Optical lens

Abstract

To provide an optical lens relating to a field of an optical lens.SOLUTION: An optical lens consists of, in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens and satisfies conditional expressions -0.80≤f12 / f10_11≤-0.50, 0.80≤f7 / f≤1.80, -83.00≤f56 / (d9+d11)≤-4.00, 0.40≤NA*f / WD≤0.60. The optical lens according to the present invention has an excellent optical performance with low strain, large magnification, and long actuation distance.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the field of optical lenses, in particular optical lenses applied in industrial microscopes. [Background technology]

[0002] Although the objective lens for microscopes can complete its specific imaging function by a certain angle of view, focal length, and aperture diameter, it is limited by the optical imaging principle, and these optical characteristic parameters are mutually constrained. The objective lens for microscopes needs to have the characteristic that a large numerical aperture brings high resolution, but the higher the magnification of the objective lens for microscopes, the larger the numerical aperture, and the more significant the impact of the thickness and refractive index changes on the imaging quality of the microscope, so that it is usually difficult to achieve both high imaging quality and high magnification at the same time. In addition, with the development of technology and the increasing diversification needs of users, when the system's requirements for imaging quality are increasing, the 12-piece lens structure gradually appears in the design of lenses. There is a demand for optical lenses with good optical performance, low distortion, large magnification, and long working distance. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the above problems, an object of the present invention is to provide an optical lens that has good optical performance and meets the requirements of low distortion, large magnification and long working distance. [Means for solving the problem]

[0004] In order to solve the above technical problem, an embodiment of the present invention provides an optical lens, which is composed of, in order from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens, When the focal length of the optical lens is f, the composite focal length of the fifth lens and the sixth lens is f56, the axial thickness of the fifth lens is d9, the axial thickness of the sixth lens is d11, the focal length of the seventh lens is f7, the composite focal length of the tenth lens and the eleventh lens is f10_11, the focal length of the twelfth lens is f12, the working distance of the optical lens is WD, and the numerical aperture of the optical lens is NA, the following conditional formulas (1) to (4) are satisfied. -0.80≦f12 / f10_11≦-0.50 (1) 0.80≦f7 / f≦1.80 (2) -83.00≦f56 / (d9+d11)≦-4.00 (3) 0.40≦NA*f / WD≦0.60 (4)

[0005] Preferably, when the axial thickness of the fourth lens is d7 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 conditional expression (5) is satisfied. 1.00≦d7 / d8≦22.50 (5)

[0006] Preferably, the first lens has positive refractive power, and an object side surface of the first lens is convex on a paraxial line, 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, the axial thickness of the first lens is d1, and the optical length of the optical lens is TTL, the following conditional expressions (6) to (8) are satisfied. 0.98≦f1 / f≦1.58 (6) -1.26≦(R1+R2) / (R1-R2)≦-0.83 (7) 0.02≦d1 / TTL≦0.09 (8)

[0007] Preferably, the second lens has negative refractive power, an object side surface of the second lens is a paraxial concave surface, and an image side surface of the second lens is a paraxial concave surface, When the focal length of the second lens is f2, 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 optical length of the optical lens is TTL, the following conditional expressions (9) to (11) are satisfied. -1.10≦f2 / f≦-0.80 (9) 0.78≦(R3+R4) / (R3−R4)≦0.96 (10) 0.00≦d3 / TTL≦0.03 (11)

[0008] Preferably, the third lens has negative refractive power, an object side surface of the third lens is a paraxial concave surface, and an image side surface of the third lens is a paraxial concave surface, When the focal length of the third lens is f3, the central radius of curvature of the object side surface of the third lens is R5, the central radius of curvature of the image side surface of the third lens is R6, the axial thickness of the third lens is d5, and the optical length of the optical lens is TTL, the following conditional expressions (12) to (14) are satisfied. -0.75≦f3 / f≦-0.56 (12) -0.85≦(R5+R6) / (R5-R6)≦-0.30 (13) 0.00≦d5 / TTL≦0.03 (14)

[0009] Preferably, the fourth lens has positive refractive power, an object side surface of the fourth lens is a convex surface on a paraxial line, and an image side surface of the fourth lens is a convex surface on a paraxial line, 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 optical length of the optical lens is TTL, the following conditional expressions (15) to (17) are satisfied. 0.62≦f4 / f≦0.95 (15) 0.16≦(R7+R8) / (R7−R8)≦1.00 (16) 0.04≦d7 / TTL≦0.10 (17)

[0010] Preferably, the fifth lens has negative refractive power, an object side surface of the fifth lens is a paraxial concave surface, and an image side surface of the fifth lens is a paraxial concave surface, When 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, and the optical length of the optical lens is TTL, the following conditional expressions (18) to (20) are satisfied. -1.20≦f5 / f≦-0.55 (18) -0.41≦(R9+R10) / (R9-R10)≦-0.24 (19) 0.00≦d9 / TTL≦0.03 (20)

[0011] Preferably, the sixth lens has a positive refractive power, an object side surface of the sixth lens is a convex surface on a paraxial line, and an image side surface of the sixth lens is a convex surface on a paraxial line, When 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, and the optical length of the optical lens is TTL, the following conditional expressions (21) to (23) are satisfied. 1.11≦f6 / f≦1.45 (21) -0.10≦(R11+R12) / (R11−R12)≦0.25 (22) 0.05≦d11 / TTL≦0.10 (23)

[0012] Preferably, the seventh lens has a positive refractive power, an object side surface of the seventh lens is a convex surface on a paraxial line, and an image side surface of the seventh lens is a convex surface on a paraxial line, When the central radius of curvature of the object side surface of the seventh lens is R13, the central radius of curvature of the image side surface of the seventh lens is R14, the axial thickness of the seventh lens is d13, and the optical length of the optical lens is TTL, the following conditional expressions (24) and (25) are satisfied. -0.60≦(R13+R14) / (R13−R14)≦0.15 (24) 0.04≦d13 / TTL≦0.07 (25)

[0013] Preferably, the eighth lens has a negative refractive power, and an image side surface of the eighth lens is concave in a paraxial direction. When the focal length of the eighth lens is f8, the central radius of curvature of the object side surface of the eighth lens is R15, the central radius of curvature of the image side surface of the eighth lens is R16, the axial thickness of the eighth lens is d15, and the optical length of the optical lens is TTL, the following conditional expressions (26) to (28) are satisfied. -3.10≦f8 / f≦-0.69 (26) 0.14≦(R15+R16) / (R15−R16)≦3.00 (27) 0.00≦d15 / TTL≦0.04 (28)

[0014] Preferably, the ninth lens has a positive refractive power, an object side surface of the ninth lens is a convex surface on a paraxial line, and an image side surface of the ninth lens is a convex surface on a paraxial line, When the focal length of the ninth lens is f9, the central radius of curvature of the object side surface of the ninth lens is R17, the central radius of curvature of the image side surface of the ninth lens is R18, the axial thickness of the ninth lens is d17, and the optical length of the optical lens is TTL, the following conditional expressions (29) to (31) are satisfied. 0.84≦f9 / f≦1.79 (29) -0.90≦(R17+R18) / (R17-R18)≦-0.14 (30) 0.08≦d17 / TTL≦0.14 (31)

[0015] Preferably, the tenth lens has positive refractive power, an object side surface of the tenth lens is a convex surface on a paraxial line, and an image side surface of the tenth lens is a convex surface on a paraxial line, When the focal length of the tenth lens is f10, the central radius of curvature of the object side surface of the tenth lens is R19, the central radius of curvature of the image side surface of the tenth lens is R20, the axial thickness of the tenth lens is d19, and the optical length of the optical lens is TTL, the following conditional expressions (32) to (34) are satisfied. 0.90≦f10 / f≦1.15 (32) -0.45≦(R19+R20) / (R19−R20)≦0.00 (33) 0.06≦d19 / TTL≦0.15 (34)

[0016] Preferably, the eleventh lens has a negative refractive power, an object side surface of the eleventh lens is a concave surface in a paraxial direction, and an image side surface of the eleventh lens is a concave surface in a paraxial direction, When the focal length of the 11th lens is f11, the central radius of curvature of the object side surface of the 11th lens is R21, the central radius of curvature of the image side surface of the 11th lens is R22, the axial thickness of the 11th lens is d21, and the optical length of the optical lens is TTL, the following conditional expressions (35) to (37) are satisfied. -0.69≦f11 / f≦-0.50 (35) 0.35≦(R21+R22) / (R21−R22)≦0.60 (36) 0.00≦d21 / TTL≦0.03 (37)

[0017] Preferably, the twelfth lens has a positive refractive power, and an object side surface of the twelfth lens is a convex surface on a paraxial line, When the focal length of the 12th lens is f12, the central radius of curvature of the object side surface of the 12th lens is R23, the central radius of curvature of the image side surface of the 12th lens is R24, the axial thickness of the 12th lens is d23, and the optical length of the optical lens is TTL, the following conditional expressions (38) to (40) are satisfied. 0.93≦f12 / f≦1.33 (38) -1.35≦(R23+R24) / (R23-R24)≦-0.65 (39) 0.04≦d23 / TTL≦0.15 (40)

[0018] Preferably, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens and the twelfth lens are all made of a glass material. Effect of the Invention

[0019] The beneficial effects of the present invention are as follows: The optical lens according to the present invention has good optical performance, and has the characteristics of low distortion, large magnification and long working distance. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic diagram illustrating a configuration of an optical lens according to a first embodiment of the present invention. [Diagram 2] 2 is a schematic diagram showing the longitudinal chromatic aberration of the optical lens shown in FIG. [Diagram 3] 2 is a schematic diagram showing chromatic aberration of magnification of the optical lens shown in FIG. [Figure 4] 2 is a schematic diagram showing the field curvature and distortion of the optical lens shown in FIG. 1. [Diagram 5] FIG. 4 is a schematic diagram showing a configuration of an optical lens according to a second embodiment of the present invention. [Figure 6] 6 is a schematic diagram showing the longitudinal chromatic aberration of the optical lens shown in FIG. 5. [Figure 7] 6 is a schematic diagram showing chromatic aberration of magnification of the optical lens shown in FIG. 5. [Figure 8] 6 is a schematic diagram showing the field curvature and distortion of the optical lens shown in FIG. 5. [Figure 9] FIG. 11 is a schematic diagram showing a configuration of an optical lens according to a third embodiment of the present invention. [Figure 10] 10 is a schematic diagram showing the longitudinal chromatic aberration of the optical lens shown in FIG. [Figure 11] 10 is a schematic diagram showing chromatic aberration of magnification of the optical lens shown in FIG. [Figure 12] 10A and 10B are schematic diagrams showing the field curvature and distortion of the optical lens shown in FIG. [Figure 13] FIG. 11 is a schematic diagram showing a configuration of an optical lens according to a fourth embodiment of the present invention. [Figure 14] 14 is a schematic diagram showing the longitudinal chromatic aberration of the optical lens shown in FIG. 13. [Figure 15] 14 is a schematic diagram showing chromatic aberration of magnification of the optical lens shown in FIG. 13. [Figure 16]14A to 14C are schematic diagrams showing the field curvature and distortion of the optical lens shown in FIG. 13. [Figure 17] FIG. 13 is a schematic diagram showing a configuration of an optical lens according to a fifth embodiment of the present invention. [Figure 18] 18 is a schematic diagram showing the longitudinal chromatic aberration of the optical lens shown in FIG. 17. [Figure 19] 18 is a schematic diagram showing chromatic aberration of magnification of the optical lens shown in FIG. 17. [Figure 20] 18A and 18B are schematic diagrams showing the field curvature and distortion of the optical lens shown in FIG. 17. [Figure 21] FIG. 13 is a schematic diagram showing a configuration of an optical lens according to a sixth embodiment of the present invention. [Figure 22] 22 is a schematic diagram showing the longitudinal chromatic aberration of the optical lens shown in FIG. 21. [Figure 23] 22 is a schematic diagram showing chromatic aberration of magnification of the optical lens shown in FIG. 21. [Figure 24] 22A to 22C are schematic diagrams showing the field curvature and distortion of the optical lens shown in FIG. 21. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In order to make the object, solution and advantages of the present invention clearer, the following describes in detail each embodiment of the present invention with reference to the drawings. However, in each embodiment of the present invention, many technical details are given so that the present invention can be well understood, but it should be understood by those skilled in the art that the present invention can be realized without the existence of various changes and modifications based on these technical details and each embodiment below.

[0022] (First embodiment) Referring to the drawings, the present invention provides an optical lens 10. FIG. 1 shows an optical lens 10 according to a first embodiment of the present invention, and the optical lens 10 includes 12 lenses. Specifically, the optical lens 10 includes, in order from the object side to the image side, a first lens L1, a second lens L2, an aperture S1, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, and a twelfth lens L12. An optical element such as an optical filter may be provided between the twelfth lens L12 and an image surface Si.

[0023] If the composite focal length of the tenth lens L10 and the eleventh lens L11 is defined as f10_11, and the focal length of the twelfth lens L12 is defined as f12, then the conditional expression -0.80≦f12 / f10_11≦-0.50 is satisfied, the range of the ratio between the focal length of the lens group on the object side and the focal length closest to the object lens is specified, and it is possible to ensure that the light rays on the image side have sufficient light-collecting ability.

[0024] If the focal length of the seventh lens L7 is defined as f7 and the focal length of the optical lens 10 is defined as f, then the conditional formula 0.80≦f7 / f≦1.80 is satisfied, the ratio of the seventh lens L7 to the total focal length f of the system is specified, the aberration is corrected to ensure the imaging quality, and the total length of the optical lens 10 can be effectively controlled.

[0025] If the composite focal length of the fifth lens L5 and the sixth lens L6 is defined as f56, the axial thickness of the fifth lens L5 as d9, and the axial thickness of the sixth lens L6 as d11, then the conditional formula -83.00≦f56 / (d9+d11)≦-4.00 is satisfied, which specifies the range of the ratio of the composite focal length of the fifth lens L5 and the sixth lens L6 to the sum of the axial thickness d9 of the fifth lens L5 and the axial thickness d11 of the sixth lens L6, makes it possible to maintain a reasonable lens thickness while ensuring sufficient refractive power, and is advantageous for correcting distortion so that |Distortion|≦1%.

[0026] If the working distance of the optical lens (i.e., the axial distance from the object surface to the object-side surface of the first lens L1) is defined as WD, and the numerical aperture of the optical lens 10 is defined as NA, the conditional formula 0.40≦NA*f / WD≦0.60 is satisfied, which specifies the condition that the numerical aperture and resolution of the optical lens 10 must satisfy, and within the range of the conditional formula, the optical lens 10 has a relatively larger numerical aperture and stronger resolution.

[0027] When the distance from the object side surface of the first lens L1 of the optical lens 10 of the present invention to the observed object, the optical length, the numerical aperture, the focal length, the associated focal length and the axial thickness satisfy the above-mentioned conditional expressions, the optical lens 10 has good optical performance and can have characteristics of low distortion, large magnification and long working distance, wherein the magnification can reach 5 times.

[0028] If the axial thickness of the fourth lens L4 is defined as d7 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 defined as d8, then the conditional formula 1.00≦d7 / d8≦22.50 is satisfied, which specifies the ratio of the thickness d7 of the fourth lens L4 to the air spacing between the fourth lens L4 and the fifth lens L5 and is advantageous for lens assembly within the range of the conditional formula.

[0029] In this embodiment, the first lens L1 is made of a glass material, the second lens L2 is made of a glass material, the third lens L3 is made of a glass material, the fourth lens L4 is made of a glass material, the fifth lens L5 is made of a glass material, the sixth lens L6 is made of a glass material, the seventh lens L7 is made of a glass material, the eighth lens L8 is made of a glass material, the ninth lens L9 is made of a glass material, the tenth lens L10 is made of a glass material, the eleventh lens L11 is made of a glass material, and the twelfth lens L12 is made of a glass material.

[0030] In this embodiment, the object side surface of the first lens L1 is a paraxially convex surface, and the image side surface of the first lens L1 is a paraxially concave surface, and the first lens L1 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the first lens L1 may be arranged in other concave-convex distribution conditions, and the first lens L1 may have a negative refractive power.

[0031] If the focal length of the first lens L1 is defined as f1, the condition 0.98≦f1 / f≦1.58 is satisfied, and the refractive power is reasonably distributed, so that the system has excellent imaging quality and low sensitivity.

[0032] If the central radius of curvature of the object side surface of the first lens L1 is defined as R1 and the central radius of curvature of the image side surface of the first lens L1 is defined as R2, then the conditional formula -1.26≦(R1+R2) / (R1-R2)≦-0.83 is satisfied, and by rationally controlling the shape of the first lens L1, the first lens can effectively correct the system spherical aberration.

[0033] If the axial thickness of the first lens L1 is defined as d1 and the optical length of the optical lens 10 is defined as TTL, the conditional formula 0.02≦d1 / TTL≦0.09 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0034] In this embodiment, the object side surface of the second lens L2 is a paraxial concave surface, and the image side surface of the second lens L2 is a paraxial concave surface, and the second lens L2 has a negative refractive power. In other optional embodiments, the object side surface and the image side surface of the second lens L2 may be arranged in other concave-convex distribution situations, and the second lens L2 may have a positive refractive power.

[0035] If the focal length of the second lens L2 is defined as f2, the conditional formula -1.10≦f2 / f≦-0.80 is satisfied, and the refractive power is reasonably distributed, so that the system has excellent imaging quality and low sensitivity.

[0036] If the central radius of curvature of the object side surface of the second lens L2 is defined as R3 and the central radius of curvature of the image side surface of the second lens L2 is defined as R4, the conditional formula 0.78≦(R3+R4) / (R3-R4)≦0.96 is satisfied, which defines the shape of the second lens L2. Within the range defined by the conditional formula, the degree of deflection of light passing through the lens can be mitigated, and aberration can be effectively reduced.

[0037] When the axial thickness of the second lens L2 is defined as d3 and the optical length of the optical lens 10 is defined as TTL, the conditional expression 0.00≦d3 / TTL≦0.03 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0038] In this embodiment, the object side surface of the third lens L3 is a paraxial concave surface, and the image side surface of the third lens L3 is a paraxial concave surface, and the third lens L3 has a negative refractive power. In other optional embodiments, the object side surface and the image side surface of the third lens L3 may be arranged in other concave-convex distribution situations, and the third lens L3 may have a positive refractive power.

[0039] If the focal length of the third lens L3 is defined as f3, the condition -0.75≦f3 / f≦-0.56 is satisfied, and the refractive power is reasonably distributed, so that the system has excellent imaging quality and low sensitivity.

[0040] If the central radius of curvature of the object side surface of the third lens L3 is defined as R5 and the central radius of curvature of the image side surface of the third lens L3 is defined as R6, the conditional formula -0.85≦(R5+R6) / (R5-R6)≦-0.30 is satisfied, which defines the shape of the third lens L3. Within the range defined by the conditional formula, the degree of deflection of light passing through the lens can be mitigated, and aberrations can be effectively reduced.

[0041] When the axial thickness of the third lens L3 is defined as d5 and the optical length of the optical lens 10 is defined as TTL, the conditional formula 0.00≦d5 / TTL≦0.03 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0042] In this embodiment, the object side surface of the fourth lens L4 is a paraxial convex surface, and the image side surface of the fourth lens L4 is a paraxial convex surface, and the fourth lens L4 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the fourth lens L4 may be arranged in other concave-convex distribution conditions, and the fourth lens L4 may have a negative refractive power.

[0043] If the focal length of the fourth lens L4 is defined as f4, then the conditional formula 0.62≦f4 / f≦0.95 is satisfied, which specifies the ratio of the focal length f4 of the fourth lens L4 to the system focal length f. Within the range of the conditional formula, this is advantageous for improving the performance of the optical system.

[0044] If the central radius of curvature of the object side surface of the fourth lens L4 is defined as R7 and the central radius of curvature of the image side surface of the fourth lens L4 is defined as R8, the conditional formula 0.16≦(R7+R8) / (R7-R8)≦1.00 is satisfied, which defines the shape of the fourth lens L4. Within the range defined by the conditional formula, it is possible to reduce the degree of deflection of light passing through the lens, and effectively reduce aberration.

[0045] When the axial thickness of the fourth lens L4 is defined as d7 and the optical length of the optical lens is defined as TTL, the conditional formula 0.04≦d7 / TTL≦0.10 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0046] In this embodiment, the object side surface of the fifth lens L5 is a paraxial concave surface, and the image side surface of the fifth lens L5 is a paraxial concave surface, and the fifth lens L5 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the fifth lens L5 may be arranged in other concave-convex distribution conditions, and the fifth lens L5 may have a negative refractive power.

[0047] If the focal length of the fifth lens L5 is defined as f5, then the conditional formula -1.20≦f5 / f≦-0.55 is satisfied, which specifies the ratio of the focal length f5 of the fifth lens L5 to the focal length f of the system. Within the range of the conditional formula, this is advantageous for improving the performance of the optical system.

[0048] If the central radius of curvature of the object side surface of the fifth lens L5 is defined as R9 and the central radius of curvature of the image side surface of the fifth lens L5 is defined as R10, the conditional expression -0.41≦(R9+R10) / (R9-R10)≦-0.24 is satisfied, which defines the shape of the fifth lens L5. Within the range defined by the conditional expression, it is possible to alleviate the degree of deflection of light rays passing through the lens, and effectively reduce aberration.

[0049] When the axial thickness of the fifth lens L5 is defined as d9, the conditional expression 0.00≦d9 / TTL≦0.03 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0050] In this embodiment, the sixth lens L6 has a paraxially convex object side surface and a paraxially convex image side surface, and the sixth lens L6 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the sixth lens L6 may be arranged in other concave-convex distribution conditions, and the sixth lens L6 may have a negative refractive power.

[0051] If the focal length of the sixth lens L6 is defined as f6, then the conditional formula 1.11≦f6 / f≦1.45 is satisfied, which specifies the ratio of the focal length f6 of the sixth lens L6 to the focal length f of the system. Within the range of the conditional formula, this is advantageous for improving the performance of the optical system.

[0052] If the central radius of curvature of the object side surface of the sixth lens L6 is defined as R11 and the central radius of curvature of the image side surface of the sixth lens L6 is defined as R12, the conditional formula -0.10≦(R11+R12) / (R11-R12)≦0.25 is satisfied, which defines the shape of the sixth lens L6. Within the range defined by the conditional formula, it is possible to alleviate the degree of deflection of light rays passing through the lens, and effectively reduce aberration.

[0053] When the axial thickness of the sixth lens L6 is defined as d11, the conditional expression 0.05≦d11 / TTL≦0.10 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0054] In this embodiment, the seventh lens L7 has a paraxially convex object side surface and a paraxially convex image side surface, and the seventh lens L7 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the seventh lens L7 may be arranged in other concave-convex distribution conditions, and the seventh lens L7 may have a negative refractive power.

[0055] If the central radius of curvature of the object side surface of the seventh lens L7 is defined as R13 and the central radius of curvature of the image side surface of the seventh lens L7 is defined as R14, then the conditional formula -0.60≦(R13+R14) / (R13-R14)≦0.15 is satisfied. This conditional formula defines the shape of the seventh lens L7, and within the range defined by the conditional formula, the degree of deflection of light passing through the lens can be alleviated, and aberration can be effectively reduced.

[0056] When the axial thickness of the seventh lens L7 is defined as d13, the conditional expression 0.04≦d13 / TTL≦0.07 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0057] In this embodiment, the object side surface of the eighth lens L8 is a paraxial convex surface, and the image side surface of the eighth lens L8 is a paraxial concave surface, and the eighth lens L8 has a negative refractive power. In other optional embodiments, the object side surface and the image side surface of the eighth lens L8 may be arranged in other concave-convex distribution conditions, and the eighth lens L8 may have a positive refractive power.

[0058] If the focal length of the eighth lens L8 is defined as f8, then the conditional formula -3.10≦f8 / f≦-0.69 is satisfied, which specifies the ratio of the focal length f8 of the eighth lens L8 to the focal length f of the system. Within the range of the conditional formula, this is advantageous for improving the performance of the optical system.

[0059] If the central radius of curvature of the object side surface of the eighth lens L8 is defined as R15 and the central radius of curvature of the image side surface of the seventh lens is defined as R16, then the conditional formula 0.14≦(R15+R16) / (R15-R16)≦3.00 is satisfied. This conditional formula defines the shape of the eighth lens L8, and within the range defined by the conditional formula, the degree of deflection of light passing through the lens can be mitigated, effectively reducing aberrations.

[0060] When the axial thickness of the eighth lens L8 is defined as d15, the conditional expression 0.00≦d15 / TTL≦0.04 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0061] In this embodiment, the object side surface of the ninth lens L9 is a paraxially convex surface, and the image side surface of the ninth lens L9 is a paraxially convex surface, and the ninth lens L9 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the ninth lens L9 may be arranged in other concave-convex distribution conditions, and the ninth lens L9 may have a negative refractive power.

[0062] If the focal length of the ninth lens L9 is defined as f9, then the conditional expression 0.84≦f9 / f≦1.79 is satisfied, which specifies the ratio of the focal length f9 of the ninth lens L9 to the focal length f of the system, and is advantageous for improving the performance of the optical system within the range of the conditional expression.

[0063] If the central radius of curvature of the object side surface of the ninth lens L9 is defined as R17 and the central radius of curvature of the image side surface of the ninth lens L9 is defined as R18, the conditional expression -0.90≦(R17+R18) / (R17-R18)≦-0.14 is satisfied, which defines the shape of the ninth lens L9. Within the range defined by the conditional expression, it is possible to reduce the degree of deflection of light passing through the lens, and effectively reduce aberrations.

[0064] When the axial thickness of the ninth lens L9 is defined as d17, the conditional expression 0.08≦d17 / TTL≦0.14 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0065] In this embodiment, the object side surface of the tenth lens L10 is a paraxially convex surface, and the image side surface of the tenth lens L10 is a paraxially convex surface, and the tenth lens L10 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the tenth lens L10 may be arranged in other concave-convex distribution conditions, and the tenth lens L10 may have a negative refractive power.

[0066] If the focal length of the tenth lens L10 is defined as f10, the conditional expression 0.90≦f10 / f≦1.15 is satisfied, which specifies the ratio of the focal length f10 of the tenth lens L10 to the focal length f of the system, and is advantageous for improving the performance of the optical system within the range of the conditional expression.

[0067] If the central radius of curvature of the object side surface of the tenth lens L10 is defined as R19 and the central radius of curvature of the image side surface of the tenth lens L10 is defined as R20, then the conditional formula -0.45≦(R19+R20) / (R19-R20)≦0.00 is satisfied. This conditional formula defines the shape of the tenth lens L10, and within the range defined by the conditional formula, the degree of deflection of light passing through the lens can be alleviated, effectively reducing aberrations.

[0068] When the axial thickness of the tenth lens L10 is defined as d19, the conditional expression 0.06≦d19 / TTL≦0.15 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0069] In this embodiment, the object side surface of the eleventh lens L11 is a paraxial concave surface, and the image side surface of the eleventh lens L11 is a paraxial concave surface, and the eleventh lens L11 has a negative refractive power. In other optional embodiments, the object side surface and the image side surface of the eleventh lens L11 may be arranged in other concave-convex distribution conditions, and the eleventh lens L11 may have a positive refractive power.

[0070] If the focal length of the eleventh lens L11 is defined as f11, then the conditional formula -0.69≦f11 / f≦-0.50 is satisfied, which specifies the ratio of the focal length f11 of the eleventh lens L11 to the focal length f of the system. Within the range of the conditional formula, this is advantageous for improving the performance of the optical system.

[0071] If the central radius of curvature of the object side surface of the eleventh lens L11 is defined as R21 and the central radius of curvature of the image side surface of the eleventh lens L11 is defined as R22, then the conditional formula 0.35≦(R21+R22) / (R21-R22)≦0.60 is satisfied, and within the range defined by the conditional formula, the degree of deflection of light passing through the lens can be mitigated, and aberration can be effectively reduced.

[0072] When the axial thickness of the eleventh lens L11 is defined as d21, the conditional expression 0.00≦d21 / TTL≦0.03 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0073] In this embodiment, the object side surface of the twelfth lens L12 is a paraxially convex surface, and the image side surface of the twelfth lens L12 is a paraxially concave surface, and the twelfth lens L12 has a positive refractive power. In other optional embodiments, the object side surface and the image side surface of the twelfth lens L12 may be arranged in other concave-convex distribution conditions, and the twelfth lens L12 may have a negative refractive power.

[0074] If the focal length of the twelfth lens L12 is defined as f12, the conditional expression 0.93≦f12 / f≦1.33 is satisfied, which specifies the ratio of the focal length f12 of the twelfth lens L12 to the focal length f of the system, and is advantageous for improving the performance of the optical system within the range of the conditional expression.

[0075] If the central radius of curvature of the object side surface of the 12th lens L12 is defined as R23 and the central radius of curvature of the image side surface of the 12th lens L12 is defined as R24, the conditional expression -1.35≦(R23+R24) / (R23-R24)≦-0.65 is satisfied, which defines the shape of the 12th lens L12. Within the range defined by the conditional expression, it is possible to reduce the degree of deflection of light passing through the lens, and effectively reduce aberration.

[0076] When the axial thickness of the twelfth lens L12 is defined as d23, the conditional expression 0.04≦d23 / TTL≦0.15 is satisfied, which is helpful in assembling the lens and effectively controls the lens thickness and overall lens length.

[0077] In this embodiment, an aperture S1 is provided between the second lens L2 and the third lens L3, the axial distance from the image side surface of the second lens L2 to the aperture S1 is 6.490 mm, and the axial distance from the aperture S1 to the object side surface of the third lens L3 is 5.110 mm.

[0078] The optical lens 10 of the present invention will be described below using examples. The symbols used in each example indicate the following: The focal length, axial distance, central radius of curvature, and axial thickness are all in mm.

[0079] TTL: Optical length (the axial distance from the object side of the first lens L1 to the image plane) in mm.

[0080] Preferably, an inflection point and / or a stationary point may be further set on the object side and / or image side of the lens to meet the demand for high quality imaging, and a specific embodiment is given below.

[0081] Table 1 shows design data for the optical lens 10 according to the first embodiment of the present invention.

[0082] [Table 1]

[0083] Here, INF stands for infinity, and the meaning of each symbol is as follows: OBJ: object plane R: Radius of curvature of the center of the optical surface R1: The central radius of curvature of the object side of the first lens L1 R2: Radius of curvature of the center of the image side of the first lens L1 R3: The central radius of curvature of the object side of the second lens L2 R4: Radius of curvature of the center of the image side of the second lens L2 R5: The central radius of curvature of the object side of the third lens L3 R6: The central radius of curvature of the image side of the third lens L3 R7: The central radius of curvature of the object side of the fourth lens L4 R8: The central radius of curvature of the image side of the fourth lens L4 R9: The central radius of curvature of the object side of the fifth lens L5 R10: Radius of central curvature of the image side of the fifth lens L5 R11: The central radius of curvature of the object side of the sixth lens L6 R12: Radius of curvature of the center of the image side of the sixth lens L6 R13: The central radius of curvature of the object side of the seventh lens L7 R14: Radius of curvature of the center of the image side of the seventh lens L7 R15: Radius of curvature of the center of the object side of the eighth lens L8 R16: Radius of curvature of the center of the image side of the eighth lens L8 R17: The central curvature radius of the object side of the ninth lens L9 R18: Radius of curvature of the center of the image side of the ninth lens L9 R19: The central curvature radius of the object side of the tenth lens L10 R20: Radius of curvature of the center of the image side of the tenth lens L10 R21: Radius of curvature of the center of the object side of the eleventh lens L11 R22: Radius of curvature of the center of the image side of the eleventh lens L11 R23: Radius of curvature of the center of the object side of the twelfth lens L12 R24: Radius of curvature of the center of the image side of the twelfth lens L12 d: Axial thickness of the lens or axial distance between lenses 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 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 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 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 L5 d10: the axial distance from the image side surface of the fifth lens L5 to the object side surface of the sixth lens L6 d11: Axial thickness of the sixth lens L6 d12: Axial distance from the image side surface of the sixth lens L6 to the object side surface of the seventh lens L7 d13: Axial thickness of the seventh lens L7 d14: Axial distance from the image side surface of the seventh lens L7 to the object side surface of the eighth lens L8 d15: Axial thickness of the eighth lens L8 d16: The axial distance from the image side surface of the eighth lens L8 to the object side surface of the ninth lens L9 d17: Axial thickness of the ninth lens L9 d18: The axial distance from the image side surface of the ninth lens L9 to the object side surface of the tenth lens L10 d19: Axial thickness of the tenth lens L10 d20: the axial distance from the image side surface of the tenth lens L10 to the object side surface of the eleventh lens L11 d21: Axial thickness of the eleventh lens L11 d22: the axial distance from the image side surface of the eleventh lens L11 to the object side surface of the twelfth lens L12 d23: Axial thickness of the twelfth lens L12 d24: The axial distance from the image side of the twelfth lens L12 to the object side of the optical filter nd: Refractive index of d line 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 d line of the third lens L3 nd4: Refractive index of the d line of the fourth lens L4 nd5: refractive index of the d line of the fifth lens L5 nd6: Refractive index of the d line of the sixth lens L6 nd7: Refractive index of the d line of the seventh lens L7 nd8: Refractive index of the d line of the eighth lens L8 nd9: Refractive index of the d line of the ninth lens L9 nd10: Refractive index of the d line of the tenth lens L10 nd11: refractive index of the d line of the eleventh lens L11 nd12: refractive index of the d line of the 12th lens L12 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 L3 v4: Abbe number of the fourth lens L4 v5: Abbe number of the fifth lens L5 v6: Abbe number of the sixth lens L6 v7: Abbe number of the seventh lens L7 v8: Abbe number of the eighth lens L8 v9: Abbe number of the ninth lens L9 v10: Abbe number of the 10th lens L10 v11: Abbe number of the 11th lens L11 v12: Abbe number of the 12th lens L12

[0084] Fig. 2 and Fig. 3 are schematic diagrams showing the axial chromatic aberration and lateral chromatic aberration of light having wavelengths of 632 nm, 546 nm, and 486 nm, respectively, after passing through the optical lens 10 according to the first embodiment. Fig. 4 is a schematic diagram showing the field curvature and distortion aberration of light having wavelength of 546 nm after passing through the optical lens 10 according to the first embodiment, where the field curvature S in Fig. 4 is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0085] Table 7 below shows values ​​corresponding to the parameters defined by various numerical values ​​and conditional expressions in each of the first, second, third, fourth, fifth and sixth embodiments.

[0086] As shown in Table 7, the first embodiment satisfies each of the conditional expressions.

[0087] In this embodiment, the optical lens has an entrance pupil diameter of 24.765 mm, a numerical aperture of 0.35, and an image height of 4.0 mm in the full field of view, and has good optical performance, and has the characteristics of low distortion, large magnification and long working distance.

[0088] Second embodiment The second embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0089] In this embodiment, an aperture S1 is provided between the second lens L2 and the third lens L3, the axial distance from the image side surface of the second lens L2 to the aperture S1 is 3.710 mm, and the axial distance from the aperture S1 to the object side surface of the third lens L3 is 3.740 mm.

[0090] In this embodiment, the first lens L1 has a paraxially convex image side surface, and the eighth lens L8 has a paraxially concave object side surface.

[0091] Table 2 shows design data for the optical lens 20 according to the second embodiment of the present invention.

[0092] [Table 2]

[0093] Fig. 6 and Fig. 7 are schematic diagrams showing the axial chromatic aberration and lateral chromatic aberration of light having wavelengths of 632 nm, 546 nm, and 486 nm, respectively, after passing through the optical lens 20 according to the second embodiment. Fig. 8 is a schematic diagram showing the field curvature and distortion aberration of light having wavelength of 546 nm after passing through the optical lens 20 according to the second embodiment, where the field curvature S in Fig. 8 is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0094] Table 7 below shows values ​​corresponding to the parameters defined by various numerical values ​​and conditional expressions in each of the first, second, third, fourth, fifth and sixth embodiments.

[0095] As shown in Table 7, the second embodiment satisfies each of the conditional expressions.

[0096] In this embodiment, the optical lens has an entrance pupil diameter of 25.250 mm, a numerical aperture of 0.35, and an image height of 4.0 mm in the full field of view, and has good optical performance, and has the characteristics of low distortion, large magnification and long working distance.

[0097] Third embodiment The third embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0098] In this embodiment, an aperture S1 is provided between the second lens L2 and the third lens L3, the axial distance from the image side surface of the second lens L2 to the aperture S1 is 2.961 mm, and the axial distance from the aperture S1 to the object side surface of the third lens L3 is 2.749 mm.

[0099] In this embodiment, the first lens L1 has a paraxially convex image side surface, the eighth lens L8 has a paraxially concave object side surface, and the twelfth lens L12 has a paraxially convex image side surface.

[0100] Table 3 shows design data for the optical lens 30 according to the third embodiment of the present invention.

[0101] [Table 3]

[0102] Fig. 10 and Fig. 11 are schematic diagrams showing the axial chromatic aberration and the chromatic aberration of magnification after light of wavelengths 632 nm, 546 nm, and 486 nm has passed through the optical lens 30 according to the third embodiment. Fig. 12 is a schematic diagram showing the field curvature and distortion aberration after light of wavelength 546 nm has passed through the optical lens 30 according to the third embodiment, where the field curvature S in Fig. 12 is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0103] Table 7 below shows values ​​corresponding to the parameters defined by various numerical values ​​and conditional expressions in each of the first, second, third, fourth, fifth and sixth embodiments.

[0104] As shown in Table 7, the third embodiment satisfies each of the conditional expressions.

[0105] In this embodiment, the optical lens has an entrance pupil diameter of 22.500 mm, a numerical aperture of 0.31, and an image height of 4.0 mm in the full field of view, and has good optical performance, and has the characteristics of low distortion, large magnification and long working distance.

[0106] (Fourth embodiment) The fourth embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0107] In this embodiment, an aperture S1 is provided between the second lens L2 and the third lens L3, the axial distance from the image side surface of the second lens L2 to the aperture S1 is 3.762 mm, and the axial distance from the aperture S1 to the object side surface of the third lens L3 is 3.386 mm.

[0108] In this embodiment, the first lens L1 has a paraxially convex image side surface, and the eighth lens L8 has a paraxially concave object side surface.

[0109] Table 4 shows design data for the optical lens 40 according to the fourth embodiment of the present invention.

[0110] [Table 4]

[0111] Fig. 14 and Fig. 15 are schematic diagrams showing the axial chromatic aberration and the chromatic aberration of magnification after light of wavelengths 632 nm, 546 nm, and 486 nm has passed through the optical lens 40 according to the fourth embodiment. Fig. 16 is a schematic diagram showing the field curvature and distortion aberration after light of wavelength 546 nm has passed through the optical lens 40 according to the fourth embodiment, where the field curvature S in Fig. 16 is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0112] Table 7 below shows values ​​corresponding to the parameters defined by various numerical values ​​and conditional expressions in each of the first, second, third, fourth, fifth and sixth embodiments.

[0113] As shown in Table 7, the fourth embodiment satisfies each of the conditional expressions.

[0114] In this embodiment, the optical lens has an entrance pupil diameter of 25.250 mm, a numerical aperture of 0.35, and an image height of 4.0 mm in the full field of view, and has good optical performance, and has the characteristics of low distortion, large magnification and long working distance.

[0115] Fifth embodiment The fifth embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0116] In this embodiment, an aperture S1 is provided between the second lens L2 and the third lens L3, the axial distance from the image side surface of the second lens L2 to the aperture S1 is 3.167 mm, and the axial distance from the aperture S1 to the object side surface of the third lens L3 is 3.244 mm.

[0117] In this embodiment, the first lens L1 has a paraxially convex image side surface, the eighth lens L8 has a paraxially concave object side surface, and the twelfth lens L12 has a paraxially convex image side surface.

[0118] Table 5 shows design data for the optical lens 50 according to the fifth embodiment of the present invention.

[0119] [Table 5]

[0120] Fig. 18 and Fig. 19 are schematic diagrams showing the axial chromatic aberration and lateral chromatic aberration of light having wavelengths of 632 nm, 546 nm, and 486 nm, respectively, after passing through the optical lens 50 according to the fifth embodiment. Fig. 20 is a schematic diagram showing the field curvature and distortion aberration of light having a wavelength of 546 nm after passing through the optical lens 50 according to the fifth embodiment, where the field curvature S in Fig. 20 is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0121] Table 7 below shows values ​​corresponding to the parameters defined by various numerical values ​​and conditional expressions in each of the first, second, third, fourth, fifth and sixth embodiments.

[0122] As shown in Table 7, the fifth embodiment satisfies each of the conditional expressions.

[0123] In this embodiment, the optical lens has an entrance pupil diameter of 24,000 mm, a numerical aperture of 0.33, and an image height of 4.0 mm in the full field of view, and has good optical performance, and has the characteristics of low distortion, large magnification and long working distance.

[0124] Sixth embodiment The sixth embodiment is basically the same as the first embodiment, and the symbols have the same meanings as in the first embodiment, so only the differences will be described below.

[0125] In this embodiment, an aperture S1 is provided between the second lens L2 and the third lens L3, the axial distance from the image side surface of the second lens L2 to the aperture S1 is 6.944 mm, and the axial distance from the aperture S1 to the object side surface of the third lens L3 is 2.811 mm.

[0126] In this embodiment, the first lens L1 has a paraxially convex image side surface, and the eighth lens L8 has a paraxially concave object side surface.

[0127] Table 6 shows design data for the optical lens 60 according to the sixth embodiment of the present invention.

[0128] [Table 6]

[0129] Fig. 22 and Fig. 23 are schematic diagrams showing the axial chromatic aberration and the chromatic aberration of magnification after light of wavelengths 632 nm, 546 nm, and 486 nm has passed through the optical lens 60 according to the sixth embodiment. Fig. 24 is a schematic diagram showing the field curvature and distortion aberration after light of wavelength 546 nm has passed through the optical lens 60 according to the sixth embodiment, where the field curvature S in Fig. 24 is the field curvature in the sagittal direction, and T is the field curvature in the tangential direction.

[0130] Table 7 below shows values ​​corresponding to the parameters defined by various numerical values ​​and conditional expressions in each of the first, second, third, fourth, fifth and sixth embodiments.

[0131] As shown in Table 7, the sixth embodiment satisfies each of the conditional expressions.

[0132] In this embodiment, the optical lens has an entrance pupil diameter of 23,000 mm, a numerical aperture of 0.32, and an image height of 4.0 mm in the full field of view, and has good optical performance, and has the characteristics of low distortion, large magnification and long working distance.

[0133] [Table 7]

[0134] The above is merely an embodiment of the present invention, and those skilled in the art may make modifications without departing from the spirit of the present invention, all of which are within the scope of protection of the present invention.

Claims

1. 1. An optical lens, comprising: The optical system is constituted by, in order from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens, The optical lens is characterized in that, when a focal length of the optical lens is f, a composite focal length of the fifth lens and the sixth lens is f56, an axial thickness of the fifth lens is d9, an axial thickness of the sixth lens is d11, a focal length of the seventh lens is f7, a composite focal length of the tenth lens and the eleventh lens is f10_11, a focal length of the twelfth lens is f12, a working distance of the optical lens is WD, and a numerical aperture of the optical lens is NA, the optical lens satisfies the following conditional expressions (1) to (4). -0.80≦f12 / f10_11≦-0.50 (1) 0.80≦f7 / f≦1.80 (2) -83.00≦f56 / (d9+d11)≦-4.00 (3) 0.40≦NA*f / WD≦0.60 (4)

2. 2. The optical lens according to claim 1, wherein the following conditional expression (5) is satisfied when an axial thickness of the fourth lens is d7 and an axial distance from an image side surface of the fourth lens to an object side surface of the fifth lens is d8: 1.00≦d7 / d8≦22.50 (5)

3. the first lens has positive refractive power, and an object side surface of the first lens is a convex surface on a paraxial line; the optical lens according to claim 1, wherein the following conditional expressions (6) to (8) are 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, an axial thickness of the first lens is d1, and an optical length of the optical lens is TTL. 0.98≦f1 / f≦1.58 (6) -1.26≦(R1+R2) / (R1-R2)≦-0.83 (7) 0.02≦d1 / TTL≦0.09 (8)

4. the second lens has negative refractive power, an object side surface of the second lens is a paraxial concave surface, and an image side surface of the second lens is a paraxial concave surface, the optical lens according to claim 1, wherein the following conditional expressions (9) to (11) are satisfied when a focal length of the second lens is f2, 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 an optical length of the optical lens is TTL: −1.10≦f2 / f≦−0.80 (9) 0.78≦(R3+R4) / (R3-R4)≦0.96 (10) 0.00≦d3 / TTL≦0.03 (11)

5. the third lens has negative refractive power, an object side surface of the third lens is a paraxial concave surface, and an image side surface of the third lens is a paraxial concave surface, the optical lens according to claim 1, wherein the following conditional expressions (12) to (14) are satisfied when a focal length of the third lens is f3, a central radius of curvature of an object side surface of the third lens is R5, a central radius of curvature of an image side surface of the third lens is R6, an axial thickness of the third lens is d5, and an optical length of the optical lens is TTL. −0.75≦f3 / f≦−0.56 (12) -0.85≦(R5+R6) / (R5-R6)≦-0.30 (13) 0.00≦d5 / TTL≦0.03 (14)

6. the fourth lens has positive refractive power, an object side surface of the fourth lens is a convex surface on a paraxial line, and an image side surface of the fourth lens is a convex surface on a paraxial line, the optical lens according to claim 1, wherein the following conditional expressions (15) to (17) are 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 an optical length of the optical lens is TTL. 0.62≦f4 / f≦0.95 (15) 0.16≦(R7+R8) / (R7-R8)≦1.00 (16) 0.04≦d7 / TTL≦0.10 (17)

7. the fifth lens has negative refractive power, an object side surface of the fifth lens is a paraxial concave surface, and an image side surface of the fifth lens is a paraxial concave surface, the optical lens according to claim 1, wherein the following conditional expressions (18) to (20) are satisfied when a focal length of the fifth lens is f5, a central radius of curvature of an object-side surface of the fifth lens is R9, a central radius of curvature of an image-side surface of the fifth lens is R10, and an optical length of the optical lens is TTL. −1.20≦f5 / f≦−0.55 (18) -0.41≦(R9+R10) / (R9-R10)≦-0.24 (19) 0.00≦d9 / TTL≦0.03 (20)

8. the sixth lens has positive refractive power, an object side surface of the sixth lens is a convex surface on a paraxial line, and an image side surface of the sixth lens is a convex surface on a paraxial line, the optical lens according to claim 1, wherein the following conditional expressions (21) to (23) are satisfied when a focal length of the sixth lens is f6, a central radius of curvature of an object-side surface of the sixth lens is R11, a central radius of curvature of an image-side surface of the sixth lens is R12, and an optical length of the optical lens is TTL: 1.11≦f6 / f≦1.45 (21) -0.10≦(R11+R12) / (R11-R12)≦0.25 (22) 0.05≦d11 / TTL≦0.10 (23)

9. the seventh lens has positive refractive power, an object side surface of the seventh lens is a convex surface on a paraxial line, and an image side surface of the seventh lens is a convex surface on a paraxial line, 2. The optical lens according to claim 1, wherein the following conditional expressions (24) and (25) are satisfied when a central radius of curvature of an object side surface of the seventh lens is R13, a central radius of curvature of an image side surface of the seventh lens is R14, an axial thickness of the seventh lens is d13, and an optical length of the optical lens is TTL. -0.60≦(R13+R14) / (R13-R14)≦0.15 (24) 0.04≦d13 / TTL≦0.07 (25)

10. the eighth lens has a negative refractive power, and an image side surface of the eighth lens is a concave surface in a paraxial direction; the optical lens according to claim 1, wherein the following conditional expressions (26) to (28) are satisfied when a focal length of the eighth lens is f8, a central radius of curvature of an object side surface of the eighth lens is R15, a central radius of curvature of an image side surface of the eighth lens is R16, an axial thickness of the eighth lens is d15, and an optical length of the optical lens is TTL. −3.10≦f8 / f≦−0.69 (26) 0.14≦(R15+R16) / (R15-R16)≦3.00 (27) 0.00≦d15 / TTL≦0.04 (28)

11. the ninth lens has positive refractive power, an object side surface of the ninth lens is a convex surface on a paraxial line, and an image side surface of the ninth lens is a convex surface on a paraxial line, the optical lens according to claim 1, wherein the following conditional expressions (29) to (31) are satisfied when a focal length of the ninth lens is f9, a central radius of curvature of an object side surface of the ninth lens is R17, a central radius of curvature of an image side surface of the ninth lens is R18, an axial thickness of the ninth lens is d17, and an optical length of the optical lens is TTL: 0.84≦f9 / f≦1.79 (29) -0.90≦(R17+R18) / (R17-R18)≦-0.14 (30) 0.08≦d17 / TTL≦0.14 (31)

12. the tenth lens has positive refractive power, an object side surface of the tenth lens is a convex surface on a paraxial line, and an image side surface of the tenth lens is a convex surface on a paraxial line, The optical lens according to claim 1, characterized in that the following conditional expressions (32) to (34) are satisfied when a focal length of the tenth lens is f10, a central radius of curvature of an object side surface of the tenth lens is R19, a central radius of curvature of an image side surface of the tenth lens is R20, an axial thickness of the tenth lens is d19, and an optical length of the optical lens is TTL. 0.90≦f10 / f≦1.15 (32) -0.45≦(R19+R20) / (R19-R20)≦0.00 (33) 0.06≦d19 / TTL≦0.15 (34)

13. the 11th lens has a negative refractive power, an object side surface of the 11th lens is a paraxial concave surface, and an image side surface of the 11th lens is a paraxial concave surface, The optical lens according to claim 1, characterized in that the following conditional expressions (35) to (37) are satisfied when a focal length of the 11 lens is f11, a central radius of curvature of an object side surface of the 11 lens is R21, a central radius of curvature of an image side surface of the 11 lens is R22, an axial thickness of the 11 lens is d21, and an optical length of the optical lens is TTL. −0.69≦f11 / f≦−0.50 (35) 0.35≦(R21+R22) / (R21-R22)≦0.60 (36) 0.00≦d21 / TTL≦0.03 (37)

14. the 12th lens has a positive refractive power, and an object side surface of the 12th lens is a convex surface on a paraxial line; the optical lens according to claim 1, wherein the following conditional expressions (38) to (40) are satisfied when a focal length of the 12 lens is f12, a central radius of curvature of an object side surface of the 12 lens is R23, a central radius of curvature of an image side surface of the 12 lens is R24, an axial thickness of the 12 lens is d23, and an optical length of the optical lens is TTL. 0.93≦f12 / f≦1.33 (38) -1.35≦(R23+R24) / (R23-R24)≦-0.65 (39) 0.04≦d23 / TTL≦0.15 (40)

15. 2. The optical lens of claim 1, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens, and the twelfth lens are all made of a glass material.

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