Image capturing optical lens

Abstract

To provide an optical lens, in particular an image capturing optical lens.SOLUTION: An image capturing optical lens comprises a total of five lenses. The five lenses consist of, from the object side to the image side, a first lens having positive refractive power, a second lens having positive refractive power, a third lens having negative refractive power, a fourth lens having positive refractive power, and a fifth lens having negative refractive power. The image capturing optical lens satisfies the following conditional expressions: 3.00≤f2 / f≤12.00, 1.10≤(R9+R10) / (R9-R10)≤1.90, 1.00≤d1 / d2≤4.00, 2.00≤R6 / R5≤15.00. The image capturing optical lens of the present invention meets the design requirements of a large aperture, a wider angle of view, and extra thinness.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of optical lenses, and more particularly to imaging optical lenses applied to imaging devices such as mobile terminal devices such as smartphones and digital cameras, monitors, and PC lenses. [Background technology]

[0002] In recent years, with the emergence of various smart devices, the need for miniaturized imaging optical lenses has been increasing. As the pixel size of photosensitive elements has been shrinking, and modern electronic products are increasingly demanding superior functionality and lightweight, slim, and portable appearances, miniaturized imaging optical lenses with good imaging quality have become mainstream in the current market. To achieve excellent imaging quality, lenses often use multiple lens structures. Furthermore, with technological advances and increasingly diverse user needs, the pixel area of ​​photosensitive elements has been shrinking, and the demand for system imaging quality has been increasing. Consequently, five-lens structures have gradually emerged in lens designs. Therefore, there is a growing demand for wide-angle imaging lenses with excellent optical properties, small volume, and sufficient aberration correction. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention has been made in consideration of the above problems, and has an object to provide an imaging optical lens that has good optical performance and can satisfy the design requirements of a large aperture, an extremely thin lens, and a wide angle lens. [Means for solving the problem]

[0004] In order to achieve the above object, a technical solution of the present invention provides an imaging optical lens, which includes a total of five lenses, which are, from the object side to the image side, a first lens having positive refractive power, a second lens having positive refractive power, a third lens having negative refractive power, a fourth lens having positive refractive power, and a fifth lens having negative refractive power, wherein the following relationship is satisfied when the focal length of the imaging optical lens is f, the focal length of the second lens is f2, the central radius of curvature of the object-side surface of the fifth lens is R9, the central radius of curvature of the image-side surface of the fifth lens is R10, the axial thickness of the first lens is d1, the axial distance from the image-side surface of the first lens to the object-side surface of the second lens is d2, the central radius of curvature of the object-side surface of the third lens is R5, and the central radius of curvature of the image-side surface of the third lens is R6: 3.00≦f2 / f≦12.00 1.10≦(R9+R10) / (R9-R10)≦1.90 1.00≦d1 / d2≦4.00 2.00≦R6 / R5≦15.00

[0005] Preferably, when the axial distance from the image-side surface of the third lens to the object-side surface of the fourth lens is d6 and the axial distance from the image-side surface of the fourth lens to the object-side surface of the fifth lens is d8, the following relational expression is satisfied: 1.00≦d6 / d8≦3.00

[0006] Preferably, when the focal length of the third lens is set to f3, the following relational expression is satisfied: -4.00≦f3 / f≦-1.20

[0007] Preferably, the first lens has an object-side surface formed as a convex surface paraxially, an image-side surface formed as a concave surface paraxially, and satisfies the following relational expression when the focal length of the first lens is f1, the central radius of curvature of the object-side surface of the first lens is R1, the central radius of curvature of the image-side surface of the first lens is R2, and the total optical length of the imaging optical lens is TTL: 0.68≦f1 / f≦2.31 -3.87≦(R1+R2) / (R1-R2)≦-1.13 0.04≦d1 / TTL≦0.25

[0008] Preferably, the object-side surface of the second lens is formed as a convex surface paraxially, and satisfies the following relational expression when the central radius of curvature of the object-side surface of the second lens is R3, the central radius of curvature of the image-side surface of the second lens is R4, the axial thickness of the second lens is d3, and the total optical length of the imaging optical lens is TTL: -2.65≦(R3+R4) / (R3-R4)≦-0.38 0.04≦d3 / TTL≦0.15

[0009] Preferably, the object-side surface of the third lens is formed as a concave surface paraxially, and the image-side surface is formed as a convex surface paraxially, and when the axial thickness of the third lens is d5 and the total optical length of the imaging optical lens is TTL, the following relational expression is satisfied: -5.98≦(R5+R6) / (R5-R6)≦-0.76 0.03≦d5 / TTL≦0.12

[0010] Preferably, the image-side surface of the fourth lens is formed as a convex surface paraxially, and satisfies the following relational expression when the focal length of the fourth lens is f4, the central radius of curvature of the object-side surface of the fourth lens is R7, the central radius of curvature of the image-side surface of the fourth lens is R8, the axial thickness of the fourth lens is d7, and the total optical length of the imaging optical lens is TTL: 0.28≦f4 / f≦1.32 0.43≦(R7+R8) / (R7-R8)≦2.45 0.05≦d7 / TTL≦0.24

[0011] Preferably, the fifth lens has an object-side surface formed as a convex surface paraxially, an image-side surface formed as a concave surface paraxially, and satisfies the following relational expression when the focal length of the fifth lens is f5, the on-axial thickness of the fifth lens is d9, and the total optical length of the imaging optical lens is TTL: -2.42≦f5 / f≦-0.39 0.07≦d9 / TTL≦0.29

[0012] Preferably, when the total optical length of the imaging optical lens is TTL and the maximum image height of the imaging optical lens is IH, the following relational expression is satisfied. TTL / IH≦1.40

[0013] Preferably, when the focal length of the imaging optical lens is f and the composite focal length of the first lens L1 and the second lens L2 is f12, the following relational expression is satisfied. 0.50≦f12 / f≦1.94 [Effects of the Invention]

[0014] The beneficial effects of the present invention are as follows: The imaging optical lens of the present invention has excellent optical performance, as well as the characteristics of a large aperture, a wide angle, and an extremely thin design, and can be applied to imaging lens components for mobile phones and web imaging lenses, in particular, which are composed of imaging elements such as high-pixel CCDs and CMOSs. [Brief explanation of the drawings]

[0015] In order to more clearly describe the technical solutions in the embodiments of the present invention, the drawings necessary for describing the embodiments will be briefly described below. Obviously, the drawings described below are only for describing some embodiments of the present invention, and those skilled in the art can obtain other drawings from these drawings without any creative efforts. [Figure 1] FIG. 1 is a diagram showing the structure of an imaging optical lens according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the spherical aberration of the imaging optical lens shown in FIG. [Figure 3] FIG. 3 is a diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 4] FIG. 4 is a diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. [Figure 5]FIG. 5 is a diagram showing the structure of an imaging optical lens according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram showing the spherical aberration of the imaging optical lens shown in FIG. [Figure 7] FIG. 7 is a diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 8] FIG. 8 is a diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. [Figure 9] FIG. 9 is a diagram showing the structure of an imaging optical lens according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing the spherical aberration of the imaging optical lens shown in FIG. [Figure 11] FIG. 11 is a diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 12] FIG. 12 is a diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. [Figure 13] FIG. 13 is a diagram showing the structure of an imaging optical lens according to a fourth embodiment of the present invention. [Figure 14] FIG. 14 is a diagram showing the spherical aberration of the imaging optical lens shown in FIG. [Figure 15] FIG. 15 is a diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 16] FIG. 16 is a diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. [Figure 17] FIG. 17 is a diagram showing the structure of an imaging optical lens according to a comparative embodiment. [Figure 18] FIG. 18 is a diagram showing the spherical aberration of the imaging optical lens shown in FIG. [Figure 19] FIG. 19 is a diagram showing chromatic aberration of magnification of the imaging optical lens shown in FIG. [Figure 20] FIG. 20 is a diagram showing the field curvature and distortion of the imaging optical lens shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] In order to clarify the objectives, technical solutions, and advantages of the present invention, the following detailed description of each embodiment of the present invention will be given with reference to the drawings. Although many technical details are described in each embodiment of the present invention to facilitate understanding of the present invention, it is obvious to those skilled in the art that the technical solutions protected by the present invention can be realized without these technical details and various changes and modifications based on the following embodiments.

[0017] Referring to the drawings, the technical solution of the present invention provides imaging optical lenses 10, 20, 30, and 40. Figures 1, 5, 9, and 13 respectively show imaging optical lenses 10, 20, 30, and 40 of the present invention, which together include five lenses. Specifically, the imaging optical lenses include, in order from the object side to the image side, a diaphragm S1, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. An optical element such as an optical filter GF may be provided between the fifth lens L5 and the image plane Si.

[0018] The first lens L1 is made of plastic, the second lens L2 is made of plastic, the third lens L3 is made of plastic, the fourth lens L4 is made of plastic, and the fifth lens L5 is made of plastic. Each lens may be made of a different material.

[0019] When the focal length of the imaging optical lens is f and the focal length of the second lens L2 is f2, the relational expression 3.00≦f2 / f≦12.00 is established, and the ratio of the focal length of the second lens L2 to the focal length f of the imaging optical lens is specified. If the focal length of the imaging optical lens is appropriately allocated within the range of this relational expression, the imaging optical lens will have excellent imaging quality and low sensitivity.

[0020] When the central radius of curvature of the object-side surface of the fifth lens L5 is R9 and the central radius of curvature of the image-side surface of the fifth lens L5 is R10, the following relational expression is established: 1.10≦(R9+R10) / (R9−R10)≦1.90. This relational expression defines the shape of the fifth lens L5 and is advantageous for correcting astigmatism and distortion of the imaging lens, keeping distortion |Distortion| at 2.7% or less and reducing the possibility of vignetting.

[0021] When the axial thickness of the first lens L1 is d1 and the axial distance from the image-side surface of the first lens L1 to the object-side surface of the second lens L2 is d2, the following relational expression is established: 1.00≦d1 / d2≦4.00, which defines the ratio of the axial thickness d1 of the first lens L1 to the axial distance d2 from the image-side surface of the first lens L1 to the object-side surface of the second lens L2. Being within the range of this relational expression contributes to shortening the overall optical length of the imaging optical lens.

[0022] When the central radius of curvature of the object-side surface of the third lens L3 is R5 and the central radius of curvature of the image-side surface of the third lens L3 is R6, the relational expression 2.00≦R6 / R5≦15.00 is established, and this relational expression defines the shape of the third lens L3. When the range of this relational expression is satisfied, the degree of deviation of light rays passing through the lens is reduced, chromatic aberration can be effectively corrected, and chromatic aberration |LC| can be kept to 5.0 μm or less.

[0023] When the above-mentioned relations are satisfied, the imaging optical lenses 10, 20, 30, and 40 have good optical performance and can meet the design requirements of a large aperture, a wide angle, and an ultra-thin design. Due to the characteristics of the imaging optical lenses 10, 20, 30, and 40, the imaging optical lenses 10, 20, 30, and 40 can be applied to imaging lens components for mobile phones and web imaging lenses, which are configured with imaging devices such as high-pixel CCDs and CMOSs.

[0024] Based on the above relationships and feasible functions, the characteristics of each lens are further refined as follows:

[0025] When the axial distance from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4 is d6 and the axial distance from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 is d8, the relational expression 1.00≦d6 / d8≦3.00 is established, and this relational expression defines the ratio of the air spacing between the third lens L3 and the fourth lens L4 to the air spacing between the fourth lens L4 and the fifth lens L5. Being within the range of this relational expression contributes to shortening the overall optical length of the imaging optical lens.

[0026] When the focal length of the third lens L3 is f3, the relational expression -4.00≦f3 / f≦−1.20 is established, and this relational expression defines the ratio between the focal length of the third lens L3 and the focal length of the imaging optical lens. If the ratio falls within the range of this relational expression, by appropriately allocating the focal lengths of the imaging optical lens, the imaging optical lens will have excellent imaging quality and low sensitivity.

[0027] The first lens L1 has a paraxially convex object-side surface and a paraxially concave image-side surface, and has positive refractive power. The object-side and image-side surfaces of the first lens L1 may have other concave / convex distributions.

[0028] When the focal length of the first lens L1 is f1, the relationship 0.68≦f1 / f≦2.31 is established, which defines the ratio of the positive refractive power of the first lens L1 to the overall focal length. If the ratio is within the range of this relationship, the first lens L1 will have an appropriate positive refractive power, which is advantageous for reducing aberrations in the system, as well as for making the lens extremely thin and widening the angle of view.

[0029] When the central radius of curvature of the object-side surface of the first lens L1 is R1 and the central radius of curvature of the image-side surface of the first lens L1 is R2, the following relationship is established: -3.87≦(R1+R2) / (R1-R2)≦-1.13. By rationally controlling the shape of the first lens L1, the first lens L1 can effectively correct the spherical aberration of the system. It is also preferable that the relationship be -2.42≦(R1+R2) / (R1-R2)≦-1.41.

[0030] When the axial thickness of the first lens L1 is d1 and the total optical length of the imaging optical lens is TTL, the relational expression 0.04≦d1 / TTL≦0.25 is established. Being within the range of this relational expression is advantageous for achieving an extremely thin lens. Furthermore, it is preferable that 0.07≦d1 / TTL≦0.20.

[0031] The second lens L2 has a paraxially convex object-side surface and a paraxially concave or convex image-side surface, and has positive refractive power. The object-side surface of the second lens L2 may have other concave / convex distribution patterns.

[0032] When the central radius of curvature of the object-side surface of the second lens L2 is R3 and the central radius of curvature of the image-side surface of the second lens L2 is R4, the relational expression -2.65≦(R3+R4) / (R3-R4)≦-0.38 is established, and this relational expression defines the shape of the second lens L2. Being within the range of this relational expression is advantageous for correcting the problem of axial chromatic aberration as lenses become increasingly thin and wider-angle lenses are developed. It is also preferable that -1.65≦(R3+R4) / (R3-R4)≦-0.47.

[0033] When the axial thickness of the second lens L2 is d3, the relationship 0.04≦d3 / TTL≦0.15 is established. Being within this relationship is advantageous for achieving extremely thin lenses. Furthermore, it is preferable that 0.06≦d3 / TTL≦0.12.

[0034] The third lens L3 has a negative refractive power, its object-side surface being concave paraxially and its image-side surface being convex paraxially, and the object-side and image-side surfaces of the third lens L3 may have other concave / convex distributions.

[0035] The imaging optical lens further satisfies the relational expression -5.98≦(R5+R6) / (R5-R6)≦-0.76, which defines the shape of the third lens L3 and is advantageous for molding the third lens L3. If the relational expression is satisfied, the degree of deviation of light rays passing through the lens can be alleviated and aberration can be effectively reduced. It is also preferable that the relational expression be -3.74≦(R5+R6) / (R5-R6)≦-0.95.

[0036] When the axial thickness of the third lens L3 is d5, the relationship 0.03≦d5 / TTL≦0.12 is established. Being within this relationship is advantageous for achieving extremely thin lenses. Furthermore, it is preferable that 0.05≦d5 / TTL≦0.10.

[0037] The fourth lens L4 has a surface on the object side that is concave or convex paraxially, a surface on the image side that is convex paraxially, and a positive refractive power. The surface on the image side of the fourth lens L4 may have other concave or convex distribution patterns.

[0038] When the focal length of the fourth lens L4 is f4, the relationship 0.28≦f4 / f≦1.32 is established. By appropriately allocating the refractive power, the system achieves excellent imaging quality and low sensitivity. It is also preferable that 0.44≦f4 / f≦1.06.

[0039] When the central radius of curvature of the object-side surface of the fourth lens L4 is R7 and the central radius of curvature of the image-side surface of the fourth lens L4 is R8, the relational expression 0.43≦(R7+R8) / (R7-R8)≦2.45 is established, and the shape of the fourth lens L4 is defined accordingly. Being within the range of this relational expression is advantageous for correcting problems such as aberrations at off-axial angles of view as lenses become increasingly thin and wider in angle of view. It is also preferable that 0.68≦(R7+R8) / (R7-R8)≦1.96.

[0040] When the axial thickness of the fourth lens L4 is d7, the relationship 0.05≦d7 / TTL≦0.24 is established. Being within this relationship is advantageous for achieving extremely thin lenses. Furthermore, it is preferable that 0.09≦d7 / TTL≦0.19.

[0041] The fifth lens L5 has a paraxially convex object-side surface and a paraxially concave image-side surface, and has negative refractive power. The object-side and image-side surfaces of the fifth lens L5 may have other concave / convex distributions.

[0042] When the focal length of the fifth lens L5 is f5, the relational expression -2.42≦f5 / f≦-0.39 is established. By limiting the fifth lens L5, the ray angle of the imaging optical lens 10 can be made gentler, reducing tolerance sensitivity. It is also preferable that -1.51≦f5 / f≦-0.49.

[0043] When the axial thickness of the fifth lens L5 is d9, the relationship 0.07≦d9 / TTL≦0.29 is established. Being within this relationship is advantageous for achieving extremely thin lenses. Furthermore, it is preferable that 0.10≦d9 / TTL≦0.23.

[0044] When the image height of the above-mentioned imaging optical lens is IH, the relational expression TTL / IH≦1.40 is established.

[0045] When the composite focal length of the first lens L1 and the second lens L2 is f12, the relational expression 0.50≦f12 / f≦1.94 is established. Within the range of this relational expression, aberrations and distortions of the imaging optical lens can be eliminated, the back focus of the imaging optical lens can be suppressed, and the imaging lens system can be kept compact.

[0046] The field of view FOV of the above imaging optical lens is 90.00° or more, which allows for a wide angle of view.

[0047] The aperture value FNO of the above imaging optical lens is 2.11 or less, which allows for a large aperture and ensures excellent imaging performance of the imaging optical lens.

[0048] The imaging optical lens according to the present invention will be described below using examples. The symbols used in each example are as follows: focal length, axial distance, central radius of curvature, axial thickness, inflection point position, and stationary point position are all in mm.

[0049] TTL: total optical length (axial distance from the object-side surface of the first lens L1 to the image plane Si), in mm.

[0050] FNO: The ratio of the effective focal length of an imaging optical lens to the entrance pupil diameter.

[0051] The technical solution of the present invention will be specifically described below using four embodiments, and comparative embodiments are provided for reference. If the range of the above relationship is exceeded, the technical effect of the present invention cannot be achieved. (First embodiment)

[0052] Tables 1 and 2 show setting data for the imaging optical lens 10 according to the first embodiment of the present invention.

[0053] [Table 1]

[0054] Here, the meanings of the symbols are as follows: S1: Aperture R: Radius of curvature at the center of the optical surface R1: Radius of curvature of the center of the object-side surface of the first lens L1 R2: Radius of central curvature of the image-side surface of the first lens L1 R3: Radius of curvature of the center of the object-side surface of the second lens L2 R4: Radius of central curvature of the image-side surface of the second lens L2 R5: Radius of central curvature of the object-side surface of the third lens L3 R6: Radius of central curvature of the image-side surface of the third lens L3 R7: Radius of curvature of the center of the object-side surface of the fourth lens L4 R8: Radius of central curvature of the image-side surface of the fourth lens L4 R9: Radius of curvature of the center of the object-side surface of the fifth lens element L5 R10: Radius of central curvature of the image-side surface of the fifth lens L5 R11: Radius of curvature at the center of the object-side surface of the optical filter GF R12: Radius of central curvature of the image-side surface of the optical filter GF d: Axial thickness of lens, axial distance between lenses d0: The axial distance from the aperture stop S1 to the object-side surface of the first lens L1 d1: Axial thickness of the first lens L1 d2: The axial distance from the image-side surface of the first lens L1 to the object-side surface of the second lens L2 d3: Axial thickness of the second lens element L2 d4: The axial distance from the image-side surface of the second lens L2 to the object-side surface of the third lens L3 d5: Axial thickness of the third lens element L3 d6: The axial distance from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4 d7: Axial thickness of the fourth lens element L4 d8: The axial distance from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 d9: Axial thickness of the fifth lens element L5 d10: The axial distance from the image-side surface of the fifth lens L5 to the object-side surface of the optical filter GF d11: On-axis thickness of optical filter GF d12: The axial distance from the image-side surface of the optical filter GF to the image plane Si nd: Refractive index of the d line (the d line is green light with a wavelength of 555 nm) nd1: Refractive index of the first lens L1 at the d line nd2: Refractive index of the d-line of the second lens L2 nd3: Refractive index of the third lens L3 at the d line nd4: Refractive index of the d line of the fourth lens element L4 nd5: Refractive index of the d line of the fifth lens L5 ndg: Refractive index of the d line of the optical filter GF vd: Abbe number v1: Abbe number of the first lens L1 v2: Abbe number of the second lens L2 v3: Abbe number of the third lens element L3 v4: Abbe number of the fourth lens element L4 v5: Abbe number of the fifth lens element L5 vg: Abbe number of the optical filter GF

[0055] Table 2 shows data on the aspheric surfaces of each lens in the imaging optical lens 10 according to the first embodiment of the present invention.

[0056] [Table 2]

[0057] For convenience, the aspherical surface of each lens surface is an aspherical surface expressed by the following formula (1), but the present invention is not limited to the aspherical polynomial of formula (1). z=(cr 2 ) / {1+[1-(k+1)(c 2 r 2 )] 1 / 2}+A4r 4 +A6r 6 +A8r 8 +A10r 10 +A12r 12 +A14r 14 +A16r 16 +A18r 18 +A20r 20 +A22r 22 +A24r 24 +A26r 26 +A28r 28 +A30r 30 (1)

[0058] Here, k is the conic coefficient, A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 are aspheric coefficients, c is the central curvature of the optical surface, r is the perpendicular distance between a point on the aspheric curve and the optical axis, and z is the aspheric depth (the perpendicular distance between a point on the aspheric surface that is a distance r from the optical axis and a tangent plane that touches the vertex of the aspheric surface on the optical axis).

[0059] 2 and 3 are diagrams showing the spherical aberration and chromatic aberration of magnification of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm, respectively, after passing through the imaging optical lens 10 according to the first embodiment. Fig. 4 is a diagram showing the curvature of field and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 10 according to the first embodiment, where the curvature of field S in Fig. 4 is the curvature of field in the sagittal direction and T is the curvature of field in the meridional direction.

[0060] In this embodiment, the imaging optical lens 10 has an entrance pupil diameter ENPD of 1.449 mm, an image height IH of 3.269 mm across the entire field of view, and a diagonal angle of view FOV of 92.63°. The imaging optical lens 10 satisfies the design requirements for a large aperture, a wide angle, and an extremely thin design, and has excellent optical characteristics with its on-axis and off-axis chromatic aberrations sufficiently corrected. (Second embodiment)

[0061] In the second embodiment, the meanings of the symbols are the same as in the first embodiment.

[0062] Shown in FIG. 5 is an imaging optical lens 20 according to a second embodiment of the present invention.

[0063] Tables 3 and 4 show setting data for the imaging optical lens 20 according to the second embodiment of the present invention.

[0064] [Table 3]

[0065] Table 4 shows data on the aspheric surfaces of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[0066] [Table 4]

[0067] 6 and 7 are diagrams showing spherical aberration and chromatic aberration of magnification of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm, respectively, after passing through the imaging optical lens 20 according to the second embodiment. Fig. 8 is a diagram showing field curvature and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 20 according to the second embodiment. In Fig. 8, field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0068] In this embodiment, the imaging optical lens 20 has an entrance pupil diameter ENPD of 1.396 mm, an image height IH of 3.269 mm across the entire field of view, and a diagonal angle of view FOV of 93.00°. The imaging optical lens 20 satisfies the design requirements for a large aperture, a wide angle, and an extremely thin design, and has excellent optical characteristics with its on-axis and off-axis chromatic aberrations sufficiently corrected. (Third embodiment)

[0069] In the third embodiment, the meanings of the symbols are the same as in the first embodiment.

[0070] 9 shows an imaging optical lens 30 according to a third embodiment of the present invention. The object-side surface of the fourth lens L4 is formed as a convex surface in the paraxial direction.

[0071] Tables 5 and 6 show setting data for the imaging optical lens 30 according to the third embodiment of the present invention.

[0072] [Table 5]

[0073] Table 6 shows data on the aspheric surfaces of the lenses in the imaging optical lens 30 according to the third embodiment of the present invention.

[0074] [Table 6]

[0075] 10 and 11 are diagrams showing spherical aberration and chromatic aberration of magnification, respectively, of light having wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm after passing through the imaging optical lens 30 according to the third embodiment. Fig. 12 is a diagram showing field curvature and distortion aberration of light having a wavelength of 555 nm after passing through the imaging optical lens 30 according to the third embodiment. In Fig. 12, field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0076] In this embodiment, the imaging optical lens 30 has an entrance pupil diameter ENPD of 1.468 mm, an image height IH of 3.269 mm across the entire field of view, and a diagonal angle of view FOV of 90.01°. The imaging optical lens 30 satisfies the design requirements for a large aperture, a wide angle, and an extremely thin design, and has excellent optical characteristics with its on-axis and off-axis chromatic aberrations sufficiently corrected. (Fourth embodiment)

[0077] In the fourth embodiment, the meanings of the symbols are the same as in the first embodiment.

[0078] 13 shows an imaging optical lens 40 according to a fourth embodiment of the present invention. The image-side surface of the second lens L2 is formed as a concave surface paraxially.

[0079] Tables 7 and 8 show setting data for the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0080] [Table 7]

[0081] Table 8 shows data on the aspheric surfaces of the lenses in the imaging optical lens 40 according to the fourth embodiment of the present invention.

[0082] [Table 8]

[0083] 14 and 15 are diagrams showing spherical aberration and lateral chromatic aberration of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm, respectively, after passing through the imaging optical lens 40 according to the fourth embodiment. Fig. 16 is a diagram showing field curvature and distortion aberration of light with a wavelength of 555 nm after passing through the imaging optical lens 40 according to the fourth embodiment. The field curvature S in Fig. 16 is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0084] In this embodiment, the imaging optical lens 40 has an entrance pupil diameter ENPD of 1.207 mm, a full field of view image height IH of 3.269 mm, and a diagonal angle of view FOV of 90.88°. The imaging optical lens 40 satisfies the design requirements for a large aperture, ultra-thinness, and ultra-wide angle, and has excellent optical characteristics with its on-axis and off-axis chromatic aberrations sufficiently corrected.

[0085] Table 11 below shows the values ​​of the first, second, third and fourth embodiments and the values ​​corresponding to the parameters defined by the relational expressions. (Comparative embodiment)

[0086] In the comparative embodiment, the symbols have the same meanings as in the first embodiment.

[0087] Shown in FIG. 17 is an imaging optical lens 50 according to a comparative embodiment of the present invention.

[0088] Tables 9 and 10 show setting data for the imaging optical lens 50 according to a comparative embodiment of the present invention.

[0089] [Table 9]

[0090] Table 10 shows data on the aspheric surfaces of each lens in the imaging optical lens 50 according to the comparative embodiment of the present invention.

[0091] [Table 10]

[0092] 18 and 19 are diagrams showing spherical aberration and lateral chromatic aberration of light having wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, 470 nm, and 435 nm, respectively, after passing through the imaging optical lens 50 according to the comparative embodiment. Fig. 20 is a diagram showing field curvature and distortion aberration of light having a wavelength of 555 nm after passing through the imaging optical lens 50 according to the comparative embodiment. The field curvature S in Fig. 20 is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0093] Below, the numerical values ​​corresponding to each of the above relational expressions in the comparative embodiment are shown in Table 11. Clearly, the imaging optical lens 50 of the comparative embodiment does not satisfy the above relational expression 3.00≦f2 / f≦12.00, and has poor imaging effect.

[0094] In the comparative embodiment, the entrance pupil diameter ENPD of the imaging optical lens 50 is 1.444 mm, the image height IH of the entire field of view is 3.269 mm, and the diagonal angle of view FOV is 90.33°. The imaging optical lens 50 does not satisfy the design requirements of a large aperture, a wide angle, and an extremely thin design.

[0095] [Table 11]

[0096] The above-described embodiments are specific embodiments for realizing the present invention, but it should be understood by those skilled in the art that in actual applications, various changes in form and details that do not deviate from the spirit and scope of the present invention will all fall within the scope of protection of the present invention.

Claims

1. An imaging optical lens including a total of five lenses, the five lenses being, in order from the object side to the image side, a first lens having positive refractive power, a second lens having positive refractive power, a third lens having negative refractive power, a fourth lens having positive refractive power, and a fifth lens having negative refractive power, Here, the imaging optical lens is characterized in that the following relational expression is satisfied when the focal length of the imaging optical lens is f, the focal length of the second lens is f2, the central radius of curvature of the object-side surface of the fifth lens is R9, the central radius of curvature of the image-side surface of the fifth lens is R10, the axial thickness of the first lens is d1, the axial distance from the image-side surface of the first lens to the object-side surface of the second lens is d2, the central radius of curvature of the object-side surface of the third lens is R5, and the central radius of curvature of the image-side surface of the third lens is R6. 3.00≦f2 / f≦12.00 1.10≦(R9+R10) / (R9-R10)≦1.90 1.00≦d1 / d2≦4.00 2.00≦R6 / R5≦15.00

2. 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when an axial distance from the image-side surface of the third lens to the object-side surface of the fourth lens is d6 and an axial distance from the image-side surface of the fourth lens to the object-side surface of the fifth lens is d8: 1.00≦d6 / d8≦3.00

3. 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when the focal length of the third lens is set to f3: −4.00≦f3 / f≦−1.20

4. the first lens has an object-side surface formed as a convex surface paraxially, and an image-side surface formed as a concave surface paraxially; 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when a focal length of the first lens is f1, a central radius of curvature of an object-side surface of the first lens is R1, a central radius of curvature of an image-side surface of the first lens is R2, and a total optical length of the imaging optical lens is TTL: 0.68≦f1 / f≦2.31 -3.87≦(R1+R2) / (R1-R2)≦-1.13 0.04≦d1 / TTL≦0.25

5. the second lens has an object-side surface formed as a convex surface paraxially; 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when a central radius of curvature of an object-side surface of the second lens is R3, a central radius of curvature of an image-side surface of the second lens is R4, an axial thickness of the second lens is d3, and a total optical length of the imaging optical lens is TTL: -2.65≦(R3+R4) / (R3-R4)≦-0.38 0.04≦d3 / TTL≦0.15

6. the third lens has an object-side surface formed as a concave surface paraxially, and an image-side surface formed as a convex surface paraxially, 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when the axial thickness of the third lens is d5 and the total optical length of the imaging optical lens is TTL: -5.98≦(R5+R6) / (R5-R6)≦-0.76 0.03≦d5 / TTL≦0.12

7. the fourth lens has an image-side surface formed as a convex surface paraxially, 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when a focal length of the fourth lens is f4, a central radius of curvature of an object-side surface of the fourth lens is R7, a central radius of curvature of an image-side surface of the fourth lens is R8, an axial thickness of the fourth lens is d7, and a total optical length of the imaging optical lens is TTL. 0.28≦f4 / f≦1.32 0.43≦(R7+R8) / (R7-R8)≦2.45 0.05≦d7 / TTL≦0.24

8. the fifth lens has an object-side surface formed as a convex surface paraxially, and an image-side surface formed as a concave surface paraxially, 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when the focal length of the fifth lens is f5, the on-axis thickness of the fifth lens is d9, and the total optical length of the imaging optical lens is TTL: −2.42≦f5 / f≦−0.39 0.07≦d9 / TTL≦0.29

9. 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when the total optical length of the imaging optical lens is TTL and the maximum image height of the imaging optical lens is IH: TTL / IH≦1.40

10. 2. The imaging optical lens according to claim 1, wherein the following relational expression is satisfied when a composite focal length of the first lens and the second lens is set to f12: 0.50≦f12 / f≦1.94

Images