Optical system with small size and large zoom

Abstract

The application discloses a small-size large-zoom optical system, which comprises a first group, a second group and a third group along an optical axis from an object side to an image side; wherein the first group comprises at least one movable lens group; the second group comprises at least four movable lens groups; the third group comprises a fixed lens group; the first group is used for adjusting the focal length of the small-size large-zoom optical system by moving the at least one movable lens group; the second group is used for changing the imaging size by moving the at least four movable lens groups; and the third group is used for correcting chromatic aberration. The embodiment of the application realizes a small-size, continuous large-magnification zoom and high-quality imaging optical system, which can be widely applied to the field of projection optical lenses.

Description

Technical Field

[0001] This invention relates to the field of projection optical lenses, and more particularly to an optical system with a small size and large zoom. Background Technology

[0002] With the development of semiconductor technology, image display products are becoming increasingly diversified, and the demand for consumer projectors is also growing. However, existing consumer projectors are usually fixed-focus projectors, and to obtain images of different sizes, the only way is to change the projection distance; while existing zoom projectors are larger and are usually used in scenarios such as exhibitions, performances, or conferences. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a small-size optical system with large zoom, achieving a small-size optical system with continuous high-magnification zoom and high imaging quality.

[0004] In a first aspect, embodiments of the present invention provide a small-size, large-zoom optical system, which includes a first group, a second group, and a third group sequentially along the optical axis from the object side to the image side; wherein, the first group includes at least one movable lens group; the second group includes at least four movable lens groups; and the third group includes a fixed lens group.

[0005] The first group is used to adjust the focal length of a small-sized, high-zoom optical system by moving at least one movable lens group.

[0006] The second group is used to change the size of the image by moving at least four movable lens groups;

[0007] The third group is used to correct color differences.

[0008] Optionally, the first group includes an aspherical lens with negative optical power, the Abbe number of which ranges from 40 to 60.

[0009] Optionally, the first group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens sequentially along the optical axis from the object side to the image side; the first lens is a meniscus aspherical lens with negative optical power, the second lens is a meniscus lens with negative optical power, the third lens is a biconcave lens with negative optical power, the fourth lens is a biconcave lens with negative optical power, and the fifth lens is a biconvex lens with positive optical power.

[0010] Optionally, the first lens, the second lens, and the third lens constitute a first movable lens group; or, the first lens constitutes a first movable lens group, and the second lens and the third lens constitute a second movable lens group; or, the fourth lens and the fifth lens constitute a first movable lens group.

[0011] Optionally, the second group includes, along the optical axis from the object side to the image side, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens; the sixth, seventh, eleventh, and thirteenth lenses are biconvex lenses with positive optical power; the eighth lens is a biconcave lens with negative optical power; the ninth and fourteenth lenses are meniscus lenses with positive optical power; the tenth lens is a meniscus lens with negative optical power; the twelfth lens is either a biconcave lens with negative optical power or a meniscus lens with negative optical power; and the tenth and eleventh lenses form a cemented lens.

[0012] Optionally, the sixth lens constitutes the third movable lens group; the seventh lens constitutes the fourth movable lens group; the eighth lens constitutes the fifth movable lens group; the ninth lens constitutes the sixth movable lens group; and the tenth, eleventh, twelfth, thirteenth, and fourteenth lenses constitute the seventh movable lens group.

[0013] Alternatively, the second group satisfies:

[0014]

[0015] Among them, f w f is the minimum focal length obtained by moving at least four movable lens groups for the second group. t The maximum focal length obtained by moving at least four movable lens groups for the second group.

[0016] Optionally, the second group of optical systems with small size and large zoom satisfies:

[0017]

[0018] Among them, f w L is the minimum focal length obtained by moving at least four movable lens groups in the second group, and L is the length of the small-sized, high-zoom optical system.

[0019] Optionally, in the second group, the range of the maximum object-side half field of view obtained by moving at least four movable lens groups is greater than or equal to 30°.

[0020] Optionally, the third group includes a fifteenth lens; the fifteenth lens is a biconvex lens with positive optical power.

[0021] The implementation of this invention provides the following beneficial effects: This invention provides a small-size, large-zoom optical system, comprising a first group, a second group, and a third group sequentially along the optical axis from the object side to the image side; wherein, the first group includes at least one movable lens group; the second group includes at least four movable lens groups; and the third group includes a fixed lens group; the first group is used to adjust the focal length of the small-size, large-zoom optical system by moving at least one movable lens group; the second group is used to change the image size by moving at least four movable lens groups; and the third group is used to focus light or correct aberrations. By moving at least one movable lens group in the first group, the optical system provided in this embodiment of the invention can obtain clear images at different projection distances; by moving at least four movable lens groups in the second group, the optical system provided in this embodiment of the invention can change the image size without changing the projection distance; the second group includes at least four movable lens groups, which effectively reduces the size of the optical system and expands the zoom range; the combination of the first group, the second group and the third group, while realizing a continuous high-magnification zoom optical system, improves the imaging quality of the optical system, enabling the optical system to support 4K resolution. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a small-size, high-zoom optical system provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure of a small-sized, large-zoom optical system with different focal lengths provided in an embodiment of the present invention; wherein, Figure 3 The focal length of (a) is 9.4 mm; Figure 3 The focal length of (b) is 15.7mm;

[0025] Figure 4 This is a modulation transfer function curve of a small-size, large-zoom optical system provided in an embodiment of the present invention;

[0026] Figure 5 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of another small-sized, large-zoom optical system with different focal lengths provided in an embodiment of the present invention; wherein, Figure 6 The focal length of (a) is 9.4 mm; Figure 6 The focal length of (b) is 15.7mm;

[0028] Figure 7 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0029] Figure 8 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0030] Figure 9 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0031] Figure 10 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0032] Figure 11 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0033] Figure 12 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0034] Figure 13 This is a schematic diagram of another small-sized, large-zoom optical system with different focal lengths provided in an embodiment of the present invention; wherein, Figure 13 The focal length of (a) is 9.0 mm; Figure 13 The focal length of (b) is 16.4 mm;

[0035] Figure 14 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0036] Figure 15 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0037] Figure 16 This is a schematic diagram of another small-sized, large-zoom optical system with different focal lengths provided in an embodiment of the present invention; wherein, Figure 16 The focal length of (a) is 9.4 mm; Figure 16 The focal length of (b) is 15.7mm;

[0038] Figure 17 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention;

[0039] Figure 18 This is a modulation transfer function curve of another small-size, large-zoom optical system provided in an embodiment of the present invention. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

[0041] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0042] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of the invention described herein can be implemented in an order other than that illustrated or described herein.

[0043] Unless otherwise defined, all technical and scientific terms used in the embodiments of this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in the embodiments of this invention is for descriptive purposes only and is not intended to limit the invention.

[0044] Before providing a further detailed description of the embodiments of the present invention, the nouns and terms involved in the embodiments of the present invention will be explained, and the nouns and terms involved in the embodiments of the present invention shall be interpreted as follows.

[0045] like Figure 1 As shown, this embodiment of the invention provides a small-size, large-zoom optical system, which includes a first group 1, a second group 2, and a third group 3 sequentially along the optical axis from the object side to the image side; wherein, the first group 1 includes at least one movable lens group; the second group 2 includes at least four movable lens groups; and the third group 3 includes a fixed lens group.

[0046] Group 1 is used to adjust the focal length of a small-sized, high-zoom optical system by moving at least one movable lens group.

[0047] The second group 2 is used to change the size of the image by moving at least four movable lens groups;

[0048] Group 3 is used to correct color differences.

[0049] Specifically, the incident light passes through the first group 1, the second group 2 and the third group 3 in sequence, and forms an image on the image plane 4.

[0050] Specifically, the optical system provided in the embodiment of the present invention is focused by moving at least one movable lens group in the first group 1.

[0051] Specifically, the magnification of the optical system provided in this embodiment of the invention is achieved by moving at least four movable lens groups in the second group 2.

[0052] Specifically, the movable lens group is moved by moving the support or the lens barrel housing.

[0053] Specifically, the movement of at least four movable lens groups in the second group 2 includes: moving several lens groups among the four movable lens groups, or moving at least four movable lens groups; the specific movable lens groups to be moved are determined according to the actual situation, and are not limited in the embodiments of the present invention.

[0054] Optionally, the first group includes an aspherical lens with negative optical power, the Abbe number of which ranges from 40 to 60.

[0055] Specifically, the diameter of the aspherical lens ranges from 0 to 50 mm, and the specific diameter is determined according to the actual situation. It is not limited in the embodiments of the present invention.

[0056] Specifically, the Abbe number is the dispersion coefficient of the lens. The greater the dispersion, the smaller the Abbe number, and the smaller the dispersion, the larger the Abbe number. The specific Abbe number of the aspherical lens is determined according to the actual situation, and is not limited in the embodiments of this invention.

[0057] Optionally, the first group includes, along the optical axis from the object side to the image side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5; the first lens L1 is a meniscus aspherical lens with negative optical power, the second lens L2 is a meniscus lens with negative optical power, the third lens L3 is a biconcave lens with negative optical power, the fourth lens L4 is a biconcave lens with negative optical power, and the fifth lens L5 is a biconvex lens with positive optical power.

[0058] Specifically, the Abbe number of the first lens L1 ranges from 40 to 60, and the diameter ranges from 0 to 50 mm.

[0059] Specifically, in the first group, the first lens L1, the second lens L2 and the third lens L3 form the first lens group, and the fourth lens L4 and the fifth lens L5 form the second lens group.

[0060] Alternatively, the first lens L1 forms the first lens group, the second lens L2 and the third lens L3 form the second lens group, and the fourth lens L4 and the fifth lens L5 form the third lens group.

[0061] Optionally, the first lens L1, the second lens L2, and the third lens L3 constitute a first movable lens group; or, the first lens L1 constitutes a first movable lens group, and the second lens L2 and the third lens L3 constitute a second movable lens group; or, the fourth lens L4 and the fifth lens L5 constitute a first movable lens group.

[0062] Specifically, when the first lens L1, the second lens L2, and the third lens L3 form the first lens group, and the fourth lens L4 and the fifth lens L5 form the second lens group, the first lens group L1 is a movable lens group; or, the second lens group L2 is a movable lens group.

[0063] Alternatively, when the first lens L1 forms the first lens group, the second lens L2 and the third lens L3 form the second lens group, and the fourth lens L4 and the fifth lens L5 form the third lens group, the first lens group and the second lens group are two movable lens groups.

[0064] Optionally, the second group includes, along the optical axis from the object side to the image side, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, and a fourteenth lens L14; the sixth lens L6, the seventh lens L7, the eleventh lens L11, and the thirteenth lens L13 are biconvex lenses with positive optical power; the eighth lens L8 is a biconcave lens with negative optical power; the ninth lens L9 and the fourteenth lens L14 are meniscus lenses with positive optical power; the tenth lens L10 is a meniscus lens with negative optical power; the twelfth lens L12 is either a biconcave lens with negative optical power or a meniscus lens with negative optical power; the tenth lens L10 and the eleventh lens L11 form a cemented lens.

[0065] Specifically, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 each form a lens group; the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, and the fourteenth lens L14 form another lens group.

[0066] Specifically, the second group also includes an aperture stop, which is positioned between the ninth lens L9 and the tenth lens L10. The aperture stop and the ninth lens L9 form a lens group.

[0067] Optionally, the sixth lens L6 constitutes the third movable lens group; the seventh lens L7 constitutes the fourth movable lens group; the eighth lens L8 constitutes the fifth movable lens group; the ninth lens L9 constitutes the sixth movable lens group; and the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13 and the fourteenth lens L14 constitute the seventh movable lens group.

[0068] Specifically, the lens groups formed by the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are all movable lens groups, and the other lens group formed by the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, and the fourteenth lens L14 is also a movable lens group.

[0069] Alternatively, the second group satisfies:

[0070]

[0071] Among them, f w f is the minimum focal length obtained by moving at least four movable lens groups for the second group. t The maximum focal length obtained by moving at least four movable lens groups for the second group.

[0072] Specifically, the focal length of the second group is changed by moving at least four movable lens groups in the second group, and the minimum and maximum focal lengths of the second group are obtained.

[0073] Optionally, the second group of optical systems with small size and large zoom satisfies:

[0074]

[0075] Among them, f w L is the minimum focal length obtained by moving at least four movable lens groups in the second group, and L is the length of the small-sized, high-zoom optical system.

[0076] Specifically, the length of the optical system is the distance between the object-side surface of the first lens along the optical axis from the object side to the image side and the image-side surface of the last lens along the optical axis from the object side to the image side in the optical system provided in the embodiment of the present invention.

[0077] Optionally, in the second group, the range of the maximum object-side half field of view obtained by moving at least four movable lens groups is greater than or equal to 30°.

[0078] Specifically, when at least four movable lens groups in the second group are moved, the size of the object-side half-field of view of the optical system provided in this embodiment of the invention changes, and the maximum object-side half-field of view is obtained; the specific maximum object-side half-field of view is determined according to the actual situation, and is not limited in this embodiment of the invention.

[0079] Optionally, the third group includes the fifteenth lens L15; the fifteenth lens L15 is a biconvex lens with positive optical power.

[0080] Specifically, such as Figure 2As shown, the optical system provided in this embodiment of the invention is mounted on an optomechanical system, which includes a prism L16. As shown, along the optical axis from the object side to the image side are the fifteenth lens L15 and the prism L16.

[0081] Specifically, both the fifteenth lens L15 and the prism L16 are fixed lenses; the fifteenth lens is a biconvex lens with positive optical power, used to focus light rays; the function of the prism L16 includes eliminating aberrations, and the specific type of prism is determined according to the actual situation, and is not limited in this embodiment of the invention.

[0082] In a specific embodiment, such as Figure 2 As shown, the first group includes a first lens group G1 and a second lens group G2; the second group includes a third lens group G3, a fourth lens group G4, a fifth lens group G5, a sixth lens group G6 and a seventh lens group G7; and the third group includes an eighth lens group G8. Among them, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6 and the seventh lens group G7 are movable lens groups.

[0083] The first lens group G1 includes a first lens L1, a second lens L2, and a third lens L3;

[0084] The second lens group G2 includes the fourth lens L4 and the fifth lens L5;

[0085] The third lens group G3 includes the sixth lens L6;

[0086] The fourth lens group G4 includes the seventh lens L7;

[0087] The fifth lens group G5 includes the eighth lens L8;

[0088] The sixth lens group G6 includes the ninth lens L9 and the aperture 5;

[0089] The seventh lens group G7 includes the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, and the fourteenth lens L14; among them, the twelfth lens L12 is a biconcave lens with negative optical power.

[0090] The eighth lens group G8 includes the fifteenth lens L15 and the prism L16.

[0091] Specifically, the optical system provided in this embodiment has a length of 136.2 mm, and the distance between the vertex of the object side of the first lens L1 and the vertex of the image side of the fifteenth lens L15 is 111.68 mm.

[0092] Specifically, the optical system provided in this embodiment achieves a 1.67x continuous zoom optical system by moving five movable lens groups in the second group; when the optical system provided in this embodiment... Figure 3 As shown in (a), the focal length is minimized to 9.4 mm; when the optical system provided in this embodiment is as follows... Figure 3 The setting shown in (b) is the maximum focal length, which is 15.7mm.

[0093] Specifically, the specific parameters of the optical system provided in this embodiment are shown in Table 1. The object-side surface of the first lens L1 is S1, and the image-side surface is S2; the object-side surface of the second lens L2 is S3, and the image-side surface is S4; the object-side surface of the third lens L3 is S5, and the image-side surface is S6; the object-side surface of the fourth lens L4 is S7, and the image-side surface is S8; the object-side surface of the fifth lens L5 is S9, and the image-side surface is S10; the object-side surface of the sixth lens L6 is S11, and the image-side surface is S12; the object-side surface of the seventh lens L7 is S13, and the image-side surface is S14; the object-side surface of the eighth lens L8 is S15, and the image-side surface is S16; The object-side surface of lens L9 is S17, and the image-side surface is S18; the object-side surface of lens L10 is S19, the cemented surface of lens L10 and lens L11 is S20, and the image-side surface of lens L11 is S21; the object-side surface of lens L12 is S22, and the image-side surface is S23; the object-side surface of lens L13 is S24, and the image-side surface is S25; the object-side surface of lens L14 is S26, and the image-side surface is S27; the object-side surface of lens L15 is S28, and the image-side surface is S29; the object-side surface of prism L16 is S30, and the image-side surface is S31.

[0094] Table 1

[0095]

[0096]

[0097] Specifically, all aspherical surfaces of the first lens L1 are even-order aspherical surfaces, and the aspherical surfaces of the first lens L1 satisfy the following:

[0098]

[0099] Where z is the sag of the vertex of the aspherical surface when the height of the aspherical surface along the optical axis is r; c is the vertex curvature of the aspherical surface; k is the conic coefficient of the aspherical surface; α2, α3, α4, α5, α6, α7, α8 and α9 are all higher-order aspherical coefficients; the specific parameters of k and the higher-order aspherical coefficients are shown in Table 2:

[0100] Table 2

[0101]

[0102]

[0103] Specifically, the air gaps in optical systems with different focal lengths are shown in Table 3:

[0104] Table 3

[0105] focal length 9.4mm 15.7mm D0 19.18 0.80 D1 0.80 11.39 D2 2.21 9.24 D3 13.79 2.02 D4 5.31 2.74 D5 0.82 15.92

[0106] Wherein, D0 is the air gap between the fifth lens L5 and the sixth lens L6, D1 is the air gap between the sixth lens L6 and the seventh lens L7, D2 is the air gap between the seventh lens L7 and the eighth lens L8, D3 is the air gap between the eighth lens L8 and the ninth lens L9, D4 is the air gap between the ninth lens L9 and the tenth lens L10, and D5 is the air gap between the fourteenth lens L14 and the fifteenth lens L15.

[0107] Specifically, the modulation transfer function (MTF) curve is used to characterize the features of an optical system. A higher MTF value indicates better and clearer image quality. For a focal length of 9.4mm, the MTF curve of the optical system provided in this embodiment is as follows: Figure 4 As shown, the vertical axis of the MTF curve represents the OTF coefficient (Optical Transfer Function), and the horizontal axis represents the spatial frequency. When the focal length is 15.7mm, the MTF curve of the optical system provided in this embodiment is as follows: Figure 5 As shown; Figure 4-5 All MTF curves were obtained under incident light with wavelengths ranging from 450 nm to 647 nm; Figure 4-5 As can be seen, the OTF coefficients are all above 0.5, indicating that the optical system provided in this embodiment has high sharpness at focal lengths of 9.4mm and 15.7mm.

[0108] In another specific embodiment, such as Figure 6 As shown, the first group includes a first lens group G1, a second lens group G2, and a third lens group G3; the second group includes a fourth lens group G4, a fifth lens group G5, a sixth lens group G6, a seventh lens group G7, and an eighth lens group G8; and the third group includes a ninth lens group G9. Among these, the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, the seventh lens group G7, and the eighth lens group G8 are movable lens groups.

[0109] The first lens group G1 includes the first lens L1;

[0110] The second lens group G2 includes a second lens L2 and a third lens L3;

[0111] The third lens group G3 includes the fourth lens L4 and the fifth lens L5;

[0112] The fourth lens group G4 includes the sixth lens L6;

[0113] The fifth lens group G5 includes the seventh lens L7;

[0114] The sixth lens group G6 includes the eighth lens L8;

[0115] The seventh lens group G7 includes the ninth lens L9 and the aperture stop 5;

[0116] The eighth lens group G8 includes the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, and the fourteenth lens L14; among them, the twelfth lens L12 is a meniscus lens with negative optical power.

[0117] The ninth lens group G9 includes the fifteenth lens L15 and the prism L16.

[0118] Specifically, the focal length of the first lens group G1 and the focal length of the second lens group G2 satisfy the following:

[0119]

[0120] Where f1 is the focal length of the first lens group G1 and f2 is the focal length of the second lens group G2.

[0121] Specifically, the focal length of the second lens group G2 and the focal length of the third lens group G3 satisfy the following:

[0122]

[0123] Where f2 is the focal length of the second lens group G2, and f3 is the focal length of the third lens group G3.

[0124] Specifically, the optical system provided in this embodiment has a length of 136.2 mm, and the distance between the vertex of the object side of the first lens L1 and the vertex of the image side of the fifteenth lens L15 is 111.68 mm.

[0125] Specifically, the optical system provided in this embodiment achieves a 1.67x continuous zoom optical system by moving five movable lens groups in the second group; when the optical system provided in this embodiment... Figure 6 As shown in (a), the focal length is minimized to 9.4 mm; when the optical system provided in this embodiment is as follows... Figure 6 The setting shown in (b) is the maximum focal length, which is 15.7mm.

[0126] Specifically, by moving the first lens group G1 and the second lens group G2, the optical system of this embodiment of the invention can obtain a clear image within a range of 1 to 5 meters.

[0127] Specifically, the specific parameters of the optical system provided in this embodiment are shown in Table 4. The object-side surface of the first lens L1 is S1, and the image-side surface is S2; the object-side surface of the second lens L2 is S3, and the image-side surface is S4; the object-side surface of the third lens L3 is S5, and the image-side surface is S6; the object-side surface of the fourth lens L4 is S7, and the image-side surface is S8; the object-side surface of the fifth lens L5 is S9, and the image-side surface is S10; the object-side surface of the sixth lens L6 is S11, and the image-side surface is S12; the object-side surface of the seventh lens L7 is S13, and the image-side surface is S14; the object-side surface of the eighth lens L8 is S15, and the image-side surface is S16; the ninth lens L... The object-side surface of lens 9 is S17, and the image-side surface is S18; the aperture 5 is S19; the object-side surface of the tenth lens L10 is S20, the cemented surface of the tenth lens L10 and the eleventh lens L11 is S21, and the image-side surface of the eleventh lens L11 is S22; the object-side surface of the twelfth lens L12 is S23, and the image-side surface is S24; the object-side surface of the thirteenth lens L13 is S25, and the image-side surface is S26; the object-side surface of the fourteenth lens L14 is S27, and the image-side surface is S28; the object-side surface of the fifteenth lens L15 is S29, and the image-side surface is S30; the object-side surface of prism L16 is S31, and the image-side surface is S32.

[0128] Table 4

[0129]

[0130] Specifically, all aspherical surfaces of the first lens L1 are even-order aspherical surfaces, and the aspherical surfaces of the first lens L1 satisfy the following:

[0131]

[0132] Where z is the sag of the vertex of the aspherical surface when the height of the aspherical surface along the optical axis is r; c is the vertex curvature of the aspherical surface; k is the conic coefficient of the aspherical surface; α2, α3, α4, α5, α6, α7, α8 and α9 are all higher-order aspherical coefficients; the specific parameters of k and the higher-order aspherical coefficients are shown in Table 5:

[0133] Table 5

[0134] Face number S1 S2 k -11.63 -4.51 <![CDATA[α2]]> 8.99E-05 1.33E-04 <![CDATA[α3]]> -4.00E-07 -6.04E-07 <![CDATA[α4]]> 1.38E-09 1.87E-09 <![CDATA[α5]]> -3.14E-12 -2.63E-12 <![CDATA[α6]]> 4.26E-15 -4.30E-15 <![CDATA[α7]]> -2.60E-18 2.51E-17 <![CDATA[α8]]> -3.54E-22 -4.01E-20 <![CDATA[α9]]> 9.53E-25 2.29E-23

[0135] Specifically, by moving the first lens group G1 and the second lens group G2, the image projection distance of the optical system provided in this embodiment is different, and the specific parameters are shown in Table 6:

[0136] Table 6

[0137] Projection distance 1m 2m 5m D6 1.20 0.80 0.62 D7 7.47 7.36 7.32

[0138] Wherein, D6 is the air gap between the first lens L1 and the second lens L2, and D7 is the air gap between the third lens L3 and the fourth lens L4.

[0139] Specifically, the air gaps in optical systems with different focal lengths are shown in Table 7:

[0140] Table 7

[0141] focal length 9.4mm 15.7mm D8 18.59 0.80 D9 0.80 12.00 D10 2.00 11.07 D11 16.61 2.00 D12 6.72 3.83 D13 0.80 15.82

[0142] Specifically, D8 is the air gap between the fifth lens L5 and the sixth lens L6, D9 is the air gap between the sixth lens L6 and the seventh lens L7, D10 is the air gap between the seventh lens L7 and the eighth lens L8, D11 is the air gap between the eighth lens L8 and the ninth lens L9, D12 is the air gap between the aperture 5 and the tenth lens L10, and D13 is the air gap between the fourteenth lens L14 and the fifteenth lens L15.

[0143] Specifically, when the focal length is 9.4mm and the projection distance is 2.4m, the MTF curve of the optical system provided in this embodiment is as follows: Figure 7 As shown; when the focal length is 9.4mm and the projection distance is 1m, the MTF curve of the optical system provided in this embodiment is as follows. Figure 8 As shown; when the focal length is 9.4mm and the projection distance is 5m, the MTF curve of the optical system provided in this embodiment is as follows. Figure 9 As shown; when the focal length is 15.7mm and the projection distance is 2.4m, the MTF curve of the optical system provided in this embodiment is as follows. Figure 10 As shown; when the focal length is 15.7mm and the projection distance is 1m, the MTF curve of the optical system provided in this embodiment is as follows. Figure 11 As shown; when the focal length is 15.7mm and the projection distance is 5m, the MTF curve of the optical system provided in this embodiment is as follows. Figure 12 As shown; by Figure 7-12 As can be seen, the OTF coefficients of the optical system provided in this embodiment are all greater than 0.5, indicating that the optical system provided in this embodiment has high clarity.

[0144] Specifically, Figure 7-12 All MTF curves were obtained under incident light with wavelengths ranging from 450 nm to 647 nm.

[0145] In another specific embodiment, such as Figure 13As shown, the first group includes a first lens group G1 and a second lens group G2; the second group includes a third lens group G3, a fourth lens group G4, a fifth lens group G5, a sixth lens group G6 and a seventh lens group G7; and the third group includes an eighth lens group G8. Among them, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6 and the seventh lens group G7 are movable lens groups.

[0146] The first lens group G1 includes a first lens L1, a second lens L2, and a third lens L3;

[0147] The second lens group G2 includes the fourth lens L4 and the fifth lens L5;

[0148] The third lens group G3 includes the sixth lens L6;

[0149] The fourth lens group G4 includes the seventh lens L7;

[0150] The fifth lens group G5 includes the eighth lens L8;

[0151] The sixth lens group G6 includes the ninth lens L9 and the aperture 5;

[0152] The seventh lens group G7 includes the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, and the fourteenth lens L14; among them, the twelfth lens L12 is a meniscus lens with negative optical power.

[0153] The eighth lens group G8 includes the fifteenth lens L15 and the prism L16.

[0154] Specifically, the focal length of the first lens group G1 and the focal length of the first lens L1 satisfy the following:

[0155]

[0156] Where f1 is the focal length of the first lens group G1, f L1 Let L be the focal length of the first lens L1.

[0157] Specifically, the focal length of the first lens group G1 and the focal length of the second lens group G2 satisfy the following:

[0158]

[0159] Where f1 is the focal length of the first lens group G1 and f2 is the focal length of the second lens group G2.

[0160] Specifically, the optical system provided in this embodiment achieves a 1.67x continuous zoom optical system by moving five movable lens groups in the second group; when the optical system provided in this embodiment... Figure 13As shown in (a), the focal length is minimized to 9.0 mm; when the optical system provided in this embodiment is as follows... Figure 13 The setting shown in (b) is the maximum focal length, which is 16.4mm.

[0161] Specifically, the specific parameters of the optical system provided in this embodiment are shown in Table 8. The object-side surface of the first lens L1 is S1, and the image-side surface is S2; the object-side surface of the second lens L2 is S3, and the image-side surface is S4; the object-side surface of the third lens L3 is S5, and the image-side surface is S6; the object-side surface of the fourth lens L4 is S7, and the image-side surface is S8; the object-side surface of the fifth lens L5 is S9, and the image-side surface is S10; the object-side surface of the sixth lens L6 is S11, and the image-side surface is S12; the object-side surface of the seventh lens L7 is S13, and the image-side surface is S14; the object-side surface of the eighth lens L8 is S15, and the image-side surface is S16; the ninth lens L... The object-side surface of lens 9 is S17, and the image-side surface is S18; the aperture 5 is S19; the object-side surface of the tenth lens L10 is S20, the cemented surface of the tenth lens L10 and the eleventh lens L11 is S21, and the image-side surface of the eleventh lens L11 is S22; the object-side surface of the twelfth lens L12 is S23, and the image-side surface is S24; the object-side surface of the thirteenth lens L13 is S25, and the image-side surface is S26; the object-side surface of the fourteenth lens L14 is S27, and the image-side surface is S28; the object-side surface of the fifteenth lens L15 is S29, and the image-side surface is S30; the object-side surface of prism L16 is S31, and the image-side surface is S32.

[0162] Table 8

[0163]

[0164]

[0165] Specifically, the aspherical surfaces of the first lens L1 and the ninth lens L9 are both even-order aspherical surfaces, and the aspherical surfaces satisfy the following:

[0166]

[0167] Where z is the sag of the vertex of the aspherical surface when the height of the aspherical surface along the optical axis is r; c is the vertex curvature of the aspherical surface; k is the conic coefficient of the aspherical surface; α2, α3, α4, α5, α6, α7, α8 and α9 are all higher-order aspherical coefficients; the specific parameters of k and the higher-order aspherical coefficients are shown in Table 9:

[0168] Table 9

[0169] Face number S1 S2 S17 S18 k -13.52 3.91 0.00E+00 0.00E+00 <![CDATA[α2]]> 8.32E-05 1.27E-04 -9.67E-05 -1.09E-04 <![CDATA[α3]]> -3.89E-07 -5.80E-07 -2.34E-07 -1.93E-07 <![CDATA[α4]]> 1.36E-09 1.82E-09 -2.03E-09 -1.62E-09 <![CDATA[α5]]> -3.15E-12 -2.49E-12 1.49E-11 2.05E-11 <![CDATA[α6]]> 4.35E-15 -4.29E-15 0.00E+00 0.00E+00 <![CDATA[α7]]> -2.71E-18 2.47E-17 0.00E+00 0.00E+00 <![CDATA[α8]]> -3.72E-22 -4.03E-20 0.00E+00 0.00E+00 <![CDATA[α9]]> 1.03E-24 2.40E-23 0.00E+00 0.00E+00

[0170] Specifically, the air gaps in optical systems with different focal lengths are shown in Table 10:

[0171] Table 10

[0172] focal length 9.0mm 16.4mm D14 20.75 0.80 D15 0.80 8.33 D16 2.00 11.64 D17 12.74 2.00 D18 6.88 2.71 D19 0.80 18.49

[0173] Wherein, D14 is the air gap between the fifth lens L5 and the sixth lens L6, D15 is the air gap between the sixth lens L6 and the seventh lens L7, D16 is the air gap between the seventh lens L7 and the eighth lens L8, D17 is the air gap between the eighth lens L8 and the ninth lens L9, D18 is the air gap between the aperture 5 and the tenth lens L10, and D19 is the air gap between the fourteenth lens L14 and the fifteenth lens L15.

[0174] Specifically, when the focal length is 9.0mm, the MTF curve of the optical system provided in this embodiment is as follows: Figure 14 As shown; when the focal length is 16.4mm, the MTF curve of the optical system provided in this embodiment is as follows. Figure 15 As shown; Figure 14-15 All MTF curves were obtained under incident light with wavelengths ranging from 450 nm to 647 nm; Figure 14-15 It can be seen that the OTF coefficient of the optical system provided in this embodiment is greater than 0.5 when the focal length is 9.0mm and 16.4mm, indicating that the optical system provided in this embodiment has high sharpness.

[0175] In another specific embodiment, such as Figure 16 As shown, the first group includes a first lens group G1 and a second lens group G2; the second group includes a third lens group G3, a fourth lens group G4, a fifth lens group G5, a sixth lens group G6, and a seventh lens group G7; and the third group includes an eighth lens group G8. Among them, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6, and the seventh lens group G7 are movable lens groups.

[0176] The first lens group G1 includes a first lens L1, a second lens L2, and a third lens L3;

[0177] The second lens group G2 includes the fourth lens L4 and the fifth lens L5;

[0178] The third lens group G3 includes the sixth lens L6;

[0179] The fourth lens group G4 includes the seventh lens L7;

[0180] The fifth lens group G5 includes the eighth lens L8;

[0181] The sixth lens group G6 includes the ninth lens L9 and the aperture 5;

[0182] The seventh lens group G7 includes the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, and the fourteenth lens L14; among them, the twelfth lens L12 is a meniscus lens with negative optical power.

[0183] The eighth lens group G8 includes the fifteenth lens L15 and the prism L16.

[0184] Specifically, the optical system provided in this embodiment has a length of 136.2 mm, and the distance between the vertex of the object side of the first lens L1 and the vertex of the image side of the fifteenth lens L15 is 111.68 mm.

[0185] Specifically, by moving the second lens group G2, the focusing of the optical system provided in this embodiment is achieved, and the field curvature aberration caused by assembly precision during the assembly process of the optical system is corrected.

[0186] Specifically, the optical system provided in this embodiment achieves a 1.67x continuous zoom optical system by moving five movable lens groups in the second group; when the optical system provided in this embodiment... Figure 16 As shown in (a), the focal length is minimized to 9.0 mm; when the optical system provided in this embodiment is as follows... Figure 16 The setting shown in (b) is the maximum focal length, which is 16.4mm.

[0187] Specifically, the specific parameters of the optical system provided in this embodiment are shown in Table 11. The object-side surface of the first lens L1 is S1, and the image-side surface is S2; the object-side surface of the second lens L2 is S3, and the image-side surface is S4; the object-side surface of the third lens L3 is S5, and the image-side surface is S6; the object-side surface of the fourth lens L4 is S7, and the image-side surface is S8; the object-side surface of the fifth lens L5 is S9, and the image-side surface is S10; the object-side surface of the sixth lens L6 is S11, and the image-side surface is S12; the object-side surface of the seventh lens L7 is S13, and the image-side surface is S14; the object-side surface of the eighth lens L8 is S15, and the image-side surface is S16; the ninth lens... The object-side surface of L9 is S17, and the image-side surface is S18; the aperture 5 is S19; the object-side surface of the tenth lens L10 is S20, the cemented surface of the tenth lens L10 and the eleventh lens L11 is S21, and the image-side surface of the eleventh lens L11 is S22; the object-side surface of the twelfth lens L12 is S23, and the image-side surface is S24; the object-side surface of the thirteenth lens L13 is S25, and the image-side surface is S26; the object-side surface of the fourteenth lens L14 is S27, and the image-side surface is S28; the object-side surface of the fifteenth lens L15 is S29, and the image-side surface is S30; the object-side surface of the prism L16 is S31, and the image-side surface is S32.

[0188] Table 11

[0189]

[0190]

[0191] Specifically, all aspherical surfaces of the first lens L1 are even-order aspherical surfaces, and the aspherical surfaces satisfy the following:

[0192]

[0193] Where z is the sag of the vertex of the aspherical surface when the height of the aspherical surface along the optical axis is r; c is the vertex curvature of the aspherical surface; k is the conic coefficient of the aspherical surface; α2, α3, α4, α5, α6, α7, α8 and α9 are all higher-order aspherical coefficients; the specific parameters of k and the higher-order aspherical coefficients are shown in Table 12:

[0194] Table 12

[0195] Face number S1 S2 k -12.16 -2.87 <![CDATA[α2]]> 8.81E-05 1.30E-04 <![CDATA[α3]]> -3.88E-07 -5.82E-07 <![CDATA[α4]]> 1.34E-09 1.79E-09 <![CDATA[α5]]> -3.08E-12 -2.46E-12 <![CDATA[α6]]> 4.24E-15 -4.46E-15 <![CDATA[α7]]> -2.72E-18 2.48E-17 <![CDATA[α8]]> -1.37E-22 -3.89E-20 <![CDATA[α9]]> 8.38E-25 2.17E-23

[0196] Specifically, the air gaps in optical systems with different focal lengths are shown in Table 13:

[0197] Table 13

[0198] focal length 9.4mm 15.7mm D20 18.76 0.80 D21 0.80 13.59 D22 1.20 9.03 D23 17.45 2.00 D24 7.02 4.49 D25 0.80 16.12

[0199] Wherein, D20 is the air gap between the fifth lens L5 and the sixth lens L6, D21 is the air gap between the sixth lens L6 and the seventh lens L7, D22 is the air gap between the seventh lens L7 and the eighth lens L8, D23 is the air gap between the eighth lens L8 and the ninth lens L9, D24 is the air gap between the aperture 5 and the tenth lens L10, and D25 is the air gap between the fourteenth lens L14 and the fifteenth lens L15.

[0200] Specifically, when the focal length is 9.4mm, the MTF curve of the optical system provided in this embodiment is as follows: Figure 17 As shown; when the focal length is 15.7mm, the MTF curve of the optical system provided in this embodiment is as follows. Figure 18 As shown; where, Figure 17-18 All MTF curves were obtained under incident light with wavelengths ranging from 450 nm to 647 nm; Figure 17-18 It can be seen that the optical system provided in this embodiment has an OTF coefficient greater than 0.5 when the focal length is 9.4mm and 15.7mm, indicating that the optical system provided in this embodiment has high sharpness.

[0201] The implementation of this invention provides the following beneficial effects: This invention provides a small-size, large-zoom optical system, comprising a first group, a second group, and a third group sequentially along the optical axis from the object side to the image side; wherein, the first group includes at least one movable lens group; the second group includes at least four movable lens groups; and the third group includes a fixed lens group; the first group is used to adjust the focal length of the small-size, large-zoom optical system by moving at least one movable lens group; the second group is used to change the image size by moving at least four movable lens groups; and the third group is used to focus light or correct aberrations. By moving at least one movable lens group in the first group, the optical system provided in this embodiment of the invention can obtain clear images at different projection distances; by moving at least four movable lens groups in the second group, the optical system provided in this embodiment of the invention can change the image size without changing the projection distance; the second group includes at least four movable lens groups, which effectively reduces the size of the optical system and expands the zoom range; the combination of the first group, the second group and the third group, while realizing a continuous high-magnification zoom optical system, improves the imaging quality of the optical system, enabling the optical system to support 4K resolution.

[0202] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A small-size, high-zoom optical system, characterized in that, The system comprises a first group, a second group, and a third group arranged sequentially along the optical axis from the object side to the image side. The first group includes at least one movable lens group; the second group includes at least four movable lens groups; and the third group includes a fixed lens group. The first group consists of a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side. The first lens is a meniscus aspherical lens with negative optical power; the second lens is a meniscus lens with negative optical power; the third lens is a biconcave lens with negative optical power; the fourth lens is a biconcave lens with negative optical power; and the fifth lens is a biconvex lens with positive optical power. The second group consists of a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side. The system comprises a sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, and fourteenth lens; the sixth, seventh, eleventh, and thirteenth lenses are biconvex lenses with positive optical power; the eighth lens is a biconcave lens with negative optical power; the ninth and fourteenth lenses are meniscus lenses with positive optical power; the tenth lens is a meniscus lens with negative optical power; the twelfth lens is either a biconcave lens or a meniscus lens with negative optical power; the tenth and eleventh lenses form a cemented lens; the third group consists of a fifteenth lens and a prism; the fifteenth lens is a biconvex lens with positive optical power. The first group is used to adjust the focal length of the small-size, high-zoom optical system by moving the at least one movable lens group; The second group is used to change the size of the image by moving the at least four movable lens groups; The third group is used to correct color differences; The second group satisfies: in, The minimum focal length obtained by moving the at least four movable lens groups in the second group. The maximum focal length obtained by moving the at least four movable lens groups in the second group.

2. The small-size, large-zoom optical system according to claim 1, characterized in that, The first group includes an aspherical lens with negative optical power, wherein the Abbe number of the aspherical lens is in the range of 40 to 60.

3. The small-size, large-zoom optical system according to claim 1, characterized in that, The first lens, the second lens, and the third lens constitute a first movable lens group; or, the first lens constitutes a first movable lens group, and the second lens and the third lens constitute a second movable lens group; or, the fourth lens and the fifth lens constitute the first movable lens group.

4. The small-size, large-zoom optical system according to claim 1, characterized in that, The sixth lens constitutes the third movable lens group; the seventh lens constitutes the fourth movable lens group; the eighth lens constitutes the fifth movable lens group; the ninth lens constitutes the sixth movable lens group; and the tenth, eleventh, twelfth, thirteenth, and fourteenth lenses constitute the seventh movable lens group.

5. The small-size, large-zoom optical system according to claim 1, characterized in that, The second group satisfies the following with the small-size, large-zoom optical system: in, The minimum focal length obtained by moving the at least four movable lens groups in the second group. The length of the small-sized, high-zoom optical system.

6. The small-size, large-zoom optical system according to claim 1, characterized in that, In the second group, the range of the maximum object-side half field of view obtained by moving the at least four movable lens groups is greater than or equal to 30°.

Images