Zoom optical system and zoom camera device

Abstract

This invention discloses a zoom optical system and a zoom imaging device, relating to the field of zoom optical technology. The zoom optical system has an object side and an image side correspondingly arranged along the optical axis. The system includes a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with positive optical power, and an image plane, arranged sequentially from the object side to the image side. The first, second, and third lens groups are all movably arranged along the optical axis. The first and second lens groups are used for zooming, and the third lens group is used for focusing. This arrangement allows the optical distortion range of the zoom optical system to be maintained between -5.91% and 0.89%, achieving high image quality and low distortion. Furthermore, by reducing the number of lens groups, the size of the zoom optical system can be reduced, thereby lowering manufacturing costs while achieving a compact size.

Description

Technical Field

[0001] This invention relates to the field of zoom optics technology, and particularly to a zoom optical system and a zoom camera device. Background Technology

[0002] With the development of chip technologies such as CCD and CMOS, and the increasing demands for video image quality, the requirements for the imaging quality of the corresponding optical systems are also becoming higher. To meet this trend, optical lenses mounted on video products are further required to have high resolution, wide shooting angle, low distortion, and small size.

[0003] However, existing zoom lenses still have some performance defects, which limit their application scenarios. For example, insufficient resolution results in low resolution; the wide-angle end is not wide enough, resulting in a limited shooting range; the lens size is large, limiting the use scenarios; and the small aperture makes it unable to meet the shooting needs in low-light environments. Summary of the Invention

[0004] The main objective of this invention is to propose a zoom optical system and zoom camera device, which aims to improve the problem that existing lenses cannot simultaneously achieve high resolution, large shooting range, and small size.

[0005] To achieve the above objectives, the present invention proposes a zoom optical system having an object side and an image side correspondingly arranged along the optical axis. The zoom optical system includes a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with positive optical power, and an image plane arranged sequentially from the object side to the image side. The first lens group, the second lens group, and the third lens group are all movably arranged along the optical axis. The first lens group and the second lens group are used for zooming, and the third lens group is used for focusing. Wherein, the focal length of the zoom optical system at the wide-angle end is fw, the focal length at the telephoto end is ft, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the zoom optical system satisfies the following conditions: -0.399 <fw / f1<-0.295;0.340<fw / f2<0.460;0.216<fw / f3<0.293。

[0006] In one embodiment, the first lens group includes a first lens with negative optical power, a second lens with positive optical power, and a third lens with negative optical power arranged sequentially from the object side to the image side. The first lens is configured as a spherical lens, and the second and third lenses are configured as aspherical lenses. The first lens has a focal length of f11, the second lens has a focal length of f12, and the third lens has a focal length of f13, where 0.988 <f1 / f11<1.336;-0.641<f1 / f11<-0.474;0.371<f1 / f11<0.502。

[0007] In one embodiment, the effective aperture of the first lens is øL11, and the total optical length of the zoom optical system is TTL, wherein 0.282 < øL11 / TTL < 0.367.

[0008] In one embodiment, the second lens group includes a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with negative optical power arranged sequentially from the object side to the image side. The fourth lens and the sixth lens are configured as aspherical lenses, and the fifth lens is configured as a spherical lens. The fourth lens has a focal length of f21, the fifth lens has a focal length of f22, and the sixth lens has a focal length of f23, where 0.584 <f2 / f21<0.790;0.981<f2 / f21<1.327;-1.518<f2 / f21<-1.122。

[0009] In one embodiment, the third lens group includes a seventh lens with positive optical power, and the seventh lens is configured as an aspherical lens; The focal length of the seventh lens is f31, where f3 = f31.

[0010] In one embodiment, the displacement of the first lens group in the optical axis extension direction is ΔZ1(WT), and the total optical length of the zoom optical system is TTL, wherein 0.05 < ΔZ1(WT) / TTL < 0.064.

[0011] In one embodiment, the displacement of the second lens group in the optical axis extension direction is ΔZ2(WT), and the total optical length of the zoom optical system is TTL, wherein 0.422<ΔZ2(WT) / TTL<0.548.

[0012] In one embodiment, the displacement of the third lens group in the optical axis extension direction is ΔZ3(WT), and the total optical length of the zoom optical system is TTL, wherein 0.048 < ΔF(WT) / TTL < 0.062.

[0013] In one embodiment, the zoom optical system further includes an aperture stop disposed between the first lens group and the second lens group. The distance between the aperture stop and the image plane is L, and the total optical length of the zoom optical system is TTL, where 0.729 <L / TTL<0.947。

[0014] The present invention further provides a zoom imaging device, including the above-mentioned zoom optical system.

[0015] In the technical solution of the present invention, the first lens group, the second lens group, and the third lens group are all set as zoom lens groups that can be movably arranged along the optical axis extension direction. Among them, when the second lens group and the third lens group move along the optical axis extension direction, they can zoom the zoom optical system. At this time, the third lens group can move cooperatively along the optical axis extension direction to focus the zoom optical system, so that the imaging of the image plane remains clear during the zoom process of the zoom optical system. Thus, by conditionally restricting the ratio of the focal lengths of the three lens groups to the focal length of the zoom optical system at the wide-angle end, the ratio of the three lens groups to the focal length of the zoom optical system at the wide-angle end is limited to -0.399 < fw / f1 < -0.295; 0.340 < fw / f2 < 0.460; 0.216 < fw / f3 < 0.293, and by reasonably matching the optical powers of the three lens groups, the optical distortion range of the zoom optical system is maintained between -5.91% and 0.89%, so as to ensure the imaging quality of the zoom optical system, achieve the effects of high imaging quality and small distortion of the zoom optical system, and by reducing the number of lens groups, the volume of the zoom optical system can be reduced, thereby reducing the manufacturing cost of the zoom optical system while achieving the small-volume effect of the zoom optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0017] Figure 1 It is a schematic structural diagram of an embodiment of the zoom optical system provided by the present invention at the wide-angle end; Figure 2 It is a schematic structural diagram of an embodiment of the zoom optical system provided by the present invention at the intermediate magnification; Figure 3 It is a schematic structural diagram of an embodiment of the zoom optical system provided by the present invention at the telephoto end; Figure 4 It is a MTF diagram of the zoom optical system provided by the present invention at the wide-angle end; Figure 5 It is a MTF diagram of the zoom optical system provided by the present invention at the intermediate magnification; Figure 6 This is a schematic diagram of the MTF (Mean Transformer) of the zoom optical system provided by the present invention at the telephoto end. Figure 7 This is a schematic diagram of MTF vs Field at the wide-angle end of the zoom optical system provided by the present invention; Figure 8 This is a schematic diagram of MTF vs Field at intermediate magnification in the zoom optical system provided by the present invention; Figure 9 A schematic diagram of MTF vs Field at the telephoto end of the zoom optical system provided by the present invention; Figure 10 A schematic diagram of the defocused MTF at the wide-angle end of the zoom optical system provided by the present invention; Figure 11 This is a schematic diagram of the defocus MTF at the intermediate magnification of the zoom optical system provided by the present invention; Figure 12 A schematic diagram of the defocused MTF at the telephoto end of the zoom optical system provided by the present invention; Figure 13 The field curvature and distortion diagram at the wide-angle end of the zoom optical system provided by this invention; Figure 14 The field curvature and distortion diagram of the zoom optical system at intermediate magnification provided by the present invention; Figure 15 The field curvature and distortion diagram at the telephoto end of the zoom optical system provided by this invention; Figure 16 A schematic diagram of the optical fan at the wide-angle end of the zoom optical system provided by the present invention; Figure 17 A schematic diagram of the optical fan at the intermediate magnification of the zoom optical system provided by the present invention; Figure 18 A schematic diagram of the optical fan at the telephoto end of the zoom optical system provided by the present invention; Figure 19 A schematic diagram of axial aberration at the wide-angle end of the zoom optical system provided by the present invention; Figure 20 A schematic diagram of axial aberration at intermediate magnification in the zoom optical system provided by the present invention; Figure 21 A schematic diagram of axial aberration at the telephoto end of the zoom optical system provided by the present invention; Figure 22 A schematic diagram of the transverse chromatic aberration at the wide-angle end of the zoom optical system provided by the present invention; Figure 23 A schematic diagram of the transverse chromatic aberration at intermediate magnification in the zoom optical system provided by the present invention; Figure 24 This is a schematic diagram of the vertical chromatic aberration at the telephoto end of the zoom optical system provided by the present invention.

[0018] Explanation of icon numbers: 100. Zoom optical system; 1. First lens group; 11. First lens; 12. Second lens; 13. Third lens; 2. Second lens group; 21. Fourth lens; 22. Fifth lens; 23. Sixth lens; 3. Third lens group; 31. Seventh lens; 4. Image plane; 5. Aperture stop; 6. Filter; 7. Protective glass.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] With the development of chip technologies such as CCD and CMOS, and the increasing demands for video image quality, the requirements for the imaging quality of the corresponding optical systems are also becoming higher. To meet this trend, optical lenses mounted on video products are further required to have high resolution, wide shooting angle, low distortion, and small size.

[0024] However, existing zoom lenses still have some performance defects, which limit their application scenarios. For example: insufficient resolution, resulting in low resolution; insufficient angle at the wide end, resulting in a limited shooting range; large lens size, limiting the application scenarios; and small aperture, resulting in an inability to meet the shooting needs in low-light environments.

[0025] This invention proposes a zoom optical system designed to address the problem that existing lenses cannot simultaneously achieve high resolution, a wide shooting range, and a small size.

[0026] Please see Figure 1 , Figure 2 and Figure 3 In one embodiment of the present invention, the zoom optical system 100 has an object side and an image side correspondingly arranged along the optical axis. The zoom optical system 100 includes a first lens group 1 with negative optical power, a second lens group 2 with positive optical power, a third lens group 3 with positive optical power, and an image plane 4 arranged sequentially from the object side to the image side. The first lens group 1, the second lens group 2, and the third lens group 3 are all movably arranged along the optical axis. The first lens group 1 and the second lens group 2 are used for zooming, and the third lens group 3 is used for focusing. The focal length of the zoom optical system 100 at the wide-angle end is fw, and the focal length at the telephoto end is ft. The focal length of the first lens group 1 is f1, the focal length of the second lens group 2 is f2, and the focal length of the third lens group 3 is f3. The zoom optical system 100 satisfies the following condition: -0.399 <fw / f1<-0.295;0.340<fw / f2<0.460;0.216<fw / f3<0.293。

[0027] In the technical solution of the present invention, the first lens group 1, the second lens group 2, and the third lens group 3 are all set as zoom lens groups that can be movably arranged along the optical axis extension direction. Among them, when the second lens group 2 and the third lens group 3 move along the optical axis extension direction, they can zoom the zoom optical system 100. At this time, the third lens group 3 can move collaboratively along the optical axis extension direction to focus the zoom optical system 100, so that the imaging of the image plane 4 remains clear during the zoom process of the zoom optical system 100. Thus, by conditionally restricting the ratio of the focal lengths of the three lens groups to the focal length of the zoom optical system 100 at the wide-angle end, the ratio of the three lens groups to the focal length of the zoom optical system 100 at the wide-angle end is limited to -0.399 < fw / f1 < -0.295; 0.340 < fw / f2 < 0.460; 0.216 < fw / f3 < 0.293, and through reasonable matching of the optical powers of the three lens groups, the optical distortion range of the zoom optical system 100 is maintained between -5.91% and 0.89%, thereby ensuring the imaging quality of the zoom optical system 100 to achieve the effects of high imaging quality and small distortion of the zoom optical system 100. Moreover, by reducing the number of lens groups, the volume of the zoom optical system 100 can be reduced, thereby reducing the manufacturing cost of the zoom optical system 100 while achieving the small-volume effect of the zoom optical system 100.

[0028] First, it should be pointed out that the present invention does not limit the specific movement times of the first lens group 1, the second lens group 2, and the third lens group 3. In the present invention, the first lens group 1, the second lens group 2, and the third lens group 3 can be set to move sequentially; it is also possible to set the first lens group 1 and the second lens group 2 to move synchronously, while the third lens group 3 moves later, as long as it is ensured that after all three have completed their movements, the zoom optical system 100 can successfully complete the zooming and focusing operations.

[0029] Of course, among the first lens group 1, the second lens group 2, and the third lens group 3, the first lens group 1 and the second lens group 2 can be made to move first to achieve the zoom function of the zoom optical system 100. After their movements are completed, the third lens group 3 is then driven to focus. In this way, the zooming and focusing purposes of the zoom optical system 100 can also be achieved.

[0030] In addition, the first lens group 1, the second lens group 2, and the third lens group 3 can also be configured to move simultaneously along the optical axis extension direction. With such a setting, when the first lens group 1 and the second lens group 2 perform zooming, the third lens group 3 can synchronously implement real-time focusing, so that the image plane 4 always maintains clear imaging during the zoom process, effectively avoiding the problems of imaging blurring or defocusing caused by the movement of each lens group along the optical axis for zooming. This not only improves the operation flexibility of the zoom optical system 100 but also significantly enhances the imaging stability and reliability of the zoom optical system 100.

[0031] It is understood that in this invention, the first mirror group 1, the second mirror group 2, and the third mirror group 3 can all move in various different ways along the optical axis. For example, in some embodiments, the three can be driven by independent drive motors, that is, each mirror group corresponds to one drive motor, so as to achieve independent movement of each along the optical axis.

[0032] Of course, the same drive motor can also be used to drive all three mirror groups: the first mirror group 1, the second mirror group 2, and the third mirror group 3. In this case, it is only necessary to ensure that the transmission ratios between the three mirror groups and the drive motor are different. In this way, when the drive motor outputs driving force, the driving force can be transmitted to the first mirror group 1, the second mirror group 2, and the third mirror group 3 respectively, thereby realizing the coordinated operation of the three.

[0033] It is understood that the first mirror group 1, the second mirror group 2, and the third mirror group 3 can also be manually driven to move along the optical axis extension direction. The specific method can be selected according to actual needs, and the present invention does not limit it.

[0034] It should also be noted that the present invention does not limit the specific ratio of the focal length of the first lens group 1, the second lens group 2 and the third lens group 3 to the focal length of the zoom optical system 100. In the present invention, the ratio of the focal length of each lens group to the focal length of the zoom optical system 100 can be selected according to the actual situation.

[0035] For example, in a specific embodiment of the present invention, the focal length of the first lens group 1 is set to -12.56mm, the focal length of the second lens group 2 is set to 10.89mm, and the focal length of the third lens group 3 is set to 17.12mm. With this configuration, the focal length of the zoom optical system 100 at the wide-angle end is 4.26mm. Therefore, in this embodiment, the focal length of the zoom optical system 100 at the wide-angle end is -0.339 compared to the first lens group 1 (fw / f1), 0.391 compared to the second lens group 2 (fw / f2), and 0.249 compared to the third lens group 3 (fw / f3). Thus, the ratios of the focal length of the zoom optical system 100 at the wide-angle end to the focal lengths of the first lens group 1, second lens group 2, and third lens group 3 are all within their respective ranges, thereby ensuring that the zoom optical system 100 maintains good image quality during zooming.

[0036] Specifically, to ensure successful imaging of the zoom optical system 100 and to guarantee the image sharpness of the zoom optical system 100, the first lens group 1 includes a first lens 11 with negative optical power, a second lens 12 with positive optical power, and a third lens 13 with negative optical power, arranged sequentially from the object side to the image side. The first lens 11 is a spherical lens, and the second lens 12 and the third lens 13 are aspherical lenses. The focal length of the first lens 11 is f11, the focal length of the second lens 12 is f12, and the focal length of the third lens 13 is f13. <f1 / f11<1.336;-0.641<f1 / f11<-0.474;0.371<f1 / f11<0.502。

[0037] The present invention does not limit the specific values ​​of the focal lengths of the first lens 11, the second lens 12 and the third lens 13. In the present invention, the specific values ​​of the focal lengths of the first lens 11, the second lens 12 and the third lens 13 can also be set to any value within the range, and the present invention does not limit this.

[0038] In this embodiment, the focal length of the first lens group 1 is set to -12.56mm. Consequently, the focal length of the first lens 11 is set to -10.81mm, the focal length of the second lens 12 is set to 22.54mm, and the focal length of the third lens 13 is set to -28.8mm. With this configuration, the focal length ratios of the first lens group 1 and the first lens 11 (f1 / f11) are f1.162, f1 / f12 and the second lens 12 (f1 / f12) are f1 / f12 = -0.557, and f1 / f13 and the third lens 13 (f1 / f13) are f1 / f13 = 0.436. Therefore, in this embodiment, the focal length ratios of the first lens group 1 and the first, second, and third lenses 11 are all within their respective ranges, ensuring a reasonable distribution of the optical power of the first lens group 1, thereby contributing to improved imaging quality of the zoom optical system 100.

[0039] It is understood that in this embodiment, the focal length of the first lens 11 is set to a negative value. This setting can further help the zoom optical system 100 to collect and converge incident light more effectively, thereby enhancing the light-gathering ability of the system.

[0040] At the same time, the setting of this negative focal length lens also plays a positive role in correcting various aberrations that may occur in the entire optical system, which helps to improve the clarity of the final image and the optical performance of the zoom optical system 100.

[0041] Furthermore, in this invention, the first lens 11 is configured as a spherical lens, while the second lens 12 and the third lens 13 are configured as aspherical lenses. This configuration allows the spherical lens to maintain good optical stability and image quality under various lighting conditions, while the aspherical lens offers superior curvature radius characteristics, improving distortion and astigmatism. Using aspherical lenses minimizes aberrations during imaging, thereby enhancing the lens's image quality and further improving the overall performance of the zoom optical system 100. By configuring the first lens 11 as a spherical lens, processing difficulty and manufacturing costs are reduced. Simultaneously, the aspherical characteristics of the second and third lenses 12 and 13 are used to compensate for and correct aberrations, balancing manufacturing cost control with improved image quality, ultimately optimizing overall performance.

[0042] Furthermore, the effective aperture of the first lens 11 is not constant. The aperture size of the first lens 11 can be selected according to the actual setup requirements of the zoom optical system 100. Specifically, the effective aperture of the first lens 11 is øL11, and the total optical length of the zoom optical system 100 is TTL, where 0.282 < øL11 / TTL < 0.367. With this setting, when the ratio of the effective aperture of the first lens 11 to the total optical length of the zoom optical system 100 is within the corresponding range, it can be ensured that the effective aperture size of the first lens 11 meets the light intake requirements of the zoom optical system 100, while avoiding the situation where the zoom optical system 100 becomes bulky due to the aperture of the first lens 11 being too large, and also avoiding the problem of insufficient light intake caused by the aperture being too small. In this way, not only is the light intake requirement guaranteed, but the miniaturization characteristics of the zoom optical system 100 are also maintained.

[0043] It should also be noted that, in this invention, since the first lens group 1 is movably arranged along the optical axis extension direction, in order to ensure the zoom capability of the zoom optical system 100, the displacement of the first lens group 1 should be determined according to the total optical length of the zoom optical system 100.

[0044] In a further embodiment of the present invention, the displacement of the first lens group 1 in the direction of optical axis extension is ΔZ1(WT), and the total optical length of the zoom optical system 100 is TTL, wherein 0.05<ΔZ1(WT) / TTL<0.064.

[0045] It should be noted that the displacement of the first lens group 1 in the optical axis extension direction is the distance that the first lens group 1 moves in the optical axis extension direction when it moves to any position during the process of zooming from the wide-angle end to the telephoto end of the self-zoom optical system 100. The displacement of the first lens group 1 in the optical axis extension direction can be any value within its range.

[0046] In a specific embodiment of the present invention, the displacement of the second lens group 2 in the optical axis extension direction is set to 2.48 mm, and the total optical length (TTL) of the zoom optical system 100 is set to 44.2 mm. At this time, the ratio of the displacement of the second lens group 2 in the optical axis extension direction to the total optical length of the zoom optical system 100 (WT) / TTL = 0.056. This setting, with the ratio within the aforementioned limit, allows for reasonable control of the movement of the first lens group 1 during the zoom process. It avoids both excessive displacement leading to an increase in the overall volume of the zoom optical system 100 and insufficient displacement failing to meet the zoom magnification requirements, effectively balancing the zoom performance and miniaturization requirements of the zoom optical system 100.

[0047] Similarly, to ensure successful imaging of the zoom optical system 100 and to guarantee its imaging quality, in some embodiments, the second lens group 2 further includes a fourth lens 21 with positive optical power, a fifth lens 22 with positive optical power, and a sixth lens 23 with negative optical power, arranged sequentially from the object side to the image side. The fourth lens 21 and the sixth lens 23 are aspherical lenses, and the fifth lens 22 is a spherical lens. The focal length of the fourth lens 21 is f21, the focal length of the fifth lens 22 is f22, and the focal length of the sixth lens 23 is f23, wherein 0.584 <f2 / f21<0.790;0.981<f2 / f21<1.327;-1.518<f2 / f21<-1.122。

[0048] The present invention does not limit the specific values ​​of the focal lengths of the fourth lens 21, the fifth lens 22 and the sixth lens 23. In the present invention, the specific values ​​of the focal lengths of the fourth lens 21, the fifth lens 22 and the sixth lens 23 can also be set to any value within the range, and the present invention does not limit this.

[0049] For example, in a specific embodiment of the present invention, the focal length of the second lens group 2 is set to 10.89 mm. Thus, the focal length of the fourth lens 21 is set to 15.86 mm, the focal length of the fifth lens 22 is set to 9.44 mm, and the focal length of the sixth lens 23 is set to -8.25 mm. In this embodiment, the focal length ratio of the second lens group 2 to the fourth lens 21 is f2 / f21 = 0.687, the focal length ratio of the second lens group 2 to the fifth lens 22 is f2 / f22 = 1.154, and the focal length ratio of the second lens group 2 to the sixth lens 23 is f2 / f23 = -1.320. With this configuration, the focal length ratios of the second lens group 2 with the fourth lens 21, fifth lens 22, and sixth lens 23 are all within their respective ranges, ensuring a reasonable distribution of optical power in the zoom optical system 100, thereby improving the imaging performance of the zoom optical system 100.

[0050] It should also be noted that, in this invention, since the second lens group 2 is also movably arranged along the optical axis extension direction, in order to further ensure the zoom capability of the zoom optical system 100, the displacement of the second lens group 2 should also be determined according to the total optical length of the zoom optical system 100.

[0051] Specifically, in a further embodiment of the present invention, the displacement of the second lens group 2 in the optical axis extension direction is ΔZ2(WT), and the total optical length of the zoom optical system 100 is TTL, wherein 0.422<ΔZ2(WT) / TTL<0.548.

[0052] It is understood that the displacement of the second lens group 2 in the optical axis extension direction is the distance that the second lens group 2 moves in the optical axis extension direction when it moves to any position during the zoom optical system 100 from the wide-angle end to the telephoto end. The displacement of the second lens group 2 in the optical axis extension direction can be any value within its range. In this invention, the displacement of the second lens group 2 in the optical axis extension direction can be set to any value within the range, and can be selected according to the requirements in actual settings. By limiting the ratio of the displacement of the second lens group 2 to the total length of the zoom optical system 100 within the above range, it is possible to ensure that the second lens group 2 provides sufficient zoom magnification while avoiding an increase in the overall size of the zoom optical system 100 due to excessive displacement of the second lens group 2. This ensures both zoom capability and maintains the miniaturized design of the system, adapting to the compact design requirements of zoom camera devices.

[0053] In a specific embodiment of the present invention, the displacement of the second lens group 2 in the optical axis extension direction is set to 21.06 mm, and the total optical length (TTL) of the zoom optical system 100 is set to 44.2 mm. In this case, the ratio of the displacement of the second lens group 2 in the optical axis extension direction to the total optical length of the zoom optical system 100 (WT) / TTL = 0.476. This setting ensures that the ratio is within the aforementioned range, guaranteeing that the second lens group 2 achieves a sufficient zoom ratio without excessively increasing the overall length of the zoom optical system 100 due to excessive displacement. Therefore, while ensuring the zoom effect, the miniaturization characteristics of the zoom optical system 100 are maintained, meeting the requirements for a compact design of zoom camera devices.

[0054] Furthermore, this invention does not limit the number or form of volume lenses within the third lens group 3. In this invention, the third lens group 3 includes a seventh lens 31 with positive optical power. The seventh lens 31 is configured as an aspherical lens, and its focal length is f31, where f3 = f31. It is understood that in this embodiment, since the third lens group 3 only includes the seventh lens 31, the focal length of the third lens group 3 is equal to the focal length of the seventh lens 31.

[0055] In this invention, the focal length of the seventh lens 31 is set to 17.12 mm. With this setting, the ratio of the focal length of the zoom optical system 100 at the wide-angle end to the focal length of the seventh lens 31 is fw / f31 = 0.249.

[0056] Similarly, the third lens 13 is also movable along the optical axis extension direction. Therefore, it is necessary to further limit the ratio between the displacement of the third lens group 3 in the optical axis extension direction and the total optical length of the zoom optical system 100.

[0057] In some embodiments, the displacement of the third lens group 3 in the optical axis extension direction is ΔZ3(WT), and the total optical length of the zoom optical system 100 is TTL, wherein 0.048<ΔF(WT) / TTL<0.062.

[0058] Similarly, the displacement of the third lens group 3 in the optical axis extension direction is the distance that the third lens group 3 moves in the optical axis extension direction when it moves to any position during the process of zooming from the wide-angle end to the telephoto end of the self-zoom optical system 100. The displacement of the third lens group 3 in the optical axis extension direction can be any value within its range. In this invention, the displacement of the third lens group 3 in the optical axis extension direction can be set to any value within the range. In actual setting, it can be selected according to the requirements.

[0059] In a specific embodiment of the present invention, the displacement of the second lens group 2 in the optical axis extension direction is set to 2.38 mm, and the total optical length (TTL) of the zoom optical system 100 is set to 44.2 mm. At this time, the ratio of the displacement of the second lens group 2 in the optical axis extension direction to the total optical length of the zoom optical system 100 (WT) / TTL = 0.054. This setting, with the ratio within the aforementioned limit, allows for reasonable control of the movement of the third lens group 3 during the zoom process. It avoids increasing the overall volume of the zoom optical system 100 due to excessive displacement, and also prevents insufficient displacement from affecting the image plane 4 compensation effect during the zoom process. This effectively ensures image clarity during zooming while maintaining the miniaturization of the zoom optical system 100.

[0060] It should also be noted that, in this invention, the zoom optical system 100 further includes an aperture stop 5, which is disposed between the first lens group 1 and the second lens group 2. The distance between the aperture stop 5 and the image plane 4 is L, and the total optical length of the zoom optical system 100 is TTL, wherein 0.729 <L / TTL<0.947。

[0061] Understandably, the aperture 5 is set to control the amount of light entering the zoom optical system 100. At the same time, the amount of light entering the system can be changed by adjusting the light-passing diameter of the aperture 5 to adapt to the light requirements of different shooting environments.

[0062] By limiting the ratio of the distance between the aperture stop 5 and the image plane 4 to the total optical length to the above range, the layout space of each optical element inside the zoom optical system 100 can be reasonably planned, avoiding the interference of the optical path due to the crowded layout of the elements. At the same time, it ensures that the position of the aperture stop 5 can leave enough room for the lens group to move during the zoom process, further optimizing the utilization rate of the internal space of the system and maintaining the compactness of the zoom optical system 100.

[0063] In a specific embodiment of the present invention, the distance between the aperture stop 5 and the image plane 4 is 36.42 mm, the total optical length of the zoom optical system 100 is 44.2 mm, and the ratio of the distance between the aperture stop 5 and the image plane 4 to the total optical length of the zoom optical system 100 is L / TTL=0.824.

[0064] It should be noted that in this invention, the aperture stop 5 is set to move synchronously with the second lens group 2. Thus, during zooming, the aperture stop 5 can move synchronously with the second lens group 2 without requiring a separate drive structure. This simplifies the overall structure of the zoom optical system 100 and ensures that the aperture stop 5 remains in a suitable position to adapt to the light incidence requirements of different lens groups during zooming, ensuring stable light intake and further improving imaging stability during zooming.

[0065] Furthermore, in this invention, the zoom optical system 100 also includes a filter 6, which is disposed between the third lens group 3 and the image plane 4. The filter 6 can filter the light entering the image plane 4, filtering out light of specific wavelengths to reduce stray light interference with imaging, and further improve the sharpness and color reproduction of the image formed by the zoom optical system 100.

[0066] In this invention, the zoom optical system 100 also includes a protective glass 7, which is disposed between the filter 6 and the image plane 4, and is used to protect the image plane 4.

[0067] In a specific embodiment of the present invention, the image plane 4 is set to a size of φ7mm, and the zoom optical system 100 has an aperture number of f / 100 at the wide-angle end. =3.1, the aperture number at the telephoto end =6.88.

[0068] In this embodiment, the surface number, surface type, radius of curvature, thickness, focal length, material refractive index, and material Abbe number of the multiple lenses are shown in Table 1 below: Table 1

[0069] It should be noted that, in this embodiment, since the first mirror group 1, the second mirror group 2, and the third mirror group 3 are all movably arranged along the optical axis, the thickness values ​​corresponding to surface numbers 7, 13, and 15 will change depending on the movable position of the first mirror group 1, the second mirror group 2, and the third mirror group 3. Please refer to Table 2 below for specific parameters: Table 2

[0070] In this embodiment, the second lens 12, the third lens 13, the fourth lens 21, the sixth lens 23, and the seventh lens 31 are all configured as aspherical lenses.

[0071] Furthermore, in this embodiment, the aspherical surface shape of the aspherical lens satisfies the following condition:

[0072] Where c is the curvature corresponding to the radius, y is the radial coordinate (its unit is the same as the lens length unit), k is the conic conic coefficient (when the coefficient k is less than -1, the surface curve is a hyperbola; when the coefficient k is equal to -1, it is a parabola; when the coefficient k is between -1 and 0, it is an ellipse; when the coefficient k is equal to 0, it is a circle; and when the coefficient k is greater than 0, it is an oval), A, B, C, D, E, and F are higher-order aspherical coefficients. The higher-order coefficients of each aspherical mirror are shown in Table 3 below: Table 3

[0073] This setup, by rationally allocating the lens power and adjusting the glass shape and material combination, effectively eliminates chromatic aberration and secondary spectrum, allowing spherical aberration, coma, astigmatism, etc. on each lens to compensate and cancel each other out, thereby achieving a clear imaging effect and realizing optimal correction of higher-order aberrations and chromatic aberration.

[0074] Please see Figure 4-6 , Figure 4 , Figure 5 and Figure 6 These are schematic diagrams of the MTF (Mean Transformation Factor) of the zoom optical system 100 provided by the present invention at the wide-angle end, the intermediate magnification, and the telephoto end.

[0075] Please see Figure 7-9 , Figure 7 , Figure 8 and Figure 9 These are schematic diagrams of the MTF (Mean Transformation Factor) of the zoom optical system 100 provided by the present invention at the wide-angle end, the intermediate magnification, and the telephoto end.

[0076] Please see Figure 10-12 , Figure 10 , Figure 11 and Figure 12 These are schematic diagrams of the MTF (Mean Transformation Factor) of the zoom optical system 100 provided by the present invention at the wide-angle end, the intermediate magnification, and the telephoto end.

[0077] Please see Figure 13-15 , Figure 13 , Figure 14 and Figure 15 These are schematic diagrams of the MTF (Mean Transformation Factor) of the zoom optical system 100 provided by the present invention at the wide-angle end, the intermediate magnification, and the telephoto end.

[0078] Please see Figure 16-18 , Figure 16 , Figure 17 and Figure 18 These are schematic diagrams of the MTF (Mean Transformation Factor) of the zoom optical system 100 provided by the present invention at the wide-angle end, the intermediate magnification, and the telephoto end.

[0079] Please see Figure 19-21 , Figure 19 , Figure 20 and Figure 21 These are schematic diagrams of the MTF (Mean Transformation Factor) of the zoom optical system 100 provided by the present invention at the wide-angle end, the intermediate magnification, and the telephoto end.

[0080] Please see Figure 22-24 , Figure 22 , Figure 23 and Figure 24 These are schematic diagrams of the MTF (Mean Transformation Factor) of the zoom optical system 100 provided by the present invention at the wide-angle end, the intermediate magnification, and the telephoto end.

[0081] The present invention also proposes a zoom camera device, which includes a zoom optical system 100. The specific structure of the zoom optical system 100 is as described in the above embodiments. Since the zoom camera device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0082] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A zoom optical system characterized in that, The zoom optical system has an object side and an image side arranged correspondingly along the optical axis. The zoom optical system includes a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with positive optical power, and an image plane arranged sequentially from the object side to the image side. The first lens group, the second lens group, and the third lens group are all movably arranged along the optical axis. The first lens group and the second lens group are used for zooming, and the third lens group is used for focusing. Wherein, the focal length of the zoom optical system at the wide-angle end is fw, the focal length at the telephoto end is ft, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the zoom optical system satisfies the following conditions: -0.399 <fw / f1<-0.295;0.340<fw / f2<0.460;0.216<fw / f3<0.293。 2. The zoom optical system according to claim 1, characterized by The first lens group includes a first lens with negative optical power, a second lens with positive optical power, and a third lens with negative optical power arranged sequentially from the object side to the image side. The first lens is a spherical lens, and the second and third lenses are aspherical lenses. The first lens has a focal length of f11, the second lens has a focal length of f12, and the third lens has a focal length of f13, where 0.988 <f1 / f11<1.336;-0.641<f1 / f11<-0.474;0.371<f1 / f11<0.502。 3. The zoom optical system as described in claim 2, characterized in that, The effective aperture of the first lens is øL11, and the total optical length of the zoom optical system is TTL, where 0.282 < øL11 / TTL < 0.

367.

4. The zoom optical system according to claim 1, characterized by The second lens group includes a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with negative optical power arranged sequentially from the object side to the image side. The fourth lens and the sixth lens are set aspherical lenses, and the fifth lens is set as a spherical lens. The fourth lens has a focal length of f21, the fifth lens has a focal length of f22, and the sixth lens has a focal length of f23, where 0.584 <f2 / f21<0.790;0.981<f2 / f21<1.327;-1.518<f2 / f21<-1.122。 5. The zoom optical system according to claim 1, wherein The third lens group includes a seventh lens with positive optical power, and the seventh lens is configured as an aspherical lens; The focal length of the seventh lens is f31, where f3 = f31.

6. The zoom optical system according to claim 1, characterized by The displacement of the first lens group in the direction of optical axis extension is ΔZ1(WT), and the total optical length of the zoom optical system is TTL, where 0.05 < ΔZ1(WT) / TTL < 0.

064.

7. The zoom optical system according to claim 1, wherein The displacement of the second lens group in the direction of optical axis extension is ΔZ2(WT), and the total optical length of the zoom optical system is TTL, where 0.422<ΔZ2(WT) / TTL<0.

548.

8. The zoom optical system according to claim 1, characterized by The displacement of the third lens group in the direction of optical axis extension is ΔZ3(WT), and the total optical length of the zoom optical system is TTL, where 0.048 < ΔF(WT) / TTL < 0.

062.

9. The zoom optical system according to claim 1, wherein The zoom optical system further includes an aperture stop, which is disposed between the first lens group and the second lens group. The distance between the aperture stop and the image plane is L. The total optical length of the zoom optical system is TTL, where 0.729 <L / TTL<0.947。 10. A zoom camera characterized by comprising: Includes the zoom optical system as described in any one of claims 1 to 9.

Images