imaging optical lens

Abstract

The present invention relates to the field of optical lenses and discloses an imaging optical lens comprising a total of five lenses, which are arranged sequentially from the object side to the image side as follows: a first lens with negative refractive power, a second lens with positive refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, and a fifth lens with negative refractive power. The following relationships are satisfied: 0.70 ≤ f2 / f ≤ 1.10, 2.00 ≤ (R5 + R6) / (R5 - R6) ≤ 10.00, 0.70 ≤ R1 / f1 ≤ 1.30, and 5.50 ≤ R7 / R8 ≤ 14.00. The imaging optical lens provided by the present invention can meet design requirements for large aperture, ultra-thinness, and wide angle.

Description

[Technical Field]

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

[0002] In recent years, with the rise of various smart devices, the demand for miniaturized imaging optical lenses has increased. Furthermore, in addition to the shrinking pixel size of photosensitive devices, current electronic products are increasingly characterized by superior functionality, thinness, and portability. Therefore, miniaturized imaging optical lenses with good image quality have become the mainstream in the market. To achieve good image quality, multi-slice lens structures are often employed. Moreover, with technological advancements and the increasing diversity of user needs, the pixel area of ​​photosensitive devices is shrinking, and the system's demands for image quality are rising. In this context, five-element lens structures are emerging in lens design. There is a strong demand for wide-angle imaging lenses that possess excellent optical characteristics, are compact, and have sufficient aberration correction. [Overview of the project]

[0003] In response to the above problems, the main objective of the present invention is to provide an imaging optical lens that has good optical performance while satisfying the design requirements for a large aperture, ultra-thinness, and wide angle.

[0004] To achieve the above objective, the present invention provides an imaging optical lens comprising a total of five lenses, the five lenses being arranged sequentially from the object side to the image side as follows: a first lens having negative 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.

[0005] Here, the focal length of the imaging optical lens is f, the focal length of the first lens is f1, the focal length of the second lens is f2, the central radius of curvature of the object side of the first lens is R1, the central radius of curvature of the object side of the third lens is R5, the central radius of curvature of the image side of the third lens is R6, the central radius of curvature of the object side of the fourth lens is R7, the central radius of curvature of the image side of the fourth lens is R8, and the following relationship is satisfied. 0.70 ≤ f² / f ≤ 1.10 2.00≦(R5+R6) / (R5-R6)≦10.00 0.70 ≤ R1 / f1 ≤ 1.30 5.50 ≤ R7 / R8 ≤ 14.00.

[0006] Preferably, the total optical length of the imaging optical lens is TTL, and the relationship 2.00 ≤ TTL / f ≤ 3.00 is satisfied.

[0007] Preferably, the edge thickness of the fifth lens is ET5, the on-axial thickness of the fifth lens is d9, and the relationship 1.35 ≤ ET5 / d9 ≤ 2.00 is satisfied.

[0008] Preferably, the object side surface of the first lens is concave near the axis, and the image side surface of the first lens is concave near the axis. The focal length of the first lens is f1, the central radius of curvature of the image side surface of the first lens is R2, the on-axial thickness of the first lens is d1, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied. -4.01 ≤ f1 / f ≤ -1.19 -1.15≦(R1+R2) / (R1-R2)≦0.23 0.03 ≤ d1 / TTL ≤ 0.12.

[0009] Preferably, the object side surface of the second lens is convex near the axis, and the image side surface of the second lens is convex near the axis. 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 on-axial thickness of the second lens is d3, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied. -0.08≦(R3+R4) / (R3-R4)≦0.17 0.07 ≤ d3 / TTL ≤ 0.28.

[0010] Preferably, the object side surface of the third lens is convex near the axis, and the image side surface of the third lens is concave near the axis. The focal length of the third lens is f3, the on-axial thickness of the third lens is d5, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied. -13.61 ≤ f3 / f ≤ -1.13 0.02 ≤ d5 / TTL ≤ 0.07.

[0011] Preferably, the object side surface of the fourth lens is concave near the axis, and the image side surface of the fourth lens is convex near the axis. The focal length of the fourth lens is f4, the on-axial thickness of the fourth lens is d7, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied. 0.64 ≤ f₄ / f ≤ 2.25 0.58 ≤ (R7 + R8) / (R7 - R8) ≤ 2.16 0.08 ≤ d7 / TTL ≤ 0.27.

[0012] Preferably, the object side surface of the fifth lens is convex near the axis, and the image side surface of the fifth lens is concave near the axis. The focal length of the fifth lens is f5, 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 on-axial thickness of the fifth lens is d9, the total optical length of the imaging optical lens is TTL, and the following relationship is satisfied. -4.29≦f5 / f≦-1.05 1.53 ≦ (R9 + R10) / (R9 - R10) ≦ 5.06 0.05 ≦ d9 / TTL ≦ 0.19。

[0013] Preferably, the overall optical length of the imaging optical lens is TTL, the maximum image height of the imaging optical lens is IH, and the relational expression TTL / IH ≦ 1.91 is satisfied.

[0014] Preferably, the combined focal length of the first lens and the second lens is f12, and the relational expression 0.45 ≦ f12 / f ≦ 2.06 is satisfied.

[0015] The beneficial effects of the present invention are as follows. The imaging optical lens according to the present invention has excellent optical characteristics, and also has the characteristics of a large aperture, wide angle, and ultra-thin type. In particular, it is suitable for an imaging lens unit for a mobile phone or an imaging lens for WEB composed of an imaging element such as a CCD or CMOS for high pixels.

Brief Description of the Drawings

[0016] In order to more clearly explain the technical solution in the embodiment of the present invention, the attached drawings necessary for the description of the embodiment are briefly introduced below. However, the attached drawings described below are only a part of the embodiments of the present invention, and it is obvious that those skilled in the art can obtain other attached drawings from these attached drawings without creative labor. [Figure 1] It is a schematic configuration diagram of the imaging optical lens in the first embodiment of the present invention. [Figure 2] It is a schematic diagram of the axial aberration of the imaging optical lens shown in FIG. 1. [Figure 3] It is a schematic diagram of the lateral chromatic aberration of the imaging optical lens shown in FIG. 1. [Figure 4] It is a schematic diagram of the field curvature and distortion of the imaging optical lens shown in FIG. 1. [Figure 5] It is a schematic configuration diagram of the imaging optical lens of the second embodiment of the present invention. [Figure 6] It is a schematic diagram of the axial aberration of the imaging optical lens shown in FIG. 5. [Figure 7] Figure 5 is a schematic diagram of the chromatic aberration of the imaging optical lens shown. [Figure 8] Figure 5 is a schematic diagram of the field curvature and distortion of the imaging optical lens shown. [Figure 9] This is a schematic diagram of the configuration of the imaging optical lens according to the third embodiment of the present invention. [Figure 10] Figure 9 is a schematic diagram of the axial aberration of the imaging optical lens shown. [Figure 11] Figure 9 is a schematic diagram of the chromatic aberration of the imaging optical lens shown. [Figure 12] Figure 9 is a schematic diagram of the field curvature and distortion of the imaging optical lens shown. [Figure 13] This is a schematic diagram of the configuration of an imaging optical lens according to the fourth embodiment of the present invention. [Figure 14] Figure 13 is a schematic diagram of the axial aberration of the imaging optical lens shown. [Figure 15] Figure 13 is a schematic diagram of the chromatic aberration of the imaging optical lens shown. [Figure 16] Figure 13 is a schematic diagram of the field curvature and distortion of the imaging optical lens shown. [Figure 17] This is a schematic diagram of the configuration of the imaging optical lens in the comparative example. [Figure 18] Figure 17 is a schematic diagram of the axial aberration of the imaging optical lens shown. [Figure 19] Figure 17 is a schematic diagram of the chromatic aberration of the imaging optical lens shown. [Figure 20] Figure 17 is a schematic diagram of the field curvature and distortion of the imaging optical lens shown. [Modes for carrying out the invention]

[0017] To further clarify the object, technical solution, and advantages of the present invention, each embodiment of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that each embodiment of the present invention presents many technical details to help the reader better understand the invention. However, the technical solutions protected by the present invention can be realized without these technical details and the various changes and modifications based on the following embodiments.

[0018] Referring to the drawings, a technical aspect of the present invention provides imaging optical lenses 10, 20, 30, and 40. Figures 1, 5, 9, and 13 show the imaging optical lenses 10, 20, 30, and 40 of the present invention, respectively, and these imaging optical lenses 10, 20, 30, and 40 comprise a total of five lenses. Specifically, the imaging optical lenses, in order from the object side to the image side, are a first lens L1, an aperture S1, 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.

[0019] 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 other materials.

[0020] The first lens has a negative refractive power, the second lens L2 has a positive refractive power, the third lens L3 has a negative refractive power, the fourth lens L4 has a positive refractive power, and the fifth lens L5 has a negative refractive power. Each lens may have a different refractive power in other embodiments.

[0021] If we define the focal length of the imaging optical lens as f and the focal length of the second lens L2 as f2, the relationship 0.70 ≤ f2 / f ≤ 1.10 is satisfied. This relationship specifies the value of the ratio of the focal length f2 of the second lens L2 to the focal length f of the imaging optical lens. Within the range of this relationship, the field curvature of the imaging optical lens can be effectively balanced so that the field curvature offset of the central field of view is less than 0.02 mm.

[0022] The central radius of curvature of the object side of the third lens L3 is R5, and the central radius of curvature of the image side is R6, satisfying the relationship 2.00 ≤ (R5 + R6) / (R5 - R6) ≤ 10.00. This relationship defines the shape of the third lens L3, and within the range of this relationship, the degree of deflection of light rays passing through the lens can be mitigated, and aberrations can be reduced effectively.

[0023] The central radius of curvature of the object side surface of the first lens L1 is R1, and the focal length of the first lens L1 is f1, satisfying the relationship 0.70 ≤ R1 / f1 ≤ 1.30. This relationship defines the surface shape of the first lens L1, and within the range of this relationship, it is advantageous for correcting aberrations in the light ray propagation process and at the same time advantageous for shortening the overall length of the imaging optical lens.

[0024] The central radius of curvature of the object side of the fourth lens L4 is R7, and the central radius of curvature of its image side is R8, satisfying the relationship 5.50 ≤ R7 / R8 ≤ 14.00. This relationship defines the shape of the fourth lens L4, and within the range of this relationship, the degree of deflection of light rays passing through the lens is mitigated, chromatic aberration is effectively corrected, and chromatic aberration is set to |LC| ≤ 4.0 μm.

[0025] When the above relationship is satisfied, the imaging optical lenses 10, 20, 30, and 40 have good optical performance and can meet the design requirements for large aperture, wide angle, and ultra-thin design. Due to the characteristics of these imaging optical lenses 10, 20, 30, and 40, they are particularly suitable for imaging lens units for mobile phones and imaging lenses for the web, which are composed of image sensors such as CCDs and CMOS sensors for high pixel counts.

[0026] Based on the aforementioned relation and feasible functions, the characteristics of each lens can be further detailed as follows: The total optical length of the aforementioned imaging optical lens is TTL, and it satisfies the relationship 2.00 ≤ TTL / f ≤ 3.00. This relationship defines the telephoto ratio, and by keeping it below the upper limit of the relationship, the total optical length can be kept short, making it easier to miniaturize. On the other hand, by exceeding the lower limit of the relationship, distortion and axial chromatic aberration can be easily corrected, and good optical performance can be maintained.

[0027] The edge thickness of the fifth lens L5 is ET5, and the on-axial thickness of the fifth lens L5 is d9, satisfying the relationship 1.35 ≤ ET5 / d9 ≤ 2.00. This relationship defines the ratio of the edge thickness to the on-axial thickness of the fifth lens L5, which is useful for lens processing and lens assembly.

[0028] The object side of the first lens L1 is concave near the axis, and the image side is also concave near the axis. The object side and image side of the first lens L1 may have other concave and convex distributions.

[0029] The focal length of the first lens L1 is f1, and it satisfies the relationship -4.01 ≤ f1 / f ≤ -1.19. This relationship defines the ratio of the focal length of the first lens L1 to the focal length of the imaging optical lens. By appropriately distributing the optical focal length of the imaging optical lens within the range of this relationship, the imaging optical lens will have better image quality and lower sensitivity. Preferably, -2.51 ≤ f1 / f ≤ -1.48 is satisfied.

[0030] By defining R1 as the central radius of curvature of the object side of the first lens L1 and R2 as the central radius of curvature of the image side of the first lens L1, and satisfying the relationship -1.15 ≤ (R1 + R2) / (R1 - R2) ≤ 0.23, the first lens L1 can effectively correct system spherical aberration by appropriately controlling the shape of the first lens L1. Preferably, -0.72 ≤ (R1 + R2) / (R1 - R2) ≤ 0.18 is satisfied.

[0031] The on-axial thickness of the first lens L1 is d1, satisfying the relationship 0.03 ≤ d1 / TTL ≤ 0.12. This relationship defines the ratio of the on-axial thickness of the first lens L1 to the total optical length. Within the range of this relationship, it is useful for controlling the thickness of the first lens L1, which is convenient for injection molding and helps in light focusing, thereby ensuring a wide-angle design. Preferably, 0.04 ≤ d1 / TTL ≤ 0.10 is satisfied.

[0032] The object side of the second lens L2 is convex near the axis, and the image side is also convex near the axis. The object side of the second lens L2 may be positioned in a different concave-convex distribution.

[0033] The central radius of curvature of the object side of the second lens L2 is R3, and the central radius of curvature of the image side of the second lens L2 is R4, satisfying the relationship -0.08 ≤ (R3 + R4) / (R3 - R4) ≤ 0.17. This relationship defines the shape of the second lens L2, and within this range, it is advantageous for correcting axial chromatic aberration as the lens becomes ultra-thin and wide-angle. Preferably, -0.05 ≤ (R3 + R4) / (R3 - R4) ≤ 0.13 is satisfied.

[0034] The on-axial thickness of the second lens L2 is d3, and it satisfies the relationship 0.07 ≤ d3 / TTL ≤ 0.28, which is advantageous for ultra-thinning within this range. Preferably, 0.11 ≤ d3 / TTL ≤ 0.22 is satisfied.

[0035] The object side of the third lens L3 is convex near the axis, and the image side is concave near the axis. The object side and image side of the third lens L3 may also have other concave / convex distributions.

[0036] The focal length of the third lens L3 is defined as f3, and the relationship -13.61 ≤ f3 / f ≤ -1.13 is satisfied. This relationship specifies the ratio of the focal length of the third lens L3 to the focal length f of the imaging optical lens. By appropriately distributing the focal length of the imaging optical lens within the range of this relationship, the imaging optical lens has better image quality and lower sensitivity. Preferably, -8.51 ≤ f3 / f ≤ -1.41 is satisfied.

[0037] The on-axial thickness of the third lens L3 is d5, and the relationship 0.02 ≤ d5 / TTL ≤ 0.07 is satisfied, which is advantageous for ultra-thinning within the range of the relationship. Preferably, 0.03 ≤ d5 / TTL ≤ 0.06 is satisfied.

[0038] The object surface of the fourth lens L4 is concave near the axis, and the image surface is convex near the axis. The image surface of the fourth lens L4 may have other concave-convex distributions.

[0039] The focal length of the fourth lens L4 is f4, satisfying the relationship 0.64 ≤ f4 / f ≤ 2.25. A rational distribution of focal power results in a system with better image quality and lower sensitivity. Preferably, 1.02 ≤ f4 / f ≤ 1.80 is satisfied.

[0040] The aforementioned imaging optical lens further satisfies the relationship 0.58 ≤ (R7 + R8) / (R7 - R8) ≤ 2.16, defining the shape of the fourth lens L4. Within this range, it is advantageous for correcting problems such as off-axis angle of view aberrations as ultra-thin wide-angle lenses develop. Preferably, 0.92 ≤ (R7 + R8) / (R7 - R8) ≤ 1.73 is satisfied.

[0041] The on-axial thickness of the fourth lens L4 is d7, and satisfies the relationship 0.08 ≤ d7 / TTL ≤ 0.27. Within this range, it is advantageous for ultra-thinning. Preferably, 0.13 ≤ d7 / TTL ≤ 0.22 is satisfied.

[0042] The object side of the fifth lens L5 is convex near the axis, and the image side is concave near the axis. The object side and image side of the fifth lens L5 may have other concave / convex distributions.

[0043] The focal length of the fifth lens L5 is f5, satisfying the relationship -4.29 ≤ f5 / f ≤ -1.05. Limiting to the fifth lens L5 is effective in smoothing the ray angle of the imaging optical lens and reducing tolerance sensitivity. Preferably, -2.68 ≤ f5 / f ≤ -1.31 is satisfied.

[0044] The central radius of curvature of the object side of the fifth lens L5 is R9, and the central radius of curvature of the image side of the fifth lens L5 is R10, and the relationship 1.53 ≤ (R9 + R10) / (R9 - R10) ≤ 5.06 is satisfied, defining the shape of the fifth lens L5. Within this range, it is advantageous for correcting problems such as off-axis angle of view aberrations as ultra-thin wide-angle lenses develop. Preferably, 2.45 ≤ (R9 + R10) / (R9 - R10) ≤ 4.05 is satisfied.

[0045] The fifth lens L5 further satisfies the relationship 0.05 ≤ d9 / TTL ≤ 0.19, and within the range of this relationship, it is advantageous for ultra-thinning. Preferably, 0.08 ≤ d9 / TTL ≤ 0.15 is satisfied.

[0046] The maximum image height of the aforementioned imaging optical lens is IH, and it satisfies the relationship TTL / IH ≤ 1.91. Within this range, it is advantageous for ultra-thinning.

[0047] The combined focal length of the first lens L1 and the second lens L2 is f12, satisfying the relationship 0.45 ≤ f12 / f ≤ 2.06. Within this range, aberrations and distortions of the imaging optical lens can be eliminated, the rear focal length of the imaging optical lens can be suppressed, and the miniaturization of the imaging lens system group can be maintained. Preferably, 0.72 ≤ f12 / f ≤ 1.65 is satisfied.

[0048] The field of view (FOV) of the aforementioned imaging optical lens is 111.00° or greater, thereby achieving a wide-angle view.

[0049] The aperture value FNO of the imaging optical lens is 2.05 or less, which enables a large aperture and good imaging performance of the imaging optical lens.

[0050] The imaging optical lens of the present invention will be described below using examples. The symbols used in each example are shown below. Hereafter, the units for focal length, axial distance, central radius of curvature, and axial thickness are mm. TTL: Total Optical Length (the on-axis distance from the side of the object to the image plane Si on the first lens L1), in units of mm. Aperture value FNO: This is the ratio of the effective focal length of the imaging optical lens to the entrance pupil diameter.

[0051] Next, the technical aspects of the present invention will be specifically described in four embodiments, and comparative examples that cannot achieve the technical effects of the present invention beyond the scope of the above relational formula will be provided as reference explanations.

[0052] First Embodiment Tables 1 and 2 show the design data for the imaging optical lens 10 according to the first embodiment of the present invention. [Table 1] The meaning of each code in JPEG2026524733000002.jpg93167 is as follows: S1: Aperture R: Radius of curvature at the center of the optical surface R1: Radius of curvature of the central side of the object at the first lens L1 R2: Radius of curvature of the central image surface of the first lens L1 R3: Radius of curvature of the central side of the object at the second lens L2 R4: Radius of curvature of the central image surface of the second lens L2 R5: Radius of curvature of the central side of the object at the third lens L3 R6: Radius of central curvature of the image surface of the third lens L3 R7: Radius of curvature of the central side of the object at the fourth lens L4 R8: Radius of central curvature of the image surface of the fourth lens L4 R9: Radius of curvature of the central side of the object at lens L5 (5th lens) R10: Radius of central curvature of the image surface of lens L5 (5th lens) R11: Radius of curvature of the central side surface of the optical filter GF R12: Center radius of curvature of the image side of optical filter GF d: Axial thickness of the lens, axial distance between lenses d0: Axial distance from aperture S1 to the side of the object on the first lens L1. d1: Axial thickness of the first lens L1 d2: On-axis distance from the image side of the first lens L1 to the object side of the second lens L2. d3: Axial thickness of the second lens L2 d4: On-axis distance from the image side of the second lens L2 to the object side of the third lens L3. d5: Axial thickness of the third lens L3 d6: On-axis distance from the image side of the third lens L3 to the object side of the fourth lens L4. d7: Axial thickness of the fourth lens L4 d8: On-axis distance from the image side of the fourth lens L4 to the object side of the fifth lens L5. d9: Axial thickness of the 5th lens L5 d10: On-axis distance from the image side of the fifth lens L5 to the object side of the optical filter GF. d11: On-axis thickness of optical filter GF d12: On-axis distance from the image side 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 550 nm) nd1: Refractive index of the d line of the first lens L1 nd2: Refractive index of the d line of the second lens L2 nd3: Refractive index of the d line of the third lens L3 nd4: Refractive index of the d-line of the 4th lens L4 nd5: Refractive index of the d-line of the 5th lens L5 ndg: Refractive index of the d-line of the optical filter GF vd: Abbe number v1: Abbe number of the 1st lens L1 v2: Abbe number of the 2nd lens L2 v3: Abbe number of the 3rd lens L3 v4: Abbe number of the 4th lens L4 v5: Abbe number of the 5th lens L5 vg: Abbe number of the optical filter GF

[0053] Table 2 shows the aspherical data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention. [Table 2] JPEG2026524733000003.jpg250170JPEG2026524733000004.jpg193170

[0054] For the aspherical surface of each lens, for convenience, the aspherical surface shown in the following formula (1) is used. However, the present invention is not limited to the aspherical polynomial form shown in this formula (1). z=(cr , 30 , 10 , 26 , 6 , 22 , 1 / 2 , 18 ,

[0054] , 2 , , 14 , , , ,

[0053] , 12 , 8 , 4 , , 28 , 2 , 24 , , 2 , 20 , , , 16 , , ) / {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<​​​​​​Here, k is the conicity coefficient, A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 are aspheric coefficients, c is the curvature at the center of the optical plane, 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 r from the optical axis on the aspheric surface and the tangent plane that touches the vertex on the optical axis of the aspheric surface).

[0055] Figures 2 and 3 show schematic diagrams of axial aberration and lateral chromatic aberration after light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm passes through the imaging optical lens 10 of the first embodiment, respectively. Here, Figure 4 shows a schematic diagram of field curvature and distortion after light with a wavelength of 555 nm passes through the imaging optical lens 10 of the first embodiment, where the field curvature S in Figure 4 is the field curvature in the sagittal direction and T is the field curvature in the meridional direction.

[0056] In this embodiment, the imaging optical lens 10 has an entrance pupil diameter (ENPD) of 1.140 mm, a total field of view height (IH) of 3.269 mm, and a diagonal field of view (FOV) of 119.15°. The imaging optical lens 10 satisfies the design requirements for a large aperture, wide angle, and ultra-thin design, and has sufficient correction of on-axis and off-axis chromatic aberration, as well as excellent optical characteristics.

[0057] Second Embodiment The meaning of the reference numerals in the second embodiment is the same as in the first embodiment. Figure 5 shows an imaging optical lens 20 according to a second embodiment of the present invention. Tables 3 and 4 show the design data for the imaging optical lens 20 of the second embodiment of the present invention. [Table 3] JPEG2026524733000005.jpg93167

[0058] Table 4 shows the aspherical data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention. [Table 4] JPEG2026524733000006.jpg250170JPEG2026524733000007.jpg193170

[0059] Figures 6 and 7 show schematic diagrams of axial aberration and lateral chromatic aberration after passing light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm through the imaging optical lens 20 of the second embodiment, respectively. Figure 8 shows a schematic diagram of field curvature and distortion after passing light with a wavelength of 555 nm through the imaging optical lens 20 of the second embodiment. In Figure 8, the field curvature S is the sagittal field curvature, and T is the meridional field curvature.

[0060] In this embodiment, the imaging optical lens 20 has an entrance pupil diameter (ENPD) of 1.015 mm, a total field of view height (IH) of 3.269 mm, and a diagonal field of view (FOV) of 121.74°. The imaging optical lens 20 satisfies the design requirements for a large aperture, wide angle, and ultra-thin design, and has excellent optical characteristics with sufficient correction of on-axis and off-axis chromatic aberration.

[0061] Third Embodiment The meaning of the reference numerals in the third embodiment is the same as in the first embodiment. Figure 9 shows an imaging optical lens 30 according to a third embodiment of the present invention. Tables 5 and 6 show the design data for the imaging optical lens 30 of the third embodiment of the present invention. [Table 5] JPEG2026524733000008.jpg93167

[0062] Table 6 shows the aspherical data for each lens in the imaging optical lens 30 according to the third embodiment of the present invention. [Table 6] JPEG2026524733000009.jpg250170JPEG2026524733000010.jpg193170

[0063] Figures 10 and 11 show schematic diagrams of axial aberration and lateral chromatic aberration after passing light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm through the imaging optical lens 30 of the third embodiment, respectively. Figure 12 shows a schematic diagram of field curvature and distortion after passing light with a wavelength of 555 nm through the imaging optical lens 30 of the third embodiment. In Figure 12, curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0064] In this embodiment, the imaging optical lens 30 has an entrance pupil diameter (ENPD) of 1.240 mm, a total field of view height (IH) of 3.269 mm, and a diagonal field of view (FOV) of 111.07°. The imaging optical lens 30 satisfies the design requirements for a large aperture, wide angle, and ultra-thin design, and has excellent optical characteristics with sufficient correction of on-axis and off-axis chromatic aberration.

[0065] Fourth Embodiment The meaning of the reference numerals in the fourth embodiment is the same as in the first embodiment. Figure 13 shows an imaging optical lens 40 according to a fourth embodiment of the present invention. Tables 7 and 8 show the design data for the imaging optical lens 40 according to the fourth embodiment of the present invention. [Table 7] JPEG2026524733000011.jpg93167

[0066] Table 8 shows the aspherical data for each lens in the imaging optical lens 40 according to the fourth embodiment of the present invention. [Table 8] JPEG2026524733000012.jpg250170JPEG2026524733000013.jpg193170

[0067] Figures 14 and 15 show schematic diagrams of axial aberration and lateral chromatic aberration after passing light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm through the imaging optical lens 40 of the fourth embodiment, respectively. Figure 16 shows a schematic diagram of field curvature and distortion after passing light with a wavelength of 555 nm through the imaging optical lens 40 of the third embodiment. In Figure 16, curve 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 40 has an entrance pupil diameter (ENPD) of 1,100 mm, a total field of view height (IH) of 3,269 mm, and a diagonal field of view (FOV) of 124.06°. The imaging optical lens 40 satisfies the design requirements for a large aperture, wide angle, and ultra-thin design, and has excellent optical characteristics with sufficient correction of on-axial and off-axial chromatic aberration.

[0069] Table 11, which will appear later, shows the corresponding values ​​of the numerical values ​​in each embodiment 1, 2, 3, and 4 and the parameters defined in the relational formulas.

[0070] Comparative Example The meaning of the symbols in the comparative example is the same as in the first embodiment. Figure 17 shows an imaging optical lens 50, which is a comparative example of the present invention. Tables 9 and 10 show the design data for the imaging optical lens 50 according to a comparative example of the present invention. [Table 9] JPEG2026524733000014.jpg93164

[0071] Table 10 shows the aspherical data for each lens in the imaging optical lens 50 according to the comparative example of the present invention. [Table 10] JPEG2026524733000015.jpg250170JPEG2026524733000016.jpg193170

[0072] Figures 18 and 19 show schematic diagrams of axial aberration and lateral chromatic aberration after passing light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm through the comparative imaging optical lens 50, respectively. Figure 20 shows a schematic diagram of field curvature and distortion of light with a wavelength of 546 nm that has passed through the comparative imaging optical lens 50. In Figure 20, the field curvature S is the sagittal curvature, and T is the meridional curvature.

[0073] Table 11 shows the numerical values ​​corresponding to each relation in the comparative example, according to the relation described above. It is clear that the imaging optical lens 50 in the comparative example does not satisfy the relation described above, 0.70 ≤ f2 / f ≤ 1.10, and therefore has a low imaging effect.

[0074] In the comparative example, the imaging optical lens 50 has an entrance pupil diameter (ENPD) of 1.268 mm, a total field of view height (IH) of 3.269 mm, and a diagonal field of view (FOV) of 117.71°. The imaging optical lens 50 does not meet the design requirements for a large aperture, wide angle, and ultra-thin design. [Table 11] JPEG2026524733000017.jpg204170

[0075] Those skilled in the art will understand that the above embodiments are specific embodiments for realizing the present invention, and that in actual applications, various modifications can be made to the form and details without departing from the spirit and scope of the invention.

Claims

1. An imaging optical lens comprising a total of five lenses, the five lenses being arranged sequentially from the object side to the image side as follows: a first lens having negative 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 focal length of the imaging optical lens is f, the focal length of the first lens is f1, the focal length of the second lens is f2, the central radius of curvature of the object side of the first lens is R1, the central radius of curvature of the object side of the third lens is R5, the central radius of curvature of the image side of the third lens is R6, the central radius of curvature of the object side of the fourth lens is R7, and the central radius of curvature of the image side of the fourth lens is R8. 0.70 ≤ f² / f ≤ 1.10 2.00≦(R5+R6) / (R5-R6)≦10.00 0.70 ≤ R1 / f1 ≤ 1.30 An imaging optical lens characterized by satisfying the relationship 5.50 ≤ R7 / R8 ≤ 14.

00.

2. The imaging optical lens according to claim 1, characterized in that the total optical length of the imaging optical lens is TTL and satisfies the relationship 2.00 ≤ TTL / f ≤ 3.

00.

3. The imaging optical lens according to claim 1, characterized in that the edge thickness of the fifth lens is ET5, the on-axial thickness of the fifth lens is d9, and the relationship 1.35 ≤ ET5 / d9 ≤ 2.00 is satisfied.

4. The object side of the first lens is concave near the axis, and the image side of the first lens is concave near the axis. The focal length of the first lens is f1, the central radius of curvature of the image surface of the first lens is R2, the axial thickness of the first lens is d1, and the total optical length of the imaging optical lens is TTL. -4.01 ≤ f1 / f ≤ -1.19 -1.15≦(R1+R2) / (R1-R2)≦0.23 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.03 ≤ d1 / TTL ≤ 0.

12.

5. The object side of the second lens is convex near the axis, and the image side of the second lens is convex near the axis. The central radius of curvature of the object side of the second lens is R3, the central radius of curvature of the image side of the second lens is R4, the on-axial thickness of the second lens is d3, and the total optical length of the imaging optical lens is TTL. -0.08≦(R3+R4) / (R3-R4)≦0.17 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.07 ≤ d3 / TTL ≤ 0.

28.

6. The object side of the third lens is convex near the axis, and the image side of the third lens is concave near the axis. The focal length of the third lens is f3, the on-axial thickness of the third lens is d5, and the total optical length of the imaging optical lens is TTL. -13.61 ≤ f³ / f ≤ -1.13 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.02 ≤ d5 / TTL ≤ 0.

07.

7. The object side of the fourth lens is concave near the axis, and the image side of the fourth lens is convex near the axis. The focal length of the fourth lens is f4, the on-axial thickness of the fourth lens is d7, and the total optical length of the imaging optical lens is TTL. 0.64 ≤ f⁴ / f ≤ 2.25 0.58≦(R7+R8) / (R7-R8)≦2.16 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.08 ≤ d7 / TTL ≤ 0.

27.

8. The object side of the fifth lens is convex near the axis, and the image side of the fifth lens is concave near the axis. The focal length of the fifth lens is f5, the central radius of curvature of the object side of the fifth lens is R9, the central radius of curvature of the image side of the fifth lens is R10, the on-axial thickness of the fifth lens is d9, and the total optical length of the imaging optical lens is TTL. -4.29 ≤ f5 / f ≤ -1.05 1.53≦(R9+R10) / (R9-R10)≦5.06 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.05 ≤ d9 / TTL ≤ 0.

19.

9. The imaging optical lens according to claim 1, characterized in that the total optical length of the imaging optical lens is TTL, the maximum image height of the imaging optical lens is IH, and the relationship TTL / IH ≤ 1.91 is satisfied.

10. The imaging optical lens according to claim 1, characterized in that the combined focal length of the first lens and the second lens is f12 and satisfies the relationship 0.45 ≤ f12 / f ≤ 2.06.

Images