Wide-angle fixed focus optical lens

Abstract

The application provides a wide-angle fixed-focus optical lens, which comprises, in sequence from the object side to the image side, a first meniscus positive lens, a second meniscus negative lens, a third meniscus negative lens, a fourth meniscus positive lens, a fifth meniscus negative lens, a sixth biconvex positive lens, a seventh biconvex positive lens, an eighth biconcave negative lens, a ninth biconvex positive lens and a tenth biconvex positive lens with the same central axis. The application can realize a 90*70 field of view angle, control the distortion within 6%, and adapt to a 768*576 resolution, 4.2 mu m pixel detector, wherein the central MTF is greater than 0.3 and the edge MTF is greater than 0.1 at 120 lp / mm, and the lens can stably work in a wide temperature environment of-40 DEG C to +60 DEG C, and has the advantages of a large field of view, low distortion and high resolution, solves the contradiction between the field of view and the distortion, temperature drift and imaging quality, and is suitable for scenes such as close-range monitoring and industrial defect detection.

Description

Technical Field

[0001] This invention relates to a fixed-focus optical lens, and more particularly to a wide-angle fixed-focus optical lens. Technical Background

[0002] Ultra-wide-angle fixed-focus lenses are widely used in security monitoring and machine vision. Currently, in the domestic and international ultra-wide-angle lens market, foreign suppliers such as Theia and Immervision occupy the high-end market with their low-distortion optical technology; while domestic companies such as Chang Gung Optics and Hongjing Optoelectronics have launched similar products. However, existing solutions generally suffer from a contradiction between field of view and distortion control: traditional ultra-wide-angle lenses often suffer from barrel distortion exceeding 15% in order to achieve a large field of view, resulting in insufficient edge imaging resolution and making it difficult to meet the high-precision requirements of industrial inspection and security scenarios. Summary of the Invention

[0003] In view of the problems mentioned above, this invention proposes a wide-angle fixed-focus optical lens, which features high resolution, ultra-wide angle, low distortion and large depth of field.

[0004] This invention is achieved through the following technical solution:

[0005] A wide-angle fixed-focus optical lens, comprising, from the object side to the image side, a first meniscus positive lens, a second meniscus negative lens, a third meniscus negative lens, a fourth meniscus positive lens, a fifth meniscus negative lens, a sixth biconvex positive lens, a seventh biconvex positive lens, an eighth biconcave negative lens, a ninth biconvex positive lens, and a tenth biconvex positive lens, all sharing the same central axis.

[0006] Furthermore, the first meniscus positive lens uses LAK9G15 glass, the second meniscus negative lens uses LF5G19 glass, the third meniscus negative lens and the fourth meniscus positive lens use H-ZF52 glass, the fifth meniscus negative lens uses H-LAK7A glass, the sixth biconvex positive lens uses H-ZF13 glass, the seventh biconvex positive lens and the ninth biconvex positive lens use H-LAK7A glass, the eighth biconcave negative lens uses H-ZF72A glass, and the tenth biconvex positive lens uses H-FK61 glass.

[0007] Furthermore, the focal length of the first meniscus lens The following conditions must be met:

[0008] .

[0009] Furthermore, the focal length of the second meniscus negative lens The following conditions must be met:

[0010] .

[0011] Furthermore, the focal length of the third meniscus negative lens The following conditions must be met:

[0012] .

[0013] Furthermore, the focal length of the fourth meniscus lens The following conditions must be met:

[0014] .

[0015] Furthermore, the focal length of the fifth meniscus negative lens The following conditions must be met:

[0016] .

[0017] Furthermore, the focal length of the sixth biconvex positive lens The following conditions must be met:

[0018] .

[0019] Furthermore, the focal length of the seventh biconvex positive lens The following conditions must be met:

[0020] .

[0021] Furthermore, the focal length of the eighth biconcave negative lens The following conditions must be met:

[0022] .

[0023] Furthermore, the focal length of the ninth biconvex positive lens The following conditions must be met:

[0024] .

[0025] Furthermore, the focal length of the tenth biconvex positive lens The following conditions must be met:

[0026] .

[0027] The wide-angle fixed-focus lens of the present invention can achieve the following beneficial results:

[0028] Wavelength used: 450-656nm;

[0029] Focal length: 1.56mm;

[0030] Imaging range: 0.15-0.6m, 0.5-5m;

[0031] Object field of view: ≥90°×70°;

[0032] Image-square MTF: ≥0.3@120lp / mm@center field of view, 90° field of view >0.1;

[0033] Distortion: ≤6%;

[0034] System transmittance: >90%;

[0035] RMS wavefront error: <0.1λ.

[0036] This invention presents a wide-angle fixed-focus optical lens based on the principle of refractive optical imaging. Through a combination of multiple lens elements, it achieves effective collection and correction of light across a large field of view. The lens employs a large-aperture negative meniscus lens at the front to receive large-angle incident light, which, in conjunction with subsequent multiple spherical / aspherical lenses, collaboratively corrects astigmatism, chromatic aberration, and distortion, ultimately converging the light onto the detector target surface for clear imaging. This invention achieves a 90°×70° field of view while controlling distortion to within 6%. The lens is compatible with detectors with a resolution of 768×576 pixels and a pixel size of 4.2μm. At 120lp / mm, the center MTF is greater than 0.3 and the edge MTF is greater than 0.1. It can operate stably in a wide temperature range of -40℃ to +60℃, balancing a large field of view, low distortion, and high resolution. This effectively resolves the contradictions between field of view and distortion, and temperature drift and image quality in existing technologies, making it suitable for scenarios such as close-range monitoring and industrial defect detection. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of the wide-angle fixed-focus optical lens of the present invention;

[0039] Figure 2 This is the MTF curve diagram of Embodiment 2 of the present invention;

[0040] Figure 3 This is a graph showing the RMS wavefront difference as a function of the field of view in Embodiment 2 of the present invention.

[0041] Figure 4 This is a distortion curve diagram of Embodiment 3 of the present invention;

[0042] Figure 5 This is a relative illumination diagram of Embodiment 3 of the present invention;

[0043] Figure 6 This is a graph showing the RMS wavefront difference versus wavelength in Embodiment 4 of the present invention.

[0044] Figure 7 This is a vertical color difference curve diagram of Embodiment 4 of the present invention;

[0045] Figure 8 This is the distortion curve of Embodiment 4 of the present invention;

[0046] Figure 9 This is a relative illumination diagram of Embodiment 4 of the present invention;

[0047] Figure 10 This is the thermal analysis MTF curve of Example 4 of the present invention at 22°C;

[0048] Figure 11 This is the MTF curve of thermal analysis at -40℃ in Example 4 of the present invention;

[0049] Figure 12 This is the thermal analysis MTF curve of Embodiment 4 of the present invention at 60°C.

[0050] The reference numerals in the diagram are: 1st positive meniscus lens, 2nd negative meniscus lens, 3rd negative meniscus lens, 4th positive meniscus lens, 5th negative meniscus lens, 6th biconvex positive lens, 7th biconvex positive lens, 8th biconcave negative lens, 9th biconvex positive lens, and 10th biconvex positive lens. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Example 1

[0053] See Figure 1 A wide-angle fixed-focus optical lens, comprising, from the object side to the image side, a first meniscus positive lens 1, a second meniscus negative lens 2, a third meniscus negative lens 3, a fourth meniscus positive lens 4, a fifth meniscus negative lens 5, a sixth biconvex positive lens 6, a seventh biconvex positive lens 7, an eighth biconcave negative lens 8, a ninth biconvex positive lens 9, and a tenth biconvex positive lens 10, all sharing the same central axis.

[0054] The first meniscus positive lens 1 is made of LAK9G15 glass, the second meniscus negative lens 2 is made of LF5G19 glass, the third meniscus negative lens 3 and the fourth meniscus positive lens 4 are made of H-ZF52 glass, the fifth meniscus negative lens 5 is made of H-LAK7A glass, the sixth biconvex positive lens 6 is made of H-ZF13 glass, the seventh biconvex positive lens 7 and the ninth biconvex positive lens 9 are made of H-LAK7A glass, the eighth biconcave negative lens 8 is made of H-ZF72A glass, and the tenth biconvex positive lens 10 is made of H-FK61 glass.

[0055] In this embodiment, the focal length of the first meniscus lens 1 is... The following conditions must be met:

[0056] .

[0057] In this embodiment, the focal length of the second meniscus negative lens 2 The following conditions must be met:

[0058] .

[0059] In this embodiment, the focal length of the third meniscus negative lens 3 The following conditions must be met:

[0060] .

[0061] In this embodiment, the focal length of the fourth meniscus lens 4 The following conditions must be met:

[0062] .

[0063] In this embodiment, the focal length of the fifth meniscus negative lens 5 The following conditions must be met:

[0064] .

[0065] In this embodiment, the focal length of the sixth biconvex positive lens 6 The following conditions must be met:

[0066] .

[0067] In this embodiment, the focal length of the seventh biconvex positive lens 7 The following conditions must be met:

[0068] .

[0069] In this embodiment, the focal length of the eighth biconcave negative lens 8 The following conditions must be met:

[0070] .

[0071] In this embodiment, the focal length of the ninth biconvex positive lens 9 The following conditions must be met:

[0072] .

[0073] In this embodiment, the focal length of the tenth biconvex positive lens 10 is... The following conditions must be met:

[0074] .

[0075] The wide-angle fixed-focus lens of the present invention can achieve the following beneficial results:

[0076] Wavelength used: 450-656nm;

[0077] Focal length: 1.56mm;

[0078] Imaging range: 0.15-0.6m, 0.5-5m;

[0079] Object field of view: ≥90°×70°;

[0080] Image-square MTF: ≥0.3@120lp / mm@center field of view, 90° field of view >0.1;

[0081] Distortion: ≤6%;

[0082] System transmittance: >90%;

[0083] RMS wavefront error: <0.1λ.

[0084] This invention presents a wide-angle fixed-focus optical lens based on the principle of refractive optical imaging. Through a combination of multiple lens elements, it achieves effective collection and correction of light across a large field of view. The lens employs a large-aperture negative meniscus lens at the front to receive large-angle incident light, which, in conjunction with subsequent multiple spherical / aspherical lenses, collaboratively corrects astigmatism, chromatic aberration, and distortion, ultimately converging the light onto the detector target surface for clear imaging. This invention achieves a 90°×70° field of view while controlling distortion to within 6%. The lens is compatible with detectors with a resolution of 768×576 pixels and a pixel size of 4.2μm. At 120lp / mm, the center MTF is greater than 0.3 and the edge MTF is greater than 0.1. It can operate stably in a wide temperature range of -40℃ to +60℃, balancing a large field of view, low distortion, and high resolution. This effectively resolves the contradictions between field of view and distortion, and temperature drift and image quality in existing technologies, making it suitable for scenarios such as close-range monitoring and industrial defect detection.

[0085] Example 2

[0086] See Figure 1 A wide-angle fixed-focus optical lens, comprising, from the object side to the image side, a first meniscus positive lens 1, a second meniscus negative lens 2, a third meniscus negative lens 3, a fourth meniscus positive lens 4, a fifth meniscus negative lens 5, a sixth biconvex positive lens 6, a seventh biconvex positive lens 7, an eighth biconcave negative lens 8, a ninth biconvex positive lens 9, and a tenth biconvex positive lens 10, all sharing the same central axis.

[0087] The first meniscus positive lens 1 is made of LAK9G15 glass, the second meniscus negative lens 2 is made of LF5G19 glass, the third meniscus negative lens 3 and the fourth meniscus positive lens 4 are made of H-ZF52 glass, the fifth meniscus negative lens 5 is made of H-LAK7A glass, the sixth biconvex positive lens 6 is made of H-ZF13 glass, the seventh biconvex positive lens 7 and the ninth biconvex positive lens 9 are made of H-LAK7A glass, the eighth biconcave negative lens 8 is made of H-ZF72A glass, and the tenth biconvex positive lens 10 is made of H-FK61 glass.

[0088] In this embodiment, the focal length of the first meniscus lens 1 The following conditions must be met:

[0089] .

[0090] In this embodiment, the focal length of the second meniscus negative lens 2 The following conditions must be met:

[0091] .

[0092] In this embodiment, the focal length of the third meniscus negative lens 3 The following conditions must be met:

[0093] .

[0094] In this embodiment, the focal length of the fourth meniscus lens 4 The following conditions must be met:

[0095] .

[0096] In this embodiment, the focal length of the fifth meniscus negative lens 5 The following conditions must be met:

[0097] .

[0098] In this embodiment, the focal length of the sixth biconvex positive lens 6 The following conditions must be met:

[0099] .

[0100] In this embodiment, the focal length of the seventh biconvex positive lens 7 The following conditions must be met:

[0101] .

[0102] In this embodiment, the focal length of the eighth biconcave negative lens The following conditions must be met:

[0103] .

[0104] In this embodiment, the focal length of the ninth biconvex positive lens 9 The following conditions must be met:

[0105] .

[0106] In this embodiment, the focal length of the tenth biconvex positive lens 10 is... The following conditions must be met:

[0107] .

[0108] The lens distribution and detailed parameters of this embodiment are shown in Table 1.

[0109] Table 1. Lens distribution and detailed parameters in Example 2

[0110] The wide-angle lens of this embodiment can achieve the following technical specifications:

[0111] Wavelength used: 450-656nm;

[0112] Focal length: 1.56mm;

[0113] Imaging range: 0.15-0.6m, 0.5-5m;

[0114] Object field of view: ≥90°×70°;

[0115] Image-square MTF: ≥0.3@120lp / mm@center field of view, 90° field of view >0.1, such as Figure 2 As shown;

[0116] Distortion: ≤6%;

[0117] System transmittance: >90%;

[0118] RMS wavefront error: <0.1λ, varying with field of view as follows: Figure 3 As shown.

[0119] Example 3

[0120] See Figure 1 A wide-angle fixed-focus optical lens, comprising, from the object side to the image side, a first meniscus positive lens 1, a second meniscus negative lens 2, a third meniscus negative lens 3, a fourth meniscus positive lens 4, a fifth meniscus negative lens 5, a sixth biconvex positive lens 6, a seventh biconvex positive lens 7, an eighth biconcave negative lens 8, a ninth biconvex positive lens 9, and a tenth biconvex positive lens 10, all sharing the same central axis.

[0121] The first meniscus positive lens 1 is made of LAK9G15 glass, the second meniscus negative lens 2 is made of LF5G19 glass, the third meniscus negative lens 3 and the fourth meniscus positive lens 4 are made of H-ZF52 glass, the fifth meniscus negative lens 5 is made of H-LAK7A glass, the sixth biconvex positive lens 6 is made of H-ZF13 glass, the seventh biconvex positive lens 7 and the ninth biconvex positive lens 9 are made of H-LAK7A glass, the eighth biconcave negative lens 8 is made of H-ZF72A glass, and the tenth biconvex positive lens 10 is made of H-FK61 glass.

[0122] In this embodiment, the focal length of the first meniscus lens 1 The following conditions must be met:

[0123] .

[0124] In this embodiment, the focal length of the second meniscus negative lens 2 The following conditions must be met:

[0125] .

[0126] In this embodiment, the focal length of the third meniscus negative lens 3 The following conditions must be met:

[0127] .

[0128] In this embodiment, the focal length of the fourth meniscus lens 4 The following conditions must be met:

[0129] .

[0130] In this embodiment, the focal length of the fifth meniscus negative lens 5 The following conditions must be met:

[0131] .

[0132] In this embodiment, the focal length of the sixth biconvex positive lens 6 The following conditions must be met:

[0133] .

[0134] In this embodiment, the focal length of the seventh biconvex positive lens 7 The following conditions must be met:

[0135] .

[0136] In this embodiment, the focal length of the eighth biconcave negative lens 8 The following conditions must be met:

[0137] .

[0138] In this embodiment, the focal length of the ninth biconvex positive lens 9 The following conditions must be met:

[0139] .

[0140] In this embodiment, the focal length of the tenth biconvex positive lens 10 is... The following conditions must be met:

[0141] .

[0142] The lens distribution and detailed parameters of this embodiment are shown in Table 2.

[0143] Table 2. Lens distribution and detailed parameters in Example 3

[0144] The wide-angle lens of this embodiment can achieve the following technical specifications:

[0145] Wavelength used: 450-656nm;

[0146] Focal length: 1.29mm;

[0147] Imaging range: 0.15-0.6m, 0.5-5m;

[0148] Object field of view: ≥90°×70°;

[0149] Image-square MTF: ≥0.3@120lp / mm@center field of view, 90° field of view >0.1;

[0150] Distortion: ≤6%, such as Figure 4 As shown;

[0151] System transmittance: >90%;

[0152] RMS wavefront error: <0.1λ;

[0153] Relative illumination: Full field of view > 0.8, such as Figure 5 As shown.

[0154] Example 4

[0155] See Figure 1 A wide-angle fixed-focus optical lens, comprising, from the object side to the image side, a first meniscus positive lens 1, a second meniscus negative lens 2, a third meniscus negative lens 3, a fourth meniscus positive lens 4, a fifth meniscus negative lens 5, a sixth biconvex positive lens 6, a seventh biconvex positive lens 7, an eighth biconcave negative lens 8, a ninth biconvex positive lens 9, and a tenth biconvex positive lens 10, all sharing the same central axis.

[0156] The first meniscus positive lens 1 is made of LAK9G15 glass, the second meniscus negative lens 2 is made of LF5G19 glass, the third meniscus negative lens 3 and the fourth meniscus positive lens 4 are made of H-ZF52 glass, the fifth meniscus negative lens 5 is made of H-LAK7A glass, the sixth biconvex positive lens 6 is made of H-ZF13 glass, the seventh biconvex positive lens 7 and the ninth biconvex positive lens 9 are made of H-LAK7A glass, the eighth biconcave negative lens 8 is made of H-ZF72A glass, and the tenth biconvex positive lens 10 is made of H-FK61 glass.

[0157] In this embodiment, the focal length of the first meniscus lens 1 The following conditions must be met:

[0158] .

[0159] In this embodiment, the focal length of the second meniscus negative lens 2 The following conditions must be met:

[0160] .

[0161] In this embodiment, the focal length of the third meniscus negative lens 3 The following conditions must be met:

[0162] .

[0163] In this embodiment, the focal length of the fourth meniscus lens 4 The following conditions must be met:

[0164] .

[0165] In this embodiment, the focal length of the fifth meniscus negative lens 5 The following conditions must be met:

[0166] .

[0167] In this embodiment, the focal length of the sixth biconvex positive lens 6 The following conditions must be met:

[0168] .

[0169] In this embodiment, the focal length of the seventh biconvex positive lens 7 The following conditions must be met:

[0170] .

[0171] In this embodiment, the focal length of the eighth biconcave negative lens 8 The following conditions must be met:

[0172] .

[0173] In this embodiment, the focal length of the ninth biconvex positive lens 9 The following conditions must be met:

[0174] .

[0175] In this embodiment, the focal length of the tenth biconvex positive lens 10 is... The following conditions must be met:

[0176] .

[0177] The lens distribution and detailed parameters of this embodiment are shown in Table 3.

[0178] Table 3. Lens distribution and detailed parameters in Example 4

[0179] The wide-angle lens of this embodiment can achieve the following technical specifications;

[0180] Wavelength used: 450-656nm;

[0181] Focal length: 1.29mm;

[0182] Imaging range: 0.15-0.6m, 0.5-5m;

[0183] Object field of view: ≥90°×70°;

[0184] RMS wavefront error: <0.1λ, varying with wavelength as follows: Figure 6 As shown;

[0185] Chromatic aberration across the vertical axis: <2.5µm across the entire field of view, such as... Figure 7 As shown;

[0186] Distortion: ≤6%, such as Figure 8 As shown;

[0187] Relative illumination: Full field of view > 0.8, such as Figure 9 As shown;

[0188] Image-based MTF: MTF curves at different temperatures (22℃, -40℃, and 60℃) all meet the following requirements: ≥0.3@120lp / mm@center field of view, and greater than 0.1 at 90° field of view. Figure 10 , 11 As shown in Figures 1 and 12.

[0189] The above embodiments are not intended to limit this application in any way. Although the preferred embodiments are disclosed above, they are not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A wide-angle fixed-focus optical lens, characterized in that: From the object side to the image side, the lenses are arranged in sequence along the same central axis: a first meniscus positive lens, a second meniscus negative lens, a third meniscus negative lens, a fourth meniscus positive lens, a fifth meniscus negative lens, a sixth biconvex positive lens, a seventh biconvex positive lens, an eighth biconcave negative lens, a ninth biconvex positive lens, and a tenth biconvex positive lens.

2. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The first meniscus positive lens is made of LAK9G15 glass, the second meniscus negative lens is made of LF5G19 glass, the third meniscus negative lens and the fourth meniscus positive lens are made of H-ZF52 glass, the fifth meniscus negative lens is made of H-LAK7A glass, the sixth biconvex positive lens is made of H-ZF13 glass, the seventh biconvex positive lens and the ninth biconvex positive lens are made of H-LAK7A glass, the eighth biconcave negative lens is made of H-ZF72A glass, and the tenth biconvex positive lens is made of H-FK61 glass.

3. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The focal length of the first meniscus lens The following conditions must be met: 。 4. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The focal length of the second meniscus negative lens The following conditions must be met: 。 5. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The focal length of the third meniscus negative lens The following conditions must be met: 。 6. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The focal length of the fourth meniscus lens The following conditions must be met: 。 7. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The focal length of the fifth meniscus negative lens The following conditions must be met: 。 8. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The focal length of the sixth biconvex positive lens The following conditions must be met: ； The focal length of the seventh biconvex positive lens The following conditions must be met: 。 9. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The focal length of the eighth biconcave negative lens The following conditions must be met: 。 10. The wide-angle fixed-focus optical lens as described in claim 1, characterized in that: The focal length of the ninth biconvex positive lens The following conditions must be met: ； The focal length of the tenth biconvex positive lens The following conditions must be met: 。

Images