A zoom lens

Abstract

The present invention discloses a zoom lens, which sequentially includes, from the object side to the image side along the optical axis: a first lens group; a second lens group with negative optical power; a third lens group with positive optical power; there is an air gap between each lens in the lens groups; the second lens group and the third lens group can move on the optical axis to achieve continuous zooming; wherein, the entrance pupil diameter EPD of the zoom lens, the maximum semi-field angle Semi-FOV of the zoom lens, and the maximum value DTmax of the effective radii of each lens in the first lens group to the third lens group satisfy: 0 < EPD × TAN(Semi-FOV) / DTmax < 0.2; the distortion DIST of the maximum field of view of the zoom lens satisfies: |DIST| < 3%; the on-axis distance TTL from the object side surface of the first lens to the imaging surface and half of the diagonal length ImgH of the effective pixel area on the imaging surface satisfy: 8 < TTL / ImgH < 10. The zoom lens provided by the present invention is composed of three lens groups, with a small change in TTL and a large zoom range, avoiding the problem that the traditional zoom lens may cause discontinuous zooming during lens switching, resulting in poor user experience.

Description

Technical Field

[0001] The invention belongs to the field of optical imaging, and in particular relates to a zoom lens comprising seven lenses. Background Art

[0002] With the continuous development of science and technology, the lenses of mobile devices such as mobile phones have also made rapid progress. In the market, mobile devices such as mobile phones have higher and higher requirements for camera quality. At present, mobile phone photography mainly achieves the zoom function through a combination of multiple lenses, which are used in combination with telephoto, wide-angle and ultra-wide-angle. However, this method will switch the lens, resulting in discontinuous zoom, and the switching of the lens will make the white balance unstable. In the process of switching, the performance of the lens will also be greatly lost, resulting in poor user experience. Therefore, a continuous zoom mobile phone lens with small TTL change and large zoom range is needed. Summary of the invention

[0003] In order to solve the problem that the existing zoom lens realizes the zoom function by combining multiple lenses, which causes discontinuous zoom when switching lenses, resulting in poor user experience, the present invention aims to provide a zoom lens composed of three lens groups, with a small TTL change and a large zoom range for continuous zoom mobile phone lenses.

[0004] One aspect of the present invention provides a zoom lens, which includes, in order from the object side to the image side along the optical axis: a first lens group; a second lens group with negative optical focal length; a third lens group with positive optical focal length; air spaces are provided between each lens in the lens group; and the second lens group and the third lens group can move on the optical axis to achieve continuous zooming.

[0005] Among them, the entrance pupil diameter EPD of the zoom lens, the maximum half field angle Semi-FOV of the zoom lens, and the maximum value DTmax of the effective radius of each lens in the first lens group to the third lens group satisfy: <EPD×TAN(Semi-FOV) / DTmax<0.2。

[0006] According to one embodiment of the present invention, the distortion DIST of the maximum field of view of the zoom lens satisfies: |DIST|<3%.

[0007] According to one embodiment of the present invention, the axial distance TTL from the object side of the first lens to the imaging surface and half the diagonal length of the effective pixel area on the imaging surface ImgH satisfy: <TTL / ImgH<10。

[0008] According to one embodiment of the present invention, the effective focal length fw of the zoom lens at the wide-angle end and the effective focal length ft of the zoom lens at the telephoto end satisfy: <fw / ft<0.5。

[0009] According to one embodiment of the present invention, the effective focal length fw of the zoom lens at the wide-angle end and the effective focal length f7 of the seventh lens satisfy: <fw / f7<1.5。

[0010] According to one embodiment of the present invention, the effective focal length ft of the zoom lens at the telephoto end and the effective focal length fG1 of the first lens group satisfy the following conditions: 1.5 <ft / fG1<2.5。

[0011] According to one embodiment of the present invention, the effective focal length ft of the zoom lens at the telephoto end and the effective focal length fG3 of the third lens group satisfy: 3.5 <ft / fG3<4.5。

[0012] According to one embodiment of the present invention, the effective focal length f6 of the sixth lens, the curvature radius R11 of the object side surface of the sixth lens, and the curvature radius R12 of the image side surface of the sixth lens satisfy: -5 <f6 / (R11-R12)<-3。

[0013] According to one embodiment of the present invention, a curvature radius R13 of the object-side surface of the seventh lens and a curvature radius R14 of the image-side surface of the seventh lens satisfy: -0.5<(R13+R14) / (R13-R14)<0.

[0014] According to one embodiment of the present invention, the zoom movement distance ΔT1 of the second lens group on the optical axis from the wide-angle end to the telephoto end, the effective focal length ft of the zoom lens at the telephoto end, and the effective focal length fw of the zoom lens at the wide-angle end satisfy: 0.2<ΔT1 / (ft-fw)<0.3.

[0015] According to one embodiment of the present invention, the zoom movement distance ΔT1 of the second lens group on the optical axis from the wide-angle end to the telephoto end and the effective focal length fG2 of the second lens group satisfy: -2<ΔT1 / fG2<-1.

[0016] According to one embodiment of the present invention, the first lens group includes a first lens and a second lens, one of which is made of glass material; the second lens group includes a third lens, a fourth lens and a fifth lens; the third lens group includes a sixth lens and a seventh lens, one of which is made of glass material; and the aperture is located between the fourth lens and the fifth lens.

[0017] According to one embodiment of the present invention, the numerical aperture Fno of the zoom lens in different zoom states satisfies: <Fno<7。

[0018] According to one embodiment of the present invention, the total number V50 of lenses having an Abbe number less than 50 in the first to seventh lenses satisfies: V50≤4.

[0019] Another aspect of the present invention provides a zoom lens, which includes, in order from the object side to the image side along the optical axis: a first lens group; a second lens with negative optical focal length; a third lens with positive optical focal length; each lens in the lens group has an air gap between them; and the second lens group and the third lens group can move on the optical axis to achieve continuous zooming.

[0020] The axial distance TTL from the object side of the first lens to the imaging surface and the half of the diagonal length of the effective pixel area on the imaging surface ImgH satisfy: 8 <TTL / ImgH<10。

[0021] Beneficial effects of the present invention:

[0022] The zoom lens provided by the present invention includes a plurality of lens groups, such as the first lens group to the third lens group. The zoom lens of the present invention is composed of three lens groups, has a small TTL change amount and a large zoom range, and avoids the problem that the traditional zoom lens will cause discontinuous zooming when switching lenses, resulting in poor user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 Schematic diagram of the wide-angle end structure of the zoom lens embodiment 1 of the present invention;

[0025] Figure 2 Schematic diagram of the structure of the middle end position of the zoom lens embodiment 1 of the present invention;

[0026] Figure 3 Schematic diagram of the structure at the telephoto end of the zoom lens embodiment 1 of the present invention;

[0027] Figures 4a to 4c They are respectively an axial chromatic aberration curve, an astigmatism curve and a distortion curve at the wide-angle end of the zoom lens of Example 1 of the present invention;

[0028] Figure 5a to Figure 5c They are respectively an axial chromatic aberration curve, an astigmatism curve and a distortion curve at the middle end position of the zoom lens of Example 1 of the present invention;

[0029] Figures 6a to 6c They are respectively an axial chromatic aberration curve, an astigmatism curve and a distortion curve at the telephoto end of the zoom lens of Example 1 of the present invention;

[0030] Figure 7Schematic diagram of the wide-angle end structure of the zoom lens embodiment 2 of the present invention;

[0031] Figure 8 Schematic diagram of the structure of the middle end position of the zoom lens embodiment 2 of the present invention;

[0032] Fig. 9 Schematic diagram of the structure at the telephoto end of the zoom lens embodiment 2 of the present invention;

[0033] Figures 10a to 10c They are respectively an axial chromatic aberration curve, an astigmatism curve and a distortion curve at the wide-angle end of the zoom lens of Example 2 of the present invention;

[0034] Figures 11a to 11c They are respectively an axial chromatic aberration curve, an astigmatism curve and a distortion curve at the middle end position of the zoom lens of Example 2 of the present invention;

[0035] Figures 12a to 12c They are respectively an on-axis chromatic aberration curve, an astigmatism curve and a distortion curve at the telephoto end of the zoom lens of Example 2 of the present invention;

[0036] Fig.13 Schematic diagram of the structure of the zoom lens embodiment 3 of the present invention at the wide-angle end;

[0037] Fig.14 Schematic diagram of the structure of the zoom lens embodiment 3 of the present invention at the middle end position;

[0038] Fig.15 Schematic diagram of the structure at the telephoto end of the zoom lens embodiment 3 of the present invention;

[0039] Figures 16a to 16c They are respectively an axial chromatic aberration curve, an astigmatism curve and a distortion curve at the wide-angle end of the zoom lens of Example 3 of the present invention;

[0040] Figures 17a to 17c They are respectively an axial chromatic aberration curve, an astigmatism curve and a distortion curve at the middle end position of the zoom lens of Example 3 of the present invention;

[0041] Figures 18a to 18c They are respectively the on-axis chromatic aberration curve, the astigmatism curve and the distortion curve at the telephoto end of the zoom lens according to Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0044] It should also be understood that the terms "comprises", "including", "having", "includes" 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. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0045] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0046] In the description of the present invention, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface 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 object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0047] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal way unless explicitly defined in this article.

[0048] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The features, principles and other aspects of the present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0049] Exemplary Embodiments

[0050] The zoom lens according to an exemplary embodiment of the present invention includes three lens groups, which sequentially include, from the object side to the image side along the optical axis: a first lens group, a second lens group having a negative optical power, and a third lens group having a positive optical power; wherein, there is an air gap between each lens in the lens group; the second lens group and the third lens group can move on the optical axis to achieve continuous zooming.

[0051] In the present exemplary embodiment, the first lens group includes a first lens and a second lens, and one of the lenses is made of glass material; the second lens group includes a third lens, a fourth lens, and a fifth lens; the third lens group includes a sixth lens and a seventh lens, and one of the lenses is made of glass material; the aperture stop is located between the fourth lens and the fifth lens.

[0052] In the present exemplary embodiment, the first lens may have a positive optical power or a negative optical power; the second lens may have a positive optical power or a negative optical power; the third lens may have a positive optical power or a negative optical power; the fourth lens may have a positive optical power or a negative optical power; the fifth lens may have a positive optical power or a negative optical power; the sixth lens may have a positive optical power or a negative optical power; the seventh lens may have a positive optical power or a negative optical power.

[0053] In the present exemplary embodiment, the condition formula satisfied by the entrance pupil diameter EPD of the zoom lens, the maximum semi-field angle Semi-FOV of the zoom lens, and the maximum value DTmax of the effective radii of the lenses in the first lens group to the third lens group is: 0 < EPD × TAN(Semi-FOV) / DTmax < 0.2. The above design ensures that sufficient light enters the optical system. More specifically, at the wide-angle end, EPD, Semi-FOV, and DTmax satisfy: 0 < EPD × TAN(Semi-FOV) / DTmax < 0.17. For example, EPD × TAN(Semi-FOV) / DTmax = 0.16; at the middle end, EPD, Semi-FOV, and DTmax satisfy: 0.05 < EPD × TAN(Semi-FOV) / DTmax < 0.15. For example, 0.07 ≤ EPD × TAN(Semi-FOV) / DTmax ≤ 0.10; at the telephoto end, EPD, Semi-FOV, and DTmax satisfy: 0 < EPD × TAN(Semi-FOV) / DTmax < 0.1. For example, ≤ EPD × TAN(Semi-FOV) / DTmax = 0.07.

[0054] In this exemplary embodiment, the conditional expression satisfied by the distortion DIST of the maximum field of view of the zoom lens is: |DIST| < 3%. The above design ensures that the distortion degree of the lens is within the perceptible range of the human eye. More specifically, at the wide-angle end, DIST satisfies: 2% < |DIST| < 3%, for example, |DIST| = 2.99%; at the middle end, DIST satisfies: 0.3% < |DIST| < 0.5%, for example, 0.33% ≤ |DIST| ≤ 0.43%; at the telephoto end, DIST satisfies: 0.1% < |DIST| < 0.7%, for example, 0.18% ≤ |DIST| ≤ 0.68%.

[0055] In this exemplary embodiment, the conditional expression satisfied by the on-axis distance TTL from the object side surface of the first lens to the imaging surface and half ImgH of the diagonal length of the effective pixel region on the imaging surface is: 8 < TTL / ImgH < 10. The above conditional expression is beneficial for further modification of the camera lens (such as a periscope structure, etc.). More specifically, at the wide-angle end, TTL and ImgH satisfy: 8.7 < TTL / ImgH < 9.5, for example, 8.79 ≤ TTL / ImgH ≤ 9.05; at the middle end, TTL and ImgH satisfy: 9.4 < TTL / ImgH < 9.6, for example, 9.42 ≤ TTL / ImgH ≤ 9.59; at the telephoto end, TTL and ImgH satisfy: 9 < TTL / ImgH < 9.1, for example, 9.03 ≤ TTL / ImgH ≤ 9.05.

[0056] In this exemplary embodiment, the conditional expression satisfied by the effective focal length fw of the zoom lens at the wide-angle end and the effective focal length ft of the zoom lens at the telephoto end is: 0 < fw / ft < 0.5. The above conditional expression is beneficial for ensuring that the lens has a sufficient zoom range. More specifically, fw and ft satisfy: 0.2 < fw / ft < 0.3, for example, fw / ft = 0.25.

[0057] In this exemplary embodiment, the conditional expression satisfied by the effective focal length fw of the zoom lens at the wide-angle end and the effective focal length f7 of the seventh lens is: 1 < fw / f7 < 1.5. The above conditional expression is beneficial for meeting the requirements of high optical performance and a compact zoom lens. More specifically, fw and f7 satisfy: 1.4 < fw / f7 < 1.5, for example, 1.45 ≤ fw / f7 ≤ 1.49.

[0058] In this exemplary embodiment, the conditional expression satisfied by the effective focal length ft of the zoom lens at the telephoto end and the effective focal length fG1 of the first lens group is: 1.5 < ft / fG1 < 2.5. The above conditional expression is beneficial for meeting the requirements of high optical performance and a compact zoom lens. More specifically, ft and fG1 satisfy: 1.9 < ft / fG1 < 2.1, for example, 1.94 ≤ ft / fG1 ≤ 2.08.

[0059] In this exemplary embodiment, the conditional expression satisfied by the effective focal length ft of the zoom lens at the telephoto end and the effective focal length fG3 of the third lens group is: 3.5 < ft / fG3 < 4.5. The above conditional expression is conducive to meeting the requirements of high optical performance and a compact zoom lens. More specifically, ft and fG3 satisfy: 3.8 < ft / fG3 < 4.1. For example, 3.90 ≤ ft / fG3 ≤ 4.04.

[0060] In this exemplary embodiment, the conditional expression satisfied by the effective focal length f6 of the sixth lens, the curvature radius R11 of the object side surface of the sixth lens, and the curvature radius R12 of the image side surface of the sixth lens is: -5 < f6 / (R11 - R12) < -3. The above conditional expression is conducive to meeting the requirement that the refractive index of L6 is negative. More specifically, f6, R11, and R12 satisfy: -4.5 < f6 / (R11 - R12) < -3.9. For example, -4.23 ≤ f6 / (R11 - R12) ≤ -3.95.

[0061] In this exemplary embodiment, the conditional expression satisfied by the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens is: -0.5 < (R13 + R14) / (R13 - R14) < 0. The above conditional expression is conducive to meeting the requirement that the refractive index of L7 is negative. More specifically, R13 and R14 satisfy: -0.3 < (R13 + R14) / (R13 - R14) < -0.2. For example, (R13 + R14) / (R13 - R14) = -0.26.

[0062] In this exemplary embodiment, the conditional expression satisfied by the zoom movement distance △T1 of the second lens group on the optical axis from the wide-angle end to the telephoto end, the effective focal length ft of the zoom lens at the telephoto end, and the effective focal length fw of the zoom lens at the wide-angle end is: 0.2 < △T1 / (ft - fw) < 0.3. The above conditional expression is conducive to reducing the movement distance of the lens group and increasing the compactness of the lens. More specifically, △T1, ft, and fw satisfy: 0.23 < △T1 / (ft - fw) < 0.28. For example, 0.25 ≤ △T1 / (ft - fw) ≤ 0.27.

[0063] In this exemplary embodiment, the conditional expression satisfied by the zoom movement distance △T1 of the second lens group on the optical axis from the wide-angle end to the telephoto end and the effective focal length fG2 of the second lens group is: -2 < △T1 / fG2 < -1. The above conditional expression is conducive to reducing the movement distance of the lens group and increasing the compactness of the lens. More specifically, △T1 and fG2 satisfy: -1.4 < △T1 / fG2 < -1.3. For example, -1.39 ≤ △T1 / fG2 ≤ -1.33.

[0064] In this exemplary embodiment, the condition satisfied by the numerical aperture Fno of the zoom lens in different zoom states is: 3 < Fno < 7. The above conditional expression is conducive to meeting the requirement that the lens has a certain amount of light acquisition. More specifically, at the wide-angle end, Fno satisfies: 3.2 < Fno < 3.3. For example, Fno = 3.23; at the middle end, Fno satisfies: 5 < Fno < 6.9. For example, 5.05 ≤ Fno ≤ 6.88; at the telephoto end, Fno satisfies: 6 < Fno < 6.9. For example, Fno = 6.88.

[0065] In this exemplary embodiment, the conditional expression satisfied by the total number V50 of lenses with an Abbe number less than 50 among the first lens to the seventh lens is: V50 ≤ 4. The above conditional expression is conducive to correcting chromatic aberration of the lens. More specifically, V50 satisfies: 3 ≤ V50 ≤ 4. For example, V50 = 4.00.

[0066] In this exemplary embodiment, the above zoom lens may further include a diaphragm. The diaphragm can be set at an appropriate position as needed. For example, the diaphragm can be set between the object side and the first lens. Optionally, the above zoom lens may further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0067] The zoom lens according to the above embodiment of the present invention may employ multiple lenses, such as the above seven lenses. By reasonably distributing the optical power, surface shape, central thickness of each lens, and the axial distance between each lens, etc., the zoom lens has a large imaging image plane, has the characteristics of a wide imaging range and high imaging quality, and ensures the ultra-thinness of the mobile phone.

[0068] In the exemplary embodiment, at least one of the lens surfaces of each lens is an aspherical surface, that is, at least one of the object side surface of the first lens to the image side surface of the seventh lens is an aspherical surface. The characteristics of an aspherical lens are: from the center of the lens to the periphery of the lens, the curvature changes continuously. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality. Optionally, at least one of the object side surface and the image side surface of each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens is an aspherical surface. Optionally, both the object side surface and the image side surface of each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are aspherical surfaces.

[0069] However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the zoom lens can be changed to obtain the various results and advantages described in this specification. For example, although seven lenses are described as an example in the embodiments, the zoom lens is not limited to including seven lenses, and the zoom lens may also include other numbers of lenses if necessary.

[0070] Specific embodiments of the zoom lens applicable to the above embodiments will be further described below with reference to the accompanying drawings. Specific embodiment 1

[0072] Figure 1 Schematic diagram of the wide-angle end structure of the zoom lens embodiment 1 of the present invention, Figure 2 Schematic diagram of the structure of the zoom lens embodiment 1 of the present invention at the middle end position, Figure 3 Schematic diagram of the structure at the telephoto end of zoom lens embodiment 1 of the present invention.

[0073] like Figures 1 to 3 As shown, the zoom lens includes, from the object side to the image side along the optical axis, a first lens group G1, a second lens group G2, a third lens group G3 and an imaging surface S15. The first lens group G1 includes a first lens E1 and a second lens E2, the second lens group G2 includes a third lens E3, a fourth lens E4, a stop STO and a fifth lens E5, and the third lens group G3 includes a sixth lens E6 and a seventh lens E7.

[0074] The first lens E1 has positive or negative focal power, and its object side surface S1 is convex, and its image side surface S2 is convex. The second lens E2 has positive or negative focal power, and its object side surface S3 is concave, and its image side surface S4 is convex. The third lens E3 has positive or negative focal power, and its object side surface S5 is concave, and its image side surface S6 is concave. The fourth lens E4 has positive or negative focal power, and its object side surface S7 is convex, and its image side surface S8 is convex. The fifth lens E5 has positive or negative focal power, and its object side surface S9 is concave, and its image side surface S10 is concave. The sixth lens E6 has positive or negative focal power, and its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens E7 has positive or negative focal power, and its object side surface S13 is convex, and its image side surface S14 is convex. Light from an object passes through each of the surfaces S1 to S14 in sequence and is finally imaged on the imaging surface S15 .

[0075] As shown in Table 1, it is a table of structural parameters of the zoom lens of Example 1, wherein the units of the radius of curvature and thickness are both millimeters (mm).

[0076]

[0077]

[0078] Table 1

[0079] As shown in Table 2, in Example 1, the units of the effective focal length f of the zoom lens, the numerical aperture Fno, the distance T1 between the first lens group G1 and the second lens group G2, the distance T2 between the second lens group G2 and the third lens group G3, and the distance T3 between the third lens group G3 and the imaging surface S15 are all in millimeters (mm), and the unit of the maximum field of view FOV of the zoom lens is in degrees (°).

[0080] f FOV Fno T1 T2 T3 Wide angle 10 26.13 3.23 0.4094 9.4451 17.7868 Middle End 25 10.31 5.05 6.7825 4.4540 18.5161 Telephoto end 40 6.43 6.88 8.3531 0.1000 19.1881

[0081] Table 2

[0082] As shown in Table 3, the specific values ​​of each conditional expression in Example 1 all satisfy the relationship of the conditional expression.

[0083]

[0084]

[0085] Table 3

[0086] The zoom lens in Example 1 satisfies:

[0087] At the wide-angle end, EPD×TAN(Semi-FOV) / DTmax=0.16, where EPD is the entrance pupil diameter of the zoom lens, Semi-FOV is the maximum half field angle of the zoom lens, and DTmax is the maximum value of the effective radius of each lens in the first lens group to the third lens group;

[0088] At the middle end, EPD×TAN(Semi-FOV) / DTmax=0.10, where EPD is the entrance pupil diameter of the zoom lens, Semi-FOV is the maximum half field angle of the zoom lens, and DTmax is the maximum value of the effective radius of each lens in the first lens group to the third lens group;

[0089] At the telephoto end, EPD×TAN(Semi-FOV) / DTmax=0.07, where EPD is the entrance pupil diameter of the zoom lens, Semi-FOV is the maximum half field angle of the zoom lens, and DTmax is the maximum value of the effective radius of each lens in the first lens group to the third lens group;

[0090] At the wide-angle end, |DIST| = 2.99%, where DIST is the distortion of the maximum field of view of the zoom lens;

[0091] At the middle end, |DIST| = 0.41%, where DIST is the distortion of the maximum field of view of the zoom lens;

[0092] At the telephoto end, |DIST| = 0.18%, where DIST is the distortion of the maximum field of view of the zoom lens;

[0093] At the wide-angle end, TTL / ImgH=9.05, where TTL is the axial distance from the object side of the first lens to the imaging surface, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface;

[0094] At the middle end, TTL / ImgH=9.52, where TTL is the axial distance from the object side of the first lens to the imaging surface, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface;

[0095] At the telephoto end, TTL / ImgH=9.05, where TTL is the axial distance from the object side of the first lens to the imaging surface, and ImgH is half of the diagonal length of the effective pixel area on the imaging surface;

[0096] At the wide-angle end, Fno=3.32, where Fno is the numerical aperture of the zoom lens at different zoom states;

[0097] At the middle end, Fno=5.05, where Fno is the numerical aperture of the zoom lens at different zoom states;

[0098] At the telephoto end, Fno=6.88, where Fno is the numerical aperture of the zoom lens at different zoom states;

[0099] fw / ft=0.25, where fw is the effective focal length of the zoom lens at the wide-angle end, and ft is the effective focal length of the zoom lens at the telephoto end;

[0100] ft / fG1=1.94, where ft is the effective focal length of the zoom lens at the telephoto end, and fG1 is the effective focal length of the first lens group;

[0101] ft / fG3=3.90, where ft is the effective focal length of the zoom lens at the telephoto end, and fG3 is the effective focal length of the third lens group;

[0102] △T1 / (ft-fw)=0.26, where △T1 is the zoom movement distance of the second lens group from the wide-angle end to the telephoto end on the optical axis, ft is the effective focal length of the zoom lens at the telephoto end, and fw is the effective focal length of the zoom lens at the wide-angle end;

[0103] △T1 / fG2=-1.33, where △T1 is the zoom movement distance of the second lens group from the wide-angle end to the telephoto end on the optical axis, and fG2 is the effective focal length of the second lens group;

[0104] fw / f7=1.45, where fw is the effective focal length of the zoom lens at the wide-angle end, and f7 is the effective focal length of the seventh lens;

[0105] f6 / (R11-R12)=-3.95, where f6 is the effective focal length of the sixth lens, R11 is the radius of curvature of the object side of the sixth lens, and R12 is the radius of curvature of the image side of the sixth lens;

[0106] (R13+R14) / (R13-R14)=-0.26, wherein R13 is the radius of curvature of the object side surface of the seventh lens, and R14 is the radius of curvature of the image side surface of the seventh lens;

[0107] V50=4.00, wherein V50 is the total number of lenses having an Abbe number less than 50 among the first lens to the seventh lens.

[0108] In Example 1, the object side surface and the image side surface of any lens among the first lens E1 to the seventh lens E7 are both aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0109]

[0110] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1); k is the cone coefficient; Ai is the correction coefficient of the i-th order aspheric surface.

[0111] In Example 1, the object side surface and the image side surface of any lens from the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 4 shows the high-order coefficients A of the aspherical mirror surfaces S1-S14 that can be used in Example 1. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0112]

[0113]

[0114] Table 4

[0115] Figure 4a The axial chromatic aberration curve at the wide-angle end of the zoom lens of Example 1 is shown, which indicates that light rays of different wavelengths deviate from the convergence point behind the lens. Figure 4b The astigmatism curve of the zoom lens of Example 1 at the wide-angle end position is shown, which indicates the meridional field curvature and the sagittal field curvature. Figure 4cThe distortion curve of the zoom lens of Example 1 at the wide-angle end is shown, which indicates the distortion magnitude values ​​corresponding to different image heights.

[0116] Figure 5a The axial chromatic aberration curve at the middle end position of the zoom lens of Example 1 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Figure 5b The astigmatism curve at the middle end position of the zoom lens of Example 1 is shown, which indicates the meridional field curvature and the sagittal field curvature. Figure 5c The distortion curve of the zoom lens of Example 1 at the middle end position is shown, which indicates the distortion magnitude values ​​corresponding to different image heights.

[0117] Figure 6a The axial chromatic aberration curve at the telephoto end of the zoom lens of Example 1 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Figure 6b The astigmatism curve at the telephoto end position of the zoom lens of Example 1 is shown, which indicates the meridional field curvature and the sagittal field curvature. Figure 6c The distortion curve of the zoom lens of Example 1 at the telephoto end is shown, which indicates the distortion magnitude values ​​corresponding to different image heights.

[0118] As shown in FIG. 4 to FIG. 6 , it can be seen that the zoom lens provided in Example 1 can achieve good imaging quality. Specific embodiment 2

[0120] Figure 7 Schematic diagram of the wide-angle end structure of the zoom lens embodiment 2 of the present invention, Figure 8 Schematic diagram of the structure of the zoom lens in the middle end position of Embodiment 2 of the present invention, Fig. 9 Schematic diagram of the structure at the telephoto end of zoom lens embodiment 2 of the present invention.

[0121] like Figures 7 to 9 As shown, the zoom lens includes, from the object side to the image side along the optical axis, a first lens group G1, a second lens group G2, a third lens group G3 and an imaging surface S15. The first lens group G1 includes a first lens E1 and a second lens E2, the second lens group G2 includes a third lens E3, a fourth lens E4, a stop STO and a fifth lens E5, and the third lens group G3 includes a sixth lens E6 and a seventh lens E7.

[0122] The first lens E1 has positive or negative focal power, and its object side surface S1 is convex, and its image side surface S2 is convex. The second lens E2 has positive or negative focal power, and its object side surface S3 is concave, and its image side surface S4 is convex. The third lens E3 has positive or negative focal power, and its object side surface S5 is concave, and its image side surface S6 is concave. The fourth lens E4 has positive or negative focal power, and its object side surface S7 is convex, and its image side surface S8 is convex. The fifth lens E5 has positive or negative focal power, and its object side surface S9 is concave, and its image side surface S10 is concave. The sixth lens E6 has positive or negative focal power, and its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens E7 has positive or negative focal power, and its object side surface S13 is convex, and its image side surface S14 is convex. Light from an object passes through each of the surfaces S1 to S14 in sequence and is finally imaged on the imaging surface S15 .

[0123] As shown in Table 5, it is a table of structural parameters of the zoom lens of Example 2, wherein the units of the radius of curvature and thickness are both millimeters (mm).

[0124] Face number Surface type Radius of curvature Thickness / distance Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless ST Spherical endless S1 Aspheric 14.4578 1.3228 1.54 55.71 -4.4712 S2 Aspheric -33.9730 0.8189 54.8003 S3 Aspheric -24.6907 3.5841 1.69 19.24 5.7758 S4 Aspheric -23.8816 T1 25.1883 S5 Aspheric -5.5371 1.0000 1.55 56.14 -6.9422 S6 Aspheric 8.6915 0.0300 -5.2215 S7 Aspheric 7.6523 0.1812 1.69 19.24 2.5067 S8 Aspheric -109.0938 0.0300 -99.0000 STO Spherical endless 0.1260 S9 Aspheric -25.9675 1.0000 1.65 23.52 18.3183 S10 Aspheric 8.3061 T2 15.4610 S11 Aspheric 10.0673 1.0000 1.69 19.24 -17.1716 S12 Aspheric 5.4995 0.0300 -4.2023 S13 Aspheric 5.0797 4.3994 1.54 55.71 -1.8225 S14 Aspheric -8.6996 T3 -10.9704 S15 Spherical endless

[0125] Table 5

[0126] As shown in Table 6, in Example 2, the units of the effective focal length f, the numerical aperture Fno, the distance T1 between the first lens group G1 and the second lens group G2, the distance T2 between the second lens group G2 and the third lens group G3, and the distance T3 between the third lens group G3 and the imaging surface S15 of the zoom lens are all millimeters (mm), and the unit of the maximum field of view FOV of the zoom lens is degree (°).

[0127] f FOV Fno T1 T2 T3 Wide angle 10 26.08 3.23 0.1496 8.7288 17.5993 Middle End 25 10.26 6.88 6.4210 4.3175 17.4689 Telephoto end 40 6.45 6.88 7.5372 0.0400 18.9004

[0128] Table 6

[0129] As shown in Table 7, the specific values ​​of each conditional expression in Example 2 all satisfy the relationship of the conditional expression.

[0130]

[0131]

[0132] Table 7

[0133] In Example 2, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 8 shows the high-order coefficients A of the aspherical mirror surfaces S1-S14 that can be used in Example 2. 4 , A 6 , A 8 , A 10 , A 12 , A14 , A 16 , A 18 and A 20 .

[0134]

[0135]

[0136] Table 8

[0137] Fig.10a The axial chromatic aberration curve at the wide-angle end of the zoom lens of Example 2 is shown, which indicates that light of different wavelengths deviates from the convergence point behind the lens. Fig.10b The astigmatism curve of the zoom lens of Example 2 at the wide-angle end position is shown, which indicates the meridional field curvature and the sagittal field curvature. Fig.10c The distortion curve of the zoom lens of Example 2 at the wide-angle end is shown, which indicates the distortion magnitude values ​​corresponding to different image heights.

[0138] Fig.11a The axial chromatic aberration curve at the middle end position of the zoom lens of Example 2 is shown, which indicates that light of different wavelengths deviates from the convergence point behind the lens. Fig.11b The astigmatism curve at the middle end position of the zoom lens of Example 2 is shown, which indicates the meridional field curvature and the sagittal field curvature. Fig.11c The distortion curve of the zoom lens of Example 2 at the middle end position is shown, which represents the distortion magnitude values ​​corresponding to different image heights.

[0139] Fig.12a The axial chromatic aberration curve at the telephoto end of the zoom lens of Example 2 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Figure 12b The astigmatism curve at the telephoto end position of the zoom lens of Example 2 is shown, which indicates the meridional field curvature and the sagittal field curvature. Fig.12c The distortion curve of the zoom lens of Example 2 at the telephoto end is shown, which indicates the distortion magnitude values ​​corresponding to different image heights.

[0140] As shown in FIG. 10 to FIG. 12 , it can be seen that the zoom lens provided in Example 2 can achieve good imaging quality. Specific embodiment 3

[0142] Fig.13 Schematic diagram of the wide-angle end structure of the zoom lens embodiment 3 of the present invention, Fig.14 Schematic diagram of the structure of the zoom lens embodiment 3 of the present invention at the middle end position, Fig.15 Schematic diagram of the structure at the telephoto end of zoom lens embodiment 3 of the present invention.

[0143] like Figures 13 to 15As shown, the zoom lens includes, from the object side to the image side along the optical axis, a first lens group G1, a second lens group G2, a third lens group G3 and an imaging surface S15. The first lens group G1 includes a first lens E1 and a second lens E2, the second lens group G2 includes a third lens E3, a fourth lens E4, a stop STO and a fifth lens E5, and the third lens group G3 includes a sixth lens E6 and a seventh lens E7.

[0144] The first lens E1 has positive or negative focal power, and its object side surface S1 is convex, and its image side surface S2 is convex. The second lens E2 has positive or negative focal power, and its object side surface S3 is concave, and its image side surface S4 is convex. The third lens E3 has positive or negative focal power, and its object side surface S5 is concave, and its image side surface S6 is concave. The fourth lens E4 has positive or negative focal power, and its object side surface S7 is convex, and its image side surface S8 is concave. The fifth lens E5 has positive or negative focal power, and its object side surface S9 is concave, and its image side surface S10 is concave. The sixth lens E6 has positive or negative focal power, and its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens E7 has positive or negative focal power, and its object side surface S13 is convex, and its image side surface S14 is convex. Light from an object passes through each of the surfaces S1 to S14 in sequence and is finally imaged on the imaging surface S15 .

[0145] As shown in Table 9, it is a table of structural parameters of the zoom lens of Example 3, wherein the units of the radius of curvature and thickness are both millimeters (mm).

[0146] Face number Surface type Radius of curvature Thickness / distance Refractive Index Dispersion coefficient Cone coefficient OBJ Spherical endless endless ST Spherical endless S1 Aspheric 14.5443 1.6944 1.54 55.71 -4.3208 S2 Aspheric -13.3252 0.5537 -0.3268 S3 Aspheric -11.3612 1.5571 1.69 19.24 0.0961 S4 Aspheric -21.8538 T1 25.8451 S5 Aspheric -7.4157 1.4724 1.55 56.14 -4.0546 S6 Aspheric 4.9066 0.1223 -0.1953 S7 Aspheric 3.8643 0.5357 1.69 19.24 2.8811 S8 Aspheric 13.8249 0.1067 -72.2852 STO Spherical endless 0.1487 S9 Aspheric -26.9968 1.0549 1.65 23.52 87.2794 S10 Aspheric 8.3201 T2 17.1740 S11 Aspheric 10.3848 1.0000 1.69 19.24 -18.1336 S12 Aspheric 5.5941 0.0445 -4.1637 S13 Aspheric 5.1813 4.5589 1.54 55.71 -1.7995 S14 Aspheric -8.8612 T3 -10.9595 S15 Spherical endless

[0147] Table 9

[0148] As shown in Table 10, in Example 3, the units of the effective focal length f, the numerical aperture Fno, the distance T1 between the first lens group G1 and the second lens group G2, the distance T2 between the second lens group G2 and the third lens group G3, and the distance T3 between the third lens group G3 and the imaging surface S15 of the zoom lens are all millimeters (mm), and the unit of the maximum field of view FOV of the zoom lens is degree (°).

[0149] f FOV Fno T1 T2 T3 Wide angle 10 26.11 3.23 0.2542 9.0877 17.8090 Middle End 25 10.31 6.88 6.3989 4.1342 19.0402 Telephoto end 40 6.44 6.88 8.3552 0.0416 18.7541

[0150] Table 10

[0151] As shown in Table 11, the specific values ​​of each conditional expression in Example 3 all satisfy the relationship of the conditional expression.

[0152]

[0153]

[0154] Table 11

[0155] In Example 3, the object side surface and the image side surface of any one of the first lens E1 to the seventh lens E7 are aspherical surfaces. Table 12 shows the high-order coefficients A of the aspherical mirror surfaces S1 to S14 that can be used in Example 3. 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0156]

[0157] Table 12

[0158] Fig.16a The axial chromatic aberration curve at the wide-angle end position of the zoom lens of Example 3 is shown, which indicates that light of different wavelengths deviates from the convergence point behind the lens. Fig.16b The astigmatism curve of the zoom lens of Example 3 at the wide-angle end position is shown, which indicates the meridional field curvature and the sagittal field curvature. Fig.16c The distortion curve of the zoom lens of Example 3 at the wide-angle end is shown, which indicates the distortion magnitude values ​​corresponding to different image heights.

[0159] Fig.17a The axial chromatic aberration curve at the middle end position of the zoom lens of Example 3 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Fig.17b The astigmatism curve at the middle end position of the zoom lens of Example 3 is shown, which indicates the meridional field curvature and the sagittal field curvature. Fig.17c The distortion curve of the zoom lens of Example 3 at the middle end position is shown, which represents the distortion magnitude values ​​corresponding to different image heights.

[0160] Fig.18a The axial chromatic aberration curve at the telephoto end of the zoom lens of Example 3 is shown, which indicates that light of different wavelengths deviates from the focal point behind the lens. Fig.18b The astigmatism curve at the telephoto end position of the zoom lens of Example 3 is shown, which indicates the meridional field curvature and the sagittal field curvature. Fig.18c The distortion curve of the zoom lens of Example 3 at the telephoto end is shown, which indicates the distortion magnitude values ​​corresponding to different image heights.

[0161] As shown in FIG. 16 to FIG. 18 , it can be seen that the zoom lens provided in Example 3 can achieve good imaging quality.

[0162] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, improvements, equivalent substitutions, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A zoom lens, It is characterized in that The zoom lens has three lens groups, and the three lens groups include: A first lens group with positive optical power, wherein the first lens group has two lenses with optical power, and the two lenses include, in order from the object side to the image side along the optical axis: The first lens has positive refractive power, and its object-side surface is convex and its image-side surface is convex; a second lens having positive or negative power, whose object side surface is concave and whose image side surface is convex; A second lens group with negative optical power, wherein the second lens group has three lenses with optical power, and the three lenses include, in order from the object side to the image side along the optical axis: The third lens has a negative optical power, and its object side surface is concave and its image side surface is concave; a fourth lens element having positive refractive power and a convex object-side surface; a fifth lens having negative optical power, whose object-side surface is concave and whose image-side surface is concave; A third lens group with positive optical power, wherein the third lens group has two lenses with optical power, and the two lenses include, in order from the object side to the image side along the optical axis: a sixth lens having negative optical power, whose object side surface is convex and whose image side surface is concave; The seventh lens has positive refractive power, and its object-side surface is convex and its image-side surface is convex; There is air space between each lens in the lens group; The second lens group and the third lens group can move on the optical axis to achieve continuous zooming; Among them, the entrance pupil diameter EPD of the zoom lens, the maximum half field of view Semi-FOV of the zoom lens, and the maximum value DTmax of the effective radius of each lens in the first lens group to the third lens group satisfy: 0.07≤EPD×TAN(Semi-FOV) / DTmax<0.

2.

2. The zoom lens according to claim 1, Features: The distortion DIST of the maximum field of view of the zoom lens satisfies: 0.18%≤|DIST|<3%.

3. The zoom lens according to claim 1, Features: The axial distance TTL from the object side of the first lens to the imaging plane and half the diagonal length of the effective pixel area on the imaging plane ImgH satisfy the following: 8.79≤TTL / ImgH≤9.

59.

4. The zoom lens according to claim 1, Features: The effective focal length fw of the zoom lens at the wide-angle end and the effective focal length ft of the zoom lens at the telephoto end satisfy: fw / ft=0.

25.

5. The zoom lens according to claim 1, Features: The effective focal length fw of the zoom lens at the wide-angle end and the effective focal length f7 of the seventh lens satisfy the following: 1.45≤fw / f7<1.

5.

6. The zoom lens according to claim 1, Features: The effective focal length ft of the zoom lens at the telephoto end and the effective focal length fG1 of the first lens group satisfy: 1.94≤ft / fG1≤2.

08.

7. The zoom lens according to claim 1, Features: The effective focal length ft of the zoom lens at the telephoto end and the effective focal length fG3 of the third lens group satisfy: 3.9≤ft / fG3≤4.

04.

8. The zoom lens according to claim 1, Features: The effective focal length f6 of the sixth lens, the curvature radius R11 of the object-side surface of the sixth lens, and the curvature radius R12 of the image-side surface of the sixth lens satisfy: -4.23≤f6 / (R11-R12)≤-3.

95.

9. The zoom lens according to claim 1, Features: A curvature radius R13 of the object-side surface of the seventh lens and a curvature radius R14 of the image-side surface of the seventh lens satisfy: (R13+R14) / (R13-R14)=-0.

26.

10. The zoom lens according to claim 1, Features: The zoom movement distance ΔT1 of the second lens group on the optical axis from the wide-angle end to the telephoto end, the effective focal length ft of the zoom lens at the telephoto end, and the effective focal length fw of the zoom lens at the wide-angle end satisfy: 0.2<ΔT1 / (ft-fw)<0.

3.

11. The zoom lens according to claim 1, Features: A zoom movement distance ΔT1 of the second lens group on the optical axis from the wide-angle end to the telephoto end and an effective focal length fG2 of the second lens group satisfy: -1.39≤ΔT1 / fG2≤-1.

33.

12. The zoom lens according to claim 1, Features: One of the first lens and the second lens is made of glass material; one of the sixth lens and the seventh lens is made of glass material; and the aperture is located between the fourth lens and the fifth lens.

13. The zoom lens according to claim 1, Features: The numerical aperture Fno of the zoom lens in different zoom states satisfies: 3.23≤Fno≤6.

88.

14. The zoom lens according to claim 1, Features: The total number V50 of lenses having an Abbe number less than 50 among the first lens to the seventh lens satisfies: V50=4.

Images