Internal focusing type imaging lens and camera device

Abstract

The invention discloses an internal focusing type imaging lens and a camera device. The lens sequentially comprises a first lens group with positive focal power, an aperture diaphragm, a second lens group with positive focal power and a third lens group with negative focal power from an object side to an image side, in the focusing process, the second lens group moves along the optical axis, and the first lens group and the third lens group remain unchanged relative to the position of the image plane. The first lens group, the second lens group and the third lens group satisfy the following conditional expressions: 1 < = F1 / F < = 3; 0.5 < = F2 / F < = 2; -3 < = F3 / F < =-1; and the second lens group comprises a lens unit with negative focal power and an eighth lens with positive focal power which are sequentially arranged from the object side to the image side. According to the technical scheme, the focal power of the focusing group can be properly increased on the premise that good aberration correction is guaranteed, so that the focusing stroke is shortened, and miniaturization of an optical system is achieved.

Description

Technical Field

[0001] The present application relates to the field of imaging technologies, and particularly to an internally focused imaging lens and an imaging device. Background Art

[0002] In recent years in the photography market, the demand for mirrorless cameras is expanding rapidly. Compared with single-lens reflex cameras which are large in size and poor in portability, mirrorless cameras are small in size, lightweight and excellent in portability due to the cancellation of the reflex mirror assembly. At the same time, thanks to the increasing development and maturity of high-precision CMOS chips, the resolution of cameras is also increasing day by day, making mirrorless cameras also have good high-quality imaging quality.

[0003] Currently, for interchangeable photographic lenses on the market, in order to obtain high imaging quality, there are generally problems such as large size, heavy weight and poor portability. Long-term use will cause fatigue to users. Therefore, there is a lack of imaging lenses that can balance imaging quality and portability. Summary of the Invention

[0004] The present application provides an imaging lens and an imaging device, aiming to solve the problem in the prior art that there is a lack of imaging lenses that can balance imaging quality and portability.

[0005] To achieve the above object, the present application proposes an internally focused imaging lens. The internally focused imaging lens sequentially includes from the object side to the image side: a first lens group with positive optical power, an aperture stop, a second lens group with positive optical power, and a third lens group with negative optical power; during the focusing process, the second lens group moves along the optical axis, and the first lens group and the third lens group remain unchanged in position relative to the image plane;

[0006] The first lens group, the second lens group and the third lens group satisfy the following conditional expressions:

[0007] 1≤F1 / F≤3;

[0008] 0.5≤F2 / F≤2;

[0009] -3≤F3 / F≤-1;

[0010] Wherein, F1 represents the combined focal length of the first lens group, F2 represents the combined focal length of the second lens group, F3 represents the combined focal length of the third lens group, and F represents the focal length of the imaging lens;

[0011] The second lens group includes a lens unit with negative optical power and an eighth lens with positive optical power.

[0012] In some embodiments, the lens unit is a second cemented lens with a negative optical power, and the second lens group includes the second cemented lens and an eighth lens with a positive optical power, which are arranged in sequence from the object side to the image side.

[0013] In some embodiments, the second cemented lens includes a sixth lens with a negative optical power and a seventh lens with a positive optical power, which are arranged in sequence from the object side to the image side.

[0014] In some embodiments, the sixth lens and the seventh lens satisfy the following conditional formula:

[0015] |Vd6 - Vd7| ≥ 20, (4);

[0016] Wherein, Vd6 is the Abbe number of the sixth lens with respect to the light ray with a wavelength of 587.6 nm; Vd7 is the Abbe number of the seventh lens with respect to the light ray with a wavelength of 587.6 nm.

[0017] In some embodiments, the lens unit is a first singlet lens with a negative optical power, and the second lens group includes an eighth lens with a positive optical power and the first singlet lens, which are arranged in sequence from the object side to the image side.

[0018] In some embodiments, at least one lens with an Abbe number Vd ≥ 60 is included in the second lens group

[0019] In some embodiments, the first lens group includes a first lens with a positive optical power and an achromatic lens unit, which are arranged in sequence from the object side to the image side.

[0020] In some embodiments, the achromatic lens unit includes a first cemented lens.

[0021] In some embodiments, the achromatic lens unit further includes two other achromatic lenses.

[0022] In some embodiments, the achromatic lens unit includes a second singlet lens.

[0023] In some embodiments, the achromatic lens unit further includes two other achromatic lenses.

[0024] In some embodiments, at least one lens with an Abbe number Vd ≥ 60 is included in the achromatic lens unit.

[0025] In some embodiments, the first lens is an aspherical aberration lens.

[0026] In some embodiments, the third lens group includes a ninth lens with a negative optical power, a tenth lens with a positive optical power, and an eleventh lens with a negative optical power, which are arranged in sequence from the object side to the image side.

[0027] In some embodiments, the third lens group includes a ninth lens with positive optical power, a tenth lens with negative optical power, and an eleventh lens with negative optical power, which are arranged in sequence from the object side to the image side.

[0028] The present application also provides an imaging device, which includes an image sensor and the in-focus imaging lens as described above, and the image sensor is detachably connected to the lens.

[0029] The technical solution of the present application proposes an in-focus imaging lens, which includes three lens groups. Among them, the first lens group and the third lens group remain unchanged with respect to the position of the image plane, and the second lens group is a focusing lens group. Among them, the second lens group includes a lens unit with negative optical power and an eighth lens with positive optical power. The composition of the second lens group is simple, which can reduce the weight of the focusing group, achieve fast focusing, and the second lens group adopts a lens unit with negative optical power and a focusing group with positive optical power. Compared with an optical system with single-lens focusing, it can effectively correct aberrations at different focusing distances, appropriately increase the optical power of the focusing group, shorten the focusing stroke, and thus realize the miniaturization of the lens size. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, where:

[0031] Figure 1 Showing the structural schematic diagram of Embodiment 1 of the present invention;

[0032] Figure 2 Showing the spherical aberration schematic diagram of Embodiment 1 of the present invention when focused at infinity;

[0033] Figure 3 Showing the field curvature and distortion schematic diagram of Embodiment 1 of the present invention when focused at infinity;

[0034] Figure 4 Showing the spherical aberration schematic diagram of Embodiment 1 of the present invention at the nearest focusing distance;

[0035] Figure 5 Showing the field curvature and distortion schematic diagram of Embodiment 1 of the present invention at the nearest focusing distance;

[0036] Figure 6 Showing the structural schematic diagram of Embodiment 2 of the present invention;

[0037] Figure 7Schematic diagram of spherical aberration when the second embodiment of the present invention is focused at infinity;

[0038] Figure 8 Schematic diagram of field curvature and distortion when the second embodiment of the present invention is focused at infinity;

[0039] Figure 9 Schematic diagram of spherical aberration when the second embodiment of the present invention is focused at the nearest focusing distance;

[0040] Figure 10 Schematic diagram of field curvature and distortion when the second embodiment of the present invention is focused at the nearest focusing distance;

[0041] Figure 11 Schematic diagram of the structure of the third embodiment of the present invention;

[0042] Figure 12 Schematic diagram of spherical aberration when the third embodiment of the present invention is focused at infinity;

[0043] Figure 13 Schematic diagram of field curvature and distortion when the third embodiment of the present invention is focused at infinity;

[0044] Figure 14 Schematic diagram of spherical aberration when the third embodiment of the present invention is focused at the nearest focusing distance;

[0045] Figure 15 Schematic diagram of field curvature and distortion when the third embodiment of the present invention is focused at the nearest focusing distance. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0047] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0048] It should also be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may be a middle element at the same time. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be a middle element at the same time.

[0049] In addition, the descriptions involving "first", "second", etc. in this application are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. Additionally, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0050] Referring to Figure 1 and Figure 3 , this application provides an internal focusing imaging lens. The internal focusing imaging lens sequentially includes, from the object side to the image side: a first lens group G1 with positive optical power, an aperture stop STP, a second lens group G2 with positive optical power, and a third lens group G3 with negative optical power; during the focusing process, the second lens group G2 moves along the optical axis, and the first lens group G1 and the third lens group G3 remain unchanged in position relative to the image plane IMG.

[0051] The technical solution of this application adopts an internal focusing design. The focal length adjustment of the lens is achieved by the movement of the second lens group G2, which can ensure the stability of the image plane position, thereby obtaining a clearer image, and the adjustment process is relatively simple and convenient. In addition, since the first lens group G1 and the third lens group G3 remain unchanged in position relative to the image plane, the influence of distortion can be effectively reduced, making the imaging closer to reality.

[0052] The first lens group G1, the second lens group G2, and the third lens group G3 satisfy the following conditional equations:

[0053] 1 ≤ F1 / F ≤ 3, (1);

[0054] 0.5 ≤ F2 / F ≤ 2; (2);

[0055] -3 ≤ F3 / F ≤ -1; (3);

[0056] Among them, F1 represents the combined focal length of the first lens group G1, F2 represents the combined focal length of the second lens group G2, F3 represents the combined focal length of the third lens group G3, and F represents the focal length of the imaging lens.

[0057] The technical solution of this application further sets that the first lens group G1, the second lens group G2, and the third lens group G3 satisfy specific proportional relationships, and this design can enable the lens to adapt to different application scenarios and requirements.

[0058] Specifically, for the first lens group G1, conditional formula (1) restricts the proportional relationship between the focal length of the first lens group G1 and the focal length of the entire imaging lens. When conditional formula (1) is satisfied, the first lens group G1 can refract incident light with a positive refractive power, enabling the light rays to be correctly focused on the image plane.

[0059] If the value of F1 / F is too small, that is, the focal length of the first lens group G1 is too short relative to the focal length of the entire lens, the light rays on the image plane may be too dispersed, resulting in reduced imaging clarity, and the aperture of the rear lens group will increase, which is not conducive to lens miniaturization. If the value of F1 / F is too large, that is, the focal length of the first lens group G1 is too long relative to the focal length of the entire lens, the light rays on the image plane may be too concentrated, leading to problems such as imaging distortion or halos, and the overall length of the lens will increase, which is also not conducive to lens miniaturization.

[0060] For the second lens group G2, conditional formula (2) restricts the proportional relationship between the focal length of the second lens group G2 and the focal length of the entire imaging lens. By reasonably selecting and adjusting the focal length of the second lens group G2 and the focal length of the entire lens to satisfy conditional formula (2), the refraction and focusing of light can be further controlled and optimized, improving the clarity and quality of the image.

[0061] Secondly, since the second lens group G2 moves along the optical axis during the focusing process, by reasonably setting the value of F2 / F, the generation and magnitude of distortion can be controlled, thereby reducing the impact of distortion on imaging.

[0062] Furthermore, the second lens group G2 includes a lens unit with a negative refractive power and an eighth lens L08 with a positive refractive power. Using a lens unit with a negative refractive power and a focusing group with a positive refractive power, compared with an optical system with single-lens focusing, the refractive power of the focusing group can be appropriately increased while ensuring good correction of aberrations, thereby shortening the focusing stroke and achieving miniaturization of the optical system.

[0063] For the third lens group G3, conditional formula (3) restricts the proportional relationship between the focal length of the second lens group G2 and the focal length of the entire imaging lens. By reasonably selecting and adjusting the focal length of the second lens group G2 and the focal length of the entire lens to satisfy conditional formula (3), the refraction and focusing of light can be further controlled and optimized, improving the clarity and quality of the image.

[0064] In some embodiments, the lens unit is a second cemented lens with a negative refractive power, and the second lens group G2 includes the second cemented lens and an eighth lens L08 with a positive refractive power arranged in sequence from the object side to the image side. Further, the second cemented lens includes a sixth lens L06 with a negative refractive power and a seventh lens L07 with a positive refractive power arranged in sequence from the object side to the image side.

[0065] In this embodiment, the second lens group G2 is provided to include a sixth lens L06 with a negative optical power, a seventh lens L07 with a positive optical power, and an eighth lens L08 with a positive optical power, which are arranged in sequence from the object side to the image side. Among them, the sixth lens L06 and the seventh lens L07 are combined to form a second cemented lens. In this way, the number of focusing lenses in the second lens group G2 is three, reducing the weight of the focusing group. At the same time, multiple lenses are used in the focusing group, which can effectively correct aberrations at different focusing distances and effectively shorten the focusing stroke, thereby achieving miniaturization of the lens size.

[0066] In some embodiments, the sixth lens L06 and the seventh lens L07 satisfy the following conditional formula:

[0067] |Vd6 - Vd7| ≥ 20, (4);

[0068] Among them, Vd6 is the Abbe number of the sixth lens L06 with respect to light with a wavelength of 587.6 nm; Vd7 is the Abbe number of the seventh lens L07 with respect to light with a wavelength of 587.6 nm.

[0069] In this embodiment, the main function of the conditional formula (4) is to control the dispersion degree of the lens, thereby improving the imaging quality. By ensuring that the absolute value of the difference in Abbe numbers between the sixth lens L06 and the seventh lens L07 is greater than or equal to 20, the chromatic aberration of the lens group can be reduced, enabling light rays of different wavelengths to converge better at the same focus, improving the clarity and authenticity of the imaging, and optimizing the imaging performance of the lens.

[0070] In some embodiments, the lens unit is a first single lens with a negative optical power, and the second lens group G2 includes an eighth lens L08 with a positive optical power and the first single lens, which are arranged in sequence from the object side to the image side.

[0071] In this embodiment, the single lens with a negative optical power is used to correct the lens aberration. The lens with a negative optical power can be used to offset various deviations and distortions generated when light passes through the lens, improving the clarity and accuracy of the image quality. Therefore, the second cemented lens described above can be replaced with a single lens with a negative optical power to achieve the same technical effect.

[0072] In some embodiments, the second lens group G2 includes at least one lens with an Abbe number Vd ≥ 60.

[0073] It can be understood that the Abbe number of ophthalmic optical lenses is generally between 30 and 60. The larger the Abbe number, the smaller the dispersion degree and the clearer the imaging. When the Abbe number is greater than or equal to 60, due to its smaller dispersion degree, chromatic aberration during imaging can be reduced, thereby obtaining a more real and clear image. At the same time, a lens with a high Abbe number usually also means better optical performance and higher imaging quality.

[0074] In some embodiments, the first lens group G1 includes a first lens L01 with a positive optical power and an achromatic lens unit arranged in sequence from the object side to the image side.

[0075] In this embodiment, the first lens L01 can be an aspherical lens, the purpose of which is to eliminate the spherical aberration of the lens. Through special optical design and manufacturing processes, the light focusing performance of the lens becomes more accurate.

[0076] In some preferred embodiments, the first lens L01 is a high refractive index lens with a refractive index nd1≥1.8. Since the larger the refractive index, the greater the refraction angle of light in the lens, the light can be better focused to a point, thereby reducing the influence of spherical aberration.

[0077] Furthermore, the achromatic lens unit eliminates the chromatic aberration of the lens to improve the imaging quality.

[0078] In some embodiments, the achromatic lens unit includes a first cemented lens.

[0079] In this embodiment, the reason why the chromatic aberration can be eliminated by the cemented lens is that it uses a combination of two or more types of optical glasses with different refractive indices and dispersion properties. Through precise cementing processes, the glasses with different refractive indices and dispersion properties are tightly combined together to form an integral lens.

[0080] Since the refractive indices and propagation speeds of light with different wavelengths in the lens are slightly different, chromatic aberration will occur. The glasses with different refractive indices and dispersion properties in the cemented lens can compensate for each other, enabling the lens to have a consistent refractive index for light with different wavelengths, thereby eliminating the influence of chromatic aberration.

[0081] In some embodiments, the achromatic lens unit includes a first cemented lens and two other achromatic lenses.

[0082] In this embodiment, using the cemented lens in combination with other lenses can further improve the achromatic performance. The main reason is that this combination provides more design freedoms and adjustment spaces, enabling better elimination of chromatic aberration and optimization of the overall lens performance. This technical means has wide applications in various optical instruments and devices, significantly improving the imaging quality and being one of the indispensable important components in scientific research, industrial production, and daily life.

[0083] In a specific embodiment, the first lens group G1 includes, arranged in sequence from the object side to the image side: a first lens L01 with a positive optical power, a second lens L02 with a positive optical power, a third lens L03 with a positive optical power, a fourth lens L04 with a positive optical power, and a fifth lens L05 with a negative optical power. Among them, the fourth lens L04 and the fifth lens L05 are combined into a first cemented lens;

[0084] The fourth lens L04 and the fifth lens L05 thereof satisfy the following conditional formula:

[0085] |Vd4 - Vd5| ≥ 30, (5);

[0086] In the formula, Vd4 is the Abbe number of the fourth lens L04 in the first lens group G1 with respect to light of a wavelength of 587.6 nm; Vd5 is the Abbe number of the fifth lens L05 in the first lens group G1 with respect to light of a wavelength of 587.6 nm.

[0087] In another specific embodiment, the first lens group G1 includes, arranged in sequence from the object side to the image side: a first lens L01 with a positive optical power, a second lens L02 with a positive optical power, a third lens L03 with a positive optical power, a fourth lens L04 with a negative optical power, and a fifth lens L05 with a negative optical power. Among them, the fourth lens L04 and the fifth lens L05 are combined into a first cemented lens;

[0088] The fourth lens L04 and the fifth lens L05 thereof satisfy the following conditional formula:

[0089] |Vd3 - Vd4| ≥ 40, (6);

[0090] In the formula, Vd3 is the Abbe number of the third lens L03 in the first lens group G1 with respect to light of a wavelength of 587.6 nm; Vd4 is the Abbe number of the fourth lens L04 in the first lens group G1 with respect to light of a wavelength of 587.6 nm.

[0091] In still another specific embodiment, the first lens group G1 includes, arranged in sequence from the object side to the image side: a first lens L01 with a positive optical power, a second lens L02 with a positive optical power, a third lens L03 with a positive optical power, a fourth lens L04 with a negative optical power, and a fifth lens L05 with a negative optical power. Among them, the second lens L02 and the third lens L03 are combined into a first cemented lens;

[0092] The second lens L02 and the third lens L03 thereof satisfy the following conditional formula:

[0093] |Vd2 - Vd3| ≥ 40, (7);

[0094] Wherein, Vd2 is the Abbe number of the second lens L02 in the first lens group G1 with respect to the light ray with a wavelength of 587.6 nm; Vd3 is the Abbe number of the third lens L03 in the first lens group G1 with respect to the light ray with a wavelength of 587.6 nm.

[0095] The above provides different combinations of the first cemented lens, and by ensuring that the absolute value of the difference in Abbe numbers between the two in the first lens group G1 is within a certain range, the chromatic aberration of the lens group can be reduced, and the imaging performance of the lens can be optimized.

[0096] In some embodiments, the achromatic lens unit includes a second singlet lens. By replacing the first cemented lens with the second singlet lens, the same achromatic effect as the first cemented lens is achieved.

[0097] In some embodiments, at least one lens with an Abbe number Vd≥60 is included in the achromatic lens unit. Similarly, when the Abbe number is greater than or equal to 60, due to its smaller degree of dispersion, the chromatic aberration during imaging can be reduced, thereby obtaining a more real and clear image. At the same time, a lens with a high Abbe number usually also means better optical performance and higher imaging quality. In some embodiments, the second lens L02 is a high-Abbe number lens with an Abbe number vd2≥60; the third lens L03 is a high-Abbe number lens with an Abbe number vd3≥60; the above-mentioned fourth lens L04 is a high-Abbe number lens with an Abbe number vd4≥60.

[0098] In some embodiments, the third lens group G3 includes, in order from the object side to the image side: a ninth lens L09 with a negative focal power, a tenth lens L10 with a positive focal power, and an eleventh lens L11 with a negative focal power.

[0099] In this embodiment, multiple lenses of the lens group can compensate for each other to correct the chromatic aberration of light rays with different wavelengths, thereby improving the imaging quality. And through the focal powers of different lenses, the propagation path of light rays can be adjusted to further optimize the imaging effect.

[0100] Among them, the focal length of the lens can be positive or negative, depending on its design and manufacturing process. A lens with a negative focal power can produce divergent light rays, while a lens with a positive focal power can converge light rays. By reasonably combining these lenses, the propagation path of light rays can be controlled and optimized, thereby obtaining a high-quality imaging effect.

[0101] Furthermore, the third lens group G3 can also be including: a ninth lens L09 with a positive focal power, a tenth lens L10 with a negative focal power, and an eleventh lens L11 with a negative focal power, which are arranged in order from the object side to the image side.

[0102] In the present application, a parallel glass plate GL configured with a filter is arranged between the eleventh lens L11 of the third lens group G3 and the image plane IMG. The function of the parallel glass plate GL is to filter light to improve the imaging quality. Specifically, it can absorb or reflect light of certain wavelengths to eliminate or reduce interference factors such as chromatic aberration and stray light, thereby improving the contrast and clarity of the image.

[0103] Embodiment 1

[0104] Figure 1 Shown is a schematic structural diagram of the optical imaging system of Embodiment 1. As Figure 1 shown, in this embodiment, the first lens group G1 includes, sequentially arranged from the object side to the image side: a first lens L01 with a positive focal power, a second lens L02 with a positive focal power, a third lens L03 with a positive focal power, a fourth lens L04 with a positive focal power, and a fifth lens L05 with a negative focal power. Among them, the fourth lens L04 and the fifth lens L05 are combined into a first cemented lens; the second lens group G2 includes, sequentially arranged from the object side: a sixth lens L06 with a negative focal power, a seventh lens L07 with a positive focal power, and an eighth lens L08 with a positive focal power. Among them, the sixth lens L06 and the seventh lens L07 are combined to form a second cemented lens; the third lens group G3 includes, sequentially arranged from the object side: a ninth lens L09 with a negative focal power, a tenth lens L10 with a positive focal power, and an eleventh lens L11 with a negative focal power.

[0105] In this embodiment, the numerical data of the full-frame optical imaging system are shown in Tables 1 and 2:

[0106] Table 1

[0107]

[0108]

[0109] Table 2

[0110]

[0111] Among them, the surface number indicates the surface number of each lens from the object side to the image side.

[0112] Figure 2 and Figure 3 show the spherical aberration, field curvature, and distortion curves of Embodiment 1 at infinite focus, Figure 4 and Figure 5 show the spherical aberration, field curvature, and distortion curves of Embodiment 1 at the closest focus.

[0113] The spherical aberration curve graph shows the spherical aberration curve at an f-number of 1.8. Among them, the F-line, D-line, and C-line respectively represent the spherical aberration at wavelengths of 486 nm, 587 nm, and 656 nm. The abscissa represents the magnitude of the spherical aberration value, and the ordinate represents the field of view. The field curvature curve graph shows the field curvature curve at a semi-field angle ω of 14.9°. Among them, the dashed line S represents the value of the chief ray d-line on the sagittal image plane, and the solid line T represents the value of the chief ray d-line on the meridional image plane. The abscissa represents the magnitude of the field curvature value, and the ordinate represents the field of view. The distortion curve graph shows the distortion curve at a semi-field angle ω of 14.9°. Among them, the abscissa represents the distortion value, and the ordinate represents the field of view. The above descriptions of various spherical aberration, field curvature, and distortion curve graphs are the same as those in other embodiments and will not be elaborated further below. As can be seen from FIGS. 2-5, the imaging lens of Embodiment 1 has a good imaging effect.

[0114] Embodiment 2

[0115] Figure 6 Shown is a schematic structural diagram of the optical imaging system of Embodiment 2. As Figure 6 shown, in this embodiment, the first lens group G1 includes, in order from the object side to the image side: a first lens L01 with a positive optical power, a second lens L02 with a positive optical power, a third lens L03 with a positive optical power, a fourth lens L04 with a positive optical power, and a fifth lens L05 with a negative optical power. Among them, the fourth lens L04 and the fifth lens L05 are combined into a first cemented lens; the second lens group G2 includes, in order from the object side: a sixth lens L06 with a negative optical power, a seventh lens L07 with a positive optical power, and an eighth lens L08 with a positive optical power. Among them, the sixth lens L06 and the seventh lens L07 are combined to form a second cemented lens; the third lens group G3 includes, in order from the object side: a ninth lens L09 with a positive optical power, a tenth lens L10 with a negative optical power, and an eleventh lens L11 with a negative optical power.

[0116] In this embodiment, the numerical data of the full-frame optical imaging system are shown in Tables 3 and 4:

[0117] Table 3

[0118]

[0119]

[0120] Table 4

[0121]

[0122] Figure 7 and Figure 8Shows the spherical aberration, field curvature, and distortion curves of Example 2 at infinite focus, Figure 9 and Figure 10 shows the spherical aberration, field curvature, and distortion curves of Example 1 at the closest focusing distance.

[0123] As can be seen from FIGS. 7-10, the imaging lens of Example 1 of the present embodiment has a good imaging effect.

[0124] Example 3

[0125] Figure 11 Shown is a schematic structural diagram of the optical imaging system of Example 3. As Figure 11 shown, in this embodiment, the first lens group G1 includes, arranged in order from the object side to the image side: a first lens L01 with a positive focal power, a second lens L02 with a positive focal power, a third lens L03 with a positive focal power, a fourth lens L04 with a negative focal power, and a fifth lens L05 with a negative focal power. Among them, the third lens L03 and the fourth lens L04 are combined to form a first cemented lens; the second lens group G2 includes, arranged in order from the object side: a sixth lens L06 with a negative focal power, a seventh lens L07 with a positive focal power, and an eighth lens L08 with a positive focal power. Among them, the sixth lens L06 and the seventh lens L07 are combined to form a second cemented lens. The third lens group G3 includes, arranged in order from the object side, a ninth lens L09 with a positive focal power, a tenth lens L10 with a negative focal power, and an eleventh lens L11 with a negative focal power.

[0126] In this embodiment, the numerical data of the full-frame optical imaging system are shown in Tables 5 and 6:

[0127] Table 5

[0128]

[0129]

[0130] Table 6

[0131]

[0132]

[0133] Figure 12 and Figure 13 shows the spherical aberration, field curvature, and distortion curves of Example 3 at infinite focus, Figure 14 and Figure 15 shows the spherical aberration, field curvature, and distortion curves of Example 1 at the closest focusing distance.

[0134] As can be seen from FIGS. 12-15, the imaging lens of Example 1 of the present embodiment has a good imaging effect.

[0135] The present application further provides an imaging device, which includes an image sensor and the above-mentioned internal focusing imaging lens, and the image sensor is detachably connected to the lens; wherein, the image sensor is a camera.

[0136] In this embodiment, the imaging device adopts all the technical solutions of all the above embodiments of the internal focusing imaging lens, and thus has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0137] The above are only partial or preferred embodiments of the present application. Neither the text nor the drawings can limit the scope of protection of the present application. Any equivalent structural transformation made by using the content of the specification and drawings of the present application under the overall concept of the present application, or any direct / indirect application in other related technical fields is included in the scope of protection of the present application.

Claims

1. An internal focusing imaging lens, characterized in that: From the object side to the image side, it sequentially includes: a first lens group with positive optical power, an aperture stop, a second lens group with positive optical power, and a third lens group with negative optical power; during the focusing process, the second lens group moves along the optical axis, and the first lens group and the third lens group remain unchanged in position relative to the image plane; The first lens group, the second lens group, and the third lens group satisfy the following conditional expressions: 1 ≤ F1 / F ≤ 3, (1); 0.5 ≤ F2 / F ≤ 2; (2); -3 ≤ F3 / F ≤ -1; (3); wherein, F1 represents the combined focal length of the first lens group, F2 represents the combined focal length of the second lens group, F3 represents the combined focal length of the third lens group, and F represents the focal length of the imaging lens; The second lens group includes a lens unit with negative optical power and an eighth lens with positive optical power.

2. The internal focusing imaging lens according to claim 1, wherein, The lens unit is a second cemented lens with negative optical power, and the second lens group includes the second cemented lens and the eighth lens with positive optical power sequentially arranged from the object side to the image side.

3. The internal focusing imaging lens according to claim 2, wherein The second cemented lens includes a sixth lens with negative optical power and a seventh lens with positive optical power sequentially arranged from the object side to the image side.

4. The internal focusing imaging lens according to claim 3, characterized in that, The sixth lens and the seventh lens satisfy the following conditional expression: |Vd6 - Vd7| ≥ 20, (4); wherein, Vd6 is the Abbe number of the sixth lens with respect to light with a wavelength of 587.6 nm; Vd7 is the Abbe number of the seventh lens with respect to light with a wavelength of 587.6 nm.

5. The internal focusing imaging lens according to claim 1, wherein, The lens unit is a first singlet lens with negative optical power, and the second lens group includes the eighth lens with positive optical power and the first singlet lens sequentially arranged from the object side to the image side.

6. The internal focusing imaging lens according to any one of claims 1-5, characterized in that, At least one lens with an Abbe number Vd ≥ 60 is included in the second lens group.

7. The internal focusing imaging lens according to claim 1, wherein The first lens group includes a first lens with positive optical power and an achromatic lens unit sequentially arranged from the object side to the image side.

8. The in-focus imaging lens according to claim 7, wherein, The achromatic lens unit includes a first cemented lens.

9. The internal focusing imaging lens according to claim 8, wherein, The achromatic lens unit further includes two other achromatic lenses.

10. The inner focusing imaging lens according to claim 7, wherein, The achromatic lens unit includes a second singlet lens.

11. The internal focusing imaging lens according to any one of claims 7-10, characterized in that, At least one lens with an Abbe number Vd ≥ 60 is included in the achromatic lens unit.

12. The internal focusing imaging lens according to claim 6, wherein, The first lens is an aspherical aberration correcting lens.

13. The internal focusing imaging lens according to claim 1, wherein, The third lens group includes a ninth lens with negative optical power, a tenth lens with positive optical power, and an eleventh lens with negative optical power sequentially arranged from the object side to the image side.

14. The internal focusing imaging lens according to claim 1, wherein, The third lens group includes a ninth lens with positive optical power, a tenth lens with negative optical power, and an eleventh lens with negative optical power sequentially arranged from the object side to the image side.

15. An imaging device, characterized in that, It includes an image sensor and an internal focusing imaging lens as described in any one of claims 1 - 14, and the image sensor is detachably connected to the lens.

Images