according to any one of claims 1 to 9, characterized in that, The half-image height IH of the large aperture lens and the total optical length TTL of the large aperture lens satisfy the following relationship: 12≤|TTL / IH|≤17.

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