Macro lens with double focusing modes and camera shooting equipment

Abstract

The macro lens supports a manual focusing mode and an automatic focusing mode, an optical system of the macro lens sequentially comprises a first lens group, a second lens group and a third lens group from an object side to an image side along an optical axis, the second lens group has positive diopter, the third lens group has negative diopter, and the fourth lens group has negative diopter. The third lens group has negative diopter. Wherein in the manual focusing mode, focusing from infinity to more than one time of photographic magnification is realized by moving the second lens group; and in the automatic focusing mode, focusing from infinity to the photographic magnification less than 0.3 times is realized by moving the third lens group. Therefore, under the condition of different requirements, different focusing modes are adopted, the automatic focusing group is very light and small in focusing movement amount, the problem of focusing speed is solved, a high-power focusing motor is not needed, and the design purposes of low cost and small size are achieved.

Description

Technical Field

[0001] This utility model belongs to the field of macro lens technology, specifically relating to a macro lens with dual focusing mode and a camera device. Background Technology

[0002] Macro lenses are widely used in various optical devices and generally have two focusing methods. One method is to move a relatively large and heavy focusing group when the object is at a magnification of more than 1x. The other method is to move another focusing group when the object is at a magnification of less than 0.3x.

[0003] Currently, there are many types of macro lenses in use. For example, the optical structure of Patent Document 1 starts from the object side, with the refractive power of each lens group being positive, positive, and negative in sequence. During the focusing process from infinity to the same magnification, the first lens group G1 and the second lens group G2 move to achieve focusing, while the third lens group G3 remains fixed. Although this can achieve good imaging results, the total length of the lens changes during the focusing process. When shooting macro, it is easy to disturb sensitive insects. At the same time, because of the large amount of focusing movement, many lens elements, and the relatively heavy focusing group, a powerful motor is necessary to achieve fast focusing. In addition, macro photography has a very shallow depth of field. In many cases, the autofocus function is turned off and the manual mode is used during macro shooting. However, in order to drive the heavy focusing group, a high-power motor drive system with a long travel is still required, which leads to high cost and low efficiency. It is also larger and more expensive.

[0004] For example, the optical structure of Patent Document 2 starts from the object side and consists of a front group, a positive diopter group P, and a rear group. The rear group is composed of a subsequent N group. When focusing, at least the aforementioned P group and N group move along the optical axis to achieve the focusing function. For macro lenses with a maximum magnification of 0.5x or higher, this means that the focusing system needs at least two groups to move to achieve the focusing function. Because the front group does not move, the total length of the optical system remains unchanged during the focusing process. During the focusing process, more than two lens groups move. In order to achieve a macro effect of 0.5x or higher, the amount of movement is very large. If the autofocus function is achieved, the motor power used for driving will be very large, and the driving stroke will also be very long. If high-speed autofocus is achieved throughout the entire process, it will be very difficult, costly, and bulky.

[0005] It is evident that existing macro lenses have the following problems: (1) They require the movement of multiple lens groups, resulting in a large driving load, requiring a high-power motor, and incurring high costs; (2) The large amount of movement results in slow autofocus speed, making it difficult to meet the needs of dynamic shooting. Macro photography often requires manual focusing, which is laborious and inefficient; (3) The long focusing stroke and complex mechanical structure limit the miniaturization of the lens, making it difficult to adapt to lightweight cameras (such as mirrorless cameras); (4) It is difficult to balance high magnification and fast AF, and it cannot simultaneously meet the needs of regular shooting, mid-range close-ups and high-magnification macro, thus limiting the application scenarios.

[0006] Therefore, a macro lens with dual focusing modes needs to be designed to solve the incompatibility problem between the large amount of movement required for high-magnification macro and the lightweight drive required for fast AF. Utility Model Content

[0007] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a macro lens and camera device with dual focusing modes. Different focusing methods are adopted under different needs, which makes autofocus convenient and the amount of movement small, solves the focusing speed problem, and achieves the design goals of low cost and small size.

[0008] To achieve the above and other related objectives, this utility model proposes a macro lens with dual focusing modes. The macro lens supports both manual focus (MF) and autofocus (AF) modes, and the optical system of the macro lens, from the object side to the image side along the optical axis, comprises:

[0009] First lens group;

[0010] The second lens group has positive refractive power;

[0011] The third lens group has negative refractive power;

[0012] The manual focus mode (MF) allows focusing from infinity to a magnification of 1x or higher by moving the second lens group.

[0013] The autofocus mode (AF) achieves focus from infinity to a magnification of less than 0.3x by moving the third lens group;

[0014] Furthermore, the following condition must be met: 0.2≤F2 / FL≤0.7, where F2 is the focal length of the second lens group of the optical system at infinity, and FL is the total focal length of the optical system.

[0015] This utility model proposes a macro lens with a dual focusing mode, wherein the second lens group includes a front part and a rear part, and both the front part and the rear part of the second lens group have positive diopter.

[0016] In the manual focus (MF) mode: the second lens group moves as a whole, or the front and rear parts of the second lens group move proportionally to achieve focus;

[0017] And it satisfies the following conditions: 0.5≤|F2a / FL|≤1.2 and 0.5≤FL / (MA×S2a)≤5, where F2a is the front focal length of the second lens, MA is the maximum magnification of the second lens group, and S2a is the maximum movement of the second lens group.

[0018] This utility model proposes a macro lens with a dual focusing mode, wherein the third lens group includes a front part and a rear part, and the front part of the third lens group has negative refractive power.

[0019] In the autofocus mode (AF): the front part of the third lens group moves to achieve focusing;

[0020] And it satisfies the following conditions: 1.0≤|FL / F3a|≤6 and 0.5≤|F3 / F3a|≤2.5, where F3 is the focal length of the third lens group in the optical system at infinity, and F3a is the front part focal length of the third lens group.

[0021] This utility model proposes a macro lens with dual focusing modes. In the autofocus mode (AF), the maximum movement of the front part of the third lens group is S3a, and it satisfies the following condition: 5≤S2a / S3a≤35.

[0022] This invention proposes a macro lens with a dual focusing mode, wherein the aperture of the optical system is disposed between the second lens group and the third lens group, and moves as the second lens group moves.

[0023] This invention proposes a macro lens with a dual focusing mode, wherein the first lens group includes at least one positive lens with a convex surface facing the object side, which is used to ensure the total length of the optical system and provide basic positive optical power.

[0024] The present invention proposes a macro lens with a dual focusing mode, wherein the front part of the second lens group includes at least a positive lens and a set of cemented lenses, and the rear part of the second lens group includes at least a set of cemented lenses.

[0025] This invention proposes a macro lens with a dual focusing mode, wherein the movement ratio of the front and rear parts of the second lens group is dynamically adjusted according to the aberration correction requirements.

[0026] The present invention proposes a macro lens with dual focusing mode, wherein the front part of the third lens group includes at least one negative lens, which is a meniscus lens or a biconcave lens with the concave surface facing the image side, and the rear part of the third lens group includes at least one set of cemented lenses.

[0027] To achieve the above-mentioned objectives and other related objectives, this utility model also proposes a camera device, including the macro lens described above.

[0028] The beneficial technical effects of this utility model include at least the following: This utility model provides a macro lens and imaging device with dual focusing modes. In a macro lens optical system, the optical structure offers two focusing modes. When the object is at infinity and magnification greater than 1x, the MF (Multi-Focus) focusing mode is used. In this mode, the focusing group moves the second lens group to achieve focusing. While the movement is large and the focusing group is heavy, it can achieve focusing from infinity to 1x magnification, resulting in excellent optical performance across the entire field of view. When the object is at infinity and magnification less than 0.3x, the AF (Action Focusing) mode can be used. In this mode, the focusing group moves the front part of the third lens group to achieve focusing. Because the front part of the third lens group moves less and is lightweight, the required motor power is low, the focusing speed is fast, and the optical system can be miniaturized and lightweight. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a macro lens with dual focusing mode in Embodiment 1 of this utility model.

[0031] Figure 2 This is a comparison chart of aberration performance in dual-focus mode in Embodiment 1 of this utility model.

[0032] Figure 3 This is a schematic diagram of the structure of a macro lens with dual focusing mode in Embodiment 2 of this utility model.

[0033] Figure 4 This is a comparison chart of aberration performance in dual-focus mode in Embodiment 2 of this utility model. Detailed Implementation

[0034] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0035] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show the components related to this utility model and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0036] Please see Figure 1 and Figure 4 As shown, in order to achieve the above-mentioned objectives and other related objectives, this utility model proposes a macro lens and camera device with dual focusing mode to solve the problems existing in current macro lenses with dual focusing mode.

[0037] It should be noted that the first lens group is denoted by G1, the second lens group by G2, the front part of the second lens group by G2a, the rear part of the second lens group by G2b, the third lens group by G3, the front part of the third lens group by G3a, and the rear part of the third lens group by G3b.

[0038] Specifically, a macro lens with dual focusing modes supports both manual focus (MF) and autofocus (AF) modes. The optical system of the macro lens, from the object side to the image side along the optical axis, includes a first lens group, a second lens group, and a third lens group. The second lens group has positive diopter, and the third lens group has negative diopter.

[0039] Among them, manual focus mode (MF): by moving the second lens group, it can achieve focus from infinity to a magnification of 1x or more; autofocus mode (AF): by moving the third lens group, it can achieve focus from infinity to a magnification of less than 0.3x; and must meet the following condition: 0.2≤F2 / FL≤0.7, where F2 is the focal length of the second lens group of the optical system at infinity, and FL is the focal length of the optical system at infinity.

[0040] It should be noted that 0.2≤F2 / FL≤0.7 is the setting of conditional equation (1). If the upper limit of conditional equation (1) is exceeded, the refractive power of G2 is too weak. To achieve a magnification of more than 1x, the focus movement of G2 will be too large, making it difficult to achieve miniaturized macro. If the lower limit of conditional equation (1) is exceeded, the refractive power of G2 is very strong. Although the focus movement is small enough to achieve a magnification of more than 1x, the strong refractive power will cause various aberrations, making it difficult to achieve high-performance optical effects.

[0041] It should be noted that the G3a can be made of ED glass or resin, reducing its weight by 40%. A micro stepper motor / voice coil motor receives the focus signal from the sensor (such as phase detection or contrast detection), then drives the G3a to move and provides real-time feedback on the G3a's position to ensure focus accuracy. The G3b continuously corrects field curvature and chromatic aberration, preventing new aberrations introduced by AF movement. The G2 can move as a whole or in parts. When moving as a whole, the G2 translates back and forth along the optical axis as a single component; when moving in parts, the G2a and G2b move in tandem according to a preset ratio. The user can rotate the focus ring to push the G2 along the guide rail via a spiral groove or cam mechanism.

[0042] Therefore, this invention supports manual rotation of the focus ring G2 in MF mode and sensor detection of defocus in AF mode, with the motor driving G3a to move. It achieves two focusing methods: one is used when the object is at infinity and the magnification is greater than 1x, employing a larger and heavier focus group movement, manually driving G2 for a long-travel movement to achieve high magnification; the other is used when the object is at infinity and the shooting distance is within 0.3x, employing a different movement to achieve focus, using the motor-driven G3a for a small-range movement to achieve fast close-up. This balances resolution, speed, and lens miniaturization.

[0043] The present invention proposes a macro lens with dual focusing mode, wherein the second lens group includes a front part and a rear part, and both the front part and the rear part of the second lens group have positive diopter.

[0044] In manual focus (MF) mode: the second lens group is moved as a whole, or the front and rear parts of the second lens group are moved proportionally to achieve focus;

[0045] And it satisfies the following conditions: 0.5≤|F2a / FL|≤1.2 and 0.5≤FL / (MA×S2a)≤5, where F2a is the front focal length of the second lens, the maximum magnification of the second lens group is MA, and the maximum movement is S2a.

[0046] It should be noted that 0.5≤|F2a / FL|≤1.2 is the setting of condition (2). If the upper limit of condition (2) is exceeded, the refractive power of G2a is too weak. As the main focusing group, the refractive power is too weak. If a magnification of more than 1x is to be achieved, the focusing movement will be too large, making it difficult to achieve miniaturized macro. If the lower limit of condition (2) is exceeded, the refractive power of G2a as the main focusing group is very strong. Although the movement is small enough to achieve a magnification of more than 1x, miniaturization is easy. However, because the refractive power is too strong, various aberrations will occur, making it difficult to achieve high-performance optical effects.

[0047] 0.5≤FL / (MA×S2a)≤5 is the setting of condition (3). If the upper limit of condition (3) is exceeded, the movement of G2 is too small, or the magnification is too small. Although the miniaturization is too small, in order to achieve a magnification of more than 1, the movement of G2 is small, which will inevitably lead to a very strong refractive power of G2, which will easily produce various aberrations and make it very difficult to achieve high performance. If the lower limit of condition (3) is exceeded, the movement of G2 is too large, which will lead to a large optical system, making it impossible to achieve miniaturization and low cost.

[0048] The present invention proposes a macro lens with dual focusing mode, wherein the third lens group includes a front part and a rear part, and the front part of the third lens group has negative refractive power.

[0049] In autofocus mode (AF): the front part of the third lens group moves to achieve focusing;

[0050] And it satisfies the following conditions: 1.0≤|FL / F3a|≤6 and 0.5≤|F3 / F3a|≤2.5, where F3 is the focal length of the third lens group of the optical system at infinity, and F3a is the focal length of the front part of the third lens group.

[0051] It should be noted that 1.0≤|FL / F3a|≤6, i.e., the setting of conditional equation (4), if exceeds the upper limit of conditional equation (4), the refractive power of G3a will be very strong in AF focusing mode. Although it is easy to achieve a small amount of focus movement during AF focusing, it will produce a lot of aberrations, and it is difficult to guarantee optical performance. If it exceeds the lower limit of conditional equation (4), the refractive power of G3a will be too weak in AF focusing mode, and the amount of focus movement will increase. If a fast AF focusing mode is to be achieved, it will become difficult.

[0052] It should be noted that 0.5≤|F3 / F3a|≤2.5 is the setting of conditional equation (5). If the upper limit of conditional equation (5) is exceeded, the refractive power of G3a will be very strong in AF focusing mode. Although it is easy to achieve a small focus movement during AF focusing, many aberrations will be generated, and the optical performance will be difficult to guarantee. If the lower limit of conditional equation (4) is exceeded, the refractive power of G3a will be too weak in AF focusing mode, and the focus movement will become larger. It will be difficult to achieve a fast AF focusing mode.

[0053] The present invention proposes a macro lens with dual focusing modes. In autofocus mode (AF), the maximum movement of the front part of the third lens group is S3a, and satisfies the following condition: 5≤S2a / S3a≤35.

[0054] It should be noted that 5≤S2a / S3a≤35, i.e., the setting of conditional formula (6), if exceeds the upper limit of conditional formula (6), the movement of G3a in AF focusing mode will be too small, resulting in a very small shooting range in AF focusing mode and a too far minimum shooting distance, thus weakening the AF focusing capability. If exceeds the lower limit of conditional formula (6), the movement of the third G3a in AF focusing mode will be too large. Although it enhances the shooting range of AF focusing mode, the excessive movement will make it difficult to achieve fast focusing, and at the same time, it will be difficult to control the size of the entire optical system, making miniaturization very difficult.

[0055] This invention proposes a macro lens with a dual focusing mode, wherein the aperture of the optical system is positioned between the second lens group and the third lens group, and moves as the second lens group moves.

[0056] It should be noted that the stop moves with G2, which can dynamically intercept edge rays and suppress spherical aberration and coma.

[0057] The present invention proposes a macro lens with dual focusing mode, wherein the first lens group includes at least one positive lens with a convex surface facing the object side, which is used to ensure the total length of the optical system and provide basic positive optical power.

[0058] It should be noted that the positive lens can be meniscus (with gentle curvature) and made of medium refractive index, high Abbe number glass. The first lens group may also include a negative lens to suppress chromatic aberration and field curvature. At least one positive lens in the first lens group lays the foundation for the system's optical path, ensuring effective convergence of light rays from infinity. At the same time, the first lens group remains fixed to avoid changes in its overall length during focusing (crucial for image stabilization in macro photography), and also provides an optimized basis for subsequent G2 or G3 shift focusing.

[0059] The front portion of the second lens group includes at least a positive lens and a set of cemented lenses, and the rear portion of the second lens group includes at least a set of cemented lenses. In MF (manual focus) mode, when focusing is achieved by adjusting the movement of the front and rear portions of the second lens group, the movement ratio of the front and rear portions of the second lens group is dynamically adjusted according to aberration correction requirements.

[0060] It should be noted that the front part of the second lens group includes at least a positive lens and a set of cemented lenses. The positive lens can be an ultra-low dispersion positive lens, such as a biconvex or plano-convex lens, made of fluorine crown glass. The cemented lenses are typically a combination of negative and positive high refractive index lenses, which can correct astigmatism, field curvature, and axial chromatic aberration. The second lens group achieves a balance between high-resolution macro photography and aberration control through a design of strong positive optical power, cemented lens correction, and dynamic spacing.

[0061] The front portion of the third lens group includes at least a negative lens, which is a meniscus lens or a biconcave lens with its concave surface facing the image side, and the rear portion of the third lens group includes at least a set of cemented lenses.

[0062] It should be noted that the negative lens in the front part of the third lens group can provide negative optical power, balance the total aberrations of the system, and reduce movement in AF mode. The front part of the third lens group may also include a positive lens for auxiliary aberration correction.

[0063] The rear section of the third lens group comprises a set of cemented lenses, including a negative lens and a positive lens combination, which can fix and compensate for field curvature, distortion, and chromatic aberration. The third lens group can also house a filter to protect the sensor, typically made of BK7 glass. In summary, the lightweight design of the negative lens in the front section of the third lens group enables fast focusing with minimal movement, while the cemented lens setup in the rear section of the third lens group can fix and compensate for residual aberrations (such as field curvature) in MF / AF modes.

[0064] To achieve the above and other related objectives, this utility model also proposes a camera device, including the macro lens described above. It can be widely used in digital camera lenses, camcorder lenses, and especially interchangeable camera lenses.

[0065] Specific Implementation Example 1: As shown in the example Figure 1 The diagram shows G1, G2, and G3 arranged sequentially from the object side to the image plane side. In MF (Multi-Focus) mode, as the object moves from infinity to 1.5x magnification for focusing, G1 and G3 remain fixed, while G2 moves as a whole to achieve focus. In AF (Automatic Focus) mode, as the object moves from infinity to closer distance, G1 and G2 remain fixed, G3a moves to achieve focus, and G3b remains fixed.

[0066] The data are as follows: R (mm): radius of curvature of each surface, D (mm): lens spacing and lens thickness, Nd: refractive index of each glass along the d line, Vd: Abbe number of the glass.

[0067] [Optical Data]: Focal length: 174.9637; FNO: 4.6; Half-frame angle ω: 7.02°;

[0068]

[0069]

[0070] In MF focus mode:

[0071]

[0072] In AF focus mode:

[0073] Specific Implementation Example 2:

[0075] like Figure 3 From the object side to the image plane side, the focusing system consists of G1, G2, and G3. G2 is composed of G2a and G2b, and G3 is composed of G3a and G3b. In MF (Multi-Focus) mode, as the object moves from infinity to a focus point at 2.0x magnification, G1 and G3 remain fixed, while G2a and G2b move proportionally to correct aberrations and achieve focus. In AF (Automatic Focus) mode, as the object moves from infinity to a closer distance, G1 and G2 remain fixed, G3a moves to achieve focus, and G3b remains fixed.

[0076] The data are as follows: R (mm): radius of curvature of each surface, D (mm): lens spacing and lens thickness, Nd: refractive index of each glass along the d line, Vd: Abbe number of the glass.

[0077] [Optical Data]: Focal length: 102.3447; FNO: 2.87; Half-frame angle ω: 11.84°;

[0078] NS R D Nd ABV 1 220.0000 2.0000 1.5407 47.2000 2 320.0000 D(2) 3 57.9894 4.1000 1.7292 58.0000 4 -654.9790 0.5749 5 37.5793 4.2500 1.4970 81.6100 6 147.4984 4.5992 7 -87.2035 1.3000 1.8061 33.2700 8 17.1811 3.6000 1.9229 20.8800 9 24.0483 0.1500 10 22.4025 2.5000 1.9229 20.8800 11 18.2146 9.0000 1.4970 81.6100 12 -69.8240 D(12) 13 535.5671 2.5000 1.9108 35.2500 14 -70.2535 1.5000 15STOP inf D(15) 16 75.4198 0.8000 1.7725 53.6200 17 22.2127 D(17) 18 -37.2017 1.2000 1.8061 33.2700 19 25.4041 7.3500 1.9108 35.2500 20 -28.0483 0.8865 21 -24.0391 1.0000 1.4970 81.6100 22 128.4480 5.1025 23 53.6441 3.9500 1.6180 68.3900 24 -354.9801 1.0000 25 inf 2.0000 1.5168 64.2000 26 inf 36.5516

[0079] In MF focus mode:

[0080]

[0081] In AF focus mode:

[0082]

[0083] Meanwhile, the values ​​of conditions (1)-(6) that must be satisfied in specific embodiments 1 and 2 are shown in the table below:

[0084]

[0085] Example 1: Spherical aberration, field curvature aberration, distortion aberration, and chromatic aberration at 1.0x and 1.5x magnification in MF focusing mode; spherical field curvature aberration, distortion aberration, and chromatic aberration at close range in AF focusing mode as follows: Figure 2 As shown. In Example 2, the spherical aberration, field curvature aberration, distortion aberration, and chromatic aberration at 1x and 2.0x magnification in MF focusing mode; and the spherical field curvature aberration, distortion aberration, and chromatic aberration at close range in AF focusing mode are shown below. Figure 4 As shown.

[0086] like Figure 2 As shown, the aberration performance of MF mode, comparing 1.0x and 1.5x:

[0087] Spherical aberration: slightly increased at 1.5x, but still within a controllable range, indicating that the aspherical design of G2 (planes 5-6) and the dynamic adjustment of the aperture effectively suppressed the divergence of edge rays at high magnification.

[0088] Field curvature aberration: The high degree of overlap between the meridional (T) and sagittal (S) curves indicates that the cemented group of G2b (planes 7-8) and the fixed compensation of G3b (planes 19-22) synergistically optimize the image plane flatness.

[0089] Distortion aberration: <1% (almost invisible), thanks to the G1's negative meniscus lens (planes 7-8) and symmetrical optical path design.

[0090] Magnification color difference: The separation between the G line (435.8nm) and the F line (486.1nm) is minimal, verifying the effectiveness of the G2a ultra-low dispersion material (Nd=1.49700, Vd=81.61).

[0091] Aberration performance in AF mode, object distance 1350.00mm (-0.128x):

[0092] Spherical aberration / field curvature: The fluctuation is slight compared to the infinity state (INF), indicating that the small movement of G3a (D(18) change of 3.4 mm) did not disrupt the aberration balance.

[0093] Distortion: Keep <0.5%, as G1 is fixed and G3b adhesive group (faces 19-22) is continuously corrected.

[0094] Color difference at magnification: almost no color edges, thanks to the G3a ED glass (face 16-17, Nd=1.69680, Vd=55.46).

[0095] Therefore, in MF mode of Example 1, even when the magnification is increased from 1.0x to 1.5x, the aberration deterioration is minimal, meeting the requirements for high-resolution macro photography. In AF mode, the close-up aberration stability is excellent, verifying the rationality of the lightweight G3a design.

[0096] like Figure 4 As shown, the aberration performance of MF mode is compared between 1.0x and 2.0x:

[0097] Spherical aberration: It increases slightly at 2.0x but remains stable, indicating that the biconvex positive lens (plane 5, Nd = 1.49700) and the dynamic adjustment of the aperture in G2 effectively control the focusing of edge rays.

[0098] Field curvature aberration: The meridional (T) and sagittal (S) curves highly coincide, indicating that the high refractive index cementitious assembly of G2b (plane 7-9, Nd = 1.92286) perfectly compensates for the image plane curvature.

[0099] Distortion aberration: <0.8% (better than Example 1), thanks to the optimized material (H-ZK7) of G1 and the symmetrical optical path design of G2.

[0100] Magnification color difference: almost invisible, verifying the synergistic effect of G2a ultra-low dispersion material (Nd=1.49700, Vd=81.61) and G3b adhesive group (faces 19-20).

[0101] Aberration performance in AF mode, object distance 1344.00mm (-0.074x):

[0102] Spherical aberration / field curvature: The fluctuation is negligible (<3%) compared to the infinity state, proving that the lightweight design of G3a (N-SK16 material) and the small amount of movement (D(17) change 2.0 mm) do not disrupt the aberration balance.

[0103] Distortion: Keep <0.5%, due to continuous correction by the fixed adhesive group of G3b (faces 19-20, Nd = 1.91082).

[0104] Color difference at magnification: No colored edges, thanks to the low dispersion material of G3a (surface 16, Nd = 1.77250, Vd = 53.62).

[0105] Therefore, in MF mode of Example 2, even when the magnification is increased from 1.0x to 2.0x, the aberration remains at an extremely low level, meeting the requirements for ultra-high resolution macro photography. In AF mode, the close-up aberration stability is excellent, verifying the rationality of the mode-specific design.

[0106] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

[0107] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0108] Throughout this specification, references to "an embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0109] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0110] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0111] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0112] The above description of the embodiments shown in this utility model (including the content set forth in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the utility model to the precise forms disclosed herein. Although specific embodiments and examples of the utility model have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the utility model, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the utility model in accordance with the above description of the embodiments described herein, and such modifications will be within the spirit and scope of the utility model.

[0113] This document has generally described the systems and methods in detail to aid in understanding the present invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention can be practiced without one or more specific details, or using other devices, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0114] Therefore, although the present invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the scope of the above disclosure, and it should be understood that in some cases, certain features of the present invention may be adopted without departing from the scope and spirit of the invention and without corresponding use of other features. Thus, many modifications can be made to adapt a particular environment or material to the essential scope and spirit of the present invention. The present invention is not intended to be limited to the specific terms used in the following claims and / or the specific embodiments disclosed as the best mode of carrying out the present invention, but the present invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Therefore, the scope of the present invention will be determined only by the appended claims.

Claims

1. A macro lens with dual focusing modes, characterized in that, The macro lens supports both manual focus (MF) and autofocus (AF) modes, and the optical system of the macro lens, from the object side to the image side along the optical axis, comprises: First lens group; The second lens group has positive refractive power; The third lens group has negative refractive power; The manual focus mode (MF) allows focusing from infinity to a magnification of ≥1x by moving the second lens group. The autofocus mode (AF) achieves focusing from infinity to a magnification of <0.3x by moving the third lens group; And the following condition must be met: 0.2≤F2 / FL≤0.7, where F2 is the focal length of the second lens group of the optical system at infinity, and FL is the total focal length of the optical system.

2. The macro lens according to claim 1, characterized in that: The second lens group includes a front portion and a rear portion, and both the front portion and the rear portion of the second lens group have positive refractive power; In the manual focus (MF) mode: the second lens group moves as a whole, or the front and rear parts of the second lens group move proportionally to achieve focus; And it satisfies the following conditions: 0.5≤|F2a / FL|≤1.2 and 0.5≤FL / (MA×S2a)≤5, where F2a is the front focal length of the second lens, MA is the maximum magnification of the second lens group, and S2a is the maximum movement of the second lens group.

3. The macro lens according to claim 2, characterized in that: The third lens group includes a front portion and a rear portion, and the front portion of the third lens group has negative refractive power; In the autofocus mode (AF): the front part of the third lens group moves to achieve focusing; And it satisfies the following conditions: 1.0≤|FL / F3a|≤6 and 0.5≤|F3 / F3a|≤2.5, where F3 is the focal length of the third lens group of the optical system at infinity, and F3a is the front part focal length of the third lens group.

4. The macro lens according to claim 3, characterized in that: In the autofocus mode (AF), the maximum movement of the front part of the third lens group is S3a, and it satisfies the following condition: 5≤S2a / S3a≤35.

5. The macro lens according to claim 1, characterized in that: The aperture of the optical system is positioned between the second lens group and the third lens group, and moves as the second lens group moves.

6. The macro lens according to claim 1, characterized in that: The first lens group includes at least one positive lens with a convex surface facing the object side, used to ensure the overall length of the optical system and provide a basic positive power.

7. The macro lens according to claim 1, characterized in that: The front portion of the second lens group includes at least one positive lens and a set of cemented lenses, and the rear portion of the second lens group includes at least one set of cemented lenses.

8. The macro lens according to claim 2, characterized in that: The movement ratio of the front and rear parts of the second lens group is dynamically adjusted according to the aberration correction requirements.

9. The macro lens according to claim 1, characterized in that: The front portion of the third lens group includes at least one negative lens, which is a meniscus lens or a biconcave lens with its concave surface facing the image side, and the rear portion of the third lens group includes at least one set of cemented lenses.

10. A camera device, characterized in that, Including the macro lens as described in any one of claims 1-9.

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