Optical system

Abstract

The application provides an optical system, which comprises a lens barrel, a lens group and a spacer assembly contained in the lens barrel; the lens group comprises, in sequence from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a fourth lens and a fifth lens; the spacer assembly at least comprises a first spacer element arranged on the image side of the first lens and in contact with the image side surface of the first lens; the optical system satisfies: 27.19≤f1 / EP01≤36.00; 3.92≤R2×N1 / D1s≤6.95; 10.00mm≤f1 / Tan(Semi-FOV)≤13.89mm.

Description

Technical Field

[0001] This application relates to the field of optical device technology, and in particular to an optical system. Background Technology

[0002] The rapid development of electronic products such as smartphones and tablets has led to a surge in demand for mobile phone lenses, and people are increasingly demanding higher image quality. This trend is constantly driving the miniaturization of portable electronic products. To meet market demands, lenses need to be as thin and small as possible, increasing design complexity. At the same time, as image sensor performance improves and size decreases, the design freedom for lenses is decreasing, further increasing the design difficulty. Summary of the Invention

[0003] One advantage of this application is that it provides a five-element optical system with a wide-angle lens and a small head, which can solve the problem of poor image quality of wide-angle lenses in traditional portable electronic products.

[0004] On one hand, this application provides an optical system, including a lens barrel and a lens group and a spacer assembly housed within the lens barrel; the lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes at least a first spacer element disposed on the image side of the first lens and in contact with the image side surface of the first lens; the optical system satisfies: 27.19≤f1 / EP01≤36.00; 3.92≤R2×N1 / D1s≤6.95; 10.00mm≤f1 / Tan(Semi-FOV)≤13.89mm;

[0005] Wherein, f1 is the effective focal length of the first lens, EP01 is the distance between the object-side end face of the lens barrel and the first spacer element in the optical axis direction, R2 is the radius of curvature of the image-side surface of the first lens, N1 is the refractive index of the first lens, D1s is the outer diameter of the object-side surface of the first spacer element, and Semi-FOV is the maximum half field of view of the optical system.

[0006] In some embodiments of this application, the optical system further satisfies: -5.64≤R3 / (D1m-d1m)≤-4.29; where D1m is the outer diameter of the image-side surface of the first spacer element, d1m is the inner diameter of the image-side surface of the first spacer element, and R3 is the radius of curvature of the object-side surface of the second lens.

[0007] In some embodiments of this application, the spacing assembly further includes a second spacing element disposed on the image side of the second lens and in contact with the image side surface of the second lens, and the optical system further satisfies: 3.89≤f2 / (CP2+CT2)≤4.49; where f2 is the effective focal length of the second lens, CP2 is the maximum thickness of the second spacing element, and CT2 is the center thickness of the second lens on the optical axis.

[0008] In some embodiments of this application, the spacing assembly further includes a second spacing element disposed on the image side of the second lens and in contact with the image side surface of the second lens, and the optical system further satisfies: 1.56≤R5 / d2m≤2.34; where R5 is the radius of curvature of the object side surface of the third lens, and d2m is the inner diameter of the image side surface of the second spacing element.

[0009] In some embodiments of this application, the spacing assembly further includes a second spacing element disposed on the image side of the second lens and in contact with the image side surface of the second lens, and a third spacing element disposed on the image side of the third lens and in contact with the image side surface of the third lens. The optical system also satisfies: 1.40≤T34 / EP23≤1.71; where T34 is the air gap between the third lens and the fourth lens on the optical axis, and EP23 is the distance between the second spacing element and the third spacing element along the optical axis.

[0010] In some embodiments of this application, the spacer assembly further includes a third spacer element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and the optical system further satisfies: 2.14≤R6×N3 / (D3s-d3s)≤2.64; where R6 is the radius of curvature of the image side surface of the third lens, N3 is the refractive index of the third lens, D3s is the outer diameter of the object side surface of the third spacer element, and d3s is the inner diameter of the object side surface of the third spacer element.

[0011] In some embodiments of this application, the spacing assembly further includes a third spacing element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and the optical system further satisfies: -10.59≤f3 / (CP3+CT3)≤-7.06; where f3 is the effective focal length of the third lens, CT3 is the center thickness of the third lens on the optical axis, and CP3 is the maximum thickness of the third spacing element.

[0012] In some embodiments of this application, the spacing assembly further includes a third spacing element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and the optical system further satisfies: -1.57≤R7 / d3m≤-0.79; where R7 is the radius of curvature of the object side surface of the fourth lens, and d3m is the inner diameter of the image side surface of the third spacing element.

[0013] In some embodiments of this application, the spacing assembly further includes a third spacing element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The optical system also satisfies: 2.00≤CT4 / EP34≤2.76; where CT4 is the center thickness of the fourth lens on the optical axis, and EP34 is the distance between the third spacing element and the fourth spacing element along the optical axis.

[0014] In some embodiments of this application, the spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system further satisfies: 2.02≤CP4 / T45≤7.72; where CP4 is the maximum thickness of the fourth spacing element and T45 is the air gap between the fourth lens and the fifth lens on the optical axis.

[0015] In some embodiments of this application, the spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system further satisfies: -6.87≤D4s / R8≤-5.60; where R8 is the radius of curvature of the image side surface of the fourth lens, and D4s is the outer diameter of the object side surface of the fourth spacing element.

[0016] In some embodiments of this application, the spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system further satisfies: 1.94≤R9 / (D4m-d4m)≤4.29; where D4m is the outer diameter of the image side surface of the fourth spacing element, d4m is the inner diameter of the image side surface of the fourth spacing element, and R9 is the radius of curvature of the object side surface of the fifth lens.

[0017] According to another aspect of this application, this application also provides an optical system, including a lens barrel and a lens group and a spacer assembly housed within the lens barrel; the lens group includes, arranged sequentially along the optical axis from the object side to the image side: a first lens having positive optical power, a second lens having positive optical power, a third lens having negative optical power, a fourth lens having positive optical power, and a fifth lens having negative optical power.

[0018] The spacing assembly includes a first spacing element placed on the image side of the first lens and in contact with the image side surface of the first lens, a second spacing element placed on the image side of the second lens and in contact with the image side surface of the second lens, a third spacing element placed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth spacing element placed on the image side of the fourth lens and in contact with the image side surface of the fourth lens; the optical system also satisfies: 2.86≤SAG42 / SAG22≤3.40; and 1.42≤EP34 / EP12≤2.05;

[0019] Wherein, SAG22 is the axial displacement between the intersection of the image side surface of the second lens and the optical axis and the vertex of the effective radius of the optical region of the image side surface of the second lens; SAG42 is the axial displacement between the intersection of the image side surface of the fourth lens and the optical axis and the vertex of the effective radius of the optical region of the image side surface of the fourth lens; EP12 is the distance between the first spacer element and the second spacer element along the optical axis; and EP34 is the distance between the third spacer element and the fourth spacer element along the optical axis.

[0020] In summary, to meet the wide-angle requirements, the first lens generally has a positive optical power and a large focal length. However, this optical system also needs to meet the requirements of being ultra-thin and having a small head. Therefore, there are certain requirements for the axial thickness of the first lens structure and the axial thickness of the lens front end. This results in light entering the first lens exiting at a large angle of deflection, making the first lens more sensitive during assembly. Based on this, this application restricts the influence of the first lens on the sensitivity of the optical system by constraining the focal length of the first lens and the ratio of the object-side end face of the lens barrel to the object-side face of the first spacer element to 27.19≤f1 / EP01≤36.00, constraining the radius of curvature of the image-side face of the first lens, the refractive index of the first lens, and the outer diameter of the first spacer element to 3.92≤R2×N1 / D1s≤6.95, and constraining the maximum half field of view of the optical system to 10.00mm≤f1 / Tan(Semi-FOV)≤13.89mm. This ensures that this optical system with ultra-thin and small head characteristics has good optical performance during assembly. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an optical system according to one embodiment provided in this application;

[0022] Figure 2 This is a schematic diagram of the optical system according to Embodiment 1 of this application;

[0023] Figure 3 This is a schematic diagram of the optical system according to Embodiment 2 of this application;

[0024] Figure 4AA schematic diagram of the on-axis chromatic aberration curves of the optical systems of Embodiments 1 and 2 according to the present application is shown;

[0025] Figure 4B A schematic diagram of the astigmatism curves of the optical systems of Embodiments 1 and 2 according to the present application is shown;

[0026] Figure 4C A schematic diagram of the distortion curves of the optical systems according to Embodiments 1 and 2 above is shown;

[0027] Figure 4D A schematic diagram of the magnification chromatic aberration curves of the optical systems of Embodiments 1 and 2 according to the present application is shown;

[0028] Figure 5 This is a schematic diagram of the optical system according to Embodiment 3 of this application;

[0029] Figure 6 This is a schematic diagram of the structure of the optical system according to Embodiment 4 of this application;

[0030] Figure 7A A schematic diagram of the on-axis chromatic aberration curves of the optical systems of Embodiments 3 and 4 according to the present application is shown;

[0031] Figure 7B A schematic diagram of the astigmatism curves of the optical systems of Embodiments 3 and 4 according to the present application is shown;

[0032] Figure 7C A schematic diagram of the distortion curves of the optical systems according to Embodiments 3 and 4 of this application is shown;

[0033] Figure 7D A schematic diagram of the magnification chromatic aberration curves of the optical systems of Embodiments 3 and 4 according to the present application is shown;

[0034] Figure 8 This is a schematic diagram of the optical system according to Embodiment 5 of this application;

[0035] Figure 9 This is a schematic diagram of the structure of an optical system according to Embodiment Six of this application;

[0036] Figure 10A A schematic diagram of the on-axis chromatic aberration curves of the optical systems of Embodiments 5 and 6 according to the present application is shown;

[0037] Figure 10B A schematic diagram of the astigmatism curves of the optical systems of Embodiments 5 and 6 according to the present application is shown;

[0038] Figure 10CA schematic diagram of the distortion curves of the optical systems of Embodiments 5 and 6 according to the present application is shown;

[0039] Figure 10D A schematic diagram of the magnification chromatic aberration curves of the optical systems of Embodiments 5 and 6 according to the present application is shown;

[0040] Figure 11 This is a schematic diagram of the optical system according to Embodiment Seven of this application;

[0041] Figure 12 This is a schematic diagram of the optical system according to Embodiment 8 of this application;

[0042] Figure 13A A schematic diagram of the on-axis chromatic aberration curves of the optical systems of Embodiments 7 and 8 according to the present application is shown;

[0043] Figure 13B A schematic diagram of astigmatism curves for the optical systems of Embodiments 7 and 8 according to this application is shown;

[0044] Figure 13C A schematic diagram of the distortion curves of the optical systems of Embodiments 7 and 8 according to the present application is shown;

[0045] Figure 13D A schematic diagram of the magnification chromatic aberration curves of the optical systems of Embodiments 7 and 8 according to the present application is shown;

[0046] Figure 14A and Figure 14B The schematic diagrams of the MTF curves of the optical system before and after assembly are shown respectively, when R2×N1 / D1s=3.5.

[0047] Figure 15A and Figure 15B The schematic diagrams of the MTF curves of the optical system before and after assembly are shown respectively, when R2×N1 / D1s=5.5.

[0048] Figure 16A and Figure 16B The schematic diagrams of the MTF curves of the optical system before and after assembly are shown respectively, when R2×N1 / D1s=7.5. Detailed Implementation

[0049] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0050] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0051] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0052] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface shape in the paraxial region can be determined by the sign of the R value (R refers to the radius of curvature of the paraxial region). In this paper, the surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens. For the object-side surface, when the R value is positive, it is determined to be convex, and when the R value is negative, it is determined to be concave; for the image-side surface, when the R value is positive, it is determined to be concave, and when the R value is negative, it is determined to be convex. Each object-side or image-side surface of a lens includes an optical region and a structural region. The optical region refers to the light-passing region, and the structural region refers to the region used for assembly.

[0053] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0054] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0055] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. The following embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this application. It should be pointed out that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0056] According to one aspect of this application, such as Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of the optical system in one embodiment of the present application. Figure 2 This is a schematic diagram of the optical system in Embodiment 1 of this application. One embodiment of this application proposes an optical system that may include a lens barrel and a lens group and a spacer assembly housed within the lens barrel. The lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side. The spacer assembly includes at least a first spacer element placed on the image side of the first lens and in contact with the image side surface of the first lens. The optical system satisfies the following conditions: 27.19≤f1 / EP01≤36.00; 3.92≤R2×N1 / D1s≤6.95; 10.00mm≤f1 / Tan(Semi-FOV)≤13.89mm.

[0057] Wherein, f1 is the effective focal length of the first lens, EP01 is the distance between the object-side end face of the lens barrel and the first spacer element P1 in the optical axis direction, R2 is the radius of curvature of the image-side surface of the first lens, N1 is the refractive index of the first lens, D1s is the outer diameter of the object-side surface of the first spacer element P1, and Semi-FOV is the maximum half field of view of the optical system.

[0058] It is worth noting that the above embodiments of this application provide five lenses, and a first spacer element is provided on the image side of the first lens. By constraining the focal length of the first lens and the distance between the first spacer element and the object-side end face of the lens barrel in the optical axis direction, the viewing angle of the optical system is ensured, meeting the requirements of a wide-angle lens with a large field of view. However, when the optical system is in the state of 27.19≤f1 / EP01≤36.00, especially if the outer diameter of the spacer element is not properly matched, it can lead to assembly instability. In addition, the first lens has a large deflection angle when it exits and is very sensitive to assembly. Specifically, this manifests as follows: The MTF performance of individual fields of view will decrease significantly. By comprehensively constraining the radius of curvature of the image side of the first lens, the refractive index of the first lens, and the outer diameter of the first spacer element to meet 3.92≤R2×N1 / D1s≤6.95, and constraining the maximum half field of view of the optical system to meet 10.00mm≤f1 / Tan(Semi-FOV)≤13.89mm, the exit angle of the first lens is not too large, the outer diameter of the first spacer element is matched with the size of the first lens, the influence of the first lens on the overall sensitivity of the optical system is limited, and the optical performance during the assembly process of the optical system is ensured.

[0059] For example, Figure 14A and Figure 14B The schematic diagrams of the MTF curves of the optical system before and after assembly are shown respectively, when R2×N1 / D1s=3.5. Figure 15A and Figure 15B The schematic diagrams of the MTF curves of the optical system before and after assembly are shown respectively, when R2×N1 / D1s=5.5. Figure 16A and Figure 16B The diagrams show the MTF curves of the optical system before and after assembly, respectively, when R2×N1 / D1s=7.5. The vertical axis represents the MTF magnitude, which is defined as always greater than 0 and less than 1. In this technical field, the closer the MTF magnitude is to 1, the better the performance of the optical system, i.e., the higher the resolution (for ease of comparison, the MTF magnitude range on the vertical axis is given as 0-0.8 or 0-0.7). The horizontal axis represents the focus shift. As can be easily seen from the diagrams:

[0060] like Figure 15A and Figure 15B As shown, when the relation R2×N1 / D1s is within the range of greater than or equal to 3.92 and less than or equal to 6.95, the average peak value of the field of view is above 0.4. There is no significant drop in the peak value before and after assembly, and the focus shift is small. The intersection value of each field of view curve with the vertical axis drops little. Therefore, this scheme has good imaging quality.

[0061] like Figure 14A and Figure 14BAs shown, when the relation R2×N1 / D1s is less than 3.92, the peak values ​​of the observed fields of view are all above 0.3. The peak values ​​of each field of view before and after assembly drop significantly, and the focus shift is large. The intersection points of each field of view curve with the vertical axis drop significantly, resulting in poor image quality.

[0062] like Figure 16A and Figure 16B As shown, when the relationship R2×N1 / D1s is greater than 6.95, the peak values ​​of the examined fields of view are all above 0.3. Before and after assembly, the peak values ​​of each field of view show a significant drop, and the focal shift is large. The intersection points of each field of view curve with the vertical axis also drop considerably, resulting in poor image quality. Table 1 below shows the changes in MTF performance of multiple fields of view of the optical system in the meridional and sagittal directions for three different R2×N1 / D1s schemes. Based on Table 1 and... Figures 14A to 16B It can be seen that when the optical system meets the constraints of the conditional formula provided in this application, the MTF performance of the optical system changes little before and after assembly, and the system is stable.

[0063] Table 1. Changes in resolving power of the optical system before and after assembly.

[0064]

[0065] According to some embodiments of this application, the optical system further satisfies the following conditions: the first lens has positive optical power, the second lens has positive optical power, the third lens has negative optical power, the fourth lens has positive optical power, and the fifth lens has negative optical power.

[0066] According to some embodiments of this application, the optical system further satisfies the following: the object-side surface and the image-side surface of the first lens are convex and concave, respectively; the object-side surface and the image-side surface of the second lens are concave and convex, respectively; the object-side surface and the image-side surface of the third lens are convex and concave, respectively; the object-side surface and the image-side surface of the fourth lens are concave and convex, respectively; and the object-side surface and the image-side surface of the fifth lens are convex and concave, respectively.

[0067] According to some embodiments of this application, the optical system also satisfies: -5.64≤R3 / (D1m-d1m)≤-4.29; where D1m is the outer diameter of the image side of the first spacer element P1, d1m is the inner diameter of the image side of the first spacer element P1, and R3 is the radius of curvature of the object side of the second lens.

[0068] In this way, by controlling the ratio of the difference between the outer diameter and inner diameter of the image-side surface of the first spacer element to the radius of curvature of the object-side surface of the second lens, it can be ensured that no excess light enters the optical system, while ensuring sufficient light flux within the optical system to guarantee its performance. This allows for the optimization of stray light while maintaining the system's optical performance.

[0069] According to some embodiments of this application, the spacing assembly further includes a second spacing element disposed on the image side of the second lens and in contact with the image side surface of the second lens, and the optical system further satisfies: 3.89≤f2 / (CP2+CT2)≤4.49; where f2 is the effective focal length of the second lens, CP2 is the maximum thickness of the second spacing element P2, and CT2 is the center thickness of the second lens on the optical axis.

[0070] In this way, by controlling the effective focal length of the second lens, the center thickness of the second lens on the optical axis, and the maximum thickness of the second spacer element, constraints are achieved on the shape of the second lens and the distance between the first and second lenses, thus optimizing the aberrations of the optical system while ensuring the assembly and processing yield of the second lens.

[0071] According to some embodiments of this application, the spacing assembly further includes a second spacing element disposed on the image side of the second lens and in contact with the image side surface of the second lens, and the optical system further satisfies: 1.56≤R5 / d2m≤2.34; where R5 is the radius of curvature of the object side surface of the third lens, and d2m is the inner diameter of the image side surface of the second spacing element P2.

[0072] In this way, by controlling the ratio of the curvature radius of the object side of the third lens to the inner diameter of the image side of the second spacer element, it can be ensured that light passes through this part of the optical system at a suitable angle and aperture. This optimizes the aberrations of the optical system while limiting the entry of excess light into the optical system, thereby reducing the impact of aberrations and stray light on the optical system.

[0073] According to some embodiments of this application, the spacing assembly further includes a second spacing element placed on the image side of the second lens and in contact with the image side surface of the second lens, and a third spacing element placed on the image side of the third lens and in contact with the image side surface of the third lens. The optical system also satisfies: 1.40≤T34 / EP23≤1.71; where T34 is the air gap between the third lens and the fourth lens on the optical axis, and EP23 is the distance between the second spacing element P2 and the third spacing element P3 along the optical axis.

[0074] By limiting the ratio of the air gap between the third and fourth lenses on the optical axis to the image-side and object-side gaps of the second and third spacers, the axial dimensions of the second and third spacers can be optimized. This limits the axial dimensions of the non-effective diameter regions of the second, third, and fourth lenses, controlling the formation of defects in the optical elements during manufacturing. This allows for optimization of the optical system's manufacturability while controlling its dimensions, improving lens manufacturing yield.

[0075] According to some embodiments of this application, the spacer assembly further includes a third spacer element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and the optical system further satisfies: 2.14≤R6×N3 / (D3s-d3s)≤2.64; where R6 is the radius of curvature of the image side surface of the third lens, N3 is the refractive index of the third lens, D3s is the outer diameter of the object side surface of the third spacer element P3, and d3s is the inner diameter of the object side surface of the third spacer element P3.

[0076] In this way, by constraining the radius of curvature of the image side of the third lens, the refractive index of the third lens, the outer diameter of the object side of the third spacer element, and the inner diameter of the object side of the third spacer element using the above-mentioned conditional formula, optical aberrations caused by environmental factors can be reduced, and the stability and adaptability of the optical system in different environments can be ensured.

[0077] According to some embodiments of this application, the spacing assembly further includes a third spacing element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and the optical system further satisfies: -10.59≤f3 / (CP3+CT3)≤-7.06; where f3 is the effective focal length of the third lens, CT3 is the center thickness of the third lens on the optical axis, and CP3 is the maximum thickness of the third spacing element P3.

[0078] In this way, adjusting the effective focal length of the third lens can improve the imaging capability of the optical system, but it will increase the size of the optical system. Further controlling the effective focal length of the third lens and the sum of the center thickness of the third lens on the optical axis and the maximum thickness of the third spacer element can improve the performance of the optical system while limiting the size of the optical system.

[0079] According to some embodiments of this application, the spacing assembly further includes a third spacing element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and the optical system further satisfies: -1.57≤R7 / d3m≤-0.79; where R7 is the radius of curvature of the object side surface of the fourth lens, and d3m is the inner diameter of the image side surface of the third spacing element P3.

[0080] In this way, adjusting the radius of curvature of the object side of the third lens can allow light to enter the image plane at a more ideal angle. While optimizing it, limiting the inner diameter of the image side of the third spacer element can reduce unnecessary light entering the optical system and affecting off-axis imaging quality, absorb stray light generated by excess light paths, and improve imaging capabilities while suppressing the formation of stray light.

[0081] According to some embodiments of this application, the spacing assembly further includes a third spacing element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The optical system also satisfies: 2.00≤CT4 / EP34≤2.76; where CT4 is the center thickness of the fourth lens on the optical axis, and EP34 is the distance between the third spacing element P3 and the fourth spacing element P4 along the optical axis.

[0082] In this way, controlling the center thickness of the fourth lens on the optical axis can reduce the size of the optical system. While adjusting this size, it is necessary to limit the spacing between the third and fourth spacers to ensure that the non-effective diameter region of the fourth lens has sufficient thickness, thereby ensuring the strength of the fourth lens. This ensures the assembly yield and reliability of the optical system while reducing its size.

[0083] According to some embodiments of this application, the spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system further satisfies: 2.02≤CP4 / T45≤7.72; wherein, CP4 is the maximum thickness of the fourth spacing element P4, and T45 is the air gap between the fourth lens and the fifth lens on the optical axis.

[0084] In this way, controlling the maximum thickness of the fourth spacer element can control and improve the strength of the spacer element to ensure that the performance of the optical system after the fourth and fifth lenses are assembled is closer to the ideal design. Controlling the air gap between the fourth and fifth lenses on the optical axis can compensate for the field curvature variation of this deviation to improve the overall optical performance of the optical system.

[0085] According to some embodiments of this application, the spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system further satisfies: -6.87≤D4s / R8≤-5.60; where R8 is the radius of curvature of the image side surface of the fourth lens, and D4s is the outer diameter of the object side surface of the fourth spacing element P4.

[0086] In this way, adjusting the radius of curvature of the image side of the fourth lens can improve the imaging deviation of the optical system. However, this may lead to an excessively large tail size of the optical system. Limiting the outer diameter of the object side of the fourth spacer element can ensure the miniaturization of the optical system. This ensures the imaging capability of the optical system without introducing excessive volumetric redundancy.

[0087] According to some embodiments of this application, the spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system further satisfies: 1.94≤R9 / (D4m-d4m)≤4.29; where D4m is the outer diameter of the image side surface of the fourth spacing element P4, d4m is the inner diameter of the image side surface of the fourth spacing element P4, and R9 is the radius of curvature of the object side surface of the fifth lens.

[0088] Thus, by optimizing the radius of curvature of the object-side surface of the fifth lens, various aberrations of the optical system, such as spherical aberration, coma, and astigmatism, can be improved. Simultaneously optimizing this radius and limiting the difference between the outer and inner diameters of the image-side surface of the fourth spacer element ensures sufficient support space for the fifth lens, guaranteeing its assembly accuracy. This improves the performance of the optical system while ensuring the stability of its assembly.

[0089] According to another aspect of this application, another embodiment of this application provides an optical system that may include a lens barrel and a lens group and a spacer assembly housed within the lens barrel; the lens group includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged sequentially along the optical axis from the object side to the image side;

[0090] The spacing assembly includes a first spacing element placed on the image side of the first lens and in contact with the image side surface of the first lens, a second spacing element placed on the image side of the second lens and in contact with the image side surface of the second lens, a third spacing element placed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth spacing element placed on the image side of the fourth lens and in contact with the image side surface of the fourth lens.

[0091] The optical system also satisfies: 2.86≤SAG42 / SAG22≤3.40; and 1.42≤EP34 / EP12≤2.05; wherein, SAG22 is the axial displacement between the intersection of the image side surface of the second lens and the optical axis and the vertex of the effective radius of the optical region of the image side surface of the second lens, SAG42 is the axial displacement between the intersection of the image side surface of the fourth lens and the optical axis and the vertex of the effective radius of the optical region of the image side surface of the fourth lens, EP12 is the distance between the first spacer element P1 and the second spacer element P2 along the optical axis, and EP34 is the distance between the third spacer element P3 and the fourth spacer element P4 along the optical axis.

[0092] It is worth noting that this application arranges the optical power of the first to fifth lenses in a "positive-positive-negative-positive-negative" order, and arranges corresponding spacer elements on the image side of each of the first to fourth lenses. This improves the assembly accuracy while ensuring the imaging of the optical system. At the same time, controlling the axial displacement between the intersection of the image side of the second lens and the optical axis and the vertex of the effective radius of the image side of the second lens, as well as the axial displacement between the intersection of the image side of the fourth lens and the optical axis and the vertex of the effective radius of the optical region of the image side of the fourth lens, can control the ease of processing or forming the second and fourth lenses. Controlling these two values ​​can balance the manufacturing yield of the second and fourth lenses. Further controlling the spacing between the first and second spacer elements, as well as the spacing between the third and fourth spacer elements, can optimize the field curvature performance of the optical system while ensuring the miniaturization of the optical system.

[0093] Furthermore, in this embodiment where 2.86≤SAG42 / SAG22≤3.40 and 1.42≤EP34 / EP12≤2.05 are satisfied, the first lens has positive optical power, the second lens has positive optical power, the third lens has negative optical power, the fourth lens has positive optical power, and the fifth lens has negative optical power.

[0094] Furthermore, in the embodiment where 2.86≤SAG42 / SAG22≤3.40 and 1.42≤EP34 / EP12≤2.05 are satisfied, the object-side surface and image-side surface of the first lens are convex and concave, respectively; the object-side surface and image-side surface of the second lens are concave and convex, respectively; the object-side surface and image-side surface of the third lens are convex and concave, respectively; the object-side surface and image-side surface of the fourth lens are concave and convex, respectively; and the object-side surface and image-side surface of the fifth lens are convex and concave, respectively.

[0095] It should be noted that those skilled in the art should understand that the number of spacers constituting the optical system can be changed to obtain the various results and advantages described in this specification without departing from the technical solutions claimed in this application, and this application does not specifically limit this. For example, the optical system may also include other numbers of spacers than those described in the above embodiments, as needed.

[0096] The following describes in more detail some specific, non-limiting embodiments of the above-described embodiments of this application with reference to the accompanying drawings. For ease of description, in the following embodiments, OBJ represents the object plane of the optical system, STO represents the surface of the aperture stop, S1 represents the object-side plane of the first lens E1, S2 represents the image-side plane of the first lens E1, S3 represents the object-side plane of the second lens E2, S4 represents the image-side plane of the second lens E2, S5 represents the object-side plane of the third lens E3, S6 represents the image-side plane of the third lens E3, S7 represents the object-side plane of the fourth lens E4, S8 represents the image-side plane of the fourth lens E4, S9 represents the object-side plane of the fifth lens E5, S10 represents the image-side plane of the fifth lens E5, S13 (not shown in the drawings) represents the object-side plane of the filter on the image side of the optical system, S14 (not shown in the drawings) represents the image-side plane of the filter, and S15 (not shown in the drawings) represents the image plane of the optical system. Furthermore, let Aj denote the j-th order aspherical coefficient, j=4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30.

[0097] Example 1

[0098] like Figure 2 As shown, in this embodiment, the optical system includes a lens barrel P0 and a lens group and a spacer assembly housed within the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes a first spacer element P1 placed on the image side of the first lens E1 and in contact with the image side surface S2 of the first lens E1, a second spacer element P2 placed on the image side of the second lens E2 and in contact with the image side surface S4 of the second lens E2, a third spacer element P3 placed on the image side of the third lens E3 and in contact with the image side surface S6 of the third lens E3, and a fourth spacer element P4 placed on the image side of the fourth lens E4 and in contact with the image side surface S8 of the fourth lens E4.

[0099] In this embodiment, the first lens E1 has positive optical power, and the object-side surface S1 and image-side surface S2 of the first lens E1 are convex and concave, respectively; the second lens E2 has positive optical power, and the object-side surface S3 and image-side surface S4 of the second lens E2 are concave and convex, respectively; the third lens E3 has negative optical power, and the object-side surface S5 and image-side surface S6 of the third lens E3 are convex and concave, respectively; the fourth lens E4 has positive optical power, and the object-side surface S7 and image-side surface S8 of the fourth lens E4 are concave and convex, respectively; the fifth lens E5 has negative optical power, and the object-side surface S9 and image-side surface S10 of the fifth lens E5 are convex and concave, respectively.

[0100] In addition, Table 2 shows the basic optical parameters of the optical system in Embodiment 1, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0101] Table 2: Basic optical parameters of the optical system in Example 1

[0102]

[0103] It should be noted that the materials in Table 2 include refractive index and Abbe number. For example, in Table 1, the materials 1.65 and 23.50 for S1 indicate that the refractive index of the first lens E1 is 1.65 and the Abbe number is 23.50, respectively.

[0104] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the fifth lens E5 are aspherical surfaces, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0105] ;

[0106] Where x is the distance vector from the vertex of the aspherical surface at a height h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Tables 3-1 and 3-2 below give the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for the aspherical mirrors S1 to S10 in Example 1.

[0107] Table 3-1: Aspherical coefficients of the optical system in Example 1 (A4~A16)

[0108]

[0109] Table 3-2: Aspherical coefficients of the optical system in Example 1 (A18~A30)

[0110]

[0111] Example 2

[0112] like Figure 3As shown, in this embodiment, the optical system includes a lens barrel P0 and a lens group and a spacer assembly housed within the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes a first spacer element P1 placed on the image side of the first lens E1 and in contact with the image side surface S2 of the first lens E1, a second spacer element P2 placed on the image side of the second lens E2 and in contact with the image side surface S4 of the second lens E2, a third spacer element P3 placed on the image side of the third lens E3 and in contact with the image side surface S6 of the third lens E3, and a fourth spacer element P4 placed on the image side of the fourth lens E4 and in contact with the image side surface S8 of the fourth lens E4.

[0113] It is worth noting that, compared with Embodiment 1 above, the optical system of Embodiment 2 has the same optical parameters, that is, the basic optical parameter table of the optical system of Embodiment 2 is the same as Table 2, and the aspherical coefficient table is the same as Table 3. However, the optical system of Embodiment 2 has different structural parameters from the optical system of Embodiment 1 above. That is, the difference between Embodiment 2 and Embodiment 1 above lies in the fact that the dimensional values ​​of some structural parameters of the lens barrel and the spacer assembly in the optical system are different.

[0114] Specifically, the values ​​of various related structural parameters in this embodiment and in the above embodiment are shown in Table 11 below. These structural parameters specifically include: the image-side inner diameter d1m of the first spacer element P1; the object-side outer diameter D1s of the first spacer element P1; the image-side outer diameter D1m of the first spacer element P1; the image-side inner diameter d2m of the second spacer element P2; the object-side inner diameter d3s of the third spacer element P3; the image-side inner diameter d3m of the third spacer element P3; the object-side outer diameter D3s of the third spacer element P3; the image-side inner diameter d4m of the fourth spacer element P4; and the image-side outer diameter D3s of the fourth spacer element P4. D4m; the object-side outer diameter D4s of the fourth spacer element P4; the maximum thickness CP2 of the second spacer element P2; the maximum thickness CP3 of the third spacer element P3; the maximum thickness CP4 of the fourth spacer element P4; the distance EP01 between the object-side end face of the lens barrel P0 and the first spacer element P1 along the optical axis; the distance EP12 between the first spacer element P1 and the second spacer element P2 along the optical axis; the distance EP23 between the second spacer element P2 and the third spacer element P3 along the optical axis; the distance EP34 between the third spacer element P3 and the fourth spacer element P4 along the optical axis. It is understood that the units of the values ​​of each parameter shown in Table 11 are millimeters (mm), and the schematic diagrams of each parameter in the optical system structure diagram are as follows: Figure 1 As shown.

[0115] The on-axis chromatic aberration curves of the optical systems in Examples 1 and 2 are as follows: Figure 4A As shown, this represents the degree of deviation of the focal point after light of different wavelengths passes through the optical system; the astigmatism curves of the optical systems in Embodiments 1 and 2 are shown below. Figure 4B As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane; the distortion curves of the optical systems in Embodiment 1 and Embodiment 2 are as follows. Figure 4C As shown, it represents the relative deviation between the actual image and the ideal image. The magnification chromatic aberration curves of the optical systems in Embodiment 1 and Embodiment 2 are shown below. Figure 4D As shown, this represents the difference in imaging height at different wavelengths. Figures 4A to 4D It can be seen that the optical systems in both Embodiment 1 and Embodiment 2 can achieve good imaging quality.

[0116] Example 3

[0117] like Figure 5 As shown, in this embodiment, the optical system includes a lens barrel P0 and a lens group and a spacer assembly housed within the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes a first spacer element P1 placed on the image side of the first lens E1 and in contact with the image side surface S2 of the first lens E1, a second spacer element P2 placed on the image side of the second lens E2 and in contact with the image side surface S4 of the second lens E2, a third spacer element P3 placed on the image side of the third lens E3 and in contact with the image side surface S6 of the third lens E3, and a fourth spacer element P4 placed on the image side of the fourth lens E4 and in contact with the image side surface S8 of the fourth lens E4.

[0118] In this embodiment, the first lens E1 has positive optical power, and the object-side surface S1 and image-side surface S2 of the first lens E1 are convex and concave, respectively; the second lens E2 has positive optical power, and the object-side surface S3 and image-side surface S4 of the second lens E2 are concave and convex, respectively; the third lens E3 has negative optical power, and the object-side surface S5 and image-side surface S6 of the third lens E3 are convex and concave, respectively; the fourth lens E4 has positive optical power, and the object-side surface S7 and image-side surface S8 of the fourth lens E4 are concave and convex, respectively; the fifth lens E5 has negative optical power, and the object-side surface S9 and image-side surface S10 of the fifth lens E5 are convex and concave, respectively.

[0119] In addition, Table 4 shows the basic optical parameters of the optical imaging system of Embodiment 3, where the units of radius of curvature and thickness / distance are millimeters (mm).

[0120] Table 4: Basic optical parameters of the optical system in Example 3

[0121]

[0122] It should be noted that the materials in Table 4 include refractive index and Abbe number. For example, in Table 4, the materials 1.65 and 23.50 for S1 indicate that the refractive index of the first lens E1 is 1.65 and the Abbe number is 23.50, respectively.

[0123] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, and the fifth lens E5 are aspherical. The surface shape of each aspherical lens can be defined by the aspherical formula given in Embodiment 1 above. Tables 5-1 and 5-2 below give the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for each aspherical mirror S1 to S10 in Embodiment 3.

[0124] Table 5-1: Aspherical coefficients of the optical system in Example 3 (A4~A16)

[0125]

[0126] Table 5-2: Aspherical coefficients of the optical system in Example 3 (A18~A30)

[0127]

[0128] Example 4

[0129] like Figure 6 As shown, in this embodiment, the optical system includes a lens barrel P0 and a lens group and a spacer assembly housed within the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes a first spacer element P1 placed on the image side of the first lens E1 and in contact with the image side surface S2 of the first lens E1, a second spacer element P2 placed on the image side of the second lens E2 and in contact with the image side surface S4 of the second lens E2, a third spacer element P3 placed on the image side of the third lens E3 and in contact with the image side surface S6 of the third lens E3, and a fourth spacer element P4 placed on the image side of the fourth lens E4 and in contact with the image side surface S8 of the fourth lens E4.

[0130] It is worth noting that, compared with Embodiment 3 above, the optical system of Embodiment 4 has the same optical parameters, that is, the basic optical parameter table of the optical system of Embodiment 4 is the same as Table 4, and the aspherical coefficient table is the same as Table 5. However, the optical system of Embodiment 4 has different structural parameters than the optical system of Embodiment 3 above. That is, the difference between Embodiment 4 and Embodiment 3 above lies in the different dimensional values ​​of some structural parameters of the lens barrel and the spacer assembly in the optical system. Specifically, the values ​​of each relevant structural parameter in Embodiment 4 are shown in Table 11 below. The specific descriptions of multiple structural parameters are the same as those in Embodiment 2 above, and will not be repeated here.

[0131] The on-axis chromatic aberration curves of the optical systems in Examples 3 and 4 are as follows: Figure 7A As shown, this represents the degree of deviation of the focal point after light of different wavelengths passes through the optical system; the astigmatism curves of the optical systems in Examples 3 and 4 are shown below. Figure 7B As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane; the distortion curves of the optical systems in Embodiments 3 and 4 are as follows. Figure 7C As shown, it represents the relative deviation between the actual image and the ideal image. The magnification chromatic aberration curves of the optical systems in Embodiments 3 and 4 are shown below. Figure 7D As shown, this represents the difference in imaging height at different wavelengths. Figures 7A to 7D It can be seen that the optical systems in both Embodiment 3 and Embodiment 4 can achieve good imaging quality.

[0132] Example 5

[0133] like Figure 8 As shown, in this embodiment, the optical system includes a lens barrel P0 and a lens group and a spacer assembly housed within the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes a first spacer element P1 placed on the image side of the first lens E1 and in contact with the image side surface S2 of the first lens E1, a second spacer element P2 placed on the image side of the second lens E2 and in contact with the image side surface S4 of the second lens E2, a third spacer element P3 placed on the image side of the third lens E3 and in contact with the image side surface S6 of the third lens E3, and a fourth spacer element P4 placed on the image side of the fourth lens E4 and in contact with the image side surface S8 of the fourth lens E4.

[0134] In this embodiment, the first lens E1 has positive optical power, and the object-side surface S1 and image-side surface S2 of the first lens E1 are convex and concave, respectively; the second lens E2 has positive optical power, and the object-side surface S3 and image-side surface S4 of the second lens E2 are concave and convex, respectively; the third lens E3 has negative optical power, and the object-side surface S5 and image-side surface S6 of the third lens E3 are convex and concave, respectively; the fourth lens E4 has positive optical power, and the object-side surface S7 and image-side surface S8 of the fourth lens E4 are concave and convex, respectively; the fifth lens E5 has negative optical power, and the object-side surface S9 and image-side surface S10 of the fifth lens E5 are convex and concave, respectively.

[0135] In addition, Table 6 shows the basic optical parameters of the optical imaging system of Embodiment 5, where the units of radius of curvature and thickness / distance are millimeters (mm).

[0136] Table 6: Basic optical parameters of the optical system in Example 5

[0137]

[0138] It should be noted that the materials in Table 6 include refractive index and Abbe number. For example, in Table 6, the materials 1.65 and 23.50 for S1 indicate that the refractive index of the first lens E1 is 1.65 and the Abbe number is 23.50, respectively.

[0139] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, and the fifth lens E5 are aspherical. The surface shape of each aspherical lens can be defined by the aspherical formula given in Embodiment 1 above. Tables 7-1 and 7-2 below give the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for each aspherical mirror S1 to S10 in Embodiment 5.

[0140] Table 7-1: Aspherical coefficients of the optical system in Example 5 (A4~A16)

[0141]

[0142] Table 7-2: Aspherical coefficients of the optical system in Example 5 (A18~A30)

[0143]

[0144] Example 6

[0145] like Figure 9As shown, in this embodiment, the optical system includes a lens barrel P0 and a lens group and a spacer assembly housed within the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes a first spacer element P1 placed on the image side of the first lens E1 and in contact with the image side surface S2 of the first lens E1, a second spacer element P2 placed on the image side of the second lens E2 and in contact with the image side surface S4 of the second lens E2, a third spacer element P3 placed on the image side of the third lens E3 and in contact with the image side surface S6 of the third lens E3, and a fourth spacer element P4 placed on the image side of the fourth lens E4 and in contact with the image side surface S8 of the fourth lens E4.

[0146] It is worth noting that, compared with Embodiment 5 above, the optical system of Embodiment 6 has the same optical parameters, that is, the basic optical parameter table of the optical system of Embodiment 6 is the same as Table 6, and the aspherical coefficient table is the same as Table 7. However, the optical system of Embodiment 6 has different structural parameters than the optical system of Embodiment 5 above. That is, the difference between Embodiment 6 and Embodiment 5 above lies in the different dimensional values ​​of some structural parameters of the lens barrel and the spacer assembly in the optical system. Specifically, the values ​​of each relevant structural parameter in Embodiment 6 are shown in Table 11 below. The specific descriptions of multiple structural parameters are the same as those in Embodiment 2 above, and will not be repeated here.

[0147] The on-axis chromatic aberration curves of the optical systems in Examples 5 and 6 are as follows: Figure 10A As shown, this represents the degree of deviation of the focal point after light of different wavelengths passes through the optical system; the astigmatism curves of the optical systems in Examples 5 and 6 are shown below. Figure 10B As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane; the distortion curves of the optical systems in Examples 5 and 6 are as follows. Figure 10C As shown, it represents the relative deviation between the actual image and the ideal image. The magnification chromatic aberration curves of the optical systems in Examples 5 and 6 are as follows: Figure 10D As shown, this represents the difference in imaging height at different wavelengths. Figures 10A to 10D It can be seen that the optical systems in both Embodiment 5 and Embodiment 6 can achieve good imaging quality.

[0148] Example 7

[0149] like Figure 11As shown, in this embodiment, the optical system includes a lens barrel P0 and a lens group and a spacer assembly housed within the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes a first spacer element P1 placed on the image side of the first lens E1 and in contact with the image side surface S2 of the first lens E1, a second spacer element P2 placed on the image side of the second lens E2 and in contact with the image side surface S4 of the second lens E2, a third spacer element P3 placed on the image side of the third lens E3 and in contact with the image side surface S6 of the third lens E3, and a fourth spacer element P4 placed on the image side of the fourth lens E4 and in contact with the image side surface S8 of the fourth lens E4.

[0150] In this embodiment, the first lens E1 has positive optical power, and the object-side surface S1 and image-side surface S2 of the first lens E1 are convex and concave, respectively; the second lens E2 has positive optical power, and the object-side surface S3 and image-side surface S4 of the second lens E2 are concave and convex, respectively; the third lens E3 has negative optical power, and the object-side surface S5 and image-side surface S6 of the third lens E3 are convex and concave, respectively; the fourth lens E4 has positive optical power, and the object-side surface S7 and image-side surface S8 of the fourth lens E4 are concave and convex, respectively; the fifth lens E5 has negative optical power, and the object-side surface S9 and image-side surface S10 of the fifth lens E5 are convex and concave, respectively.

[0151] In addition, Table 8 shows the basic optical parameters of the optical imaging system of Embodiment 7, where the units of radius of curvature and thickness / distance are millimeters (mm).

[0152] Table 8: Basic optical parameters of the optical system in Example 7

[0153]

[0154] It should be noted that the materials in Table 8 include refractive index and Abbe number. For example, in Table 8, the materials 1.65 and 23.50 for S1 indicate that the refractive index of the first lens E1 is 1.65 and the Abbe number is 23.50, respectively.

[0155] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1, the second lens E2, the third lens E3, the fourth lens E4, and the fifth lens E5 are aspherical. The surface shape of each aspherical lens can be defined by the aspherical formula given in Embodiment 1 above. Tables 9-1 and 9-2 below give the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for each aspherical mirror S1 to S10 in Embodiment 7.

[0156] Table 9-1: Aspherical coefficients of the optical system in Example 7 (A4~A16)

[0157]

[0158] Table 9-2: Aspherical coefficients of the optical system in Example 7 (A18~A30)

[0159]

[0160] Example 8

[0161] like Figure 12 As shown, in this embodiment, the optical system includes a lens barrel P0 and a lens group and a spacer assembly housed within the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side; the spacer assembly includes a first spacer element P1 placed on the image side of the first lens E1 and in contact with the image side surface S2 of the first lens E1, a second spacer element P2 placed on the image side of the second lens E2 and in contact with the image side surface S4 of the second lens E2, a third spacer element P3 placed on the image side of the third lens E3 and in contact with the image side surface S6 of the third lens E3, and a fourth spacer element P4 placed on the image side of the fourth lens E4 and in contact with the image side surface S8 of the fourth lens E4.

[0162] It is worth noting that, compared with Embodiment 7 above, the optical system of Embodiment 8 has the same optical parameters, that is, the basic optical parameter table of the optical system of Embodiment 8 is the same as Table 8, and the aspherical coefficient table is the same as Table 9. However, the optical system of Embodiment 8 has different structural parameters than the optical system of Embodiment 7 above. That is, the difference between Embodiment 8 and Embodiment 7 above lies in the different dimensional values ​​of some structural parameters of the lens barrel and the spacer assembly in the optical system. Specifically, the values ​​of each relevant structural parameter in Embodiment 8 are shown in Table 11 below. The specific descriptions of multiple structural parameters are the same as those in Embodiment 2 above, and will not be repeated here.

[0163] The on-axis chromatic aberration curves of the optical systems in Examples 7 and 8 are as follows: Figure 13A As shown, this indicates the degree of deviation of the focal point after light of different wavelengths passes through the optical system; the astigmatism curves of the optical systems in Examples 7 and 8 are shown below. Figure 13B As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane; the distortion curves of the optical systems in Examples 7 and 8 are as follows. Figure 13C As shown, it represents the relative deviation between the actual image and the ideal image. The magnification chromatic aberration curves of the optical systems in Examples 7 and 8 are as follows: Figure 13DAs shown, this represents the difference in imaging height at different wavelengths. Figures 13A to 13D It can be seen that the optical systems in both Embodiment 7 and Embodiment 8 can achieve good imaging quality.

[0164] In summary, in Embodiments 1 to 8, the effective focal lengths f1 to f5 of the first lens E1 to the fifth lens E5 in the optical system, the effective focal length f of the optical system, the axial displacement SAG22 between the intersection of the image side surface of the second lens E2 and the optical axis and the vertex of the effective radius of the optical region of the image side surface of the second lens E2, the axial displacement SAG42 between the intersection of the image side surface of the fourth lens E4 and the optical axis and the vertex of the effective radius of the optical region of the image side surface of the fourth lens E4, and half of the maximum field of view (Semi-FOV) of the optical system are shown in Table 10 below.

[0165] Table 10: Optical Parameters of the Optical System

[0166]

[0167] In addition, some structural parameters of the optical systems in Examples 1 to 8 are shown in Table 11.

[0168] Table 11: Partial Structural Parameters of the Optical System

[0169]

[0170] In summary, the optical systems in Examples 1 to 8 satisfy the relationships shown in Table 11, as detailed in Table 12.

[0171] Table 12: Relationships satisfied by the optical system

[0172]

[0173] It is worth mentioning that, according to one aspect of this application, one embodiment of this application further provides a camera module, which may include the aforementioned optical system and a photosensitive element, the photosensitive element being disposed on the image side of the optical system for imaging. It is understood that the photosensitive element mentioned in this application may, but is not limited to, be implemented as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device, and this application will not elaborate further on this.

[0174] Furthermore, according to another aspect of this application, one embodiment of this application provides an electronic device that may include a camera module and a processor as described above. The camera module is communicatively connected to the processor for acquiring image data and inputting the image data into the processor for processing. It is understood that the electronic device mentioned in this application may, but is not limited to, a device such as a mobile phone equipped with the camera module, and this application will not elaborate further on this.

[0175] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0176] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An optical system, characterized in that: The system includes a lens barrel and a lens assembly and a spacer assembly housed within the lens barrel. The lens assembly includes, arranged sequentially along the optical axis from the object side to the image side, a first lens with positive optical power, a second lens with positive optical power, a third lens with negative optical power, a fourth lens with positive optical power, and a fifth lens with negative optical power. The spacer assembly includes at least a first spacer element disposed on the image side of the first lens and in contact with the image side surface of the first lens, and a third spacer element disposed on the image side of the third lens and in contact with the image side surface of the third lens. The lens group contains five lenses; Wherein, the object-side surface and image-side surface of the first lens are convex and concave respectively, the object-side surface and image-side surface of the second lens are concave and convex respectively, the object-side surface and image-side surface of the third lens are convex and concave respectively, the object-side surface and image-side surface of the fourth lens are concave and convex respectively, and the object-side surface and image-side surface of the fifth lens are convex and concave respectively. The optical system satisfies the following conditions: 27.19≤f1 / EP01≤36.00; 3.92≤R2×N1 / D1s≤6.95; 10.00mm≤f1 / Tan(Semi-FOV)≤13.89mm; -10.59≤f3 / (CP3+CT3)≤-7.06; Wherein, f1 is the effective focal length of the first lens, EP01 is the distance between the object-side end face of the lens barrel and the first spacer element in the optical axis direction, R2 is the radius of curvature of the image-side surface of the first lens, N1 is the refractive index of the first lens, D1s is the outer diameter of the object-side surface of the first spacer element; Semi-FOV is the maximum half field of view of the optical system; f3 is the effective focal length of the third lens, CP3 is the maximum thickness of the third spacer element; CT3 is the center thickness of the third lens in the optical axis.

2. The optical system according to claim 1, characterized in that, The optical system also satisfies: -5.64≤R3 / (D1m-d1m)≤-4.29; Wherein, D1m is the outer diameter of the image side of the first spacer element, d1m is the inner diameter of the image side of the first spacer element, and R3 is the radius of curvature of the object side of the second lens.

3. The optical system according to claim 1, characterized in that, The spacer assembly further includes a second spacer element placed on the image side of the second lens and in contact with the image side surface of the second lens, and the optical system also satisfies: 3.89≤f2 / (CP2+CT2)≤4.49; Where f2 is the effective focal length of the second lens, CP2 is the maximum thickness of the second spacer element, and CT2 is the center thickness of the second lens on the optical axis.

4. The optical system according to claim 1, characterized in that, The spacer assembly further includes a second spacer element placed on the image side of the second lens and in contact with the image side surface of the second lens, and the optical system also satisfies: 1.56≤R5 / d2m≤2.34; Wherein, R5 is the radius of curvature of the object side of the third lens, and d2m is the inner diameter of the image side of the second spacer element.

5. The optical system according to any one of claims 1 to 4, characterized in that, The spacing assembly further includes a second spacing element placed on the image side of the second lens and in contact with the image side surface of the second lens, and a third spacing element placed on the image side of the third lens and in contact with the image side surface of the third lens. The optical system also satisfies: 1.40≤T34 / EP23≤1.

71. Wherein, T34 is the air gap between the third lens and the fourth lens on the optical axis, and EP23 is the distance between the second spacer element and the third spacer element along the optical axis.

6. The optical system according to any one of claims 1 to 4, characterized in that, The spacing assembly further includes a third spacing element placed on the image side of the third lens and in contact with the image side surface of the third lens, and the optical system also satisfies: 2.14≤R6×N3 / (D3s-d3s)≤2.64; Wherein, R6 is the radius of curvature of the image side of the third lens, N3 is the refractive index of the third lens, D3s is the outer diameter of the object side of the third spacer element, and d3s is the inner diameter of the object side of the third spacer element.

7. The optical system according to any one of claims 1 to 4, characterized in that, The spacing assembly further includes a third spacing element disposed on the image side of the third lens and in contact with the image side surface of the third lens, and the optical system also satisfies: -1.57≤R7 / d3m≤-0.79; Wherein, R7 is the radius of curvature of the object side of the fourth lens, and d3m is the inner diameter of the image side of the third spacer element.

8. The optical system according to any one of claims 1 to 4, characterized in that, The spacing assembly further includes a third spacing element placed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth spacing element placed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The optical system also satisfies: 2.00≤CT4 / EP34≤2.

76. Wherein, CT4 is the center thickness of the fourth lens on the optical axis, and EP34 is the distance between the third spacer element and the fourth spacer element along the optical axis.

9. The optical system according to any one of claims 1 to 4, characterized in that, The spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system also satisfies: 2.02≤CP4 / T45≤7.72; Wherein, CP4 is the maximum thickness of the fourth spacer element, and T45 is the air gap between the fourth lens and the fifth lens on the optical axis.

10. The optical system according to any one of claims 1 to 4, characterized in that, The spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system also satisfies: -6.87≤D4s / R8≤-5.60; Wherein, R8 is the radius of curvature of the image side of the fourth lens, and D4s is the outer diameter of the object side of the fourth spacer element.

11. The optical system according to any one of claims 1 to 4, characterized in that, The spacing assembly further includes a fourth spacing element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens, and the optical system also satisfies: 1.94≤R9 / (D4m-d4m)≤4.29; Wherein, D4m is the outer diameter of the image side of the fourth spacer element, d4m is the inner diameter of the image side of the fourth spacer element, and R9 is the radius of curvature of the object side of the fifth lens.

12. The optical system according to any one of claims 1 to 4, characterized in that: The spacing assembly includes a first spacing element placed on the image side of the first lens and in contact with the image side surface of the first lens, a second spacing element placed on the image side of the second lens and in contact with the image side surface of the second lens, a third spacing element placed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth spacing element placed on the image side of the fourth lens and in contact with the image side surface of the fourth lens; the optical system also satisfies: 2.86≤SAG42 / SAG22≤3.40; and 1.42≤EP34 / EP12≤2.05; Wherein, SAG22 is the axial displacement between the intersection of the image side surface of the second lens and the optical axis and the vertex of the effective radius of the optical region of the image side surface of the second lens; SAG42 is the axial displacement between the intersection of the image side surface of the fourth lens and the optical axis and the vertex of the effective radius of the optical region of the image side surface of the fourth lens; EP12 is the distance between the first spacer element and the second spacer element along the optical axis; and EP34 is the distance between the third spacer element and the fourth spacer element along the optical axis.

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