High-resolution fixed-focus lenses and cameras
By designing a high-resolution fixed-focus lens including a front lens group, a mid lens group and a rear focus group, the problem that existing industrial lenses are difficult to match larger target surfaces and higher resolution cameras is solved, and high-resolution and low distortion imaging performance is achieved.
Patent Information
- Application Number
- CN202110039251.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-01-12
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2041-01-12
Smart Images
Figure CN112698500B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lenses, and in particular to a high-resolution fixed-focus lens and a camera. Background Art
[0002] With the development of industrial automation, industrial lenses are widely used in the field of machine vision inspection, such as workpiece measurement and judgment, defect detection, food packaging, intelligent logistics, medical judgment, etc. At present, most industrial lenses on the market can only match cameras with 2 / 3-inch target surface and 5 million pixels and 1.1-inch target surface and 12 million pixels. With the continuous improvement of detection accuracy requirements and the widespread application of high-resolution cameras, the demand for industrial lenses that can match larger target surfaces and higher-resolution cameras is increasing. Therefore, a high-resolution fixed-focus lens with excellent performance that can meet the above requirements is needed. Summary of the invention
[0003] The purpose of the present invention is to provide a high-resolution fixed-focus lens, which is conducive to matching a camera with a larger target surface and a higher resolution.
[0004] Another object of the present invention is to provide a camera that is conducive to achieving a larger target area and higher resolution.
[0005] In order to achieve the above object, the present invention discloses a high-resolution fixed-focus lens, which includes a mechanical device and an optical system installed inside the mechanical device, wherein the optical system is provided with a front lens group, a middle lens group, an aperture and a rear focusing group in sequence from the object side to the image side;
[0006] The front lens group includes a first lens having positive power and a meniscus structure, a second lens having negative power and a meniscus structure, and a third lens having negative power and a biconcave structure, wherein the first lens, the second lens and the third lens are arranged in sequence from the object side to the image side;
[0007] The middle lens group includes a fourth lens having positive refractive power and a fifth lens having positive refractive power, and the fourth lens and the fifth lens are arranged in sequence from the object side to the image side;
[0008] The rear focusing group includes a sixth lens with positive power, a seventh lens with negative power and a biconcave structure, an eighth lens with positive power and a biconvex structure, a ninth lens with positive power and a meniscus structure, a tenth lens with negative power and a meniscus structure, and an eleventh lens with positive power and a biconvex structure, wherein the seventh lens and the eighth lens form a first cemented lens, and the ninth lens and the tenth lens form a second cemented lens; the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are arranged in sequence from the object side to the image side.
[0009] Preferably, the focal length of the optical system is f; the combined focal length of the front lens group is f S1 , f S1 The ratio of f satisfies the relationship: 0.8<|f S1 / f|<1.8; the combined focal length of the middle lens group is f S2 , f S2 The ratio of f satisfies the relationship: 1<|f S2 / f|<2; the combined focal length of the rear focusing group is f S3 , f S3 The ratio of f satisfies the relationship: 1.25<|f S3 / f|<2.25.
[0010] Preferably, the focal length of the first lens is f G1 , f G1 and f S1 The ratio satisfies the relationship: 3<|f G1 / f S1 |<4.5; the focal length of the second lens is f G2 , f G2 and f S1 The ratio satisfies the relationship: 1<|f G2 / f S1 |<2.5; the focal length of the third lens is f G3 , f G3 and f S1 The ratio satisfies the relationship: 0.8<|f G3 / f S1 |<1.8.
[0011] Preferably, the focal length of the sixth lens is f G6 , f G6 and f S3 The ratio satisfies the relationship: 1<|f G6 / f S3 |<2; the focal length of the seventh lens is f G7 , f G7 and f S3 The ratio satisfies the relationship: 0.2<|f G7 / f S3 |<0.6; the focal length of the eighth lens is f G8 , f G8 and f S3 The ratio satisfies the relationship: 0.5<|f G8 / f S3 |<1; the focal length of the ninth lens is f G9 , f G9 and f S3 The ratio satisfies the relationship: 0.4<|f G9 / f S3|<0.9; the focal length of the tenth lens is f G10 , f G10 and f S3 The ratio satisfies the relationship: 0.4<|f G10 / f S3 |<0.9; the focal length of the eleventh lens is f G11 , f G11 and f S3 The ratio satisfies the relationship: 0.8<|f G11 / f S3 |<1.8.
[0012] Preferably, the fourth lens is a meniscus lens, a cemented lens or a split lens.
[0013] Preferably, the fifth lens is configured as a meniscus lens, a cemented lens or a split lens.
[0014] Preferably, the ratio of the half image height y' of the optical system to the focal length f of the optical system satisfies the relationship: |y' / f|<0.75.
[0015] In order to achieve the above another object, the present invention discloses a camera, comprising the above high-resolution fixed-focus lens.
[0016] Compared with the prior art, the structure of the front lens group of the high-resolution fixed-focus lens of the present invention has a better correction effect on the distortion of the optical system, while the structure of the middle lens group can better correct the field curvature of the optical system, and the rear focusing group acts as a floating focusing group, so that the present invention can clearly image at long and short distances. By setting the above lens structure, the high-resolution fixed-focus lens of the present invention is conducive to matching cameras with larger target surfaces and higher resolutions. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 Schematic diagram of the structure of the optical system in Example 1 of the present invention.
[0018] Figure 2 This is the MTF diagram of the optical system in Example 1 of the present invention.
[0019] Figure 3 3 is a distortion diagram of the optical system in Example 1 of the present invention.
[0020] Figure 4 Schematic diagram of the structure of the optical system in Example 2 of the present invention.
[0021] Figure 5 This is the MTF diagram of the optical system in Example 2 of the present invention.
[0022] Figure 6 This is a distortion diagram of the optical system in Example 2 of the present invention. DETAILED DESCRIPTION
[0023] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.
[0024] like Figure 1 and Figure 4 As shown, the present invention discloses a high-resolution fixed-focus lens, including a mechanical device and an optical system installed inside the mechanical device, wherein the optical system is provided with a front lens group S1, a middle lens group S2, an aperture and a rear focusing group S3 in sequence from the image side to the object side.
[0025] The front lens group S1 includes a first lens G1 with positive power and a meniscus structure, a second lens G2 with negative power and a meniscus structure, and a third lens G3 with negative power and a biconcave structure. The structure of the front lens group S1 enables the distortion of the optical system to be better corrected.
[0026] The middle lens group S2 includes a fourth lens G4 with positive refractive power and a fifth lens G5 with positive refractive power. The structure of the middle lens group S2 enables the field curvature of the optical system to be well corrected.
[0027] The rear focusing group S3 includes a sixth lens G6 with positive focal power, a seventh lens G7 with negative focal power and a biconcave structure, an eighth lens G8 with positive focal power and a biconvex structure, a ninth lens G9 with positive focal power and a meniscus structure, a tenth lens G10 with negative focal power and a meniscus structure, and an eleventh lens G11 with positive focal power and a biconvex structure, wherein the seventh lens G7 and the eighth lens G8 form a first cemented lens U1, and the ninth lens G9 and the tenth lens G10 form a second cemented lens U2. The rear focusing group S3 is used for floating focus during long-distance and short-distance imaging, so that the high-resolution lens of the present invention can have better performance during long-distance and short-distance imaging, and the imaging is clearer.
[0028] By configuring the lens structure as described above, the high-resolution fixed-focus lens of the present invention is advantageous for matching cameras with larger target surfaces and higher resolutions.
[0029] Specifically, the focal length of the optical system is f; the combined focal length of the front lens group is f S1 , f S1 The ratio of f satisfies the relationship: 0.8<|f S1 / f|<1.8. The combined focal length of the middle lens group is f S2 , f S2 The ratio of f satisfies the relationship: 1<|f S2 / f|<2. The combined focal length of the rear focusing group is f S3 , f S3 The ratio of f satisfies the relationship: 1.25<|fS3 / f|<2.25.
[0030] More specifically, the focal length of the first lens is f G1 , f G1 and f S1 The ratio satisfies the relationship: 3<|f G1 / f S1 |<4.5. The focal length of the second lens is f G2 , f G2 and f S1 The ratio satisfies the relationship: 1<|f G2 / f S1 |<2.5. The focal length of the third lens is f G3 , f G3 and f S1 The ratio satisfies the relationship: 0.8<|f G3 / f S1 |<1.8.
[0031] More specifically, the focal length of the sixth lens is f G6 , f G6 and f S3 The ratio satisfies the relationship: 1<|f G6 / f S3 |<2. The focal length of the seventh lens is f G7 , f G7 and f S3 The ratio satisfies the relationship: 0.2<|f G7 / f S3 |<0.6. The focal length of the eighth lens is f G8 , f G8 and f S3 The ratio satisfies the relationship: 0.5<|f G8 / f S3 |<1. The focal length of the ninth lens is f G9 , f G9 and f S3 The ratio satisfies the relationship: 0.4<|f G9 / f S3 |<0.9. The focal length of the tenth lens is f G10 , f G10 and f S3 The ratio satisfies the relationship: 0.4<|f G10 / f S3 |<0.9. The focal length of the eleventh lens is f G11 , f G11 and f S3 The ratio satisfies the relationship: 0.8<|f G11 / f S3 |<1.8.
[0032] exist Figure 1 In the specific example of , the fourth lens is a meniscus structure; Figure 4 In the specific example, the fourth lens is a cemented lens; in addition, the fourth lens can also be a split lens. The invention does not limit the specific form of the fourth lens. The cemented lens can not only correct the field curvature of the optical system, but also balance the chromatic aberration.
[0033] exist Figure 1 and Figure 4 In the specific example, the fifth lens is a meniscus structure, but is not limited thereto. For example, the fifth lens may also be a cemented lens or a split lens.
[0034] Specifically, the ratio of the half-image height y' of the optical system to the focal length f of the optical system satisfies the relationship: |y' / f|<0.75.
[0035] refer to Figures 1 to 3 ,exist Figure 1 In the specific example, the specific data of the optical system are as follows:
[0036] surface Radius(mm) Thickness(mm) Refractive Index G1 front surface 29.38 7.34 1.85 G1 rear surface 70.85 0.10 G2 front surface 19.52 1.20 1.90 G2 rear surface 11.06 6.46 G3 front surface -194.00 1.20 1.90 G3 rear surface 15.36 16.20 G4 front surface 119.55 3.07 1.65 G4 rear surface -25.09 0.10 G5 front surface 14.80 5.41 1.90 G5 rear surface 18.76 5.07 Aperture flat (variable) G6 front surface -79.11 1.50 1.75 G6 rear surface -19.35 1.81 U1 front surface -10.43 1.20 1.85 First bonding surface 23.06 2.75 1.75 U1 rear surface -17.62 0.10 U2 front surface -261.77 4.17 1.75 Second bonding surface -8.45 1.20 1.85 U2 rear surface -40.07 1.39 G11 front surface 30.41 3.29 1.90 G11 rear surface -86.53 (variable) Image plane flat
[0037] In the above table, the sixth lens G6 is a meniscus structure, the cemented surface of the first cemented lens U1 composed of the seventh lens G7 and the eighth lens G8 is the first cemented surface, and the cemented surface of the second cemented lens U2 composed of the ninth lens G9 and the tenth lens G10 is the second cemented surface.
[0038] refer to Figure 1 From the above table, it can be obtained that when the focal length f is 12mm, the combined focal length f of the front lens group S1 is S1 is -14.60mm, satisfying the relationship: 0.8<(|f S1 / f|=1.22)<1.8; the combined focal length of the middle lens group S2 is f S2 is 17.65 mm, satisfying the relationship: 1<(|f S2 / f|=1.47)<2; the combined focal length f of the rear focusing group S3 S3 is 22.62 mm, satisfying the relationship: 1.25<(|f S3 / f|=1.88)<2.25.
[0039] Continue to refer Figure 1 From the above table, we can get that the focal length f of the first lens G1 of the front lens group S1 is G1 is 54.29 mm, satisfying the relationship: 3<(|f G1 / f S1 |=3.72)<4.5; the focal length f of the second lens G2 G2is -30.23mm, satisfying the relationship: 1<(|f G2 / f S1 |=2.07)<2.5; the focal length f of the third lens G3 G3 is -15.59mm, satisfying the relationship: 0.8<(|f G3 / f S1 |=1.07)<1.8.
[0040] Continue to refer Figure 1 From the above table, we can get that the focal length f of the sixth lens G6 of the rear focusing group S3 is G6 is 33.65 mm, satisfying the relationship: 1<(|f G6 / f S3 |=1.49)<2; the focal length f of the seventh lens G7 G7 is -8.23mm, satisfying the relationship: 0.2<(|f G7 / f S3 |=0.36)<0.6; the focal length f of the eighth lens G8 G8 is 13.65 mm, satisfying the relationship: 0.5<(|f G8 / f S3 |=0.60)<1; the focal length f of the ninth lens G9 G9 is 11.51 mm, satisfying the relationship: 0.4<(|f G9 / f S3 |=0.51)<0.9; the focal length f of the tenth lens G10 G10 is -12.74 mm, satisfying the relationship: 0.4<(|f G10 / f S3 |=0.56)<0.9; the focal length f of the eleventh lens G11 G11 is 25.06 mm, satisfying the relationship: 0.8<(|f G11 / f S3 |=1.11)<1.8.
[0041] refer to Figure 2 , Figure 2 for Figure 1 The MTF diagram of the optical system in the example shows that the highest resolution of the optical system can reach 200lp / mm, and the MTF value of the full field of view at 200lp / mm is >0.25.
[0042] refer to Figure 3 , Figure 3 for Figure 1 The distortion diagram of the optical system in the example shows that the maximum optical distortion of the optical system in the entire field of view is less than 1% and is negative distortion.
[0043] refer to Figures 4 to 6 , Figure 4The specific data of the optical system of the specific example are as follows:
[0044]
[0045]
[0046] In the above table, the G4 cementing surface is the cementing surface of the fourth lens G4 in a cemented form, the sixth lens G6 is a meniscus structure, the cementing surface of the first cemented lens U1 composed of the seventh lens G7 and the eighth lens G8 is the first cementing surface, and the cementing surface of the second cemented lens U2 composed of the ninth lens G9 and the tenth lens G10 is the second cementing surface.
[0047] refer to Figure 4 From the above table, it can be obtained that when the focal length f is 12mm, the combined focal length f of the front lens group S1 is S1 is -15.55mm, satisfying the relationship: 0.8<(|f S1 / f|=1.29)<1.8; the combined focal length of the middle lens group S2 is f S2 is 17.45 mm, satisfying the relationship: 1<(|f S2 / f|=1.45)<2; the combined focal length f of the rear focusing group S3 S3 is 20.63 mm, satisfying the relationship: 1.25<(|f S3 / f|=1.72)<2.25.
[0048] Continue to refer Figure 4 From the above table, we can get that the focal length f of the first lens G1 of the front lens group S1 is G1 is 56.30 mm, satisfying the relationship: 3<(|f G1 / f S1 |=3.62)<4.5; the focal length f of the second lens G2 G2 is -26.66mm, satisfying the relationship: 1<(|f G2 / f S1 |=1.71)<2.5; the focal length f of the third lens G3 G3 is -20.09 mm, satisfying the relationship: 0.8<(|f G3 / f S1 |=1.29)<1.8.
[0049] Continue to refer Figure 4 From the above table, we can get that the focal length f of the sixth lens G6 of the rear focusing group S3 is G6 =29.79mm, satisfying the relationship: 1<(|f G6 / f S3 |=1.44)<2; the focal length f of the seventh lens G7 G7is -8.28mm, satisfying the relationship: 0.2<(|f G7 / f S3 |=0.40)<0.6; the focal length f of the eighth lens G8 G8 is 16.08 mm, satisfying the relationship: 0.5<(|f G8 / f S3 |=0.78)<1; the focal length f of the ninth lens G9 G9 is 11.95 mm, satisfying the relationship: 0.4<(|f G9 / f S3 |=0.58)<0.9; the focal length f of the tenth lens G10 G10 is -13.03mm, satisfying the relationship: 0.4<(|f G10 / f S3 |=0.63)<0.9; the focal length f of the eleventh lens G11 G11 is 19.55 mm, satisfying the relationship: 0.8<(|f G11 / f S3 |=0.95)<1.8.
[0050] refer to Figure 5 , Figure 5 for Figure 4 In the specific example of the MTF diagram of the optical system, the highest resolution of the optical system can reach 200lp / mm, and the MTF value of the full field of view at 200lp / mm is >0.25.
[0051] refer to Figure 6 , Figure 6 for Figure 4 In the distortion diagram of the optical system in the specific example, the maximum optical distortion of the optical system over the entire field of view is less than 1% and is negative distortion.
[0052] In summary, the optical system of a high-resolution fixed-focus lens with a focal length f of 12 mm is realized through the above structure, the maximum aperture is F2.8, the half image height y' is 8.8 mm, the maximum imaging surface is φ17.6 mm, and it can match a 2.5 μm pixel chip, a maximum target surface size of 1.1 inches, and a camera with a pixel of 20 million pixels. The highest resolution can reach 200lp / mm, the MTF value of the full field of view at 200lp / mm is greater than 0.25, and the maximum optical distortion of the full field of view is less than 1%, so that the high-resolution fixed-focus lens of the present invention has good imaging performance such as high resolution, low distortion, and clear imaging at long and short distances.
[0053] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.
Claims
1. A high-resolution fixed-focus lens, characterized in that: It comprises a mechanical device and an optical system installed inside the mechanical device, wherein the optical system is provided with a front lens group, a middle lens group, an aperture and a rear focusing group in sequence from the object side to the image side; The front lens group includes a first lens with positive optical power and a meniscus structure, a second lens with negative optical power and a meniscus structure, and a third lens with negative optical power and a biconcave structure, wherein the first lens, the second lens and the third lens are arranged in sequence from the object side to the image side; The middle lens group includes a fourth lens having positive power and a fifth lens having positive power, and the fourth lens and the fifth lens are arranged in sequence from the object side to the image side; The rear focusing group includes a sixth lens with positive power, a seventh lens with negative power and a biconcave structure, an eighth lens with positive power and a biconvex structure, a ninth lens with positive power and a meniscus structure, a tenth lens with negative power and a meniscus structure, and an eleventh lens with positive power and a biconvex structure, wherein the seventh lens and the eighth lens form a first cemented lens, and the ninth lens and the tenth lens form a second cemented lens; the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are arranged in sequence from the object side to the image side; The focal length of the optical system is f; The combined focal length of the front lens group is f S1 , f S1 The ratio of f satisfies the relationship: 0.8<|f S1 / f|<1.8; The combined focal length of the middle lens group is f S2 , f S2 The ratio of f satisfies the relationship: 1<|f S2 / f|<2; The combined focal length of the rear focusing group is f S3 , f S3 The ratio of f satisfies the relationship: 1.25<|f S3 / f|<2.25; The focal length of the first lens is f G1 , f G1 and f S1 The ratio satisfies the relationship: 3<|f G1 / f S1 |<4.5; The focal length of the second lens is f G2 , f G2 and f S1 The ratio satisfies the relationship: 1<|f G2 / f S1 |<2.5; The focal length of the third lens is f G3 , f G3 and f S1 The ratio satisfies the relationship: 0.8<|f G3 / f S1 |<1.8; The focal length of the sixth lens is f G6 , f G6 and f S3 The ratio satisfies the relationship: 1<|f G6 / f S3 |<2; The focal length of the seventh lens is f G7 , f G7 and f S3 The ratio satisfies the relationship: 0.2<|f G7 / f S3 |<0.6; The focal length of the eighth lens is f G8 , f G8 and f S3 The ratio satisfies the relationship: 0.5<|f G8 / f S3 |<1; The focal length of the ninth lens is f G9 , f G9 and f S3 The ratio satisfies the relationship: 0.4<|f G9 / f S3 |<0.9; The focal length of the tenth lens is f G10 , f G10 and f S3 The ratio satisfies the relationship: 0.4<|f G10 / f S3 |<0.9; The focal length of the eleventh lens is f G11 , f G11 and f S3 The ratio satisfies the relationship: 0.8<|f G11 / f S3 |<1.8; The ratio of the half image height y' of the optical system to the focal length f of the optical system satisfies the relationship: |y' / f|<0.
75.
2. The high-resolution fixed-focus lens according to claim 1, characterized in that: The fourth lens is a meniscus lens, a cemented lens or a split lens.
3. The high-resolution fixed-focus lens according to claim 1, characterized in that: The fifth lens is configured as a meniscus lens, a cemented lens or a split lens.
4. A camera, characterized in that: The invention comprises a high-resolution fixed-focus lens as claimed in any one of claims 1 to 3.
Citation Information
Patent Citations
High-resolution prime lens and camera
CN214151208U