Optical lens
By combining the specific optical power and surface shape of the five lenses, the problems of insufficient confocality and imaging quality during the day and night in complex environments are solved, achieving high-definition, large aperture, miniaturization and low-cost imaging effects.
Patent Information
- Application Number
- CN202510645447.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-20
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2045-05-20
AI Technical Summary
Existing lenses have difficulty achieving day and night focus in environments with large temperature differences between high and low temperatures, and the imaging quality is insufficient to meet the needs of shooting during the day and at night.
Design an optical lens with five lenses, using a specific combination of optical power and surface shape, including a combination of lenses with positive and negative optical power, a reasonable distribution of optical power and lens thickness, the use of aspheric lenses to reduce aberrations, and equipped with apertures and filters to control the amount of light and filter out interfering light.
It achieves confocality during the day and night, and has high-definition, large aperture, miniaturization and low-cost imaging effects, and can maintain good imaging quality in complex environments.
Smart Images
Figure CN120195848B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND
[0002] Due to the difference of application environment, the performance requirements of consumers for lenses are not the same, but the overall requirements are getting higher and higher. In some application scenarios with complex environment, not only is it required that the lens can not be defocused under the condition of large temperature difference between high and low temperature, but also it is required that the shooting demand can be met in both day and night. Therefore, the lens nowadays is developing towards the direction of lower cost, high definition, small size and day and night co-focusing, and accordingly, the day and night co-focusing lens with new architecture becomes an object to be developed. SUMMARY
[0003] In view of the above problems, the purpose of the present application is to provide an optical lens with the advantages of day and night co-focusing and excellent imaging quality.
[0004] The present application provides an optical lens, which has five lenses, and sequentially comprises, along the optical axis from the object side to the imaging surface:
[0005] a first lens with positive refractive power, the image side surface of which is a convex surface;
[0006] a second lens with negative refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;
[0007] a third lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface;
[0008] a fourth lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface;
[0009] a fifth lens with negative refractive power, the image side surface of which is a concave surface near the optical axis;
[0010] wherein the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.1 < f1 / f < 1.4.
[0011] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -6.8 < f5 / f < -0.75.
[0012] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.5 < f3 / f < 0.81.
[0013] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.45 < TTL / f < 1.5.
[0014] It is further preferred that the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens and the real image height IH corresponding to the maximum field angle FOV of the optical lens satisfy: 49° < (f x FOV) / IH < 50°.
[0015] It is further preferred that the object side surface radius of curvature R5 of the third lens and the image side surface radius of curvature R6 of the third lens satisfy: 0.5 < (R5 + R6) / (R5 - R6) < 0.8.
[0016] It is further preferred that the Abbe number Vd1 of the first lens, the Abbe number Vd2 of the second lens, the Abbe number Vd3 of the third lens and the Abbe number Vd4 of the fourth lens satisfy: 54 < Vd1 < 58, 18 < Vd2 < 25, 54 < Vd3 < 58, 19 < Vd4 < 25; the refractive index Nd1 of the first lens, the refractive index Nd2 of the second lens, the refractive index Nd3 of the third lens and the refractive index Nd4 of the fourth lens satisfy: 1.52 < Nd1 < 1.56, 1.62 < Nd2 < 1.7, 1.5 < Nd3 < 1.56, 1.62 < Nd4 < 1.68.
[0017] It is further preferred that the Abbe number Vd5 of the fifth lens and the refractive index Nd5 of the fifth lens satisfy: 35 < Vd5 < 58, 1.52 < Nd5 < 1.58.
[0018] It is further preferred that the image side surface radius of curvature R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.35 < R10 / f < 0.65.
[0019] It is further preferred that the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -4.1 < f2 / f3 < -1.6.
[0020] The optical lens provided by the application adopts five lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of large aperture, miniaturization, low cost and the like while realizing good day and night confocal effect. BRIEF DESCRIPTION OF DRAWINGS
[0021] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:
[0022] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.
[0023] Figure 2MTF curve of the optical lens in Embodiment 1 at a wavelength of 470nm to 650nm.
[0024] Figure 3 MTF curve of the optical lens in Embodiment 1 at a wavelength of 850nm.
[0025] Figure 4 Through-focus curve of the optical lens in Embodiment 1 at a wavelength of 470nm to 650nm.
[0026] Figure 5 Through-focus curve of the optical lens in Embodiment 1 at a wavelength of 850nm.
[0027] Figure 6 Distortion curve of the optical lens in Embodiment 1.
[0028] Figure 7 Astigmatism curve of the optical lens in Embodiment 1.
[0029] Figure 8 Lateral chromatic aberration curve of the optical lens in Embodiment 1.
[0030] Figure 9 Axial chromatic aberration curve of the optical lens in Embodiment 1.
[0031] Figure 10 Structure diagram of the optical lens in Embodiment 2.
[0032] Figure 11 MTF curve of the optical lens in Embodiment 2 at a wavelength of 470nm to 650nm.
[0033] Figure 12 MTF curve of the optical lens in Embodiment 2 at a wavelength of 850nm.
[0034] Figure 13 Through-focus curve of the optical lens in Embodiment 2 at a wavelength of 470nm to 650nm.
[0035] Figure 14 Through-focus curve of the optical lens in Embodiment 2 at a wavelength of 850nm.
[0036] Figure 15 Distortion curve of the optical lens in Embodiment 2.
[0037] Figure 16 Astigmatism curve of the optical lens in Embodiment 2.
[0038] Figure 17A graph of the lateral chromatic aberration curve of the optical lens in Embodiment 2 of the present application.
[0039] Figure 18 A graph of the axial aberration curve of the optical lens in Embodiment 2 of the present application.
[0040] Figure 19 A schematic structural diagram of the optical lens in Embodiment 3 of the present application.
[0041] Figure 20 A graph of the MTF curve of the optical lens in Embodiment 3 of the present application at a wavelength of 470nm to 650nm.
[0042] Figure 21 A graph of the MTF curve of the optical lens in Embodiment 3 of the present application at a wavelength of 850nm.
[0043] Figure 22 A graph of the defocus curve of the optical lens in Embodiment 3 of the present application at a wavelength of 470nm to 650nm.
[0044] Figure 23 A graph of the defocus curve of the optical lens in Embodiment 3 of the present application at a wavelength of 850nm.
[0045] Figure 24 A graph of the distortion curve of the optical lens in Embodiment 3 of the present application.
[0046] Figure 25 A graph of the astigmatism curve of the optical lens in Embodiment 3 of the present application.
[0047] Figure 26 A graph of the lateral chromatic aberration curve of the optical lens in Embodiment 3 of the present application.
[0048] Figure 27 A graph of the axial aberration curve of the optical lens in Embodiment 3 of the present application.
[0049] Figure 28 A schematic structural diagram of the optical lens in Embodiment 4 of the present application.
[0050] Figure 29 A graph of the MTF curve of the optical lens in Embodiment 4 of the present application at a wavelength of 470nm to 650nm.
[0051] Figure 30 A graph of the MTF curve of the optical lens in Embodiment 4 of the present application at a wavelength of 850nm.
[0052] Figure 31 A graph of the defocus curve of the optical lens in Embodiment 4 of the present application at a wavelength of 470nm to 650nm.
[0053] Figure 32The defocus curve of the optical lens in Example 4 of the present application at a wavelength of 850 nm.
[0054] Figure 33 The distortion curve of the optical lens in Example 4 of the present application.
[0055] Figure 34 The astigmatism curve of the optical lens in Example 4 of the present application.
[0056] Figure 35 The lateral chromatic aberration curve of the optical lens in Example 4 of the present application.
[0057] Figure 36 The axial chromatic aberration curve of the optical lens in Example 4 of the present application.
[0058] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION
[0059] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that these detailed descriptions are only descriptions of embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.
[0060] It should be noted that, in the present specification, the expressions first, second, third, and the like are used only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as a second lens or a third lens without departing from the teachings of the present application.
[0061] In the drawings, the thickness, size, and shape of lenses have been slightly exaggerated for the sake of convenience in explanation. Specifically, the shape of a spherical surface or an aspherical surface shown in the drawings is shown by way of example. That is, the shape of a spherical surface or an aspherical surface is not limited to the shape of a spherical surface or an aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.
[0062] In the present specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.
[0063] It should also be understood that the words "comprise," "comprising," "include," "including," and / or "has," "having," when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Furthermore, when describing the embodiments of the present application, the word "may" is used to mean "one or more embodiments of the present application." Also, the word "exemplary" is used to mean "an example of' or "an example."
[0064] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an overly literal or overly formal sense unless expressly so defined herein.
[0065] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.
[0066] The optical lens provided by the embodiments of the present application is a day and night confocal lens, which can realize confocal of wavelengths of 470nm-650nm and 850nm, and the defocus amount is ≤2um. The optical lens of the present application includes five lenses in total along the optical axis from the object side to the imaging surface, including: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens.
[0067] In some embodiments, the first lens can have a positive focal power, the object side surface thereof can be a concave surface or a convex surface, and the image side surface thereof is a convex surface. The second lens can have a negative focal power, the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface. The third lens can have a positive focal power, the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface. The fourth lens can have a negative focal power, the object side surface thereof is a concave surface, and the image side surface thereof is a convex surface. The fifth lens can have a negative focal power, the object side surface thereof can be a concave surface or a convex surface, and the image side surface thereof is a concave surface at the near optical axis.
[0068] In some embodiments, the optical lens can further include a diaphragm, which can be located between the first lens and the second lens or between the second lens and the third lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging.
[0069] In some embodiments, the optical lens can further include a filter, which can be disposed between the fifth lens and the imaging surface. The filter is used to filter out interference light, preventing the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.
[0070] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.1 < f1 / f < 1.4. Satisfying the above condition, the first lens is moderately focused, which can balance the aberration contributions of the front group and the rear group, and avoid the deterioration of the image quality at the edge field of view.
[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -6.8 < f5 / f < -0.75. Satisfying the above condition, the optical power of the fifth lens is reasonably distributed, which is beneficial to correct the residual aberration generated by the front edge lens and improve the resolution.
[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.5 < f3 / f < 0.81. Satisfying the above condition, the third lens further converges the incident light at the front end, which is beneficial to correct the aberration and distortion at the edge field of view brought by the front lens group, so that the lens has smaller distortion and can provide high-definition imaging effect.
[0073] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.45 < TTL / f < 1.5. Satisfying the above condition, the length of the lens can be effectively limited, which is beneficial to realize the miniaturization of the optical lens.
[0074] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 49° < (f x FOV) / IH < 50°. Satisfying the above range, by reasonably limiting the relationship among the focal length, the field of view angle, and the image height of the optical lens, the optical lens has good optical performance and can well capture the details of the object.
[0075] In some embodiments, the object side surface radius of curvature R5 of the third lens and the image side surface radius of curvature R6 of the third lens satisfy: 0.5 < (R5+R6) / (R5-R6) < 0.8. Satisfying the above condition, the object side surface and the image side surface of the third lens at the near optical axis are reasonably controlled, which is beneficial to control the shape of the third lens, optimize the aberration balance of the lens group, and improve the imaging quality.
[0076] In some embodiments, the Abbe number Vd1 of the first lens, the Abbe number Vd2 of the second lens, the Abbe number Vd3 of the third lens, and the Abbe number Vd4 of the fourth lens satisfy: 54 < Vd1 < 58, 18 < Vd2 < 25, 54 < Vd3 < 58, and 19 < Vd4 < 25; the refractive index Nd1 of the first lens, the refractive index Nd2 of the second lens, the refractive index Nd3 of the third lens, and the refractive index Nd4 of the fourth lens satisfy: 1.52 < Nd1 < 1.56, 1.62 < Nd2 < 1.7, 1.5 < Nd3 < 1.56, and 1.62 < Nd4 < 1.68. By satisfying the above conditions, the low-Abbe-number lens and the high-Abbe-number lens are paired to offset the axial chromatic aberration, which is conducive to achieving infrared confocal.
[0077] In some embodiments, the Abbe number Vd5 of the fifth lens and the refractive index Nd5 of the fifth lens satisfy: 35 < Vd5 < 58 and 1.52 < Nd5 < 1.58. By satisfying the above conditions, the high-Abbe-number low-infrared-dispersion material is used in the last lens to reduce the 850 nm focal point shift and correct the infrared resolution.
[0078] In some embodiments, the image-side surface radius of curvature R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.35 < R10 / f < 0.65. By satisfying the above range, the image-side surface radius of curvature of the fifth lens is reasonably set, which is conducive to balancing the aberration generated by the front-end lens, collecting the light rays of the edge field of view, improving the imaging quality of the edge field of view, and increasing the imaging area of the optical lens.
[0079] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -4.1 < f2 / f3 < -1.6. By satisfying the above range, the optical power of the second lens and the third lens is reasonably distributed, which is conducive to the correction of chromatic aberration and the improvement of the resolution capability of the system.
[0080] In some embodiments, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.3 < IH / f < 1.4; and the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 1 < TTL / IH < 1.15. By satisfying the above conditions, the miniaturization of the lens can be better achieved, and meanwhile, the lens has a larger image surface under the condition of the same total length, which can match a larger imaging chip to achieve high-definition imaging.
[0081] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -2.1 < f2 / f < -1.3. By satisfying the above conditions, the negative lens of the second lens can adjust the chief ray angle and reduce the lens distortion.
[0082] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -3.5 < f4 / f < -1.2. By reasonably setting the focal length of the fourth lens, the light is smoothly transitioned, the correction of astigmatism and field curvature is facilitated, the imaging quality of the optical lens is improved, and the stability of the optical system is ensured.
[0083] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.9 < f1 / f2 < -0.65. By satisfying the above condition, the first lens and the second lens form chromatic aberration compensation, and the system length is compressed and the field curvature is balanced.
[0084] In some embodiments, the total length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis satisfy: 0.6 < ∑CT / TTL < 0.71. By satisfying the above condition, the total length of the optical lens can be effectively compressed, and the structural design and production process of the optical lens are facilitated.
[0085] In some embodiments, the optical lens satisfies the following conditions: 3.4 mm < f < 3.6 mm; 66° < FOV < 68°; 5.1 mm < TTL < 5.25 mm; 4.6 mm < IH < 4.8 mm; 1.95 < Fno < 2. In the above condition, f represents the effective focal length of the optical lens, FOV represents the maximum field of view of the optical lens, TTL represents the total optical length of the optical lens, IH represents the real image height corresponding to the maximum half field of view of the optical lens, and Fno represents the aperture value of the optical lens. By satisfying the above range, the optical lens has one or more advantages such as large aperture and miniaturization.
[0086] In some embodiments, the lens material in the optical lens provided by the present application can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass. The first lens, the second lens, the third lens, the fourth lens, and the fifth lens in the optical lens provided by the present application all adopt plastic lenses, thereby reducing the cost.
[0087] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving lens miniaturization. More specifically, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens in the present application can all adopt aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better achieving lens miniaturization.
[0088] In various embodiments of the present application, when the lens adopts an aspheric lens, the shape of each aspheric surface of the optical lens satisfies the following equation:
[0089] ;
[0090] wherein z is the distance of the curved surface from the vertex of the curved surface in the direction of the optical axis, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the quadratic surface coefficient, and B, C, D, E, F, G, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients, respectively.
[0091] The present application is further described in the following embodiments. In various embodiments, the thickness, the radius of curvature, and the material selection of each lens in the optical lens are different, and the specific differences can be found in the parameter table of each embodiment. The following embodiments are merely preferred embodiments of the present application, but the embodiments of the present application are not limited to the following embodiments only, and any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present application should be considered as equivalent replacement methods, and are included in the protection scope of the present application.
[0092] Embodiment 1
[0093] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens provided in Embodiment 1 of the present application. The optical lens includes, in order from the object side to the imaging surface along the optical axis, a first lens L1, a stop ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a filter G1.
[0094] The first lens L1 has positive focal power, the object side surface S1 thereof is a convex surface, and the image side surface S2 thereof is a convex surface.
[0095] The second lens L2 has negative focal power, the object side surface S3 thereof is a convex surface, and the image side surface S4 thereof is a concave surface.
[0096] The third lens L3 has positive focal power, the object side surface S5 thereof is a convex surface, and the image side surface S6 thereof is a convex surface.
[0097] The fourth lens L4 has negative focal power, the object side surface S7 thereof is a concave surface, and the image side surface S8 thereof is a convex surface.
[0098] The fifth lens L5 has negative focal power, the object side surface S9 thereof is a convex surface near the optical axis, and the image side surface S10 thereof is a concave surface near the optical axis.
[0099] The object side surface S11 and the image side surface S12 of the filter G1 are both flat surfaces.
[0100] The imaging surface S13 is a flat surface.
[0101] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are all plastic aspherical lenses.
[0102] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.
[0103] Table 1-1
[0104]
[0105] The surface parameters of the aspheric lens of the optical lens in Example 1 are shown in Table 1-2.
[0106] Table 1-2
[0107]
[0108] In this embodiment, the MTF curve diagram of the wavelength of 470nm to 650nm, the MTF curve diagram of the wavelength of 850nm, the defocus curve diagram of the wavelength of 470nm to 650nm, the defocus curve diagram of the wavelength of 850nm, the distortion curve diagram, the astigmatism curve diagram, the magnification chromatic aberration curve diagram, and the axial aberration curve diagram of the optical lens 100 are respectively as shown in FIG. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 shown.
[0109] Figure 2 The MTF (Modulation Transfer Function) curves for Example 1 at wavelengths from 470nm to 650nm are shown. These curves represent the degree of lens imaging modulation at different spatial frequencies across the field of view (FOV) from 470nm to 650nm. The horizontal axis represents spatial frequency (lp / mm), and the vertical axis represents MTF. As can be seen from the graph, the MTF values for this example are consistently above 0.4 across the entire FOV. Within the range of 0 to 180 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the FOV, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.
[0110] Figure 3The MTF curve of the optical lens 100 at a wavelength of 850 nm is shown in FIG. 6, which represents the modulation of the lens imaging at different spatial frequencies in each field of view at a wavelength of 850 nm, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the present embodiment is above 0.38 in the full field of view, and in the range of 0-180 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in the case of low frequency and high frequency.
[0111] Figure 4 The defocus curve of the optical lens 100 at a wavelength of 470 nm to 650 nm is shown in FIG. 7, which represents the modulation of the lens imaging when the spatial frequency is 92 lp / mm, the horizontal axis represents the defocus offset (unit: mm), and the vertical axis represents the OTF modulus. As can be seen from the figure, the OTF value of the center field of view at the focus point is greater than 80%, which indicates that the lens has good resolving power.
[0112] Figure 5 The defocus curve of the optical lens 100 at a wavelength of 850 nm is shown in FIG. 8, which represents the modulation of the lens imaging when the spatial frequency is 92 lp / mm, the horizontal axis represents the defocus offset (unit: mm), and the vertical axis represents the OTF modulus. As can be seen from the figure, the OTF value of the center field of view at the focus point is greater than 80%, which indicates that the lens has good resolving power.
[0113] Figure 6 The distortion curve of the optical lens 100 is shown in FIG. 9, which represents the distortion at different image heights on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the image height (unit: mm). As can be seen from the figure, the distortion of the optical lens is controlled within 0-1.5%, which indicates that the distortion of the optical lens 100 is well corrected.
[0114] Figure 7 The astigmatism curve of the optical lens 100 is shown in FIG. 10, which represents the astigmatism of the light rays on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the image height (unit: mm). As can be seen from the figure, the astigmatism of the meridional image surface and the sagittal image surface is controlled within ±0.1 mm, which indicates that the optical lens 100 can better correct the astigmatism.
[0115] Figure 8 The lateral chromatic aberration curve of the optical lens 100 is shown in FIG. 11, which represents the chromatic aberration of different wavelengths relative to the center wavelength (555 nm) at different image heights on the imaging surface, the horizontal axis represents the chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, which indicates that the optical lens 100 can better correct the chromatic aberration.
[0116] Figure 9 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, with the horizontal axis representing the axial aberration value (unit: mm) and the vertical axis representing the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ±0.03mm, indicating that the optical lens 100 is able to correct the axial aberration well.
[0117] Example 2
[0118] See also Figure 10 , shown is a schematic structural diagram of an optical lens provided in Example 2 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the object-side surface S1 of the first lens L1 is a concave surface; the object-side surface S9 of the fifth lens L5 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.
[0119] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.
[0120] Table 2-1
[0121]
[0122] The surface parameters of the aspheric lens of the optical lens in Example 2 are shown in Table 2-2.
[0123] Table 2-2
[0124]
[0125] In this embodiment, the MTF curve diagram of the wavelength of 470nm to 650nm, the MTF curve diagram of the wavelength of 850nm, the defocus curve diagram of the wavelength of 470nm to 650nm, the defocus curve diagram of the wavelength of 850nm, the distortion curve diagram, the astigmatism curve diagram, the magnification chromatic aberration curve diagram, and the axial aberration curve diagram of the optical lens 200 are respectively as shown in FIG. Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 、 Figure 16 、 Figure 17 、 Figure 18 shown.
[0126] from Figure 11 As can be seen, the MTF value of this embodiment is above 0.45 throughout the entire field of view. In the range of 0 to 180 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, demonstrating good imaging quality and detail resolution at both low and high frequencies.
[0127] from Figure 12As can be seen from the MTF curves in the full field of view, the MTF values of the optical lens in the embodiment are all above 0.3, the MTF curves are uniformly and smoothly decreased from the center to the edge of the field of view in the range of 0-180 lp / mm, and the imaging quality and the detail resolution capability are good in both low-frequency and high-frequency cases.
[0128] As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power. Figure 13 As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power.
[0129] Figure 14 As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power.
[0130] As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power. Figure 15 As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power.
[0131] Figure 16 As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power.
[0132] As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power. Figure 17 As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power.
[0133] Figure 18 As can be seen from the OTF curves in the full field of view, the OTF values of the optical lens in the embodiment are all greater than 80% at the focal point, which indicates that the lens has good resolving power.
[0134] Embodiment 3
[0135] As can be seen from the MTF curves in the full field of view, the MTF values of the optical lens in the embodiment are all above 0.3, the MTF curves are uniformly and smoothly decreased from the center to the edge of the field of view in the range of 0-180 lp / mm, and the imaging quality and the detail resolution capability are good in both low-frequency and high-frequency cases. Figure 19 , which is a structural schematic diagram of the optical lens provided in Embodiment 3 of the present application, and the main difference between the embodiment and Embodiment 1 is that the diaphragm ST is arranged between the second lens L2 and the third lens L3; the object side S1 of the first lens L1 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.
[0136] The related parameters of each lens in the optical lens in Embodiment 3 are shown in Table 3-1.
[0137] Table 3-1
[0138]
[0139] The surface type parameters of the aspherical lens of the optical lens in Embodiment 3 are shown in Table 3-2.
[0140] Table 3-2
[0141]
[0142] In the present embodiment, the MTF curve graph of the optical lens 300 at wavelengths of 470nm to 650nm, the MTF curve graph at a wavelength of 850nm, the defocus curve graph at wavelengths of 470nm to 650nm, the defocus curve graph at a wavelength of 850nm, the distortion curve graph, the astigmatism curve graph, the lateral chromatic aberration curve graph, and the axial chromatic aberration curve graph are respectively as shown in Figure 20 、 Figure 21 、 Figure 22 、 Figure 23 、 Figure 24 、 Figure 25 、 Figure 26 、 Figure 27 .
[0143] It can be seen from Figure 20 that the MTF value of the present embodiment is above 0.4 in the full field of view, and in the range of 0-180lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in low and high frequency cases.
[0144] It can be seen from Figure 21 that the MTF value of the present embodiment is above 0.2 in the full field of view, and in the range of 0-180lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in low and high frequency cases.
[0145] It can be seen from Figure 22 that the OTF value of the center field of view at the focus point is greater than 80%, indicating that the lens has good resolving power.
[0146] It can be seen from Figure 23 that the OTF value of the center field of view at the focus point is greater than 80%, indicating that the lens has good resolving power.
[0147] It can be seen from Figure 24 that the distortion of the optical lens is controlled within 0-2%, indicating that the distortion of the optical lens 300 is well corrected.
[0148] It can be seen from Figure 25 that the astigmatism of the meridional image surface and the sagittal image surface is controlled within ±0.1mm, indicating that the optical lens 300 can better correct astigmatism.
[0149] It can be seen from Figure 26 that the chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1.5μm, indicating that the optical lens 300 can better correct chromatic aberration.
[0150] From Figure 27 It can be seen that the shift of axial aberration is controlled within ±0.02mm, which indicates that the optical lens 300 can correct axial aberration well.
[0151] Embodiment 4
[0152] Referring to Figure 28 , a structural schematic diagram of an optical lens provided in Embodiment 4 of the present application is shown, and the main difference between this embodiment and Embodiment 1 is that the diaphragm ST is arranged between the second lens L2 and the third lens L3; the object side surface S9 of the fifth lens L5 is a concave surface; and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.
[0153] The related parameters of each lens in the optical lens in Embodiment 4 are shown in Table 4-1.
[0154] Table 4-1
[0155]
[0156] The surface type parameters of the aspheric lens of the optical lens in Embodiment 4 are shown in Table 4-2.
[0157] Table 4-2
[0158]
[0159] In this embodiment, the MTF curve graph of the optical lens 400 at wavelengths of 470nm to 650nm, the MTF curve graph at a wavelength of 850nm, the defocus curve graph at wavelengths of 470nm to 650nm, the defocus curve graph at a wavelength of 850nm, the distortion curve graph, the astigmatism curve graph, the lateral chromatic aberration curve graph, and the axial aberration curve graph are respectively shown in Figure 29 , Figure 30 , Figure 31 , Figure 32 , Figure 33 , Figure 34 , Figure 35 , Figure 36 .
[0160] From Figure 29 It can be seen that the MTF value of this embodiment is above 0.48 in the full field of view, and in the range of 0-180lp / mm, the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.
[0161] From Figure 30As can be seen from the MTF curves in FIG. 6, the MTF values of the optical lens according to the embodiment are all greater than 0.35 in the full field of view, and the MTF curves are uniformly and smoothly decreased from the center to the edge of the field of view in the range of 0-180 lp / mm, and the optical lens has good imaging quality and good detail resolution capability in both low-frequency and high-frequency cases.
[0162] As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power. Figure 31 As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power.
[0163] Figure 32 As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power.
[0164] As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power. Figure 33 As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power.
[0165] Figure 34 As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power.
[0166] As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power. Figure 35 As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power.
[0167] Figure 36 As can be seen from the OTF curves in FIG. 7, the OTF value of the center field of view at the focal point is greater than 80%, which indicates that the lens has good resolving power.
[0168] Referring to Table 5, the optical properties corresponding to the above embodiments are shown, including the effective focal length f, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, and the numerical values corresponding to each conditional expression in each embodiment.
[0169] Table 5
[0170]
[0171] In summary, the optical lens provided by the present application adopts five lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved. The lens can achieve good day and night confocal effect and defocus amount ≤2um, and also has one or more advantages of large aperture, miniaturization, low cost, etc.
[0172] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0173] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as a limitation on the patent scope of the present application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.
Claims
1. An optical lens, comprising five lenses, characterized in that: It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with positive optical power, whose image side is convex; A second lens with negative optical power, whose object side is convex and whose image side is concave; A third lens with positive optical power, whose object side is convex and whose image side is convex; A fourth lens with negative optical power, whose object side is concave and whose image side is convex; A fifth lens with negative optical power, whose image side is concave near the optical axis; Wherein, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.1 < f1 / f < 1.4; The effective focal length f of the optical lens, the maximum field angle FOV of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 49° < (f × FOV) / IH < 50°.
2. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -6.8 < f5 / f < -0.
75.
3. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.5 < f3 / f < 0.
81.
4. The optical lens according to claim 1, wherein: The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.45 < TTL / f < 1.
5.
5. The optical lens according to claim 1, wherein: The overall optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis respectively satisfy: 0.6 < ∑CT / TTL < 0.
71.
6. The optical lens according to claim 1, wherein: The curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: 0.5 < (R5 + R6) / (R5 - R6) < 0.
8.
7. The optical lens according to claim 1, wherein: The Abbe number Vd1 of the first lens, the Abbe number Vd2 of the second lens, the Abbe number Vd3 of the third lens, and the Abbe number Vd4 of the fourth lens satisfy: 54 < Vd1 < 58, 18 < Vd2 < 25, 54 < Vd3 < 58, 19 < Vd4 < 25; the refractive index Nd1 of the first lens, the refractive index Nd2 of the second lens, the refractive index Nd3 of the third lens, and the refractive index Nd4 of the fourth lens satisfy: 1.52 < Nd1 < 1.56, 1.62 < Nd2 < 1.7, 1.5 < Nd3 < 1.56, 1.62 < Nd4 < 1.
68.
8. The optical lens according to claim 1, wherein: The Abbe number Vd5 of the fifth lens and the refractive index Nd5 of the fifth lens satisfy: 35 < Vd5 < 58, 1.52 < Nd5 < 1.
58.
9. The optical lens according to claim 1, wherein: The curvature radius R10 of the image side of the fifth lens and the effective focal length f of the optical lens satisfy: 0.35 < R10 / f < 0.
65.
10. The optical lens according to claim 1, wherein: The focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -4.1 < f2 / f3 < -1.6.
Citation Information
Patent Citations
Image capturing optical lens system
CN103454753A