imaging optical lens

Abstract

The present invention relates to the field of optical lenses and discloses an imaging optical lens comprising a total of seven 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 negative refractive power, a third lens with positive refractive power, a fourth lens with positive refractive power, a fifth lens with positive refractive power, a sixth lens with negative refractive power, and a seventh lens with positive refractive power. Here, the imaging optical lens satisfies the following relationships: -1.30 ≤ f1 / f ≤ -1.00, 0.02 ≤ d4 / TTL ≤ 0.06, n2 ≥ 1.70, and 0.10 ≤ BFL / TTL ≤ 0.30. The imaging optical lens provided by the present invention satisfies the design requirements for a large aperture and wide angle.

Description

[Technical Field]

[0001] This invention relates to the field of optical lenses, and more particularly to imaging optical lenses applied to portable terminal devices such as smartphones and digital cameras, and imaging devices such as monitors, PC lenses, and in-vehicle 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, seven-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 Initiative]

[0003] To address the above problems, the object 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 and wide angle.

[0004] To achieve the above objective, the present invention provides an imaging optical lens comprising a total of seven lenses, the seven lenses being, in order from the object side to the image side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having positive refractive power, a fourth lens having positive refractive power, a fifth lens having positive refractive power, a sixth lens having negative refractive power, and a seventh lens having positive refractive power.

[0005] Here, the focal length of the imaging optical lens is f, the focal length of the first lens is f1, the on-axial distance from the image side of the second lens to the object side of the third lens is d4, the total optical length of the imaging optical lens is TTL, the refractive index of the second lens is nd2, and the on-axial distance from the image side of the seventh lens to the image plane is BFL. The following relationship is satisfied. -1.30 ≤ f1 / f ≤ -1.00 0.02 ≤ d4 / TTL ≤ 0.06 n2≧1.70 0.10 ≤ BFL / TTL ≤ 0.30.

[0006] Preferably, the fifth lens and the sixth lens are bonded together.

[0007] Preferably, the Abbe number of the fifth lens is v5, the Abbe number of the sixth lens is v6, and the relationship v5-v6≧35.00 is satisfied.

[0008] Preferably, the central radius of curvature of the image surface of the seventh lens is R14, and the relationship -8.00 ≤ R14 / f ≤ -2.00 is satisfied.

[0009] Preferably, the image surface of the first lens is concave near the axis.

[0010] The central radius of curvature of the object side of the first lens is R1, the central radius of curvature of the image side of the first lens is R2, and the on-axial thickness of the first lens is d1, satisfying the following relationship. 0.47 ≤ (R1 + R2) / (R1 - R2) ≤ 1.81 0.01 ≤ d1 / TTL ≤ 0.14

[0011] Preferably, the object side surface of the second lens is concave near the axis, and the image side surface of the second lens is convex near the axis.

[0012] The second lens has a focal length of f2, a central radius of curvature of the object side of the second lens of R3, a central radius of curvature of the image side of the second lens of R4, an on-axial thickness of the second lens of d3, and satisfies the following relationship. -6.56 ≤ f² / f ≤ -1.72 -2.84≦(R3+R4) / (R3-R4)≦-0.83 0.03 ≤ d3 / TTL ≤ 0.09.

[0013] Preferably, the object side surface of the third lens is convex near the axis, and the image side surface of the third lens is convex near the axis.

[0014] The third lens has a focal length of f3, a central radius of curvature of the object side of the third lens is R5, a central radius of curvature of the image side of the third lens is R6, an on-axial thickness of the third lens is d5, and satisfies the following relationship. 0.70 ≤ f3 / f ≤ 2.37 0.01 ≤ (R5 + R6) / (R5 - R6) ≤ 0.23 0.03 ≤ d5 / TTL ≤ 0.16.

[0015] Preferably, the object side surface of the fourth lens is convex near the axis, and the image side surface of the fourth lens is convex near the axis.

[0016] The fourth lens has a focal length of f4, a central radius of curvature of the object side of the fourth lens is R7, a central radius of curvature of the image side of the fourth lens is R8, an on-axial thickness of the fourth lens is d7, and satisfies the following relationship. 1.30 ≤ f4 / f ≤ 4.28 0.20 ≤ (R7 + R8) / (R7 - R8) ≤ 0.79 0.02 ≤ d7 / TTL ≤ 0.13.

[0017] Preferably, the object side surface of the fifth lens is convex near the axis, and the image side surface of the fifth lens is convex near the axis.

[0018] 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-axis thickness of the fifth lens is d9, and the following relational expressions are satisfied. 0.49 ≦ f5 / f ≦ 1.92 0.13 ≦ (R9 + R10) / (R9 - R10) ≦ 0.45 0.07 ≦ d9 / TTL ≦ 0.23.

[0019] Preferably, the object side surface of the sixth lens is concave in the vicinity of the axis, and the image side surface of the sixth lens is concave in the vicinity of the axis.

[0020] The focal length of the sixth lens is f6, the central radius of curvature of the object side surface of the sixth lens is R11, the central radius of curvature of the image side surface of the sixth lens is R12, the on-axis thickness of the sixth lens is d11, and the following relational expressions are satisfied. -2.18 ≦ f6 / f ≦ -0.62 -1.77 ≦ (R11 + R12) / (R11 - R12) ≦ -0.51 0.01 ≦ d11 / TTL ≦ 0.08.

[0021] Preferably, the image side surface of the seventh lens is convex in the vicinity of the axis. <00001​​​​​​​​​​​​​​​​A beneficial effect of the present invention is that the imaging optical lens of the present invention has excellent optical properties, large aperture and wide-angle characteristics, and is particularly suitable for web imaging lenses and automotive lenses composed of image sensors such as CCDs and CMOSs ​​for high pixel counts. [Brief explanation of the drawing]

[0025] To more clearly illustrate the technical aspects of the embodiments of the present invention, the drawings used in the description of the embodiments are briefly introduced below. However, the drawings in the following description represent only some embodiments of the present invention, and it is clear that those skilled in the art can obtain other drawings from these without any creative effort. [Figure 1] This is a schematic diagram of the configuration of an imaging optical lens according to the first embodiment of the present invention. [Figure 2] Figure 1 is a schematic diagram of the axial aberration of the imaging optical lens shown. [Figure 3] Figure 1 is a schematic diagram of the chromatic aberration of the imaging optical lens shown. [Figure 4] Figure 1 is a schematic diagram of the field curvature and distortion of the imaging optical lens shown. [Figure 5] This is a schematic diagram of the configuration of an imaging optical lens according to a second embodiment of the present invention. [Figure 6] Figure 5 is a schematic diagram of the axial aberration of the imaging optical lens shown. [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 an imaging optical lens in a comparative example of the present invention. [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]

[0026] 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 solution for which the present invention seeks protection can be achieved without these technical details and the various changes and modifications based on the following embodiments.

[0027] 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 show the imaging optical lenses 10, 20, 30, and 40 of the present invention, which include seven lenses. Specifically, the imaging optical lens is configured in the following order from the object side to the image side: first lens L1, second lens L2, aperture S1, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, and seventh lens L7. An optical element such as an optical filter GF may be provided between the seventh lens L7 and the image plane Si.

[0028] The first lens L1 is made of glass, the second lens L2 is made of glass, the third lens L3 is made of glass, the fourth lens L4 is made of glass, the fifth lens L5 is made of glass, the sixth lens L6 is made of glass, and the seventh lens L7 is made of glass. Each lens may be made of other materials.

[0029] The first lens L1 has a negative refractive power, the second lens L2 has a negative refractive power, the third lens L3 has a positive refractive power, the fourth lens L4 has a positive refractive power, the fifth lens L5 has a positive refractive power, the sixth lens L6 has a negative refractive power, and the seventh lens L7 has a positive refractive power. Each lens may have other refractive powers in any other embodiment.

[0030] The object and image surfaces of the first lens L1, third lens L3, fourth lens L4, fifth lens L5, and sixth lens L6 are all spherical, while the object and image surfaces of the second lens L2 and seventh lens L7 are all aspherical.

[0031] The focal length of the imaging optical lens is defined as f, and the focal length of the first lens L1 is defined as f, satisfying the relationship -1.30 ≤ f1 / f ≤ -1.00, which defines the value of the ratio of the focal length of the first lens L1 to the focal length of the imaging optical lens. By rationally distributing the focal power of the system, the amount of field curvature of the imaging optical lens is effectively balanced, and the amount of field curvature offset in the central field of view is made smaller than 0.01 mm.

[0032] The on-axis distance from the image side of the second lens L2 to the object side of the third lens L3 is defined as d4, and the total optical length of the imaging optical lens is defined as TTL. The relationship 0.02 ≤ d4 / TTL ≤ 0.06 is satisfied, and a value is defined for the ratio of the on-axis distance between the second lens L2 and the third lens L3, which is close to the aperture, to the total optical length. If it is higher than the lower limit, it helps in the smooth transition of light rays near the aperture and helps in improving image quality, and if it is lower than the upper limit, it helps in the control of the total optical length.

[0033] The refractive index of the second lens L2 is n2, and the relationship n2 ≥ 1.70 is satisfied. The tip lens is preferentially selected from high refractive index materials, which helps to reduce the tip aperture and improve image quality.

[0034] The on-axial distance from the image side to the image plane of the seventh lens L7, i.e., the back focus length, is defined as BFL, and the relationship 0.10 ≤ BFL / TTL ≤ 0.30 is satisfied. In order to achieve miniaturization, a long back focus is helpful for module assembly, the total optical length is short, the structure is compact, the sensitivity of the lens to MTF is reduced, the yield rate of good products is improved, and production costs are reduced.

[0035] 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 and wide angle. Based on the characteristics of the imaging optical lenses 10, 20, 30, and 40, they are particularly suitable for web imaging lenses and automotive lenses composed of image sensors such as CCDs and CMOSs ​​for high pixel counts.

[0036] Based on the aforementioned relation and feasible functions, the characteristics of each lens can be further detailed as follows:

[0037] The fifth lens L5 and the sixth lens L6 are bonded together. By bonding them together, the overall volume of the imaging optical lens can be reduced, and by bonding them together, the two lenses become a single integrated structure, allowing the mounting of the two lenses to be completed in a single step when assembling the optical module.

[0038] The Abbe number of the fifth lens L5 is defined as v5, and the Abbe number of the sixth lens L6 is defined as v6. The relationship v5-v6≧35.00 is satisfied, and the difference in Abbe numbers between the bonded fifth lens L5 and sixth lens L6 is defined. Within this range, the material properties are effectively distributed, chromatic aberration is effectively corrected, and chromatic aberration |LC|≦5μm is set.

[0039] By defining the central radius of curvature of the image side of the seventh lens L7 as R14 and satisfying the relationship -8.00 ≤ R14 / f ≤ -2.00, and by defining the surface shape of the light ray emission surface, it becomes advantageous to mitigate the degree of deflection of light rays passing through the lens within the range of the relationship, and aberrations can be reduced effectively.

[0040] The image surface of the first lens L1 is concave near the axis, and the image surface of the first lens L1 may have other concave and convex distributions.

[0041] The central radius of curvature of the object side of the first lens is R1, and the central radius of curvature of the image side of the first lens is R2, satisfying the relationship 0.47 ≤ (R1 + R2) / (R1 - R2) ≤ 1.81. By rationally controlling the shape of the first lens L1, the first lens L1 can effectively correct system spherical aberration. Preferably, 0.75 ≤ (R1 + R2) / (R1 - R2) ≤ 1.45 is satisfied.

[0042] The on-axial thickness of the first lens L1 is d1, satisfying the relationship 0.01 ≤ d1 / TTL ≤ 0.14. Within this range, it is advantageous to control the lens thickness, smooth the light rays, and effectively control aberrations. Preferably, 0.01 ≤ d1 / TTL ≤ 0.11 is satisfied.

[0043] The object side of the second lens L2 is concave near the axis, and the image side is convex near the axis. The object side and image side of the second lens L2 may have other concave and convex distributions.

[0044] The focal length of the second lens L2 is f2, satisfying the relationship -6.56 ≤ f2 / f ≤ -1.72. Controlling the focal power of the second lens L2 within an appropriate range is advantageous for correcting aberrations in the optical system. Preferably, -4.10 ≤ f2 / f ≤ 2.15 is satisfied.

[0045] The central radius of curvature of the object side of the second lens L2 is defined as R3, and the central radius of curvature of the image side of the second lens L2 is defined as R4. The relationship -2.84 ≤ (R3 + R4) / (R3 - R4) ≤ -0.83 is satisfied, and by appropriately controlling the shape of the second lens L2, the second lens L2 is effective in correcting system spherical aberration. Preferably, -1.77 ≤ (R3 + R4) / (R3 - R4) ≤ 1.04 is satisfied.

[0046] The on-axial thickness of the second lens L2 is d3, satisfying the relationship 0.03 ≤ d3 / TTL ≤ 0.09. By controlling the lens thickness within the range of this relationship, the light rays are smoothed and aberrations are effectively controlled. Preferably, 0.04 ≤ d3 / TTL ≤ 0.07 is satisfied.

[0047] The object side of the third lens L3 is convex near the axis, and the image side is also convex near the axis. The object side and image side of the third lens L3 may have other concave / convex distributions.

[0048] The focal length of the third lens L3 is defined as f3, and the relationship 0.70 ≤ f3 / f ≤ 2.37 is satisfied. With a rational distribution of focal power, the system has better image quality and lower sensitivity. Preferably, 1.11 ≤ f3 / f ≤ 1.90 is satisfied.

[0049] 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 of the third lens L3 is R6, satisfying the relationship 0.01 ≤ (R5 + R6) / (R5 - R6) ≤ 0.23, which defines the shape of the third lens L3. Within this range, it is advantageous for correcting axial chromatic aberration as the lens widens. Preferably, 0.02 ≤ (R5 + R6) / (R5 - R6) ≤ 0.18 is satisfied.

[0050] The on-axial thickness of the third lens L3 is d5, satisfying the relationship 0.03 ≤ d5 / TTL ≤ 0.16. By controlling the lens thickness within the range of this relationship, the light rays are smoothed and aberrations are effectively controlled. Preferably, 0.05 ≤ d5 / TTL ≤ 0.13 is satisfied.

[0051] The object side of the fourth lens L4 is convex near the axis, and the image side is also convex near the axis. The object side and image side of the fourth lens L4 may have other concave and convex distributions.

[0052] By defining the focal length of the fourth lens L4 as f4, and satisfying the relationship 1.30 ≤ f4 / f ≤ 4.28, the system achieves better image quality and lower sensitivity by rationally distributing the focal power. Preferably, 2.08 ≤ f4 / f ≤ 3.43 is satisfied.

[0053] The central radius of curvature of the object side of the fourth lens L4 is R7, and the central radius of curvature of the image side of the fourth lens L4 is R8, satisfying the relationship 0.20 ≤ (R7 + R8) / (R7 - R8) ≤ 0.79. This relationship defines the shape of the fourth lens L4, and within the range of this relationship, light rays transition smoothly, which helps improve image quality. Preferably, 0.31 ≤ (R7 + R8) / (R7 - R8) ≤ 0.63 is satisfied.

[0054] The on-axial thickness of the fourth lens L4 is d7, satisfying the relationship 0.02 ≤ d7 / TTL ≤ 0.13. By controlling the lens thickness within this range, the light rays are smoothed and aberrations are effectively controlled. Preferably, 0.03 ≤ d7 / TTL ≤ 0.11 is satisfied.

[0055] The object side of the fifth lens L5 is convex near the axis, and the image side is also convex near the axis. The object side and image side of the fifth lens L5 may have other concave / convex distributions.

[0056] The focal length of the fifth lens L5 is f5, satisfying the relationship 0.49 ≤ f5 / f ≤ 1.92. Limiting to the fifth lens L5 is effective in smoothing the ray angle of the imaging optical lens and reducing tolerance sensitivity. Preferably, 0.79 ≤ f5 / f ≤ 1.54 is satisfied.

[0057] 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, satisfying the relationship 0.13 ≤ (R9 + R10) / (R9 - R10) ≤ 0.45, which defines the shape of the fifth lens L5 and is effective in correcting astigmatism and distortion of the imaging optical lens within the range of this relationship. Preferably, 0.21 ≤ (R9 + R10) / (R9 - R10) ≤ 0.36 is satisfied.

[0058] The on-axial thickness of the fifth lens L5 is d9, satisfying the relationship 0.07 ≤ d9 / TTL ≤ 0.23. By controlling the lens thickness within this range, the light rays are smoothed and aberrations are effectively controlled. Preferably, 0.12 ≤ d9 / TTL ≤ 0.19 is satisfied.

[0059] The object side of lens L6 is concave near the axis, and the image side is also concave near the axis. The object side and image side of lens L6 may have other concave / convex distributions.

[0060] The focal length of the sixth lens L6 is f6, satisfying the relationship -2.18 ≤ f6 / f ≤ -0.62, and the rational distribution of focal power ensures that the system has better image quality and lower sensitivity. Preferably, -1.36 ≤ f6 / f ≤ -0.77 is satisfied.

[0061] The central radius of curvature of the object side of the sixth lens L6 is R11, and the central radius of curvature of the image side of the sixth lens L6 is R12, and the relationship -1.77 ≤ (R11 + R12) / (R11 - R12) ≤ -0.51 is satisfied, defining the shape of the sixth lens L6, and within the range of the relationship, as the wide-angle increases, it is advantageous for correcting off-axis angle of view aberrations, etc. Preferably, -1.10 ≤ (R11 + R12) / (R11 - R12) ≤ -0.64 is satisfied.

[0062] The on-axial thickness of the sixth lens L6 is d11, satisfying the relationship 0.01 ≤ d11 / TTL ≤ 0.08. By controlling the lens thickness within the range of this relationship, the light rays are smoothed and aberrations are effectively controlled. Preferably, 0.02 ≤ d11 / TTL ≤ 0.06 is satisfied.

[0063] The image surface of lens L7 is convex near the axis. The image surface of lens L7 may have other concave or convex distributions.

[0064] The focal length of the seventh lens L7 is defined as f7, and the relationship 1.94 ≤ f7 / f ≤ 21.57 is satisfied. This specifies the ratio of the focal length of the last lens to the total focal length of the imaging optical lenses, contributing to light collection and ensuring light transmission by appropriately distributing the focal power of the distribution system. Preferably, 3.10 ≤ f7 / f ≤ 17.26 is satisfied.

[0065] The central radius of curvature of the object side surface of the seventh lens L7 is R13, and the relationship 0.24 ≤ (R13 + R14) / (R13 - R14) ≤ 1.97 is satisfied, defining the shape of the seventh lens L7. Within the range of this relationship, it is advantageous for correcting off-axis angle of view aberrations as the angle of view widens. Preferably, 0.39 ≤ (R13 + R14) / (R13 - R14) ≤ 1.58 is satisfied.

[0066] The on-axis thickness of the seventh lens L7 is d13, satisfying the relationship 0.05 ≤ d13 / TTL ≤ 0.28. By controlling the lens thickness within the range of this relationship, the light rays are smoothed and aberrations are effectively controlled. Preferably, 0.08 ≤ d13 / TTL ≤ 0.23 is satisfied.

[0067] The imaging optical lens has a field of view (FOV) of 130.00° or more, enabling wide-angle imaging.

[0068] The aperture value FNO of the aforementioned imaging optical lens is 2.05 or less, achieving a large aperture and good imaging performance of the imaging optical lens.

[0069] The imaging optical lenses of the present invention will be described below using practical examples. The reference numerals used in each example are as follows. 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.

[0070] 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.

[0071] 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. The object side surface of the first lens L1 is convex near its axis, and the object side surface of the seventh lens L7 is concave near its axis. [Table 1] JPEG2026524734000002.jpg117170 Here, the meaning of each symbol 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 curvature of the central image surface of lens L5 (5th lens) R11: Radius of curvature of the central side of the object at lens L6 (6th lens) R12: Radius of central curvature of the image surface of lens L6 (6th lens) R13: Radius of curvature of the central side of the object at lens L7 (7th lens) R14: Radius of central curvature of the image surface of lens L7 (7th lens) R15: Radius of curvature of the central side surface of the optical filter GF R16: Radius of curvature of the central side of the image surface 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 5th lens L5 to the object side of the 6th lens L6. d11: Axial thickness of the 6th lens L6 d12: On-axis distance from the image side of lens 6 L6 to the object side of lens 7 L7. d13: Axial thickness of lens L7 (7th lens) d14: On-axis distance from the image side of lens L7 to the object side of optical filter GF d15: On-axis thickness of optical filter GF d16: 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 555 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 nd6: Refractive index of the d-line of the 6th lens L6 nd7: Refractive index of the d-line of the 7th lens L7 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 v6: Abbe number of the 6th lens L6 v7: Abbe number of the 7th lens L7 vg: Abbe number of the optical filter GF

[0072] Table 2 shows the aspherical data of the 2nd lens L2 and the 7th lens L7 in the imaging optical lens 10 according to the first embodiment of the present invention. [Table 2] JPEG2026524734000003.jpg154170

[0073] For the aspherical surface of each lens surface, for the sake of 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 2 ) / {1+[1-(k+1)(c 2 r 2 )] 1 / 2}m+A4r 4 +A6r 6 +A8r 8 +A10r 10 +A12r 12 +A14r 14 +A16r 16 +A18r 18 +A20r 20 +A22r 22 (1) Here, k is the conicity coefficient, A4, A6, A8, A10, A12, A14, A16, A18, A20, and A22 are aspheric coefficients, c is the curvature of 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).

[0074] 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. 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. In Figure 4, the field curvature S is the sagittal field curvature, and T is the meridional field curvature.

[0075] In this embodiment, the imaging optical lens 10 has an entrance pupil diameter (ENPD) of 2.11 mm, a total field of view height (IH) of 4.450 mm, and a diagonal field of view (FOV) of 139.60°. 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.

[0076] 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. The object side surface of the first lens L1 is concave near its axis, and the object side surface of the seventh lens L7 is concave near its axis. Tables 3 and 4 show the design data for the imaging optical lens 20 of the second embodiment of the present invention. [Table 3] JPEG2026524734000004.jpg117170

[0077] Table 4 shows the aspherical data of the second lens L2 and the seventh lens L7 in the imaging optical lens 20 according to the second embodiment of the present invention. [Table 4] JPEG2026524734000005.jpg154170

[0078] 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.

[0079] In this embodiment, the imaging optical lens 20 has an entrance pupil diameter (ENPD) of 2.191 mm, a total field of view height (IH) of 4.399 mm, and a diagonal field of view (FOV) of 137.62°. The imaging optical lens 20 satisfies the design requirements for a large aperture and wide angle, has sufficient correction of on-axis and off-axis chromatic aberration, and possesses excellent optical characteristics.

[0080] 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. The object side surface of the first lens L1 is convex near the axis, and the object side surface of the seventh lens L7 is concave near the axis. Tables 5 and 6 show the design data for the imaging optical lens 30 of the third embodiment of the present invention. [Table 5] JPEG2026524734000006.jpg117170

[0081] Table 6 shows the aspherical data of the second lens L2 and the seventh lens L7 in the imaging optical lens 30 according to the third embodiment of the present invention. [Table 6] JPEG2026524734000007.jpg154170

[0082] 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, the field curvature S is the sagittal field curvature, and T is the meridional field curvature.

[0083] In this embodiment, the imaging optical lens 30 has an entrance pupil diameter (ENPD) of 2.128 mm, a total field of view height (IH) of 4.591 mm, and a diagonal field of view (FOV) of 136.73°. The imaging optical lens 30 satisfies the design requirements for a large aperture and wide angle, has sufficient correction of on-axis and off-axis chromatic aberration, and possesses excellent optical characteristics.

[0084] 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. The object side surface of the first lens L1 is convex near its axis, and the object side surface of the seventh lens L7 is convex near its axis. Tables 7 and 8 show the design data for the imaging optical lens 40 of the fourth embodiment of the present invention. [Table 7] JPEG2026524734000008.jpg117170

[0085] Table 8 shows the aspherical data of the second lens L2 and the seventh lens L7 in the imaging optical lens 40 according to the fourth embodiment of the present invention. [Table 8] JPEG2026524734000009.jpg154170

[0086] 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 fourth embodiment. In Figure 16, the field curvature S is the field curvature in the sagittal direction, and T is the field curvature in the meridional direction.

[0087] In this embodiment, the imaging optical lens 40 has an entrance pupil diameter (ENPD) of 1.93 mm, a total field of view height (IH) of 4.468 mm, and a diagonal field of view (FOV) of 130.84°. The imaging optical lens 40 satisfies the design requirements for a large aperture and wide angle, has sufficient correction of on-axis and off-axis chromatic aberration, and possesses excellent optical characteristics.

[0088] 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.

[0089] 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. The object side surface of the first lens L1 is concave near its axis, and the object side surface of the seventh lens L7 is concave near its axis. Tables 9 and 10 show the design data for the comparative example imaging optical lens 50. [Table 9] JPEG2026524734000010.jpg117170

[0090] Table 10 shows the aspherical data of the second lens L2 and the seventh lens L7 in the imaging optical lens 50 according to a comparative example of the present invention. [Table 10] JPEG2026524734000011.jpg154170

[0091] 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 555 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.

[0092] 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 60 in the comparative example does not satisfy the relation -1.3 ≤ f1 / f ≤ -1 described above, and therefore has a low imaging effect.

[0093] In this embodiment, the imaging optical lens 50 has an entrance pupil diameter (ENPD) of 2.405 mm, a total field of view height (IH) of 4.400 mm, and a diagonal field of view (FOV) of 129.20°. Therefore, the imaging optical lens 50 does not meet the design requirements for a large aperture and wide angle. On-axis and off-axis chromatic aberration are sufficiently corrected, and it has excellent optical characteristics. [Table 11] JPEG2026524734000012.jpg148149

[0094] Those skilled in the art will understand that the embodiments described above are specific embodiments for realizing the present invention, and that in actual applications, various formal and detailed modifications are possible without departing from the spirit and scope of the invention.

Claims

1. It is an imaging optical lens, The imaging optical lens comprises a total of seven lenses, which, in order from the object side to the image side, are a first lens with negative refractive power, a second lens with negative refractive power, a third lens with positive refractive power, a fourth lens with positive refractive power, a fifth lens with positive refractive power, a sixth lens with negative refractive power, and a seventh lens with positive refractive power. Here, the focal length of the imaging optical lens is f, the focal length of the first lens is f1, the on-axial distance from the image side of the second lens to the object side of the third lens is d4, the total optical length of the imaging optical lens is TTL, the refractive index of the second lens is nd2, and the on-axial distance from the image side of the seventh lens to the image plane is BFL. -1.30 ≤ f1 / f ≤ -1.00 0.02 ≤ d4 / TTL ≤ 0.06 n² ≥ 1.70 An imaging optical lens characterized by satisfying the relationship 0.10 ≤ BFL / TTL ≤ 0.

30.

2. The imaging optical lens according to claim 1, characterized in that the fifth lens and the sixth lens are bonded together.

3. The imaging optical lens according to claim 2, characterized in that the Abbe number of the fifth lens is v5, the Abbe number of the sixth lens is v6, and the relationship v5 - v6 ≥ 35.00 is satisfied.

4. The imaging optical lens according to claim 1, characterized in that the central radius of curvature of the image side surface of the seventh lens is R14 and satisfies the relationship -8.00 ≤ R14 / f ≤ -2.

00.

5. The image surface of the first lens is concave near the axis. The central radius of curvature of the object side of the first lens is R1, the central radius of curvature of the image side of the first lens is R2, and the axial thickness of the first lens is d1. 0.47≦(R1+R2) / (R1-R2)≦1.81 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.01 ≤ d1 / TTL ≤ 0.

14.

6. The object side of the second lens is concave near the axis, and the image side of the second lens is convex near the axis. The focal length of the second lens is f2, 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, and the on-axial thickness of the second lens is d3. -6.56 ≤ f² / f ≤ -1.72 -2.84≦(R3+R4) / (R3-R4)≦-0.83 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.03 ≤ d3 / TTL ≤ 0.

09.

7. The object side of the third lens is convex near the axis, and the image side of the third lens is convex near the axis. The focal length of the third lens is f3, 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, and the on-axial thickness of the third lens is d5. 0.70 ≤ f³ / f ≤ 2.37 0.01≦(R5+R6) / (R5-R6)≦0.23 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.03 ≤ d5 / TTL ≤ 0.

16.

8. The object side of the fourth lens is convex 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 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 on-axial thickness of the fourth lens is d7. 1.30 ≤ f4 / f ≤ 4.28 0.20≦(R7+R8) / (R7-R8)≦0.79 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.02 ≤ d7 / TTL ≤ 0.

13.

9. The object side of the fifth lens is convex near the axis, and the image side of the fifth lens is convex 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, and the on-axial thickness of the fifth lens is d9. 0.49 ≤ f5 / f ≤ 1.92 0.13≦(R9+R10) / (R9-R10)≦0.45 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.07 ≤ d9 / TTL ≤ 0.

23.

10. The object side of the sixth lens is concave near the axis, and the image side of the sixth lens is concave near the axis. The focal length of the sixth lens is f6, the central radius of curvature of the object side of the sixth lens is R11, the central radius of curvature of the image side of the sixth lens is R12, and the axial thickness of the sixth lens is d11. -2.18 ≤ f6 / f ≤ -0.62 -1.77≦(R11+R12) / (R11-R12)≦-0.51 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.01 ≤ d11 / TTL ≤ 0.

08.

11. The image surface of the seventh lens is convex near the axis. The focal length of the seventh lens is f7, the central radius of curvature of the object side of the seventh lens is R13, the central radius of curvature of the image side of the seventh lens is R14, and the on-axial thickness of the seventh lens is d13. 1.94 ≤ f7 / f ≤ 21.57 0.24≦(R13+R14) / (R13-R14)≦1.97 The imaging optical lens according to claim 1, characterized in that it satisfies the relationship 0.05 ≤ d13 / TTL ≤ 0.

28.

12. The imaging optical lens according to claim 1, characterized in that the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are made of glass.

Images