Zoom lens and imaging device
Patent Information
- Application Number
- CN202510716259.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2025-11-07
Smart Images
Figure CN120908978A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of optics, in particular to a zoom lens and an imaging device. BACKGROUND
[0002] A zoom lens is a lens that can change the focal length within a certain range, thereby obtaining different field angles, different image sizes and different scene ranges. The zoom lens can change the shooting range by changing the focal length without changing the shooting distance, and is therefore very beneficial to picture composition.
[0003] At present, the zoom lens with a certain magnification usually needs to consider multiple factors such as the shooting distance, resolution, focal length, volume and the like of the zoom lens to design, and the design process is relatively complex. Therefore, when the zoom lens with a certain magnification is used in a limited space, the volume of the zoom lens is usually large, and if a smaller zoom lens is used, the resolution will be insufficient. SUMMARY
[0004] The present application will solve the existing technical problems, and provide a zoom lens and an imaging device. Through the above structure and parameter limitation, the miniaturization of the zoom lens with a certain magnification is realized, and a larger aperture can also be realized with a smaller volume, thereby increasing the brightness and resolution of the zoom lens and improving the user experience.
[0005] The technical scheme provided by the present application is as follows:
[0006] A zoom lens, which comprises, from the object side to the image side, a first fixed lens group with positive refractive power, a variable magnification lens group with negative refractive power, a diaphragm, a second fixed lens group with positive refractive power, a focusing lens group with negative refractive power, and a third fixed lens group with positive refractive power.
[0007] The variable magnification lens group and the focusing lens group move along the main optical axis direction of the zoom lens.
[0008] The third fixed lens group is a lens with positive refractive power.
[0009] The zoom lens satisfies the following conditional expression:
[0010] 15 < ft / fw < 20;
[0011] TTL < 90mm;
[0012] fnom < 1.8;
[0013] wherein ft is the focal length of the zoom lens in a telephoto state, fw is the focal length of the zoom lens in a wide-angle state, TTL is the total optical length of the zoom lens, and fnom is the minimum aperture number of the zoom lens.
[0014] In the technical solution,
[0015] Through the above structure and parameter limitation, the compactness of the middle zoom lens is realized, and a larger aperture can be realized with a smaller volume, thereby increasing the brightness and resolving power of the zoom lens and improving the user experience.
[0016] Preferably, the first fixed lens group sequentially comprises, from the object side to the image side, a first fixed lens with negative focal power, a second fixed lens with positive focal power, and a third fixed lens with positive focal power, wherein the first fixed lens and the second fixed lens are cemented.
[0017] Preferably, the second fixed lens group sequentially comprises, from the object side to the image side, a fourth fixed lens with positive focal power, a fifth fixed lens with positive focal power, and a sixth fixed lens with negative focal power, wherein the fifth fixed lens and the sixth fixed lens are cemented.
[0018] Preferably, the variable zoom lens group sequentially comprises, from the object side to the image side, a first variable zoom lens with negative focal power, a second variable zoom lens with negative focal power, and a third variable zoom lens with positive focal power.
[0019] Preferably, the focusing lens group sequentially comprises, from the object side to the image side, a first focusing lens with positive focal power and a second focusing lens with negative focal power.
[0020] Preferably, the first focusing lens and the second focusing lens are cemented.
[0021] In the technical solution, the cemented lenses greatly improve the chromatic aberration and astigmatism of imaging, and increase the imaging quality.
[0022] Preferably, the second fixed lens group and the third fixed lens group each contain at least one aspherical lens.
[0023] In the technical solution, the use of aspherical lenses reduces the number of spherical lenses in the zoom lens, simplifies the structure of the zoom lens, and realizes the compactness of the zoom lens.
[0024] Preferably, the zoom lens satisfies the following condition formula:
[0025] XG2 / TTL>0.35;
[0026] Wherein, XG2 is the moving distance of the variable zoom lens group.
[0027] In the technical solution, the large moving distance of the variable zoom lens group increases the moving range of the zoom lens, thereby reducing the lateral chromatic aberration and coma of the zoom lens and increasing the resolving power of the zoom lens.
[0028] Preferably, the zoom lens satisfies the following conditional expression:
[0029] XG4 / fw<0.1;
[0030] Wherein, XG2 is the moving distance of the focusing lens group.
[0031] In the technical solution, the zoom lens is miniaturized on the basis of improving the resolving power of the zoom lens by setting the small moving distance of the focusing lens group.
[0032] Preferably, the second fixed lens group satisfies the following conditional expression:
[0033] Da5 / DG2>0.4;
[0034] Wherein, Da5 is the total optical length of the fifth fixed lens, and DG2 is the total optical length of the second fixed lens group.
[0035] In the technical solution, the zoom lens is miniaturized and the cost of the zoom lens is reduced by setting the thicker fifth fixed lens, which reduces the number of lenses in the zoom lens.
[0036] One of the purposes of the present application is also to provide an imaging device, comprising: a zoom lens; and an imaging element configured to receive an image formed by the zoom lens.
[0037] Compared with the prior art, the zoom lens and the imaging device provided by the present application have the following beneficial effects:
[0038] 1. By limiting the structure and parameters, the miniaturization of the medium magnification zoom lens is realized, and a larger aperture can be realized with a smaller volume, which increases the brightness and resolving power of the zoom lens and improves the user experience.
[0039] 2. By setting the small moving distance of the focusing lens group, the zoom lens is miniaturized on the basis of improving the resolving power of the zoom lens.
[0040] 3. By setting the thicker fifth fixed lens, the number of lenses in the zoom lens is reduced, the zoom lens is miniaturized, and the cost of the zoom lens is reduced. BRIEF DESCRIPTION OF DRAWINGS
[0041] The above-mentioned features, technical characteristics, advantages and implementation modes of the zoom lens and the imaging device will be further described in an explicit and easy-to-understand manner in combination with the preferred embodiments and the accompanying drawings.
[0042] Figure 1 is a structural schematic diagram of a zoom lens of the present application;
[0043] Figure 2 is an aberration diagram of a zoom lens in a wide-angle state according to the present application;
[0044] Figure 3 is an aberration diagram of a zoom lens in a wide-angle state according to the present application;
[0045] Figure 4 is an aberration diagram of a zoom lens in a telephoto state according to the present application;
[0046] Figure 5 is an aberration diagram of a zoom lens in a telephoto state according to the present application;
[0047] Figure 6 is a structural schematic diagram of another zoom lens according to the present application; Figure 7 is an aberration diagram of another zoom lens in a wide-angle state according to the present application; Figure 8 is an aberration diagram of another zoom lens in a wide-angle state according to the present application; Figure 9 is an aberration diagram of another zoom lens in a telephoto state according to the present application; Figure 10 is an aberration diagram of another zoom lens in a telephoto state according to the present application.
[0048] BRIEF DESCRIPTION OF DRAWINGS G1, first fixed lens group; G2, variable lens group; G3, second fixed lens group; G4, focusing lens group; G5, third fixed lens group; G6, auxiliary assembly; a1, first fixed lens; a2, second fixed lens; a3, third fixed lens; a4, fourth fixed lens; a5, fifth fixed lens; a6, sixth fixed lens; a7, seventh fixed lens; b1, first variable lens; b2, second variable lens; b3, third variable lens; c1, first focusing lens; c2, second focusing lens; STO, stop; CG, protective glass. DETAILED DESCRIPTION
[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.
[0050] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."
[0051] Example 1
[0052] like Figure 1 and Figure 6 As shown, a zoom lens is composed of, from the object plane side to the image plane side, a first fixed lens group G1 with positive optical power, a zoom lens group G2 with negative optical power, an aperture stop STO, a second fixed lens group G3 with positive optical power, a focusing lens group G4 with negative optical power, and a third fixed lens group G5 with positive optical power.
[0053] The zoom lens group G2 and the focusing lens group G4 move along the main optical axis of the zoom lens;
[0054] The third fixed lens group G5 is a lens with positive optical power;
[0055] The zoom lens satisfies the following condition:
[0056] 15 < ft / fw < 20;
[0057] TTL < 90mm;
[0058] fnom < 1.8;
[0059] Wherein, ft is the focal length of the zoom lens in telephoto mode, fw is the focal length of the zoom lens in wide-angle mode, TTL is the total optical length of the zoom lens, and fnom is the minimum aperture number of the zoom lens.
[0060] In this embodiment, by limiting the structure and parameters described above, the miniaturization of the medium-magnification zoom lens is achieved. At the same time, a large aperture can be achieved with a small volume, which increases the brightness and resolution of the zoom lens and enhances the user experience.
[0061] The first fixed lens group G1 consists of a first fixed lens a1 with negative optical power, a second fixed lens a2 with positive optical power, and a third fixed lens a3 with positive optical power, from the object plane side to the image plane side, wherein the first fixed lens a1 and the second fixed lens a2 are cemented together.
[0062] The second fixed lens group G3 comprises, in order from the object side to the image side, a fourth fixed lens a4 with positive refractive power, a fifth fixed lens a5 with positive refractive power, and a sixth fixed lens a6 with negative refractive power, and the fifth fixed lens a5 and the sixth fixed lens a6 are cemented.
[0063] The variable lens group G2 comprises, in order from the object side to the image side, a first variable lens b1 with negative refractive power, a second variable lens b2 with negative refractive power, and a third variable lens b3 with positive refractive power.
[0064] The focusing lens group G4 comprises, in order from the object side to the image side, a first focusing lens c1 with positive refractive power and a second focusing lens c2 with negative refractive power.
[0065] The first focusing lens c1 and the second focusing lens c2 are cemented.
[0066] In the embodiment, the setting of the cemented lenses greatly improves the chromatic aberration and astigmatism of imaging, and increases the quality of imaging.
[0067] The second fixed lens group G3 and the third fixed lens group G5 each contain at least one aspheric lens.
[0068] In the embodiment, the setting of the aspheric lens reduces the number of spherical lenses used in the zoom lens, simplifies the structure of the zoom lens, and realizes miniaturization of the zoom lens.
[0069] The zoom lens satisfies the following conditional expression:
[0070] XG2 / TTL>0.35;
[0071] Wherein, XG2 is the moving distance of the variable lens group G2.
[0072] In the embodiment, the setting of the larger moving distance of the variable lens group G2 increases the moving range of the zoom lens, thereby reducing the lateral chromatic aberration and coma of the zoom lens, and increasing the resolving power of the zoom lens.
[0073] The zoom lens satisfies the following conditional expression:
[0074] XG4 / fw<0.1;
[0075] Wherein, XG2 is the moving distance of the focusing lens group G4.
[0076] In the embodiment, the setting of the smaller moving distance of the focusing lens group G4 realizes miniaturization of the zoom lens on the basis of improving the resolving power of the zoom lens.
[0077] The second fixed lens group G3 satisfies the following conditional expression:
[0078] Da5 / DG2>0.4;
[0079] Wherein, Da5 is the total optical length of the fifth fixed lens a5, and DG2 is the total optical length of the second fixed lens group G3.
[0080] In the embodiment, the number of lenses in the zoom lens is reduced by setting the thicker fifth fixed lens a5, the zoom lens is miniaturized, and the cost of the zoom lens is reduced.
[0081] Embodiment 2
[0082] As shown in Figures 1 to 5 A zoom lens, which comprises, in order from the object side to the image side, a first fixed lens group G1 with positive refractive power, a variable lens group G2 with negative refractive power, a diaphragm STO, a second fixed lens group G3 with positive refractive power, a focusing lens group G4 with negative refractive power, a third fixed lens group G5 with positive refractive power, and an auxiliary assembly G6.
[0083] The variable lens group G2 and the focusing lens group G4 move along the direction of the main optical axis of the zoom lens.
[0084] The first fixed lens group G1 comprises, in order from the object side to the image side, a first fixed lens a1 with negative refractive power, a second fixed lens a2 with positive refractive power, and a third fixed lens a3 with positive refractive power, wherein the first fixed lens a1 and the second fixed lens a2 are cemented.
[0085] The variable lens group G2 comprises, in order from the object side to the image side, a first variable lens b1 with negative refractive power, a second variable lens b2 with negative refractive power, and a third variable lens b3 with positive refractive power.
[0086] The second fixed lens group G3 comprises, in order from the object side to the image side, a fourth fixed lens a4 with positive refractive power, a fifth fixed lens a5 with positive refractive power, and a sixth fixed lens a6 with negative refractive power, wherein the fifth fixed lens a5 and the sixth fixed lens a6 are cemented.
[0087] The focusing lens group G4 comprises, in order from the object side to the image side, a first focusing lens c1 with positive refractive power and a second focusing lens c2 with negative refractive power, wherein the first focusing lens c1 and the second focusing lens c2 are cemented.
[0088] The third fixed lens group G5 is a seventh fixed lens a7 with positive refractive power.
[0089] The auxiliary assembly G6 is a protective glass CG.
[0090] The basic lens data of the zoom lens of the present embodiment is shown in Table 1, the variable parameters in Table 1 are shown in Table 2, and the aspheric coefficients are shown in Table 3.
[0091] The face number in the face number column is shown when the face on the object side is set as the 1st face and the number is increased one by one as it goes toward the image side; the surface type in the surface type column is shown for a certain lens; the radius of curvature in the radius of curvature column is shown for a certain lens, and the radius of curvature is positive when the surface is curved toward the object side and is negative when the surface is curved toward the image side; the center thickness in the center thickness column is shown for the interval between the faces on the optical axis of each face and the face adjacent to it on the image side; the refractive index in the refractive index column is shown for a certain lens; and the Abbe number in the Abbe number column is shown for a certain lens.
[0092] In Table 2, the specific values of each variable parameter when the zoom lens is in the wide-angle end state are shown in the WIDE column, and the specific values of each variable parameter when the zoom lens is in the telephoto end state are shown in the TELE column.
[0093] In Table 3, K is the conic coefficient, e is the scientific notation number, for example, e-005 means 10 -5 .
[0094] [Table 1]
[0095]
[0096]
[0097] [Table 2]
[0098] Wide TELE D1 0.64 31.69 D2 32.55 1.5 D3 1.12 0.84 D4 6.3 6.58
[0099] [Table 3]
[0100]
[0101]
[0102] In the present embodiment, fw=5.76 mm, ft=91.2 mm, fno=1.67-3.26, TTL=83.7 mm, ft / fw=15.83; fnom=1.67;
[0103] wherein ft is the focal length of the zoom lens in the telephoto state, fw is the focal length of the zoom lens in the wide-angle state, TTL is the total optical length of the zoom lens, fno is the F-number of the zoom lens, and fnom is the minimum F-number of the zoom lens.
[0104] XG2=31.05 mm, XG2 / TTL=0.371;
[0105] Wherein, XG2 is the moving distance of the zoom lens group G2.
[0106] XG4=0.28; XG4 / fw=0.049;
[0107] Da5=5.81mm, DG2=13.84mm, Da5 / DG2=0.42;
[0108] Wherein, Da5 is the total optical length of the fifth fixed lens a5, and DG2 is the total optical length of the second fixed lens group G3.
[0109] Example 3
[0110] like Figures 6 to 10 As shown, a zoom lens is composed of, from the object plane side to the image plane side, a first fixed lens group G1 with positive optical power, a zoom lens group G2 with negative optical power, an aperture stop STO, a second fixed lens group G3 with positive optical power, a focusing lens group G4 with negative optical power, a third fixed lens group G5 with positive optical power, and an auxiliary component G6.
[0111] The zoom lens group G2 and the focusing lens group G4 move along the main optical axis of the zoom lens;
[0112] The first fixed lens group G1 consists of a first fixed lens a1 with negative optical power, a second fixed lens a2 with positive optical power, and a third fixed lens a3 with positive optical power, from the object plane side to the image plane side, wherein the first fixed lens a1 and the second fixed lens a2 are cemented together.
[0113] The zoom lens group G2 consists of a first zoom lens b1 with negative optical power, a second zoom lens b2 with negative optical power, and a third zoom lens b3 with positive optical power, arranged sequentially from the object plane side to the image plane side.
[0114] The second fixed lens group G3 consists of a fourth fixed lens a4 with positive optical power, a fifth fixed lens a5 with positive optical power, and a sixth fixed lens a6 with negative optical power, from the object plane side to the image plane side. The fifth fixed lens a5 and the sixth fixed lens a6 are cemented together.
[0115] The focusing lens group G4 consists of a first focusing lens c1 with positive optical power and a second focusing lens c2 with negative optical power, arranged sequentially from the object plane side to the image plane side. The first focusing lens c1 and the second focusing lens c2 are cemented together.
[0116] The third fixed lens group G5 is a seventh fixed lens a7 with positive optical power;
[0117] The auxiliary component G6 is a protective glass CG.
[0118] The basic lens data of the zoom lens of the present embodiment is shown in Table 4, the variable parameters in Table 4 are shown in Table 5, and the aspheric coefficients are shown in Table 6.
[0119] The face number in the face number column is shown when the face on the object side is set as the 1st face and the number is increased one by one as it goes toward the image side; the surface type in the surface type column is shown for a certain lens; the radius of curvature in the radius of curvature column is shown for a certain lens, and the radius of curvature is positive when the surface is curved toward the object side and is negative when the surface is curved toward the image side; the center thickness in the center thickness column is shown for the interval between the faces on the optical axis of each face and the face adjacent to it on the image side; the refractive index in the refractive index column is shown for a certain lens; and the Abbe number in the Abbe number column is shown for a certain lens.
[0120] In Table 5, the specific values of each variable parameter when the zoom lens is in the wide-angle end state are shown in the WIDE column, and the specific values of each variable parameter when the zoom lens is in the telephoto end state are shown in the TELE column.
[0121] In Table 6, K is the conic coefficient, e is the scientific notation number, for example, e-005 means 10 -5 .
[0122] [Table 4]
[0123]
[0124]
[0125] [Table 5]
[0126] Wide TELE D1 0.5 34.5 D2 35.5 1.5 D3 1.19 1.61 D4 5.97 5.55
[0127] [Table 6]
[0128]
[0129]
[0130] In the present embodiment, fw=5.81 mm, ft=95.05 mm, fno=1.63-3.74, TTL=86.91 mm, ft / fw=16.36; fnom=1.63;
[0131] wherein ft is the focal length of the zoom lens in the telephoto state, fw is the focal length of the zoom lens in the wide-angle state, TTL is the total optical length of the zoom lens, fno is the F-number of the zoom lens, and fnom is the minimum F-number of the zoom lens.
[0132] XG2=34 mm, XG2 / TTL=0.391;
[0133] XG2= 0.42; XG2 / fw = 0.072;
[0134] XG4= 0.42; XG4 / fw = 0.072;
[0135] Da5= 5.5mm, DG2= 12.31mm, Da5 / DG2= 0.447;
[0136] wherein Da5 is the total optical length of the fifth fixed lens a5, and DG2 is the total optical length of the second fixed lens group G3.
[0137] Embodiment 4
[0138] An imaging device, such as a camera, includes a zoom lens as described in any of the embodiments above, and an imaging element configured to receive an image formed by the zoom lens. Figures 1 to 10 As shown, the imaging device includes a zoom lens as described in any of the embodiments above, and an imaging element configured to receive an image formed by the zoom lens.
[0139] It should be noted that the above embodiments can be freely combined as needed. The above description is merely preferred embodiments of the present application, and it should be noted that those of ordinary skill in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should be considered within the scope of the present application.
Claims
1. A zoom lens, characterized in that, The zoom lens comprises, in order from the object side to the image side, a first fixed lens group with positive refractive power, a variable magnification lens group with negative refractive power, a diaphragm, a second fixed lens group with positive refractive power, a focusing lens group with negative refractive power, and a third fixed lens group with positive refractive power; The variable magnification lens group and the focusing lens group move along the direction of the main optical axis of the zoom lens; The third fixed lens group is a single lens with positive refractive power; The zoom lens satisfies the following condition formula: 15 < ft / fw < 20; TTL < 90 mm; fnom < 1.8; Wherein, ft is the focal length of the zoom lens in a telephoto state, fw is the focal length of the zoom lens in a wide-angle state, TTL is the total optical length of the zoom lens, and fnom is the minimum aperture number of the zoom lens.
2. The zoom lens according to claim 1, wherein: The first fixed lens group comprises, in order from the object side to the image side, a first fixed lens with negative refractive power, a second fixed lens with positive refractive power, and a third fixed lens with positive refractive power, and the first fixed lens and the second fixed lens are cemented together.
3. The zoom lens according to claim 1, wherein: The second fixed lens group comprises, in order from the object side to the image side, a fourth fixed lens with positive refractive power, a fifth fixed lens with positive refractive power, and a sixth fixed lens with negative refractive power, and the fifth fixed lens and the sixth fixed lens are cemented together.
4. The zoom lens according to claim 1, wherein: The variable magnification lens group comprises, in order from the object side to the image side, a first variable magnification lens with negative refractive power, a second variable magnification lens with negative refractive power, and a third variable magnification lens with positive refractive power.
5. The zoom lens according to claim 1, wherein: The focusing lens group comprises, in order from the object side to the image side, a first focusing lens with positive refractive power and a second focusing lens with negative refractive power.
6. The zoom lens according to claim 5, wherein: The first focusing lens and the second focusing lens are cemented together.
7. The zoom lens according to claim 1, wherein: Each of the second fixed lens group and the third fixed lens group comprises at least one aspheric lens.
8. The zoom lens according to claim 1, wherein: The zoom lens satisfies the following condition formula: XG2 / TTL > 0.35; Wherein, XG2 is the moving distance of the variable magnification lens group.
9. The zoom lens according to claim 5, wherein: The zoom lens satisfies the following condition formula: XG4 / fw < 0.1; Wherein, XG2 is the moving distance of the focusing lens group.
10. The zoom lens according to claim 3, wherein: The second fixed lens group satisfies the following condition formula: Da5 / DG2 > 0.4; Wherein, Da5 is the total optical length of the fifth fixed lens, and DG2 is the total optical length of the second fixed lens group.
11. An image forming apparatus characterized by comprising: The zoom lens according to any one of claims 1 to 10; and an imaging element configured to receive an image formed by the zoom lens.