Imaging system

Abstract

An imaging system is disclosed. The imaging system includes a lens group, a plurality of spacer elements, and a lens barrel for accommodating the lens group and the plurality of spacer elements. The lens group includes, in order from an object side to an image side along an optical axis, a first lens having a refractive power, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, wherein an object side surface of the sixth lens is convex, and an image side surface of the seventh lens is concave. At least one of the spacer elements includes a sixth spacer element located on an image side of the sixth lens and partially in contact with the image side surface of the sixth lens. The imaging system satisfies: 0 < (D6s x d6s) / (R11 x R14) < 19 and 40 mm < (d0s + d0m) / Fno x L < 55 mm. 2 . 2 .

Description

Technical Field

[0001] This application relates to the field of optical components, and more specifically, to an imaging system. Background Technology

[0002] In recent years, with the continuous development of technology, consumer electronics products with camera functions have gained increasing market exposure. At the same time, the continuous upgrading and iteration of consumer electronics products has driven the continuous optimization and upgrading of related industries, such as the most representative mobile phone industry. The continuous optimization and upgrading of the mobile phone industry has led to the continuous iteration and upgrading of the imaging systems integrated into mobile phones, making mobile phone camera technology one of the main factors in improving mobile phone competitiveness.

[0003] However, in imaging systems, phenomena such as imperfect outer diameter step differences between lenses often exist. Under normal circumstances, imperfect outer diameter step differences between lenses can severely reduce the assembly yield and image quality of the imaging system. Therefore, improving the image quality of imaging systems is crucial. Summary of the Invention

[0004] This application provides an imaging system comprising, along the optical axis from the object side to the image side, a lens group, at least one spacer element, and a lens barrel for accommodating the lens group and the at least one spacer element. The lens group, along the optical axis from the object side to the image side, comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, each having optical power. The object side of the sixth lens is convex, and the image side of the seventh lens is concave. The at least one spacer element is a sixth spacer element located on the image side of the sixth lens and partially in contact with the image side surface of the sixth lens. The imaging system satisfies: 0 < (D6s × d6s) / (R11 × R14) < 19 and 40 mm. 2 <(d0s+d0m) / Fno×L<55mm 2 D6s is the outer diameter of the object-side surface of the sixth spacer element, d6s is the inner diameter of the object-side surface of the sixth spacer element, R11 is the radius of curvature of the object-side surface of the sixth lens, R14 is the radius of curvature of the image-side surface of the seventh lens, d0s is the inner diameter of the object-side end of the lens barrel, d0m is the inner diameter of the image-side end of the lens barrel, Fno is the aperture value of the imaging system, and L is the maximum height of the lens barrel.

[0005] In one embodiment, at least one of the object-side surface of the first lens to the image-side surface of the seventh lens is an aspherical mirror.

[0006] In one embodiment, at least one spacer element further includes a fourth spacer element located on the image side of the fourth lens and in partial contact with the image side surface of the fourth lens. Both the fourth and fifth lenses have negative optical power; and the imaging system satisfies: -26 < (f4 + f5) / (d4s + d4m) < 0, where f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, d4s is the inner diameter of the object side surface of the fourth spacer element, and d4m is the inner diameter of the image side surface of the fourth spacer element.

[0007] In one embodiment, the sixth lens has a positive optical power; the seventh lens has a negative optical power; and the imaging system satisfies: 2 < (f6 - f7) / (CP6 + CT7) < 21, where f6 is the effective focal length of the sixth lens, f7 is the effective focal length of the seventh lens, CP6 is the maximum thickness of the sixth spacer element, and CT7 is the center thickness of the seventh lens on the optical axis.

[0008] In one embodiment, at least one spacer element further includes a first spacer element located on the image side of the first lens and partially in contact with the image side surface of the first lens. The imaging system may satisfy: 10mm < f1 / EP01×EPD < 25mm, where f1 is the effective focal length of the first lens, EP01 is the spacing distance from the object side end of the lens barrel to the object side surface of the first spacer element in the direction along the optical axis, and EPD is the entrance pupil diameter of the imaging system.

[0009] In one embodiment, at least one spacer element further includes: a first spacer element located on the image side of the first lens and in contact with a portion of the image side surface of the first lens; a second spacer element located on the image side of the second lens and in contact with a portion of the image side surface of the second lens; and a third spacer element located on the image side of the third lens and in contact with a portion of the image side surface of the third lens. The imaging system may satisfy: -35 < f2 / EP12 < -15 and 12 < f3 / EP23 < 60, where f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, EP12 is the spacing distance along the optical axis from the image side surface of the first spacer element to the object side surface of the second spacer element, and EP23 is the spacing distance along the optical axis from the image side surface of the second spacer element to the object side surface of the third spacer element.

[0010] In one embodiment, at least one spacer element further includes a first spacer element located on the image side of the first lens and in partial contact with the image side surface of the first lens. The imaging system can satisfy: 3mm < R2 / (D1s-d1s)×CT1 < 18mm and 0mm < R3 / (D1m-d1m)×CT2 < 3mm, where R2 is the radius of curvature of the image side surface of the first lens, D1s is the outer diameter of the object side surface of the first spacer element, d1s is the inner diameter of the object side surface of the first spacer element, CT1 is the center thickness of the first lens on the optical axis, R3 is the radius of curvature of the object side surface of the second lens, 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 CT2 is the center thickness of the second lens on the optical axis.

[0011] In one embodiment, at least one spacer element further includes a second spacer element located on the image side of the second lens and in partial contact with the image side surface of the second lens. The imaging system can satisfy: 2mm < R4×d2s / (CT2+CP2) < 16mm and 18mm < R5×D2m / (CP2+CT3) < 80mm, where R4 is the radius of curvature of the image side surface of the second lens, d2s is the inner diameter of the object side surface of the second spacer element, CT2 is the center thickness of the second lens on the optical axis, CP2 is the maximum thickness of the second spacer element, R5 is the radius of curvature of the object side surface of the third lens, D2m is the outer diameter of the image side surface of the second spacer element, and CT3 is the center thickness of the third lens on the optical axis.

[0012] In one embodiment, at least one spacer element further includes: a third spacer element located on the image side of the third lens and in contact with a portion of the image side surface of the third lens, and a fourth spacer element located on the image side of the fourth lens and in contact with a portion of the image side surface of the fourth lens. The imaging system can satisfy: 1 ​​< f3 / d3s < 8 and 12 < R8 / (EP34+CP3) < 70, where f3 is the effective focal length of the third lens, d3s is the inner diameter of the object side surface of the third spacer element, R8 is the radius of curvature of the image side surface of the fourth lens, EP34 is the spacing distance from the image side surface of the third spacer element to the object side surface of the fourth spacer element in the direction along the optical axis, and CP3 is the maximum thickness of the third spacer element.

[0013] In one embodiment, at least one spacer element further includes: a fourth spacer element located on the image side of the fourth lens and in partial contact with the image side surface of the fourth lens, and a fifth spacer element located on the image side of the fifth lens and in partial contact with the image side surface of the fifth lens. The imaging system can satisfy: -12 < f4 / D4m < 0 and 5 < R10 / (EP45+T45) < 35, where f4 is the effective focal length of the fourth lens, D4m is the outer diameter of the image side surface of the fourth spacer element, R10 is the radius of curvature of the image side surface of the fifth lens, EP45 is the spacing distance between the image side surface of the fourth spacer element and the object side surface of the fifth spacer element along the optical axis, and T45 is the air gap between the fourth lens and the fifth lens along the optical axis.

[0014] In one embodiment, at least one spacer element further includes: a first spacer element located on the image side of the first lens and in contact with a portion of the image side surface of the first lens; a second spacer element located on the image side of the second lens and in contact with a portion of the image side surface of the second lens; and a third spacer element located on the image side of the third lens and in contact with a portion of the image side surface of the third lens. The imaging system can satisfy: 10mm < (|f1×d1m| + |f2×d2m| + |f3×d3m|) / f123 < 18mm, where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f123 is the combined focal length of the first, second, and third lenses, d1m is the inner diameter of the image side surface of the first spacer element, d2m is the inner diameter of the image side surface of the second spacer element, and d3m is the inner diameter of the image side surface of the third spacer element.

[0015] In one embodiment, at least one spacer element further includes: a first spacer element located on the image side of the first lens and in contact with the image side portion of the first lens; a second spacer element located on the image side of the second lens and in contact with the image side portion of the second lens; a third spacer element located on the image side of the third lens and in contact with the image side portion of the third lens; a fourth spacer element located on the image side of the fourth lens and in contact with the image side portion of the fourth lens; and a fifth spacer element located on the image side of the fifth lens and in contact with the image side portion of the fifth lens.

[0016] In one embodiment, the imaging system may satisfy: 40 < Va × EP12 / EP23 < 86 and 5 < Vb × EP45 / EP56 < 40, where Va is the Abbe number of the lens with the smallest absolute value of effective focal length among the first, second, and third lenses, Vb is the Abbe number of the lens with the largest absolute value of effective focal length among the fifth, sixth, and seventh lenses, EP12 is the spacing distance along the optical axis from the image side of the first spacer element to the object side of the second spacer element, EP23 is the spacing distance along the optical axis from the image side of the second spacer element to the object side of the third spacer element, EP45 is the spacing distance along the optical axis from the image side of the fourth spacer element to the object side of the fifth spacer element, and EP56 is the spacing distance along the optical axis from the image side of the fifth spacer element to the object side of the sixth spacer element.

[0017] In one embodiment, the imaging system may satisfy: 2mm < (D1m + D2m + D3m) / Na < 10mm and 10mm < (D4m + D5m + D6m) / Nb < 16mm, where Na is the refractive index of the lens with the smallest Abbe number among the first, second, and third lenses, Nb is the refractive index of the lens with the largest Abbe number among the fifth, sixth, and seventh lenses, D1m is the outer diameter of the image-side surface of the first spacer element, D2m is the outer diameter of the image-side surface of the second spacer element, D3m is the outer diameter of the image-side surface of the third spacer element, D4m is the outer diameter of the image-side surface of the fourth spacer element, D5m is the outer diameter of the image-side surface of the fifth spacer element, and D6m is the outer diameter of the image-side surface of the sixth spacer element.

[0018] In one embodiment, the inner diameter of the object side of the third spacer is smaller than the inner diameter of the object side of any one of the first to sixth spacers; and the inner diameter of the image side of the third spacer is smaller than the inner diameter of the image side of any one of the first to sixth spacers.

[0019] In one embodiment, at least one spacer element further includes an auxiliary spacer element located on the image side of the sixth spacer element and in contact with the image side portion of the sixth spacer element.

[0020] In an exemplary embodiment of this application, by reasonably arranging seven lenses, spacer elements, and lens barrel, and by reasonably setting the surface shape of the sixth and seventh lenses, and the key technical parameters of the imaging system such as 0 < (D6s × d6s) / (R11 × R14) < 19 and 40mm, the imaging system is improved. 2 <(d0s+d0m) / Fno×L<55mm 2This allows the imaging system provided by this application to possess characteristics such as better outer diameter step difference, better assembly yield, and higher imaging quality. For example, by reasonably matching seven lenses, spacers, and the lens barrel, this application can achieve a certain imaging effect. Furthermore, by reasonably setting the curvature radii of the relevant surfaces of the sixth and seventh lenses, as well as the relevant dimensions of the lens barrel and the sixth spacer, a better outer diameter step difference can be achieved between the sixth lens, the sixth spacer, and the seventh lens. This helps to improve the assembly yield of the imaging system and enhance its product competitiveness. Attached Figure Description

[0021] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0022] Figures 1A to 1C These are schematic diagrams of the imaging system under the three implementation methods in Example 1;

[0023] Figures 2A to 2D The on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the imaging system of Example 1 are shown respectively.

[0024] Figures 3A to 3C These are schematic diagrams of the imaging system under the three implementation methods in Example 2;

[0025] Figures 4A to 4D The on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the imaging system of Example 2 are shown respectively.

[0026] Figures 5A to 5C These are schematic diagrams of the imaging system under the three implementation methods in Example 3;

[0027] Figures 6A to 6D The on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the imaging system of Example 3 are shown respectively; and

[0028] Figure 7 This is a schematic diagram of some parameters of an imaging system according to an embodiment of this application. Detailed Implementation

[0029] 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.

[0030] 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, and the first spacer element may also be referred to as the second spacer element or the third spacer element.

[0031] 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 drawn strictly to scale. It should be understood that, for ease of illustration, the thickness, size, and shape of the spacer elements and lens barrel have also been slightly exaggerated in the accompanying drawings.

[0032] In this text, 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 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. It should be understood that the surface of each spacer element closest to the subject is called the object-side surface of the spacer element, and the surface of each spacer element closest to the imaging plane is called the image-side surface of the spacer element. The surface of the lens barrel closest to the subject is called the object-side end of the lens barrel, and the surface of the lens barrel closest to the imaging plane is called the image-side end of the lens barrel.

[0033] 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.

[0034] 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 the 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.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. The following embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. For example, the lens groups (i.e., the first to the seventh lenses), lens barrel structures, and spacer elements in the various embodiments of this application can be arbitrarily combined, and it is not limited to the lens group in one embodiment being only combined with the lens barrel structure, spacer elements, etc. of that embodiment. The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] The features, principles and other aspects of this application are described in detail below.

[0037] An imaging system according to an exemplary embodiment of this application may include seven lenses with optical power, namely a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. These seven lenses are arranged sequentially along the optical axis from the object side to the image side. Any two adjacent lenses among the first to seventh lenses may have a spacing distance. Any lens among the first to seventh lenses may have a central thickness along the optical axis.

[0038] According to an exemplary embodiment of this application, each of the first to seventh lenses may have an optical region for optical imaging and a non-optical region extending outward from the outer periphery of the optical region. Generally speaking, the optical region refers to the area of ​​the lens used for optical imaging, while the non-optical region is the structural area of ​​the lens. During the assembly of the imaging system, spacer elements can be set at the non-optical regions of each lens using processes such as adhesive bonding, and each lens can be connected to the lens barrel. During the imaging process of the imaging system, the optical regions of each lens can transmit light from the object to form an optical path, forming the final optical image; while the non-optical regions of each assembled lens are housed in the lens barrel, which cannot transmit light, thus the non-optical regions do not directly participate in the imaging process of the imaging system. It should be noted that, for ease of description, this application describes each lens as divided into two parts: an optical region and a non-optical region. However, it should be understood that the optical region and the non-optical region of the lens can be formed as a whole during the manufacturing process, rather than as two separate parts.

[0039] An imaging system according to an exemplary embodiment of this application may include at least one spacer element, such as at least one of a first spacer element, a second spacer element, a third spacer element, a fourth spacer element, a fifth spacer element, a sixth spacer element, and an auxiliary spacer element. Exemplarily, the first spacer element may be located on the image side of a first lens and partially contact the image side surface of the first lens, and may abut against a non-optical region of the image side surface of the first lens. The second spacer element may be located on the image side of a second lens and partially contact the image side surface of the second lens, and may abut against a non-optical region of the image side surface of the second lens. The third spacer element may be located on the image side of a third lens and partially contact the image side surface of the third lens, and may abut against a non-optical region of the image side surface of the third lens. The fourth spacer element may be located on the image side of a fourth lens and partially contact the image side surface of the fourth lens, and may abut against a non-optical region of the image side surface of the fourth lens. The fifth spacer element may be located on the image side of a fifth lens and partially contact the image side surface of the fifth lens, and may abut against a non-optical region of the image side surface of the fifth lens. A sixth spacer element may be located on the image side of the sixth lens and partially contact the image-side surface of the sixth lens, and may abut against a non-optical region of the image-side surface of the sixth lens. An auxiliary spacer element may be located on the image side of the sixth spacer element and partially contact the image-side surface of the sixth spacer element, and may abut against the image-side surface of the sixth spacer element. Exemplarily, a first spacer element may contact a non-optical region of the image-side surface of the first lens, and simultaneously contact a non-optical region of the object-side surface of the second lens. For example, the object-side surface of the first spacer element may contact a non-optical region of the image-side surface of the first lens, and the image-side surface of the first spacer element may contact a non-optical region of the object-side surface of the second lens.

[0040] An imaging system according to an exemplary embodiment of this application may include a lens barrel housing a lens group and a plurality of spacer elements. For example, as... Figures 1A to 1C As shown, the lens barrel can be a one-piece lens barrel used to house the first to seventh lenses and the first to sixth spacer elements.

[0041] According to an exemplary embodiment of this application, the spacer element may include at least one spacer plate. By reasonably setting the number, thickness, inner diameter, and outer diameter of the spacers plate, it is beneficial to improve the assembly of the imaging system, to block stray light, and to improve the imaging quality of the imaging system.

[0042] In an exemplary embodiment, the imaging system according to this application may include a sixth spacer element located on the image side of the sixth lens and partially in contact with the image side surface of the sixth lens. The imaging system may satisfy: 0 < (D6s × d6s) / (R11 × R14) < 19 and 40 mm. 2 <(d0s+d0m) / Fno×L<55mm 2D6s is the outer diameter of the object-side surface of the sixth spacer element, d6s is the inner diameter of the object-side surface of the sixth spacer element, R11 is the radius of curvature of the object-side surface of the sixth lens, R14 is the radius of curvature of the image-side surface of the seventh lens, d0s is the inner diameter of the object-side end of the lens barrel, d0m is the inner diameter of the image-side end of the lens barrel, Fno is the aperture value of the imaging system, and L is the maximum height of the lens barrel.

[0043] In this application, by rationally combining seven lenses, spacer elements, and lens barrel, and by rationally setting the surface shape of the sixth and seventh lenses, as well as the key technical parameters of the imaging system such as 0 < (D6s × d6s) / (R11 × R14) < 19 and 40mm, the imaging system achieves this. 2 <(d0s+d0m) / Fno×L<55mm 2 This allows the imaging system provided by this application to possess characteristics such as better outer diameter step difference, better assembly yield, and higher imaging quality. For example, by reasonably matching seven lenses, spacers, and the lens barrel, this application can achieve a certain imaging effect. Furthermore, by reasonably setting the curvature radii of the relevant surfaces of the sixth and seventh lenses, as well as the relevant dimensions of the lens barrel and the sixth spacer, a better outer diameter step difference can be achieved between the sixth lens, the sixth spacer, and the seventh lens. This helps to improve the assembly yield of the imaging system and enhance its product competitiveness.

[0044] In an exemplary embodiment, both the fourth and fifth lenses can have negative optical power. Exemplarily, the imaging system according to this application may include a fourth spacer element located on the image side of the fourth lens and partially in contact with the image-side surface of the fourth lens. The imaging system can satisfy: -26 < (f4 + f5) / (d4s + d4m) < 0, where f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, d4s is the inner diameter of the object-side surface of the fourth spacer element, and d4m is the inner diameter of the image-side surface of the fourth spacer element. By satisfying -26 < (f4 + f5) / (d4s + d4m) < 0, reasonable control of the effective focal lengths of the fourth and fifth lenses and the inner diameter of the fourth spacer element can ensure that the quality of the image light after divergence through the fourth lens is maximized when passing through the fourth spacer element, reducing the generation of stray light and other light, thereby improving the quality of the imaging system.

[0045] In an exemplary embodiment, the sixth lens may have a positive optical power, and the seventh lens may have a negative optical power. Exemplarily, the imaging system according to this application satisfies: 2 < (f6-f7) / (CP6+CT7) < 21, where f6 is the effective focal length of the sixth lens, f7 is the effective focal length of the seventh lens, CP6 is the maximum thickness of the sixth spacer element, and CT7 is the center thickness of the seventh lens along the optical axis. This application, by reasonably setting the optical power of the sixth and seventh lenses, can ensure the quality of light after passing through them. Exemplarily, satisfying 2 < (f6-f7) / (CP6+CT7) < 21 allows for control of the relationship between the effective focal lengths of the sixth and seventh lenses, the relevant dimensions of the sixth spacer element, and the center thickness of the seventh lens. This ensures that the dimensions of the sixth and seventh lenses along and perpendicular to the optical axis are within a reasonable range, thereby improving the assembly stability and product quality of the imaging system.

[0046] In an exemplary embodiment, the imaging system according to this application may include a first spacer element located on the image side of a first lens and partially in contact with the image side surface of the first lens. The imaging system may satisfy: 10mm < f1 / EP01 × EPD < 25mm, where f1 is the effective focal length of the first lens, EP01 is the distance between the object side end of the lens barrel and the object side surface of the first spacer element along the optical axis, and EPD is the entrance pupil diameter of the imaging system. By satisfying 10mm < f1 / EP01 × EPD < 25mm, the relationship between the effective focal length of the first lens, the entrance pupil diameter, and the distance between the object side end of the lens barrel and the object side surface of the first spacer element along the optical axis can be controlled to achieve high structural uniformity and high molding feasibility of the first lens, provided that there is sufficient incident light, thereby improving the imaging quality of the imaging system.

[0047] In an exemplary embodiment, the imaging system according to this application may include a first spacer element located on the image side of a first lens and in contact with a portion of the image side surface of the first lens, a second spacer element located on the image side of a second lens and in contact with a portion of the image side surface of the second lens, and a third spacer element located on the image side of a third lens and in contact with a portion of the image side surface of the third lens. The imaging system may satisfy: -35 < f2 / EP12 < -15 and 12 < f3 / EP23 < 60, where f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, EP12 is the spacing distance between the image side surface of the first spacer element and the object side surface of the second spacer element along the optical axis, and EP23 is the spacing distance between the image side surface of the second spacer element and the object side surface of the third spacer element along the optical axis. By satisfying -35 < f2 / EP12 < -15 and 12 < f3 / EP23 < 60, the overall structure of the second and third lenses can be improved in the radial direction (i.e., perpendicular to the optical axis) by controlling the ratio of the effective focal length of the second lens to the on-axis distance between the first and second spacers, and the ratio of the effective focal length of the third lens to the on-axis distance between the second and third spacers. This is beneficial to improving the axial (i.e., optical axis) and radial stability of the overall structure of the lens group, and ensuring the assembly yield of the imaging system.

[0048] In an exemplary embodiment, the imaging system according to this application may include a first spacer element located on the image side of a first lens and in partial contact with the image side surface of the first lens. The imaging system may satisfy: 3mm < R2 / (D1s-d1s)×CT1 < 18mm and 0mm < R3 / (D1m-d1m)×CT2 < 3mm, where R2 is the radius of curvature of the image side surface of the first lens, D1s is the outer diameter of the object side surface of the first spacer element, d1s is the inner diameter of the object side surface of the first spacer element, CT1 is the center thickness of the first lens on the optical axis, R3 is the radius of curvature of the object side surface of the second lens, 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 CT2 is the center thickness of the second lens on the optical axis. By satisfying 3mm < R2 / (D1s-d1s)×CT1 < 18mm and 0mm < R3 / (D1m-d1m)×CT2 < 3mm, the non-imaging light rays refracted from the first lens can be reduced by controlling the relationship between the curvature radius of the image side of the first lens, the difference between the inner and outer diameters of the object side of the first spacer element, and the center thickness of the first lens, and by adding the relationship between the curvature radius of the object side of the second lens, the difference between the inner and outer diameters of the image side of the first spacer element, and the center thickness of the second lens. This helps to reduce stray light in the imaging system and improve the imaging quality of the imaging system.

[0049] In an exemplary embodiment, the imaging system according to this application may include a second spacer element located on the image side of the second lens and in partial contact with the image side surface of the second lens. The imaging system may satisfy: 2mm < R4×d2s / (CT2+CP2) < 16mm and 18mm < R5×D2m / (CP2+CT3) < 80mm, where R4 is the radius of curvature of the image side surface of the second lens, d2s is the inner diameter of the object side surface of the second spacer element, CT2 is the center thickness of the second lens on the optical axis, CP2 is the maximum thickness of the second spacer element, R5 is the radius of curvature of the object side surface of the third lens, D2m is the outer diameter of the image side surface of the second spacer element, and CT3 is the center thickness of the third lens on the optical axis. By satisfying 2mm < R4×d2s / (CT2+CP2) < 16mm and 18mm < R5×D2m / (CP2+CT3) < 80mm, the dimensions of the non-optical areas of the second and third lenses, as well as the dimensions of the second spacer element, can be rationally designed by controlling the relationship between the curvature radius and center thickness of the second and third lenses and the dimensions of the second spacer element. This helps to ensure the stability of the assembly and thus improve the product yield of the imaging system.

[0050] In an exemplary embodiment, the imaging system according to this application may include a third spacer element located on the image side of a third lens and in contact with a portion of the image side surface of the third lens, and a fourth spacer element located on the image side of a fourth lens and in contact with a portion of the image side surface of the fourth lens. The imaging system may satisfy: 1 ​​< f3 / d3s < 8 and 12 < R8 / (EP34+CP3) < 70, where f3 is the effective focal length of the third lens, d3s is the inner diameter of the object side surface of the third spacer element, R8 is the radius of curvature of the image side surface of the fourth lens, EP34 is the spacing distance between the image side surface of the third spacer element and the object side surface of the fourth spacer element in the direction along the optical axis, and CP3 is the maximum thickness of the third spacer element. By satisfying 1 < f3 / d3s < 8 and 12 < R8 / (EP34+CP3) < 70, the amount of non-imaging light rays refracted from the third lens to the fourth lens can be reduced by controlling the ratio of the effective focal length of the third lens to the inner diameter of the object side of the third spacer element, plus the ratio of the radius of curvature of the image side of the fourth lens, the maximum thickness of the third spacer element, and the on-axis distance between the third and fourth spacers elements. At the same time, it can also ensure that the third lens, the fourth lens and their surrounding elements such as the third spacer element form a more stable structure, which is beneficial to improving the imaging quality and assembly yield of the system.

[0051] In an exemplary embodiment, the imaging system according to this application may include a fourth spacer element located on the image side of a fourth lens and in partial contact with the image side surface of the fourth lens, and a fifth spacer element located on the image side of a fifth lens and in partial contact with the image side surface of the fifth lens. The imaging system may satisfy: -12 < f4 / D4m < 0 and 5 < R10 / (EP45+T45) < 35, where f4 is the effective focal length of the fourth lens, D4m is the outer diameter of the image side surface of the fourth spacer element, R10 is the radius of curvature of the image side surface of the fifth lens, EP45 is the distance between the image side surface of the fourth spacer element and the object side surface of the fifth spacer element along the optical axis, and T45 is the air gap between the fourth lens and the fifth lens along the optical axis. By satisfying -12 < f4 / D4m < 0 and 5 < R10 / (EP45+T45) < 35, the ratio of the effective focal length of the fourth lens to the inner diameter of the image-side surface of the adjacent fourth spacer element, plus the ratio of the radius of curvature of the image-side surface of the fifth lens to the distance between the fourth lens, the fifth lens, and their surrounding elements such as the fourth and fifth spacers along the optical axis, can be controlled to prevent light passing through the fourth lens from being transmitted to the non-optical area of ​​the fifth lens to the maximum extent. At the same time, it can also ensure that the fourth lens, the fifth lens, and their surrounding elements such as the fourth and fifth spacers have better structural dimensions, which is beneficial to improving the imaging quality of the system and the reliability of the product.

[0052] In an exemplary embodiment, the imaging system according to this application may include a first spacer element located on the image side of a first lens and in contact with a portion of the image side surface of the first lens, a second spacer element located on the image side of a second lens and in contact with a portion of the image side surface of the second lens, and a third spacer element located on the image side of a third lens and in contact with a portion of the image side surface of the third lens. The imaging system may satisfy: 10mm < (|f1×d1m| + |f2×d2m| + |f3×d3m|) / f123 < 18mm, where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f123 is the combined focal length of the first, second, and third lenses, d1m is the inner diameter of the image side surface of the first spacer element, d2m is the inner diameter of the image side surface of the second spacer element, and d3m is the inner diameter of the image side surface of the third spacer element. By satisfying 10mm < (∣f1×d1m∣ + ∣f2×d2m∣ + ∣f3×d3m∣) / f123 < 18mm, the generation of non-imaging rays in the first, second, and third lenses can be reduced by controlling the relationship between the effective focal lengths of the first, second, and third lenses, the image-side inner diameter of the spacer element connected to these three lenses, and the combined focal lengths of these three lenses. At the same time, the uniformity of the dimensions of the first, second, and third lenses in the optical axis direction can also be controlled, which is beneficial to improving the product stability and product yield of the system.

[0053] In an exemplary embodiment, the imaging system according to this application may include a first spacer element located on the image side of a first lens and in contact with a portion of the image side surface of the first lens; a second spacer element located on the image side of a second lens and in contact with a portion of the image side surface of the second lens; a third spacer element located on the image side of a third lens and in contact with a portion of the image side surface of the third lens; a fourth spacer element located on the image side of a fourth lens and in contact with a portion of the image side surface of the fourth lens; and a fifth spacer element located on the image side of a fifth lens and in contact with a portion of the image side surface of the fifth lens.

[0054] In an exemplary embodiment, the imaging system according to this application may satisfy: 40 < Va × EP12 / EP23 < 86 and 5 < Vb × EP45 / EP56 < 40, where Va is the Abbe number of the lens with the smallest absolute value of effective focal length among the first, second, and third lenses, Vb is the Abbe number of the lens with the largest absolute value of effective focal length among the fifth, sixth, and seventh lenses, EP12 is the spacing distance between the image side of the first spacer element and the object side of the second spacer element along the optical axis, EP23 is the spacing distance between the image side of the second spacer element and the object side of the third spacer element along the optical axis, EP45 is the spacing distance between the image side of the fourth spacer element and the object side of the fifth spacer element along the optical axis, and EP56 is the spacing distance between the image side of the fifth spacer element and the object side of the sixth spacer element along the optical axis. By satisfying 40 < Va × EP12 / EP23 < 86 and 5 < Vb × EP45 / EP56 < 40, the refractive index and dispersion generated by the first to third lenses can be balanced with those generated by the fifth to seventh lenses through the relationship between the Abbe number of the relevant lenses and the on-axis distance between the relevant spacers. This helps to ensure that the imaging system has good imaging quality while meeting the requirements of structural stability, thereby improving the overall imaging quality of the system.

[0055] In an exemplary embodiment, the imaging system according to this application satisfies: 2mm < (D1m + D2m + D3m) / Na < 10mm and 10mm < (D4m + D5m + D6m) / Nb < 16mm, where Na is the refractive index of the lens with the smallest Abbe number among the first, second, and third lenses, Nb is the refractive index of the lens with the largest Abbe number among the fifth, sixth, and seventh lenses, D1m is the outer diameter of the image-side surface of the first spacer element, D2m is the outer diameter of the image-side surface of the second spacer element, D3m is the outer diameter of the image-side surface of the third spacer element, D4m is the outer diameter of the image-side surface of the fourth spacer element, D5m is the outer diameter of the image-side surface of the fifth spacer element, and D6m is the outer diameter of the image-side surface of the sixth spacer element. By satisfying 2mm < (D1m + D2m + D3m) / Na < 10mm and 10mm < (D4m + D5m + D6m) / Nb < 16mm, the relationship between the outer diameter of the image side of each relevant spacer element and the refractive index of the relevant lens can be controlled to ensure that the imaging system has sufficient effective imaging light while maintaining a reasonable structural size in the direction perpendicular to the optical axis. This is beneficial to improving the product's imaging quality and assembly stability.

[0056] In an exemplary embodiment, the inner diameter of the object-side surface of the third spacer element is smaller than the inner diameter of the object-side surface of any one of the first to sixth spacers; and the inner diameter of the image-side surface of the third spacer element is smaller than the inner diameter of the image-side surface of any one of the first to sixth spacers. By limiting the inner diameters of the object and image sides of the third spacer element to be smaller than the inner diameters of the object and image sides of any one of the first to sixth spacers, this application can effectively improve the imaging quality of the off-axis points of the imaging system, resulting in better light quality in the final image and improved product quality.

[0057] In an exemplary embodiment, the imaging system according to this application may further include an auxiliary spacer element located on the image side of the sixth spacer element and in partial contact with the image side surface of the sixth spacer element. By adding an auxiliary spacer element on the image side of the sixth spacer element, this application can improve the performance of the imaging system during environmental testing and enhance the reliability of the imaging system.

[0058] In an exemplary embodiment, the imaging system according to this application further includes an aperture stop disposed between the object side and the first lens. Optionally, the imaging system may also include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface. This application proposes an imaging system with characteristics such as good outer diameter step difference, high assembly yield, and high imaging quality. The imaging system according to the above embodiments of this application can employ multiple lenses, such as the seven lenses mentioned above. By rationally allocating the optical power, surface shape, material, center thickness of each lens, and on-axis spacing between each lens, incident light can be effectively converged, the total optical length of the imaging system can be reduced, and the manufacturability of the imaging system can be improved, making the imaging system more conducive to manufacturing. In the imaging system of the above embodiments of this application, by setting a spacer element between adjacent lenses and designing the inner and outer diameters of the spacer element according to the optical path, stray light can be effectively blocked and eliminated, improving the imaging quality of the imaging system.

[0059] In the embodiments of this application, at least one of the mirror surfaces of each lens is an aspherical mirror surface; that is, at least one mirror surface from the object-side surface of the first lens to the image-side surface of the seventh lens is an aspherical mirror surface. The characteristic of an aspherical lens is that its curvature changes continuously from the center to the periphery of the lens. Unlike a spherical lens, which has a constant curvature from the center to the periphery, an aspherical lens has better radius of curvature characteristics, offering advantages in improving distortion aberrations and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality. Optionally, at least one of the object-side and image-side surfaces of each of the first, second, third, fourth, fifth, sixth, and seventh lenses is an aspherical mirror surface. Optionally, both the object-side and image-side surfaces of each of the first, second, third, fourth, fifth, sixth, and seventh lenses are aspherical mirror surfaces.

[0060] However, those skilled in the art will understand that the number of lenses constituting the imaging system can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although seven lenses are described as an example in the embodiments, the imaging system is not limited to including seven lenses. If desired, the imaging system may also include other numbers of lenses.

[0061] Specific embodiments of the imaging system applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

[0062] Example 1

[0063] The following is for reference Figures 1A to 2D An imaging system according to Embodiment 1 of this application is described. Figures 1A to 1CThe imaging systems in three different implementations of Example 1 are shown respectively.

[0064] like Figures 1A to 1C As shown, the imaging system includes, in sequence from the object side to the image side: aperture STO (not shown), first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, filter (not shown), and imaging surface (not shown).

[0065] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has negative optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The filter has an object-side surface S15 and an image-side surface S16. Light from the object passes sequentially through each surface S1 to S16 and is finally imaged onto the imaging plane.

[0066] Table 1 shows the basic parameters of the imaging system of Example 1, where the units for radius of curvature, thickness / distance, and focal length are millimeters (mm).

[0067]

[0068]

[0069] Table 1

[0070] In this example, the entrance pupil diameter (EPD) of the imaging system is 3.3634 mm, the aperture value (Fno) of the imaging system is 1.6050, the total effective focal length (f) of the imaging system is 5.3500 mm, and the combined focal length (f123) of the first lens, the second lens, and the third lens is 6.2340 mm.

[0071] like Figures 1A to 1C As shown, the imaging system may include six spacer elements: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, and a sixth spacer element P6. The lens barrel may accommodate first lenses E1 to seventh lenses E7 and first spacer elements P1 to sixth spacer elements P6.

[0072] Table 2 shows the basic parameters of each spacer element in the imaging system of Example 1 under three implementations, where the unit of each basic parameter is millimeters (mm).

[0073]

[0074]

[0075] Table 2

[0076] It should be understood that this example only exemplifies the structure and parameters of each spacer element under three implementation methods, and does not explicitly limit the specific structure and actual parameters of each spacer element. In actual production, the specific structure and actual parameters of each spacer element can be set in any suitable manner.

[0077] In Embodiment 1, the object-side surface and image-side surface of any one of the first lens E1 to the seventh lens E7 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:

[0078]

[0079] Where x is the distance vector from the vertex of the aspherical surface at a height of 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, A14 that can be used for each aspherical mirror S1-S14 in Example 1. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0080]

[0081]

[0082] Table 3-1

[0083] Face number A18 A20 A22 A24 A26 A28 A30 S1 -9.4103E-05 -4.1630E-04 -3.8099E-04 -2.1405E-04 -5.1519E-05 8.8568E-06 1.4036E-05 S2 3.6397E-04 1.8762E-04 1.4137E-04 6.4283E-05 3.1819E-05 9.4809E-06 3.8619E-06 S3 2.6853E-05 -6.2195E-05 8.8617E-06 3.3921E-06 7.5427E-06 3.2918E-06 2.5167E-06 S4 -4.3883E-05 1.9318E-05 1.2732E-04 7.4012E-05 3.2697E-05 1.0539E-05 6.1527E-06 S5 5.9279E-06 -2.6946E-05 1.8564E-05 1.8551E-05 2.4433E-06 -1.7725E-06 -1.4877E-06 S6 -5.7149E-05 -7.9166E-05 -7.6705E-05 -6.3871E-05 -4.4735E-05 -3.0256E-05 -1.4826E-05 S7 1.0199E-03 8.1832E-04 5.6065E-04 2.8215E-04 9.2917E-05 8.3402E-06 -6.3203E-06 S8 2.1987E-05 1.1915E-04 2.4236E-04 -9.2950E-06 -5.6427E-05 -2.9516E-05 1.5478E-05 S9 -4.6319E-03 7.0973E-04 2.4308E-03 2.6609E-03 2.1781E-03 1.0988E-03 2.4510E-04 S10 -5.6080E-03 2.9467E-03 4.5454E-03 1.8360E-03 9.3769E-05 -2.1195E-04 -4.7674E-05 S11 -8.0248E-03 -1.3795E-03 1.3642E-03 -7.1314E-04 -1.2338E-03 -7.7232E-04 -1.4845E-04 S12 -3.0442E-03 -7.0045E-04 2.9545E-04 1.4016E-03 1.1175E-03 -1.6739E-04 1.6213E-04 S13 6.6682E-03 -6.4947E-03 3.8924E-03 -1.6395E-03 9.8275E-04 -7.9248E-05 7.0694E-04 S14 2.1495E-02 -5.3404E-03 2.6215E-03 -5.8258E-03 6.2902E-04 7.8677E-06 1.3763E-03

[0084] Table 3-2

[0085] Figure 2AThe on-axis chromatic aberration curve of the imaging system of Embodiment 1 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the imaging system. Figure 2B The astigmatism curves of the imaging system of Example 1 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 2C The distortion curves of the imaging system of Example 1 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 2D The magnification chromatic aberration curve of the imaging system of Embodiment 1 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the imaging system. According to Figures 2A to 2D It can be seen that the imaging system given in Example 1 can achieve good imaging quality.

[0086] Example 2

[0087] The following is for reference Figures 3A to 4D An imaging system according to Embodiment 2 of this application is described. In this embodiment and the following embodiments, for the sake of brevity, descriptions similar to those in Embodiment 1 will be omitted. Figures 3A to 3C The imaging systems in three different implementations of Example 1 are shown respectively.

[0088] like Figures 3A to 3C As shown, the imaging system includes, in sequence from the object side to the image side: aperture STO (not shown), first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, filter (not shown), and imaging surface (not shown).

[0089] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has negative optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The seventh lens E7 has negative optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The filter has an object-side surface S15 and an image-side surface S16. Light from the object passes sequentially through surfaces S1 to S16 and is finally imaged onto the imaging plane.

[0090] In this example, the entrance pupil diameter (EPD) of the imaging system is 3.2043 mm, the aperture value (Fno) of the imaging system is 1.6050, the total effective focal length (f) of the imaging system is 5.1000 mm, and the combined focal length (f123) of the first lens, the second lens, and the third lens is 5.9896 mm.

[0091] like Figures 3A to 3C As shown, the imaging system may include six spacer elements: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, and a sixth spacer element P6. The lens barrel may accommodate first lenses E1 to seventh lenses E7 and first spacer elements P1 to sixth spacer elements P6.

[0092] It should be understood that this example only exemplifies the structure and parameters of each spacer element under three implementation methods, and does not explicitly limit the specific structure and actual parameters of each spacer element. In actual production, the specific structure and actual parameters of each spacer element can be set in any suitable manner.

[0093] Table 4 shows the basic parameters of the imaging system of Example 2, where the units for radius of curvature, thickness / distance, and focal length are millimeters (mm). Table 5 shows the basic parameters of each spacer element under three implementations of the imaging system of Example 2, where the units for each basic parameter are millimeters (mm). Tables 6-1 and 6-2 show the higher-order coefficients that can be used for each aspherical mirror in Example 2, where each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0094]

[0095] Table 4

[0096]

[0097]

[0098] Table 5

[0099]

[0100]

[0101] Table 6-1

[0102] Face number A18 A20 A22 A24 A26 A28 A30 S1 5.4988E-05 -5.4433E-05 -8.9625E-05 -8.3927E-05 -5.5511E-05 -2.5337E-05 -7.0474E-06 S2 -3.3897E-06 3.1116E-05 -9.1854E-06 2.4436E-06 -7.0865E-07 5.4419E-07 1.8744E-06 S3 -7.1546E-05 5.8557E-06 -9.9727E-06 1.1210E-05 4.0042E-06 3.0183E-06 7.2508E-07 S4 -3.5395E-04 -1.5662E-04 1.1118E-05 3.9498E-05 1.3346E-06 -1.2978E-05 -5.9138E-06 S5 1.0860E-05 -6.8408E-05 -1.5493E-05 3.0146E-05 2.3297E-05 1.2164E-05 3.1137E-06 S6 8.1175E-05 4.4291E-05 2.2905E-05 1.5129E-05 8.7182E-06 4.6956E-06 -6.4401E-07 S7 -1.9179E-04 -8.6678E-05 8.1725E-06 3.3655E-05 4.9980E-05 2.9998E-05 2.4008E-05 S8 -1.1010E-03 -6.6169E-04 -4.6696E-04 -3.4839E-04 -1.6943E-04 -3.0849E-05 1.5219E-05 S9 8.1969E-06 9.1252E-04 5.9360E-04 6.4565E-05 -1.4234E-04 -3.6324E-05 -1.1997E-06 S10 -1.7551E-03 -6.8445E-04 -8.6572E-04 -1.4782E-03 -1.6204E-03 -8.8244E-04 -2.3847E-04 S11 -2.4644E-03 2.3623E-03 -1.8636E-03 -6.4305E-04 8.4792E-04 3.0522E-04 -2.5797E-04 S12 -6.0014E-03 6.7948E-04 1.9489E-03 2.4415E-03 -1.4239E-04 -9.4879E-04 6.1791E-05 S13 -1.3802E-02 1.5381E-02 -4.4567E-03 -2.9032E-03 2.4319E-03 -9.9191E-04 5.0367E-05 S14 5.4210E-03 -4.7840E-03 1.0702E-03 -1.2105E-03 5.0780E-04 -3.3538E-04 1.6220E-04

[0103] Table 6-2

[0104] Figure 4A The on-axis chromatic aberration curve of the imaging system of Embodiment 2 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the imaging system. Figure 4B The astigmatism curves of the imaging system of Example 2 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 4C The distortion curves of the imaging system of Example 2 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 4DThe magnification chromatic aberration curve of the imaging system of Embodiment 2 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the imaging system. According to Figures 4A to 4D It can be seen that the imaging system given in Example 2 can achieve good imaging quality.

[0105] Example 3

[0106] The following is for reference Figures 5A to 6D An imaging system according to Embodiment 3 of this application is described. Figures 5A to 5C The imaging systems of the three embodiments in Example 3 are shown respectively.

[0107] like Figures 5A to 5C As shown, the imaging system includes, in sequence from the object side to the image side: aperture STO (not shown), first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, filter (not shown), and imaging surface (not shown).

[0108] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being concave. The fifth lens E5 has negative optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The seventh lens E7 has negative optical power, with its object-side surface S13 being concave and its image-side surface S14 being concave. The filter has an object-side surface S15 and an image-side surface S16. Light from the object passes sequentially through surfaces S1 to S16 and is finally imaged onto the imaging plane.

[0109] In this example, the entrance pupil diameter (EPD) of the imaging system is 3.2261 mm, the aperture value (Fno) of the imaging system is 1.6000, the total effective focal length (f) of the imaging system is 5.1171 mm, and the combined focal length (f123) of the first lens, the second lens, and the third lens is 5.0098 mm.

[0110] like Figures 5A to 5C As shown, the imaging system may include six spacer elements: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, and a sixth spacer element P6. The lens barrel may accommodate first lenses E1 to seventh lenses E7 and first spacer elements P1 to sixth spacer elements P6.

[0111] It should be understood that this example only exemplifies the structure and parameters of each spacer element under three implementation methods, and does not explicitly limit the specific structure and actual parameters of each spacer element. In actual production, the specific structure and actual parameters of each spacer element can be set in any suitable manner.

[0112] Table 7 shows the basic parameters of the imaging system of Embodiment 3, wherein the units of radius of curvature, thickness / distance, and focal length are millimeters (mm). Table 8 shows the basic parameters of each spacer element in the three embodiments of the imaging system of Embodiment 3, wherein the units of each basic parameter are millimeters (mm). Tables 9-1 and 9-2 show the higher-order coefficients that can be used for each aspherical mirror in Embodiment 3, wherein each aspherical surface shape can be defined by formula (1) given in Embodiment 1 above.

[0113]

[0114] Table 7

[0115]

[0116]

[0117] Table 8

[0118]

[0119]

[0120] Table 9-1

[0121] Face number A18 A20 A22 A24 A26 A28 A30 S1 2.5800E-05 2.6529E-05 1.2869E-05 7.2203E-06 3.5743E-06 -1.7591E-06 -6.2385E-06 S2 2.9323E-04 2.3662E-04 2.3576E-04 1.4640E-04 7.5466E-05 1.9372E-05 7.2937E-06 S3 -1.5015E-05 -1.3895E-05 -5.5012E-06 5.5279E-06 -2.1185E-06 -6.3191E-08 -4.0656E-06 S4 -3.0935E-05 -9.5294E-06 3.7631E-05 3.3833E-05 2.3405E-05 1.5087E-05 6.2862E-06 S5 -8.6818E-05 -1.0521E-04 -1.7982E-05 -1.7379E-05 -2.0597E-06 -5.4511E-06 6.5158E-06 S6 -1.1236E-04 2.2329E-05 -4.0570E-05 1.8773E-05 -8.9682E-06 1.2768E-05 -6.9813E-06 S7 -6.0703E-04 -3.1402E-04 -1.2997E-04 -3.5334E-05 4.7208E-06 1.1849E-05 1.0692E-05 S8 -2.2418E-04 -5.7782E-04 -4.9619E-04 -4.1945E-04 -2.3762E-04 -1.0096E-04 -1.2048E-05 S9 1.5149E-03 5.0476E-04 1.6105E-04 6.2040E-05 -4.1593E-05 -3.8631E-05 -3.3061E-05 S10 3.5359E-04 7.2968E-05 2.9641E-04 -1.1116E-04 -3.3067E-04 -2.6436E-04 -6.8082E-05 S11 -9.5047E-04 -1.1878E-03 -6.9879E-04 8.5383E-05 2.6072E-04 -6.4368E-05 -1.5805E-04 S12 1.8950E-03 2.7656E-03 1.1650E-03 2.2176E-03 1.6436E-03 5.6744E-04 2.7846E-04 S13 -1.4182E-02 3.6824E-03 -3.6749E-03 -1.3724E-03 -1.3390E-03 6.5400E-04 -6.1246E-04 S14 -1.5096E-03 2.8316E-03 -7.8250E-04 2.0747E-03 -6.7786E-04 -1.7718E-04 -7.2939E-04

[0122] Table 9-2

[0123] Figure 6A The on-axis chromatic aberration curve of the imaging system of Embodiment 3 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the imaging system. Figure 6B The astigmatism curves of the imaging system of Example 3 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 6C The distortion curves of the imaging system of Example 3 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 6D The magnification chromatic aberration curve of the imaging system of Example 3 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the imaging system. According to Figures 6A to 6D It can be seen that the imaging system given in Example 3 can achieve good imaging quality.

[0124] In summary, Examples 1 to 3 satisfy the relationships shown in Tables 10-1, 10-2 and 10-3, respectively.

[0125]

[0126]

[0127] Table 10-1

[0128]

[0129]

[0130] Table 10-2

[0131]

[0132] Table 10-3

[0133] This application also provides an imaging device, wherein the electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the imaging system described above.

[0134] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An imaging system, characterized in that, include: The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, each with optical power. The first lens has positive optical power, with a convex object side and a concave image side; the second lens has negative optical power, with a convex object side and a concave image side; the third lens has positive optical power, with a convex object side; the fourth lens has negative optical power, with a concave image side; the fifth lens has negative optical power, with a concave image side; the sixth lens has positive optical power, with a convex object side; and the seventh lens has negative optical power, with a concave image side. The imaging system has seven lenses with optical power. At least one spacer element includes: a first spacer element located on the image side of the first lens and in contact with a portion of the image side surface of the first lens; a second spacer element located on the image side of the second lens and in contact with a portion of the image side surface of the second lens; a third spacer element located on the image side of the third lens and in contact with a portion of the image side surface of the third lens; a fourth spacer element located on the image side of the fourth lens and in contact with a portion of the image side surface of the fourth lens; and a sixth spacer element located on the image side of the sixth lens and in contact with a portion of the image side surface of the sixth lens; and A lens barrel for housing the lens group and the at least one spacer element; The imaging system satisfies the following conditions: 2.1335 ≤ (D6s × d6s) / (R11 × R14) ≤ 13.5542, 45.6599 mm. 2 ≤(d0s+d0m) / Fno×L≤49.8913mm 2 -27.5953≤f2 / EP12≤-20.2065 and 18.7469≤R8 / (EP34+CP3)≤67.8061, D6s is the outer diameter of the object-side surface of the sixth spacer element, d6s is the inner diameter of the object-side surface of the sixth spacer element, R11 is the radius of curvature of the object-side surface of the sixth lens, R14 is the radius of curvature of the image-side surface of the seventh lens, d0s is the inner diameter of the object-side end of the lens barrel, d0m is the inner diameter of the image-side end of the lens barrel, F no is the aperture value of the imaging system, L is the maximum height of the lens barrel, f2 is the effective focal length of the second lens, EP12 is the distance between the image side of the first spacer element and the object side of the second spacer element along the optical axis, R8 is the radius of curvature of the image side of the fourth lens, EP34 is the distance between the image side of the third spacer element and the object side of the fourth spacer element along the optical axis, and CP3 is the maximum thickness of the third spacer element.

2. The imaging system according to claim 1, characterized in that, The imaging system satisfies: -21.8543≤(f4+f5) / (d4s+d4m)≤-5.2249, where f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, d4s is the inner diameter of the object side of the fourth spacer element, and d4m is the inner diameter of the image side of the fourth spacer element.

3. The imaging system according to claim 1, characterized in that, The imaging system satisfies: 7.4403≤(f6-f7) / (CP6+CT7)≤16.8368, where f6 is the effective focal length of the sixth lens, f7 is the effective focal length of the seventh lens, CP6 is the maximum thickness of the sixth spacer element, and CT7 is the center thickness of the seventh lens on the optical axis.

4. The imaging system according to claim 1, characterized in that, The imaging system satisfies the following condition: 15.1205mm ≤ f1 / EP01×EPD ≤ 19.5351mm, where f1 is the effective focal length of the first lens, EP01 is the distance between the object-side end of the lens barrel and the object-side surface of the first spacer element along the optical axis, and EPD is the entrance pupil diameter of the imaging system.

5. The imaging system according to claim 1, characterized in that, The imaging system satisfies: 17.3776≤f3 / EP23≤55.8018, where f3 is the effective focal length of the third lens and EP23 is the distance between the image side of the second spacer element and the object side of the third spacer element along the optical axis.

6. The imaging system according to claim 1, characterized in that, The imaging system satisfies the following conditions: 4.0418mm≤R2 / (D1s-d1s)×CT1≤14.8152mm and 0.5715mm≤R3 / (D1m-d1m)×CT2≤2.0072mm, where R2 is the radius of curvature of the image-side surface of the first lens, D1s is the outer diameter of the object-side surface of the first spacer element, d1s is the inner diameter of the object-side surface of the first spacer element, CT1 is the center thickness of the first lens on the optical axis, R3 is the radius of curvature of the object-side surface of the second lens, 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 CT2 is the center thickness of the second lens on the optical axis.

7. The imaging system according to claim 1, characterized in that, The imaging system satisfies the following condition: 27.3096mm≤R5×D2m / (CP2+CT3)≤65.7006mm, where CP2 is the maximum thickness of the second spacer element, R5 is the radius of curvature of the object side of the third lens, D2m is the outer diameter of the image side of the second spacer element, and CT3 is the center thickness of the third lens on the optical axis.

8. The imaging system according to claim 1, characterized in that, The imaging system satisfies: 3.1656≤f3 / d3s≤6.3282, where f3 is the effective focal length of the third lens and d3s is the inner diameter of the object side surface of the third spacer element.

9. The imaging system according to claim 1, characterized in that, The at least one spacer element further includes: a fifth spacer element located on the image side of the fifth lens and in contact with a portion of the image side surface of the fifth lens. The imaging system satisfies: -9.6900≤f4 / D4m≤-3.6478 and 9.5720≤R10 / (EP45+T45)≤30.6447, where f4 is the effective focal length of the fourth lens, D4m is the outer diameter of the image-side surface of the fourth spacer element, R10 is the radius of curvature of the image-side surface of the fifth lens, EP45 is the distance between the image-side surface of the fourth spacer element and the object-side surface of the fifth spacer element along the optical axis, and T45 is the air gap between the fourth lens and the fifth lens along the optical axis.

10. The imaging system according to claim 1, characterized in that, The imaging system satisfies: 12.0174mm≤(∣f1×d1m∣+∣f2×d2m∣+∣f3×d3m∣) / f123≤15.4235mm, where f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f123 is the combined focal length of the first lens, the second lens and the third lens, d1m is the inner diameter of the image-side surface of the first spacer element, d2m is the inner diameter of the image-side surface of the second spacer element, and d3m is the inner diameter of the image-side surface of the third spacer element.

11. The imaging system according to claim 1, characterized in that, The at least one spacer element further includes: A fifth spacer element located on the image side of the fifth lens and in contact with the image side surface of the fifth lens.

12. The imaging system according to claim 11, characterized in that, The imaging system satisfies the following conditions: 44.0005 ≤ Va × EP12 / EP23 ≤ 83.4960 and 9.0743 ≤ Vb × EP45 / EP56 ≤ 37.8659, where Va is the Abbe number of the lens with the smallest absolute value of effective focal length among the first, second, and third lenses; Vb is the Abbe number of the lens with the largest absolute value of effective focal length among the fifth, sixth, and seventh lenses; EP12 is the spacing distance between the image side of the first spacer element and the object side of the second spacer element along the optical axis; EP23 is the spacing distance between the image side of the second spacer element and the object side of the third spacer element along the optical axis; EP45 is the spacing distance between the image side of the fourth spacer element and the object side of the fifth spacer element along the optical axis; and EP56 is the spacing distance between the image side of the fifth spacer element and the object side of the sixth spacer element along the optical axis.

13. The imaging system according to claim 11, characterized in that, The imaging system satisfies the following conditions: 6.3733mm ≤ (D1m + D2m + D3m) / Na ≤ 8.6195mm and 12.5366mm ≤ (D4m + D5m + D6m) / Nb ≤ 14.8085mm, where Na is the refractive index of the lens with the smallest Abbe number among the first, second, and third lenses; Nb is the refractive index of the lens with the largest Abbe number among the fifth, sixth, and seventh lenses; D1m is the outer diameter of the image-side surface of the first spacer element; D2m is the outer diameter of the image-side surface of the second spacer element; D3m is the outer diameter of the image-side surface of the third spacer element; D4m is the outer diameter of the image-side surface of the fourth spacer element; D5m is the outer diameter of the image-side surface of the fifth spacer element; and D6m is the outer diameter of the image-side surface of the sixth spacer element.

14. The imaging system according to claim 11, characterized in that, The inner diameter of the object side surface of the third spacer element is smaller than the inner diameter of the object side surface of any one of the spacer elements from the first to the sixth spacer element; and The inner diameter of the image side of the third spacer element is smaller than the inner diameter of the image side of any of the spacers from the first to the sixth spacer elements.

15. The imaging system according to any one of claims 1-14, characterized in that, The at least one spacer element further includes an auxiliary spacer element located on the image side of the sixth spacer element and in contact with the image side portion of the sixth spacer element.

Images