A macro shift lens

Abstract

The present invention discloses a macro shift lens. Its optical system includes a first lens group with a positive optical power, a second lens group with a negative optical power, a third lens group with a positive optical power, and a fourth lens group with a negative optical power, which are sequentially arranged along the optical axis from the object side to the image plane. The first lens group is a front fixed group, the fourth lens group is a rear fixed group, the second lens group is a compensation group, and the third lens group is a variable magnification group, so that the second lens group and the third lens group move. There is a diaphragm between the first lens group and the second lens group. A macro shift lens of the present invention adopts a four-group continuous zoom structure. When the object distance changes from far to near, the first lens group and the fourth lens group are fixed, the third lens group moves towards the object side to change the focal length of the lens, making the magnification of the lens larger, and the second lens group moves towards the image plane side. By changing its relative position with the third lens group, the offset of the image plane caused by the change of the object distance is compensated, so that the lens always forms a clear image.

Description

Technical Field

[0001] The present invention relates to the technical field of camera lenses, and in particular to a macro shift lens. Background Art

[0002] A macro lens is a special lens for macro photography, mainly used for photographing fine objects such as flowers, insects, handicrafts, and observing workpieces at close range. In recent years, with the development of online shopping, more and more merchants have joined the ranks of online sales. Many merchants need to use macro lenses to take pictures of their products and display them online for customers to view. Since different products have different characteristics, the positions that need to be focused on in the captured pictures are different. Some are in the middle, some are at the edge, and some are at a special position in the picture. If a traditional macro lens is used to photograph products, since the traditional macro lens can only clearly focus on the plane perpendicular to the optical axis of the lens, this greatly increases the difficulty of photographing products whose focus is not at the center of the picture. When taking pictures, auxiliary brackets are often needed, and later image editing software is required for image editing. A shift lens can swing the lens to take pictures from different angles, enabling an inclined plane to be focused on the focal plane, so that the objects on the inclined plane are clearly imaged. In this way, creative shooting with close-ups at any position of the picture can be achieved without using an auxiliary bracket. However, traditional shift lenses do not have a macro function. Lenses with a long focal length have a long object distance and cannot perform macro shooting; although shift lenses with a short focal length have a short minimum object distance and can perform macro shooting, their magnification is small and the distortion is large, so they cannot take pictures that meet the requirements. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a macro shift lens for photographing fine objects and capable of directly taking close-ups at any position of the picture.

[0004] To solve the above technical problem, the object of the present invention is achieved through the following technical solutions: A macro shift lens is provided. The optical system of the macro shift lens includes a first lens group with a positive optical power, a second lens group with a negative optical power, a third lens group with a positive optical power, and a fourth lens group with a negative optical power, which are sequentially arranged along the optical axis from the object side to the image plane. The first lens group is a front fixed group, the fourth lens group is a rear fixed group, the second lens group is a compensation group, and the third lens group is a variable magnification group, so that the second lens group and the third lens group move between the first lens group and the fourth lens group, and a diaphragm is provided between the first lens group and the second lens group.

[0005] A further technical solution of it is: The following conditional formula is satisfied between the focal length of the first lens group and the focal length of the macro shift lens when imaging clearly at an infinite object distance:

[0006] 0.45 < f1 / f0 < 0.55

[0007] Wherein, f1 represents the focal length of the first lens group, and f0 represents the focal length of the macro shift lens when imaging clearly at an infinite object distance.

[0008] Its further technical solution is: the focal length of the fourth lens group and the combined focal length of the first lens group, the second lens group and the third lens group satisfy the following conditional formula during focusing:

[0009] -1.35 < f4 / f 123 < -1.15

[0010] Wherein, f4 represents the focal length of the fourth lens group, and f 123 represents the combined focal length of the first lens group, the second lens group and the third lens group.

[0011] Its further technical solution is: the first lens group includes a first lens, a second lens, a third lens and a fourth lens arranged in sequence along the optical axis from the object side to the image side, the second lens group includes a fifth lens, a sixth lens and a seventh lens arranged in sequence along the optical axis from the object side to the image side, the third lens group includes an eighth lens, a ninth lens and a tenth lens arranged in sequence along the optical axis from the object side to the image side, the eighth lens and the ninth lens are arranged at intervals, and the fourth lens group includes an eleventh lens.

[0012] Its further technical solution is: the optical powers of the first lens, the second lens, the fourth lens, the seventh lens, the eighth lens and the ninth lens are all positive, and the optical powers of the third lens, the fifth lens, the sixth lens, the tenth lens and the eleventh lens are all negative.

[0013] Its further technical solution is: the first lens group is arranged in the front lens barrel, the aperture stop is arranged in the aperture sleeve group, the macro shift lens includes a base and a shift adapter, the central axis of the base is coaxial with the optical axis, the front lens barrel is arranged outside the base through the aperture sleeve group and is located at the object-side end of the base, the second lens group is arranged in the base and is located at the object-side end of the base, the third lens group is arranged in the base and is located at the image-side end of the base, the second lens group and the third lens group move along the base, the shift adapter is sleeved outside the image-side end of the base, a shift transmission member is connected to the image-side end of the shift adapter, the fourth lens group is arranged in the K-piece lens barrel, and the K-piece lens barrel is arranged at the image-side end of the third lens group and is connected to the image-side end of the base.

[0014] Its further technical solution is: the radius of the engagement surface of the shift adapter and the radius of the engagement surface of the shift transmission member satisfy the following conditional formula:

[0015] 0.995 < R7 / R10 < 1

[0016] Wherein, R7 represents the radius of the engagement surface of the shift adapter, and R10 represents the radius of the engagement surface of the shift transmission member.

[0017] A further technical solution thereof is that: the distance from the intersection point of the engagement surface of the shift transmission member and the optical axis to the center of the engagement surface and the distance from the intersection point of the engagement surface of the shift transmission member and the optical axis to the image plane satisfy the following conditional formula:

[0018] 1.75 < D1 / D2 < 1.85

[0019] Wherein, D1 represents the distance from the intersection point of the engagement surface of the shift transmission member and the optical axis to the center of the engagement surface, and D2 represents the distance from the intersection point of the engagement surface of the shift transmission member and the optical axis to the image plane.

[0020] A further technical solution thereof is that: a corner sleeve is connected to one end of the shift transmission member close to the image plane, a bayonet socket is provided at one end of the corner sleeve close to the image plane, and the bayonet socket is locked to the corner sleeve by a corner lock ring, so that the bayonet socket rotates 360° around the central axis on the corner sleeve.

[0021] A further technical solution thereof is that: a shift rack and a shift limit block parallel to the optical axis are oppositely provided on one end of the corner sleeve close to the object side, the suspended end of the shift limit block extends into the interior of the shift adapter, a shift locking screw is inserted into the shift limit block, the other end of the shift locking screw extends out of the shift adapter and is sleeved in a locking knob, a shift gear meshing with the shift rack is provided inside the shift adapter, a shift knob is provided outside the shift adapter, and the shift knob is coaxially rotatably connected to the shift gear and installed on the shift adapter; wherein, the module and the number of teeth of the shift rack satisfy the following conditional formula:

[0022] R7 = m × n

[0023] Wherein, m represents the module of the shift rack, n represents the number of teeth of the shift rack, and R7 represents the radius of the engagement surface of the shift adapter.

[0024] The beneficial technical effects of the present invention are as follows: A macro shift lens of the present invention is provided with an optical system including a first lens group with a positive optical power, a second lens group with a negative optical power, a third lens group with a positive optical power, and a fourth lens group with a negative optical power, which are sequentially arranged along the optical axis from the object side to the image plane. By adopting a four-group continuous zoom structure, when the object distance changes from far to near, the first lens group and the fourth lens group remain stationary, the third lens group moves towards the object side to change the focal length of the lens, so that the magnification of the lens becomes larger, and the second lens group moves towards the image plane side. By changing the relative positions of the second lens group and the third lens group, the offset of the image plane caused by the change of the object distance is compensated, so that the lens always forms a clear image, enabling it to have both telephoto and macro shooting functions, preventing the image of the object from being distorted during macro shooting, being able to take a close-up at any position of the picture during shooting, without the need to rely on an auxiliary bracket, being convenient to operate and use, and also not requiring post-processing through image editing software, saving time and improving the user experience, and having a broad market prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic structural diagram of the macro shift lens provided by the embodiment of the present invention;

[0027] Figure 2 It is a side view of the macro shift lens provided by the embodiment of the present invention;

[0028] Figure 3 It is a front view of the macro shift lens provided by the embodiment of the present invention;

[0029] Figure 4 For Figure 3 The sectional view of the macro shift lens shown along the line A-A;

[0030] Figure 5 For Figure 3 The sectional view of the macro shift lens shown along the line B-B;

[0031] Figure 6 It is an optical system diagram of the macro shift lens provided by the embodiment of the present invention in the initial state;

[0032] Figure 7 It is an optical system diagram of the macro shift lens provided by the embodiment of the present invention in the focusing working state;

[0033] Figure 8The MTF of the macro shift lens provided by the embodiment of the present invention when the object distance is infinity.

[0034] Figure 9 The MTF of the macro shift lens provided by the embodiment of the present invention when the object distance is 110 mm. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0037] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in this specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0038] It should be further understood that the term " / and / " used in this specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the related listed items, and includes these combinations.

[0039] Please refer to Figures 1 to 9 as shown Figure 1 is a schematic structural diagram of the macro shift lens provided by the embodiment of the present invention. The optical system of the macro shift lens includes a first lens group G1 with a positive optical power, a second lens group G2 with a negative optical power, a third lens group G3 with a positive optical power, and a fourth lens group G4 with a negative optical power, which are sequentially arranged along the optical axis from the object side to the image plane. The first lens group G1 is a front fixed group, the fourth lens group G4 is a rear fixed group, the second lens group G2 is a compensation group, and the third lens group G3 is a variable magnification group, so that the second lens group G2 and the third lens group G3 move between the first lens group G1 and the fourth lens group G4, and a diaphragm S is provided between the first lens group G1 and the second lens group G2.

[0040] Among them, the macro shift lens is provided with an optical system including a first lens group G1 with a positive focal power, a second lens group G2 with a negative focal power, a third lens group G3 with a positive focal power, and a fourth lens group G4 with a negative focal power, which are arranged in sequence along the optical axis from the object side to the image plane. By adopting a four-group continuous zoom structure, when the object distance changes from far to near, the first lens group G1 and the fourth lens group G4 remain stationary, the third lens group G3 moves towards the object side to change the focal length of the lens, increasing the magnification of the lens, and the second lens group G2 moves towards the image plane. By changing the relative positions of the second lens group G2 and the third lens group G3, the offset of the image plane caused by the change of the object distance is compensated, enabling the lens to always form a clear image, thus simultaneously having the functions of telephoto and macro shooting, preventing distortion of the object image during macro shooting, being able to take close-ups at any position in the picture during shooting without the need for an auxiliary bracket, being convenient to operate and use, and not requiring post-processing through image editing software, saving time and improving the user experience, and having a broad market prospect.

[0041] Combined Figure 6 and Figure 7 , Figure 6 and Figure 7 respectively show the optical system diagrams of the macro shift lens in the initial state and the focusing working state, as Figure 6 shown, dI is the optical back focal length. Specifically, the following conditional formula is satisfied between the focal length of the first lens group G1 and the focal length of the macro shift lens when imaging clearly at an infinite object distance:

[0042] 0.45 < f1 / f0 < 0.55 (1)

[0043] In the formula, f1 represents the focal length of the first lens group G1, and f0 represents the focal length of the macro shift lens when imaging clearly at an infinite object distance.

[0044] Among them, the ratio of the focal length of the first lens group G1 to the focal length of the macro shift lens when imaging clearly at an infinite object distance is greater than 0.45 and less than 0.55, so that while meeting the optical parameter requirements, the volume of the macro shift lens will not be too large. According to the conditional formula (1), it can be known that if the ratio of the focal length of the first lens group G1 to the focal length of the macro shift lens when imaging clearly at an infinite object distance is not greater than 0.45, it will lead to too large a focal power allocated to the first lens group G1, resulting in low tolerance performance of the overall lens and being not conducive to mass production; if the ratio of the focal length of the first lens group G1 to the focal length of the macro shift lens when imaging clearly at an infinite object distance is not less than 0.55, it will lead to a larger outer diameter of the lens, thus making the volume and weight of the lens greatly exceed those of conventional products and being not conducive to shooting work and market promotion.

[0045] Specifically, when focusing, the focal length of the fourth lens group G4 and the combined focal length of the first lens group G1, the second lens group G2, and the third lens group G3 satisfy the following conditional formula:

[0046] -1.35 < f4 / f 123 < -1.15 (2)

[0047] In the formula, f4 represents the focal length of the fourth lens group G4, and f 123 represents the combined focal length of the first lens group G1, the second lens group G2, and the third lens group G3.

[0048] Among them, when focusing, the ratio of the focal length of the fourth lens group G4 to the combined focal length of the first lens group G1, the second lens group G2, and the third lens group G3 is greater than -1.35 and less than -1.15, so as to ensure aberration correction while the optical back focal length of the macro shift lens meets the shift structure. According to the conditional formula (2), it can be known that if the ratio of the focal length of the fourth lens group G4 to the combined focal length of the first lens group G1, the second lens group G2, and the third lens group G3 is not greater than -1.35 when focusing, the optical power of the fourth lens group G4 will be too low, which is not conducive to aberration correction; if the ratio of the focal length of the fourth lens group G4 to the combined focal length of the first lens group G1, the second lens group G2, and the third lens group G3 is not less than -1.15 when focusing, the optical back focal length of the macro shift lens will be too short, so that there is not enough space for the shift structure design.

[0049] Specifically, the first lens group G1 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged in sequence along the optical axis from the object side to the image side. The second lens group G2 includes a fifth lens L5, a sixth lens L6, and a seventh lens L7 arranged in sequence along the optical axis from the object side to the image side. The third lens group G3 includes an eighth lens L8, a ninth lens L9, and a tenth lens L10 arranged in sequence along the optical axis from the object side to the image side. The eighth lens L8 and the ninth lens L9 are arranged at intervals. The fourth lens group G4 includes an eleventh lens L11.

[0050] Specifically, in this embodiment, the optical powers of the first lens L1, the second lens L2, the fourth lens L4, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are all positive, and the optical powers of the third lens L3, the fifth lens L5, the sixth lens L6, the tenth lens L10, and the eleventh lens L11 are all negative. Preferably, the first lens L1, the second lens L2, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are all biconvex lenses, the third lens L3, the fifth lens L5, the sixth lens L6, the tenth lens L10, and the eleventh lens L11 are all biconcave lenses, and the fourth lens L4 is a convex-concave lens.

[0051] Among them, the second lens L2 and the third lens L3 are cemented into a first cemented lens, the sixth lens L6 and the seventh lens L7 are cemented into a second cemented lens, and the ninth lens L9 and the tenth lens L0 are cemented into a third cemented lens.

[0052] The following table gives the relevant parameter data of this embodiment:

[0053]

[0054]

[0055] Among them, R: the curvature radius of each surface;

[0056] D: the distance between each surface (including air gap and glass thickness);

[0057] Nd: the refractive index of each glass at d light;

[0058] Vd: the Abbe number of each glass at d light;

[0059] Focal length: 85 mm to 50 mm

[0060] FNO: 2.8 to 16

[0061] Half field of view angle: 14° to 9.2°

[0062] Among them, the minimum value of the shooting object distance of the macro shift lens is 110 mm, the magnification is 1x, and the shift angle of the macro shift lens can reach ±8.5°.

[0063] Specifically, in this embodiment, the first lens group G1 is disposed in the front lens barrel 1, the aperture stop S is disposed in the aperture stop sleeve group, the macro shift lens includes a base 18 and a shift adapter 7, the central axis of the base 18 is coaxial with the optical axis, the front lens barrel 1 is disposed outside the base 18 through the aperture stop sleeve group and is located at the object side end of the base 18, the second lens group G2 is disposed in the base 18 and is located at the object side end of the base 18, the third lens group G3 is disposed in the base 18 and is located at the image side end of the base 18, the second lens group G2 and the third lens group G3 move along the base 18, the image side end of the base 18 is externally sleeved with the shift adapter 7, a shift transmission member 10 is connected to the image side end of the shift adapter 7, the fourth lens group G4 is disposed in the K-piece lens barrel 19, and the K-piece lens barrel 19 is disposed at the image side end of the third lens group G3 and is connected to the image side end of the base 18.

[0064] Among them, the front lens barrel 1, the diaphragm sleeve group, the base 18, and the shift adapter 7 are coaxially arranged. The fifth lens L5, the sixth lens L6, and the seventh lens L7 are sequentially loaded into the compensation lens barrel 4 along the optical axis from the object side to the image plane and then tightened with a retaining ring. The eighth lens L8, the ninth lens L9, and the tenth lens L10, together with the corresponding spacer rings, are sequentially loaded into the zoom lens barrel 6 along the optical axis from the object side to the image plane and then tightened with a retaining ring. The compensation lens barrel 4 and the zoom lens barrel 6 are arranged inside the base 18. A cam 17 is sleeved outside the base 18 and connected by a guide pin. A focusing collar 16 is sleeved outside the cam 17. One end of the shift adapter 7 close to the object side is connected with a focusing ring 5 by a screw. The focusing ring 5 is sleeved outside the focusing collar 16. The focusing ring 5 is connected with the cam 17 through a guide pin passing through a notch milled on the focusing collar 16, so that when the focusing ring 5 is rotated, the cam 17 can be driven to rotate along the optical axis, and the compensation lens barrel 4 and the zoom lens barrel 6 make relative displacements along the base 18. The eleventh lens L11 is loaded into the K-piece lens barrel 19 and then tightened with a retaining ring. The K-piece lens barrel 19 is connected with one end of the base 18 close to the image plane by a screw.

[0065] Preferably, the diaphragm sleeve group includes a diaphragm adjustment ring 3 and a diaphragm moving ring 2. The diaphragm blade S is loaded into the diaphragm moving ring 2 and then installed in the front lens barrel 1 and clamped with a snap ring. The diaphragm adjustment ring 3 is connected with the diaphragm moving ring 2 by a guide pin, so that when the diaphragm adjustment ring 3 is rotated, the diaphragm moving ring 2 can be driven to rotate, thereby controlling the change of the diaphragm aperture. The diaphragm adjustment ring 3 is sleeved on one end of the adjustment collar 16 close to the object side, so that the front lens barrel 1 is arranged at one end of the base 18 close to the object side through the diaphragm sleeve group. The diaphragm adjustment ring 3, the focusing ring 5, and the shift adapter 7 are sequentially sleeved outside the adjustment collar 16 along the optical axis from the object side to the image plane, and the diaphragm adjustment ring 3 and the shift adapter 7 are respectively connected with both ends of the focusing ring 5. The first lens L1, the second lens L2, the third lens L3, and the fourth lens L4, together with the spacer rings, are sequentially loaded into the front lens barrel 1 along the optical axis from the object side to the image plane and locked with a retaining ring. The shift adapter 7 and the shift transmission member 10 are respectively provided with a connecting structure in the shape of a semi-dovetail groove that cooperate with each other.

[0066] Combined with Figure 5 , as Figure 5 shown, I is the image plane; S7 is the joint surface of the shift adapter 7 and the shift transmission member 10, that is, the joint surface of the shift adapter 7; S10 is the joint surface of the shift transmission member 10 and the shift adapter 7, that is, the joint surface of the shift transmission member 10; Q is the intersection point of the joint surface S10 of the shift transmission member 10 and the optical axis; O is the center of the joint surface S10 of the shift transmission member 10. Specifically, the radius of the joint surface S7 of the shift adapter 7 and the radius of the joint surface S10 of the shift transmission member 10 satisfy the following conditional formula:

[0067] 0.995 < R7 / R10 < 1 (3)

[0068] In the formula, R7 represents the radius of the engagement surface S7 of the shift adapter 7, and R10 represents the radius of the engagement surface S10 of the shift transmission member 10.

[0069] Among them, the ratio of the radius of the engagement surface S7 of the shift adapter 7 to the radius of the engagement surface S10 of the shift transmission member 10 is greater than 0.995 and less than 1, so that the radius of the engagement surface S7 of the shift adapter 7 is slightly smaller than the radius of the engagement surface S10 of the shift transmission member 10, to ensure that the shift transmission member 10 can closely adhere to the shift adapter 7 without jamming during shift deflection, thereby realizing the shift shooting function. If the ratio of the radius of the engagement surface S7 of the shift adapter 7 to the radius of the engagement surface S10 of the shift transmission member 10 is not greater than 0.995 or not less than 1, it will cause the shift adapter 7 and the shift transmission member 10 to jam and the shift function cannot be realized. Preferably, the radius of the engagement surface S7 of the shift adapter 7 can be 66 mm.

[0070] Specifically, in this embodiment, the distance from the intersection point Q of the engagement surface S10 of the shift transmission member 10 and the optical axis to the center O of the engagement surface S10 of the shift transmission member 10 and the distance from the intersection point Q of the engagement surface S10 of the shift transmission member 10 and the optical axis to the image plane I satisfy the following conditional formula:

[0071] 1.75 < D1 / D2 < 1.85 (4)

[0072] In the formula, D1 represents the distance from the intersection point Q of the engagement surface S10 of the shift transmission member 10 and the optical axis to the center O of the engagement surface S10 of the shift transmission member 10, and D2 represents the distance from the intersection point Q of the engagement surface S10 of the shift transmission member 10 and the optical axis to the image plane I.

[0073] Among them, the ratio of D1 and D2 is greater than 1.75 and less than 1.85 to ensure that there is no vignetting during the shift of the macro shift lens, and at the same time, there is enough space to reasonably distribute the size ratio of the shift adapter 7 and the shift transmission member 10 to realize the shift shooting function. If the ratio of D1 and D2 is not greater than 1.75, the size space of the shift adapter 7 becomes smaller, and it will interfere with the shift adapter 7 during the shift and cannot reach the predetermined shift angle; if the ratio of D1 and D2 is not less than 1.85, the peripheral field light of the macro shift lens is easily blocked during the shift, and vignetting is likely to occur. Preferably, the distance from the intersection point Q of the engagement surface S10 of the shift transmission member 10 and the optical axis to the image plane I can be 36.1 mm.

[0074] Continue to refer to Figures 1 to 9, specifically, a corner collar 11 is connected to one end of the shift transmission member 10 close to the image plane. A bayonet socket 12 is provided at one end of the corner collar 11 close to the image plane, and the bayonet socket 12 is locked to the corner collar 11 by a corner lock ring 14, so that the bayonet socket 12 can rotate 360° around the central axis on the corner collar 11. Among them, a bayonet 13 is fixed to the bayonet socket 12 by screws, so as to mount the macro shift lens on the camera body.

[0075] Specifically, a shift rack 15 parallel to the optical axis and a shift limit block 22 are oppositely provided at one end of the corner collar 11 close to the object side. The shift rack 15 can be vertically opposite to the shift limit block 22. The suspended end of the shift limit block 22 extends into the interior of the shift adapter 7. A shift locking screw 21 is inserted into the shift limit block 22. The other end of the shift locking screw 21 extends out of the shift adapter 7 and is sleeved in a locking knob 20. A shift gear 8 meshing with the shift rack 15 is provided inside the shift adapter 7, so that the shift gear 8 is in transmission connection with the shift rack 15; a shift knob 9 is provided outside the shift adapter 7. The shift knob 9 is coaxially rotatably connected to the shift gear 8 and mounted on the shift adapter 7 to control the rotation of the shift gear 8 through the shift knob 9; among them, the module and the number of teeth of the shift rack 15 satisfy the following conditional formula:

[0076] R7 = m×n (5)

[0077] In the formula, m represents the module of the shift rack 15, n represents the number of teeth of the shift rack 15, and R7 represents the radius of the connection surface S7 of the shift adapter 7.

[0078] Among them, the product of the module and the number of teeth of the shift rack 15 being equal to the radius of the connection surface S7 of the shift adapter 7 can ensure that the shift knob 9 can smoothly drive the shift transmission member 10 to perform shift sliding on the shift adapter 7. The shift limit block 22 may be provided with a curved groove for inserting one end of the shift locking screw 21, so that one end of the shift locking screw 21 is inserted into the shift limit block 22.

[0079] In summary, a macro shift lens according to the present invention includes an optical system in which a first lens group with a positive focal power, a second lens group with a negative focal power, a third lens group with a positive focal power, and a fourth lens group with a negative focal power are sequentially arranged along the optical axis from the object side to the image plane. By adopting a four-group continuous zoom structure, when the object distance changes from far to near, the first lens group and the fourth lens group remain stationary, the third lens group moves towards the object side to change the focal length of the lens and increase the magnification of the lens, and the second lens group moves towards the image plane. By changing the relative positions of the second lens group and the third lens group, the offset of the image plane caused by the change of the object distance is compensated, so that the lens always forms a clear image, enabling the lens to have both telephoto and macro shooting functions, preventing distortion of the object image during macro shooting, being able to take close-ups at any position of the picture during shooting without the need to rely on an auxiliary bracket, being convenient to operate and use, and not requiring post-processing through image editing software, saving time and improving the user experience, and having a broad market prospect.

[0080] As described above, the above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A macro shift lens, characterized in that, The optical system of the macro shift lens includes, in order from the object side to the image plane along the optical axis, a first lens group with a positive optical power, a second lens group with a negative optical power, a third lens group with a positive optical power, and a fourth lens group with a negative optical power. The first lens group is a front fixed group, the fourth lens group is a rear fixed group, the second lens group is a compensation group, and the third lens group is a zoom group, so that the second lens group and the third lens group move between the first lens group and the fourth lens group. An aperture stop is provided between the first lens group and the second lens group; The focal length of the first lens group and the focal length of the macro shift lens when clearly imaging at an infinite object distance satisfy the following conditional formula: 0.45 < f1 / f0 < 0.55 In the formula, f1 represents the focal length of the first lens group, and f0 represents the focal length of the macro shift lens when clearly imaging at an infinite object distance; The focal length of the fourth lens group and the combined focal length of the first lens group, the second lens group, and the third lens group satisfy the following conditional formula during focusing: -1.35 < f4 / f 123 < -1.15 where f4 represents the focal length of the fourth lens group, and f 123 represents the combined focal length of the first, second, and third lens groups; The first lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in order from the object side to the image plane along the optical axis. The second lens group includes a fifth lens, a sixth lens, and a seventh lens arranged in order from the object side to the image plane along the optical axis. The third lens group includes an eighth lens, a ninth lens, and a tenth lens arranged in order from the object side to the image plane along the optical axis. The eighth lens and the ninth lens are spaced apart. The fourth lens group includes an eleventh lens; The optical powers of the first lens, the second lens, the fourth lens, the seventh lens, the eighth lens, and the ninth lens are all positive, and the optical powers of the third lens, the fifth lens, the sixth lens, the tenth lens, and the eleventh lens are all negative.

2. The macro shift lens according to claim 1, wherein The first lens group is disposed in the front lens barrel. The aperture stop is disposed in the aperture sleeve group. The macro shift lens includes a base and a shift adapter. The central axis of the base is coaxial with the optical axis. The front lens barrel is disposed outside the base through the aperture sleeve group and is located at the object-side end of the base. The second lens group is disposed in the base and is located at the object-side end of the base. The third lens group is disposed in the base and is located at the image-side end of the base. The second lens group and the third lens group move along the base. The shift adapter is sleeved on the image-side end of the base. A shift transmission member is connected to the image-side end of the shift adapter. The fourth lens group is disposed in the K-piece lens barrel. The K-piece lens barrel is disposed at the image-side end of the third lens group and is connected to the image-side end of the base.

3. The macro shift lens according to claim 2, wherein, The radius of the engagement surface of the shift adapter and the radius of the engagement surface of the shift transmission member satisfy the following conditional formula: 0.995 < R7 / R10 < 1 In the formula, R7 represents the radius of the engagement surface of the shift adapter, and R10 represents the radius of the engagement surface of the shift transmission member.

4. The macro shift lens according to claim 2, wherein The distance from the intersection point of the engagement surface of the shift transmission member and the optical axis to the center of the engagement surface and the distance from the intersection point of the engagement surface of the shift transmission member and the optical axis to the image plane satisfy the following conditional formula: 1.75 < D1 / D2 < 1.85 Wherein, D1 represents the distance from the intersection point of the engagement surface of the shift transmission member and the optical axis to the center of the engagement surface, and D2 represents the distance from the intersection point of the engagement surface of the shift transmission member and the optical axis to the image plane.

5. The macro shift lens according to claim 2, wherein, One end of the shift transmission member close to the image plane is connected with a rotation angle collar. One end of the rotation angle collar close to the image plane is provided with a bayonet socket, and the bayonet socket is locked on the rotation angle collar through a rotation angle locking ring, so that the bayonet socket rotates 360° around the central axis on the rotation angle collar.

6. The macro shift lens according to claim 5, wherein On one end of the rotation angle collar close to the object side, a shift rack parallel to the optical axis and a shift limit block are oppositely arranged. The suspended end of the shift limit block extends into the interior of the shift adapter seat. A shift locking screw is inserted into the shift limit block. The other end of the shift locking screw extends out of the shift adapter seat and is sleeved in a locking knob. Inside the shift adapter seat, there is a shift gear meshing with the shift rack. Outside the shift adapter seat, there is a shift knob. The shift knob is coaxially and rotatably connected to the shift gear and is installed on the shift adapter seat. Wherein, the module and the number of teeth of the shift rack satisfy the following conditional formula: R7 = m × n Wherein, m represents the module of the shift rack, n represents the number of teeth of the shift rack, and R7 represents the radius of the engagement surface of the shift adapter seat.

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