Zoom projection optical system
By designing a zoom projection optical system and utilizing a combination of movable mirror groups and lenses, the problem of high-temperature stability of the projection system under small size and low cost was solved, achieving high-quality 1080P imaging.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHONGSHAN UNITED OPTOELECTRONIC DISPLAY TECHNOLOGY CO LTD
- Filing Date
- 2026-03-17
- Publication Date
- 2026-05-01
AI Technical Summary
Existing projection systems cannot simultaneously address the issues of small size, low cost, and maintaining focus at high temperatures.
Design a zoom projection optical system comprising five lens groups arranged along the optical axis. Zooming is achieved by flexibly setting the second, third, and fourth lens groups, while the first lens group is used for focusing. A combination of plastic aspherical lenses and glass spherical lenses is used to control the light path, ensuring clear imaging and stability at high temperatures.
It achieves a small-size, low-cost projection system while maintaining good image quality at high temperatures, avoiding thermal defocusing, and achieving an image quality of 1080P or higher.
Smart Images
Figure CN121956313A_ABST
Abstract
Description
Zoom Projection Optical System Technical Field
[0001] The present invention relates to the technical field of projection systems, and particularly relates to a zoom projection optical system. Background Art
[0002] In recent years, with the development of projection technology, projectors have been widely used in household, education, office and other fields. The common projections on the market are all realized by direct projection.
[0003] However, currently, they generally have disadvantages such as a narrow projection screen range, high cost and expensive price, and low resolution. There are also a small number of lenses that sacrifice some resolution in order to reduce costs, or use plastic aspherical surfaces. However, due to the large heat generation of projectors, such lenses are prone to defocus due to high temperature, affecting the use effect. Summary of the Invention
[0004] The main purpose of the present invention is to propose a zoom projection optical system, aiming to improve the problem that the existing projection systems cannot balance small volume, low cost and no defocus at high temperature.
[0005] To achieve the above object, the zoom projection optical system proposed by the present invention has an object side and an image side arranged corresponding to each other along the optical axis direction. The zoom projection optical system includes a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group and a light-emitting chip arranged in sequence from the object side to the image side. The first lens group, the second lens group, the third lens group and the fourth lens group are all movably arranged along the optical axis direction. The second lens group, the third lens group and the fourth lens group are used for zooming, and the first lens group is used for focusing.
[0006] Among them, the focal length of the zoom projection optical system at the wide-angle end is f, 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, the focal length of the fourth lens group is F4, and the focal length of the fifth lens group is F5. The zoom projection optical system satisfies the following conditions: -50 < F1 < 0, -6.75 < F1 / f < 0, and 10 < F2 < 60, 1.3 < F2 / f < 8.1, and 10 < F3 < 60, 1.3 < F3 / f < 8.1, and 20 < F4 < 80, 2.6 < F4 / f < 10.9, and 10 < F5 < 60, 1.3 < F5 / f < 8.1.
[0007] In one embodiment, the first lens group includes a first lens, a second lens, and a third lens arranged in sequence from the object side to the image side; the second lens group includes a fourth lens; the third lens group includes a fifth lens; the fourth lens group includes a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged in sequence from the object side to the image side; the fifth lens group includes a tenth lens; wherein, the first lens and the second lens are plastic aspherical lenses.
[0008] In one embodiment, the sixth lens, the seventh lens, and the eighth lens are adhesively connected.
[0009] In one embodiment, the focal length of the first lens is f1, -60 < f1 < -10; the focal length of the second lens is f2, -150 < f2 < -100; the focal length of the third lens is f3, -60 < f3 < -10; the focal length of the fourth lens is f4, 10 < f4 < 60; the focal length of the fifth lens is f5, 10 < f5 < 60; the focal length of the sixth lens is f6, -60 < f6 < -10; the focal length of the seventh lens is f7, 10 < f7 < 60; the focal length of the eighth lens is f8, -60 < f8 < -10; the focal length of the ninth lens is f9, 10 < f9 < 60; the focal length of the tenth lens is f10, 10 < f10 < 60.
[0010] In one embodiment, the refractive index of the first lens is n1, and the dispersion coefficient is v1, 1.40 ≤ n1 ≤ 1.60; 50.0 ≤ v1 ≤ 60.0; the refractive index of the second lens is n2, and the dispersion coefficient is v2, 1.40 ≤ n2 ≤ 1.60; 50.0 ≤ v2 ≤ 60.0; the refractive index of the third lens is n3, and the dispersion coefficient is v3, 1.40 ≤ n3 ≤ 1.60; 50.0 ≤ v3 ≤ 90.0; the refractive index of the fourth lens is n4, and the dispersion coefficient is v4, 1.60 ≤ n4 ≤ 1.80; 20.0 ≤ v4 ≤ 40.0; the refractive index of the fifth lens is n5, and the dispersion coefficient is v5, 1.60 ≤ n5 ≤ 1.80; 20.0 ≤ v5 ≤ 40.0; the refractive index of the sixth lens is n6, and the dispersion coefficient is v6, 1.70 ≤ n6 ≤ 1.90; 20.0 ≤ v6 ≤ 40.0; the refractive index of the seventh lens is n7, and the dispersion coefficient is v7, 1.40 ≤ n7 ≤ 1.60; 60.0 ≤ v7 ≤ 90.0; the refractive index of the eighth lens is n8, and the dispersion coefficient is v8, 1.70 ≤ n8 ≤ 1.90; 20.0 ≤ v8 ≤ 50.0; the refractive index of the ninth lens is n9, and the dispersion coefficient is v9, 1.40 ≤ n9 ≤ 1.60; 60.0 ≤ v9 ≤ 90.0; the refractive index of the tenth lens is n10, and the dispersion coefficient is v10, 1.80 ≤ n10 ≤ 2.00; 10.0 ≤ v10 ≤ 40.0.
[0011] In one embodiment, the diameter of the first lens is D1, where D1 < 30.6 mm.
[0012] In one embodiment, the zoom projection optical system further includes an aperture stop, which is disposed between the third lens group and the fourth lens group. The aperture stop is used to adjust the aperture value F of the zoom projection optical system, where 1.7 ≤ F ≤ 2.6.
[0013] In one embodiment, the total system length of the zoom projection optical system is L, 50 mm. <L<70mm。
[0014] In one embodiment, the fifth lens group includes a tenth lens; the zoom projection optical system further includes an aperture stop, which is disposed between the third and fourth lens groups, and the distance between the aperture stop and the tenth lens is set to the back working distance BFL, 0.05. <BFL / L<1。
[0015] In one embodiment, the end face of the light-emitting chip facing the fifth mirror group is the light-emitting surface, and the diameter of the light-emitting surface is IC, where IC ≤ 11.4 mm.
[0016] In the technical solution of this invention, the light emitted by the light-emitting chip passes sequentially through the fifth lens group, the fourth lens group, the third lens group, the second lens group, and the first lens group to finally form an image. At this point, the fifth lens group is set as a fixed lens group, while the second, third, and fourth lens groups are movable along the optical axis to zoom the zoom projection optical system. Simultaneously, the first lens group is movable along the optical axis to focus the zoom projection optical system, thereby ensuring that the zoom projection optical system maintains a clear image after zooming. Thus, by conditionally limiting the ratio of the focal length of the five lens groups to the focal length of the zoom projection optical system at the wide-angle end... The system is designed to effectively control the light path, allowing for a more compact structure while introducing more light. This ensures that the total lens length of the zoom projection optical system is kept to 61.7mm, while maintaining high image quality, achieving an image quality of 1080P or higher. It also meets the requirements of small size and low cost, and provides excellent thermal stability, reducing thermal defocusing at high temperatures. This allows the zoom projection optical system to maintain good imaging performance even with a temperature deviation of no more than 20℃. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0018] Figure 1 is a structural schematic diagram of an embodiment of the zoom projection optical system provided by the present invention; Figure 2 is a schematic diagram of the SPOT point at the wide-angle end of the zoom projection optical system provided by the present invention; Figure 3 is a schematic diagram of the MTF at the wide-angle end of the zoom projection optical system provided by the present invention; Figure 4 is a schematic diagram of the SPOT point at the telephoto end of the zoom projection optical system provided by the present invention; Figure 5 is a schematic diagram of the MTF at the telephoto end of the zoom projection optical system provided by the present invention.
[0019] Explanation of reference numerals in the attached diagram: 100, zoom projection optical system; 1, first lens group; 11, first lens; 12, second lens; 13, third lens; 2, second lens group; 21, fourth lens; 3, third lens group; 31, fifth lens; 4, fourth lens group; 41, sixth lens; 42, seventh lens; 43, eighth lens; 44, ninth lens; 5, fifth lens group; 51, tenth lens; 6, light-emitting chip; 7, aperture.
[0020] 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
[0021] 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.
[0022] 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.
[0023] In addition, if the descriptions such as "first", "second", etc. are involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating 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. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes scenario A, or scenario B, or the scenario where A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those skilled in the art can implement them. When the combination of technical solutions is contradictory 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 the present invention.
[0024] The present invention provides a zoom projection optical system, aiming to improve the problem that the existing projection systems cannot take into account small volume, low cost, and no defocusing at high temperatures.
[0025] Please refer to FIG. 1. In an embodiment of the present invention, the zoom projection optical system 100 has an object side and an image side arranged corresponding to each other along the optical axis direction. The zoom projection optical system 100 includes a first lens group 1, a second lens group 2, a third lens group 3, a fourth lens group 4, a fifth lens group 5, and a light-emitting chip 6 arranged in sequence from the object side to the image side. The first lens group 1, the second lens group 2, the third lens group 3, and the fourth lens group 4 are all movably arranged along the optical axis direction. The second lens group 2, the third lens group 3, and the fourth lens group 4 are used for zooming, and the first lens group 1 is used for focusing. The focal length of the zoom projection optical system 100 at the wide-angle end is f, the focal length of the first lens group 1 is F1, the focal length of the second lens group 2 is F2, the focal length of the third lens group 3 is F3, the focal length of the fourth lens group 4 is F4, and the focal length of the fifth lens group 5 is F5. The zoom projection optical system 100 satisfies the following conditions: -50 < F1 < 0, -6.75 < F1 / f < 0, and 10 < F2 < 60, 1.3 < F2 / f < 8.1, and 10 < F3 < 60, 1.3 < F3 / f < 8.1, and 20 < F4 < 80, 2.6 < F4 / f < 10.9, and 10 < F5 < 60, 1.3 < F5 / f < 8.1.
[0026] In the technical solution of this invention, the light emitted by the light-emitting chip 6 passes sequentially through the fifth lens group 5, the fourth lens group 4, the third lens group 3, the second lens group 2, and the first lens group 1 to finally form an image. At this time, the fifth lens group 5 is set as a fixed lens group, and the second lens group 2, the third lens group 3, and the fourth lens group 4 are movable along the optical axis to zoom the zoom projection optical system 100. Simultaneously, the first lens group 1 is movable along the optical axis to focus the zoom projection optical system 100, thereby ensuring that the zoom projection optical system 100 maintains a clear image after zooming. Thus, by conditionally adjusting the focal length ratio of the five lens groups at the wide-angle end of the zoom projection optical system 100... The system is designed to effectively control the light path, allowing for a more compact structure while introducing more light. This ensures that the total lens length of the zoom projection optical system 100 is kept to 61.7mm, while maintaining high image quality. The image quality of the zoom projection optical system 100 can reach 1080P or higher. Simultaneously, it satisfies the requirements of small size and low cost, and provides excellent thermal stability, reducing thermal defocusing at high temperatures. This allows the zoom projection optical system 100 to maintain good imaging performance even with a temperature deviation of no more than 20℃.
[0027] Of course, the present invention does not limit the specific order of the activities of the first lens group 1, the second lens group 2, the third lens group 3, and the fourth lens group 4. In one embodiment of the present invention, the second lens group 2, the third lens group 3, and the fourth lens group 4 are active simultaneously, and the first lens group 1 is active after the above three lens groups have completed their activities. With this configuration, after the second lens group 2, the third lens group 3, and the fourth lens group 4 are active along the optical axis to complete the zoom projection optical system 100 zoom, the first lens group 1 is active along the optical axis to focus the zoom projection optical system 100, thereby adjusting the imaging clarity of the zoom projection optical system 100 to ensure the imaging clarity of the zoom projection optical system 100.
[0028] In another embodiment of the present invention, during the movement of the second lens group 2, the third lens group 3, and the fourth lens group 4 along the optical axis extension direction, the first lens group 1 moves simultaneously along the optical axis extension direction with the above three lens groups. This arrangement is such that when the second lens group 2, the third lens group 3, and the fourth lens group 4 move along the optical axis extension direction to zoom the zoom projection optical system 100, the first lens group 1 can perform real-time focusing on the zoom projection optical system 100. This ensures that the light emitted by the light-emitting chip 6 remains clear during the zooming process of the zoom projection optical system 100, thereby avoiding image blurring and defocusing problems caused by the movement of the second lens group 2, the third lens group 3, and the fourth lens group 4 along the optical axis extension direction to zoom the zoom projection optical system 100. This not only improves the operational flexibility of the zoom projection optical system 100 but also significantly improves the imaging stability and reliability of the zoom projection optical system 100.
[0029] It is understood that in this invention, the first mirror group 1, the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 can all move in various different ways. For example, in one embodiment of this invention, the first mirror group 1, the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 can be configured to be driven by a drive motor, that is, a single drive motor is used to drive one mirror group to move along the optical axis. With this configuration, the first mirror group 1, the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 can move independently along the extension direction of the optical axis.
[0030] In another embodiment of the present invention, the first mirror group 1, the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 can also be configured to be driven by the same drive motor. In this case, it is only necessary to ensure that there is a difference in the transmission ratio between the different mirror groups and the drive motor. With this configuration, when the drive motor outputs driving force, the driving force of the drive motor can be transmitted to the first mirror group 1, the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 respectively. In this way, the linkage activity of the first mirror group 1, the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 can be realized.
[0031] In another embodiment of the present invention, the first mirror group 1, the second mirror group 2, the third mirror group 3 and the fourth mirror group 4 can also be configured to be manually driven to move along the optical axis extension direction. Specifically, in actual settings, they can be selected according to needs, and the present invention does not limit them.
[0032] It is also understood 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, the third lens group 3, the fourth lens group 4, and the fifth lens group 5 to the focal length of the zoom projection optical system 100 at the wide-angle end. In the present invention, the ratio of the focal length of each lens group to the focal length of the zoom projection optical system 100 at the wide-angle end can be selected according to the actual situation. It is only necessary to ensure that the ratio of the focal length of the first lens group 1, the second lens group 2, the third lens group 3, the fourth lens group 4, and the fifth lens group 5 to the focal length of the zoom projection optical system 100 at the wide-angle end is within the corresponding ratio range, thereby ensuring that the zoom projection optical system 100 can maintain good image quality during zooming.
[0033] It should be noted that the present invention does not limit the specific lens form or number of the first lens group 1, the second lens group 2, the third lens group 3, the fourth lens group 4, and the fifth lens group 5. In actual setup, they can be selected according to requirements.
[0034] In a specific embodiment of the present invention, to ensure smooth imaging of the zoom projection optical system 100 and to guarantee the image clarity of the zoom projection optical system 100, the first lens group 1 includes a first lens 11, a second lens 12, and a third lens 13 arranged sequentially from the object side to the image side; the second lens group 2 includes a fourth lens 21; the third lens group 3 includes a fifth lens 31; the fourth lens group 4 includes a sixth lens 41, a seventh lens 42, an eighth lens 43, and a ninth lens 44 arranged sequentially from the object side to the image side; and the fifth lens group 5 includes a tenth lens 51. The first lens 11 and the second lens 12 are configured as plastic aspherical lenses. This configuration, through the rational design of the positive and negative polarities and focal lengths of the ten projections, ensures clear imaging of the zoom projection optical system 100.
[0035] Meanwhile, the first lens 11 and the second lens 12 are configured as plastic aspherical lenses. Aspherical lenses are characterized by a continuously changing curvature from the lens center to the periphery, unlike spherical lenses which have a constant curvature from the lens center to the periphery. Aspherical lenses have better curvature radius characteristics, offering advantages in improving distortion aberrations and astigmatism. Using aspherical lenses can minimize aberrations that occur during imaging, thereby improving the lens's image quality. Furthermore, plastic lenses have lower material costs, effectively reducing the overall manufacturing cost of the zoom projection optical system 100 while maintaining image quality. Additionally, plastic materials possess a certain degree of flexibility, making them less prone to damage than glass lenses when subjected to minor external impacts, thus improving the durability of the zoom projection optical system 100.
[0036] It can be understood that in the present invention, except for the first lens 11 and the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 42, the eighth lens 43, the ninth lens 44, and the tenth lens 51 are all set as glass spherical lenses. With such a setting, the glass material has high thermal stability and a low coefficient of thermal expansion, so that the glass lens can have a good ability to resist thermal deformation, can reduce the influence of temperature on the zoom projection optical system 100. When the temperature changes, the shape and size of the glass aspherical lens change very little, and it can effectively resist the problem of thermal deformation of the zoom projection optical system 100, enabling the zoom projection optical system 100 to maintain stable optical performance in different temperature environments, reducing aberration caused by temperature changes, ensuring consistent imaging quality. At the same time, the spherical lens can reduce the cost of the zoom projection optical system 100 on the premise of ensuring the imaging quality and reliability of the zoom projection optical system 100, thereby reducing the assembly sensitivity and improving the yield rate of the finished product.
[0037] In order to achieve clear imaging of the zoom projection optical system 100, in a further embodiment of the present invention, the focal length of the first lens 11 is f1, -60 < f1 < -10, the focal length of the second lens 12 is f2, -150 < f2 < -100, the focal length of the third lens 13 is f3, -60 < f3 < -10, the focal length of the fourth lens 21 is f4, 10 < f4 < 60, the focal length of the fifth lens 31 is f5, 10 < f5 < 60, the focal length of the sixth lens 41 is f6, -60 < f6 < -10, the focal length of the seventh lens 42 is f7, 10 < f7 < 60, the focal length of the eighth lens 43 is f8, -60 < f8 < -10, the focal length of the ninth lens 44 is f9, 10 < f9 < 60, and the focal length of the tenth lens 51 is f10, 10 < f10 < 60.
[0038] It should be noted that the present invention does not limit the specific focal length values of the first lens 11, the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 42, the eighth lens 43, the ninth lens 44, and the tenth lens 51. In specific embodiments of the present invention, the specific focal length values of the first lens 11, the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 42, the eighth lens 43, the ninth lens 44, and the tenth lens 51 can be set to any value within the corresponding range. In actual settings, it is only necessary to ensure that the focal lengths of the ten lenses are coordinated to achieve clear imaging of the zoom projection optical system 100.
[0039] Furthermore, in this invention, each lens can have multiple surface shapes, as long as the surface shape of each lens corresponds to its focal length. Specifically, in a specific embodiment of this invention, the first lens 11 can be configured as a meniscus lens with negative optical power, the second lens 12 can be configured as a meniscus lens with negative optical power, the third lens 13 can be configured as a biconcave lens with negative optical power, the fourth lens 21 can be configured as a biconvex lens with positive optical power, the fifth lens 31 can be configured as a convex-concave lens with positive optical power, the sixth lens 41 can be configured as a convex-concave lens with negative optical power, the seventh lens 42 can be configured as a biconvex lens with positive optical power, the eighth lens 43 can be configured as a meniscus lens with negative optical power, the ninth lens 44 can be configured as a concave-convex lens with positive optical power, and the tenth lens 51 can be configured as a biconvex lens with positive optical power.
[0040] It is understandable that by setting the optical power of the first lens 11, the second lens 12 and the third lens 13 to negative values, it is beneficial to expand the field of view of the zoom projection optical system 100 and increase the projection ratio of the zoom projection optical system 100.
[0041] Furthermore, to further improve the imaging clarity of the zoom projection optical system 100, in a further embodiment of the present invention, the sixth lens 41, the seventh lens 42, and the eighth lens 43 are cemented together. This arrangement, by cementing together the sixth lens 41, the seventh lens 42, and the eighth lens 43, can better correct the chromatic aberration of the zoom projection optical system 100. Simultaneously, the cemented connection can reduce light energy loss, increase imaging clarity, and protect the scale surface, thereby further optimizing the manufacturing process to meet design requirements. Therefore, the reasonable use of cemented components allows optical components to improve the image quality of the optical system.
[0042] Furthermore, in this invention, the first lens 11 has a refractive index of n1 and a dispersion coefficient of v1, where 1.40 ≤ n1 ≤ 1.60 and 50.0 ≤ v1 ≤ 60.0; the second lens 12 has a refractive index of n2, where 1.40 ≤ n2 ≤ 1.60; the third lens 13 has a refractive index of n3, where 1.40 ≤ n3 ≤ 1.60; the fourth lens 21 has a refractive index of n4, where 1.60 ≤ n4 ≤ 1.80; and the fifth lens 31 has a refractive index of n5. The refractive index of the sixth lens 41 is n6, 1.70≤n6≤1.90; the refractive index of the seventh lens 42 is n7, 1.40≤n7≤1.60; the refractive index of the eighth lens 43 is n8, 1.70≤n8≤1.90; the refractive index of the ninth lens 44 is n9, 1.40≤n9≤1.60; and the refractive index of the tenth lens 51 is n10, 1.80≤n10≤2.00.
[0043] Of course, the present invention does not limit the specific values of the refractive indices of the first lens 11, the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 42, the eighth lens 43, the ninth lens 44, and the tenth lens 51. The refractive indices of the first lens 11, the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 42, the eighth lens 43, the ninth lens 44, and the tenth lens 51 can all be selected according to the actual situation, as long as the specific values of the refractive indices of each lens are within the corresponding value range and the stable imaging of the zoom projection optical system 100 can be guaranteed.
[0044] Similarly, this invention does not limit the specific values of the dispersion coefficients of the first lens 11, the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 42, the eighth lens 43, the ninth lens 44, and the tenth lens 51. In another embodiment of this invention, the refractive index of the first lens 11 is n1, and the dispersion coefficient is v1, 50.0≤v1≤60.0; the dispersion coefficient of the second lens 12 is v2, 50.0≤v2≤60.0; and the dispersion coefficient of the third lens 13 is v3, 50.0≤v3≤ The dispersion coefficient of the fourth lens 21 is v4, 20.0≤v4≤40.0; the dispersion coefficient of the fifth lens 31 is v5, 20.0≤v5≤40.0; the dispersion coefficient of the sixth lens 41 is v6, 20.0≤v6≤40.0; the dispersion coefficient of the seventh lens 42 is v7, 60.0≤v7≤90.0; the dispersion coefficient of the eighth lens 43 is v8, 20.0≤v8≤50.0; the dispersion coefficient of the ninth lens 44 is v9, 60.0≤v9≤90.0; the dispersion coefficient of the tenth lens 51 is v10, 10.0≤v10≤40.0. With this configuration, the dispersion coefficients of the first lens 11, the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 42, the eighth lens 43, the ninth lens 44, and the tenth lens 51 can also be selected according to the actual situation. It is only necessary to ensure that the specific values of the dispersion coefficients of each lens are within the corresponding value range and that the zoom projection optical system 100 can achieve stable imaging.
[0045] Furthermore, to limit the size of the zoom projection optical system 100 and achieve its miniaturization, in one embodiment of the present invention, the diameter of the first lens 11 is D1, where D1 < 30.6 mm. This configuration, by limiting the diameter of the first lens 11, restricts the aperture of the zoom projection optical system 100, thereby preventing the aperture from becoming too large and ensuring the installation space requirements of the final product are met.
[0046] It should also be noted that, in this invention, the volume of the zoom projection optical system 100 can be further controlled. In another embodiment of this invention, the end face of the light-emitting chip 6 facing the fifth mirror group 5 is the light-emitting surface, and the diameter of the light-emitting surface is IC, IC≤11.4mm.
[0047] It is also understandable that, in order to limit the length of the zoom projection optical system 100 to further meet the design requirements of miniaturization, in a further embodiment of the present invention, the total length of the zoom projection optical system 100 is L, and 50 mm < L < 70 mm. With such a setting, by reasonably limiting the total length of the system, the size of the zoom projection optical system 100 in the optical axis direction can be effectively controlled, making it more compact and portable while ensuring the imaging quality, and adapting to the installation and use requirements in different scenarios. Thus, not only space is saved, but also the material cost is reduced.
[0048] In addition, in order to adjust the light passing amount of the zoom projection optical system 100 so that the zoom projection optical system 100 can present excellent imaging effects in different lighting environments, in an embodiment of the present invention, the zoom projection optical system 100 further includes an aperture 7, and the aperture 7 is arranged between the third lens group 3 and the fourth lens group 4. The aperture 7 is used to adjust the aperture value F of the zoom projection optical system 100, and 1.7 ≤ F ≤ 2.6. With such a setting, the zoom projection optical system 100 has a large light passing amount and high picture brightness, the picture is brighter, the projection effect is good, and it can clearly image in an environment with a relatively high brightness.
[0049] In a further embodiment of the present invention, the distance between the aperture 7 and the tenth lens 51 is set as the back focal length BFL, and 0.05 < BFL / L < 1. In this embodiment, by restricting the back focal length, the structural layout of the zoom projection optical system 100 can be further optimized, avoiding the influence on the imaging quality due to the distance between the aperture 7 and the tenth lens 51 being too close or too far. When the ratio of the back focal length BFL to the total length L of the system is within the reasonable range of 0.05 to 1, it can ensure that after the light passes through the aperture 7, it can reach the tenth lens 51 at a more ideal angle and path, reducing the scattering and loss of light, thereby improving the clarity and contrast of the image.
[0050] Of course, in the present invention, the zoom projection optical system 100 further includes a filter, a protective glass, etc.
[0051] In a specific embodiment of the present invention, the focal length f at the wide-angle end of the zoom projection optical system 100 is 7.42 m, the aperture value F is 2.2, the diameter IC of the light-emitting surface is 11.4 mm, and the surface types, curvature radii, thicknesses, and optical materials of multiple lenses in the zoom projection optical system 100 are as shown in Table 1 below: Table 1
[0052] It is understood that in this embodiment, the sixth lens 41, the seventh lens 42, and the eighth lens 43 are cemented together, the first lens 11 and the second lens 12 are plastic aspherical lenses, and the third lens 13, the fourth lens 21, the fifth lens 31, the sixth lens 41, the seventh lens 42, the eighth lens 43, the ninth lens 44, and the tenth lens 51 are glass spherical lenses.
[0053] Furthermore, in this embodiment, the aspherical surface shape of the aspherical lens satisfies the following condition:
[0054] Where z represents the axial sagitta in the Z-direction of the aspherical surface; y represents the height of the aspherical surface; c represents the curvature of the fitted sphere, numerically the reciprocal of the radius of curvature; k represents the conic coefficient; and the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms represent higher-order aspherical coefficients, respectively. The higher-order coefficients for each aspherical lens are shown in Table 2 below: Table 2 Conic and Aspherical Coefficients Corresponding to Aspherical Lenses
[0055] 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.
[0056] In this embodiment, taking the wide-angle end of the zoom projection optical system 100 as the zero point, the movement distances of the second lens group 2, the third lens group 3, and the fourth lens group 4 are shown in Table 3 below: Table 3
[0057] Please refer to Figure 2, which is a schematic diagram of the SPOT point of the zoom projection optical system 100 provided by the present invention at the wide-angle end.
[0058] Please refer to Figure 3, which is a schematic diagram of the MTF of the zoom projection optical system 100 provided by the present invention at the wide-angle end.
[0059] Please refer to Figure 4, which is a schematic diagram of the SPOT point at the telephoto end of the zoom projection optical system 100 provided by the present invention.
[0060] Please refer to Figure 5, which is a schematic diagram of the MTF of the zoom projection optical system 100 provided by the present invention at the telephoto end.
[0061] 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 projection optical system, characterized in that, It has an object side and an image side arranged correspondingly along the optical axis direction. The zoom projection optical system includes a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, and a light-emitting chip arranged in sequence from the object side to the image side. The first lens group, the second lens group, the third lens group, and the fourth lens group are all arranged to move along the optical axis direction. The second lens group, the third lens group, and the fourth lens group are used for zooming, and the first lens group is used for focusing. Among them, the focal length of the zoom projection optical system at the wide-angle end is f, 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, the focal length of the fourth lens group is F4, and the focal length of the fifth lens group is F5. The zoom projection optical system satisfies the following conditions: -50 < F1 < 0, -6.75 < F1 / f < 0, and 10 < F2 < 60, 1.3 < F2 / f < 8.1, and 10 < F3 < 60, 1.3 < F3 / f < 8.1, and 20 < F4 < 80, 2.6 < F4 / f < 10.9, and 10 < F5 < 60, 1.3 < F5 / f < 8.
1.
2. The zoom projection optical system as described in claim 1, characterized in that, The first lens group includes a first lens, a second lens, and a third lens arranged in sequence from the object side to the image side; the second lens group includes a fourth lens; the third lens group includes a fifth lens; the fourth lens group includes a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged in sequence from the object side to the image side; the fifth lens group includes a tenth lens. Among them, the first lens and the second lens are set as plastic aspherical lenses.
3. The zoom projection optical system as described in claim 2, characterized in that, The sixth lens, the seventh lens, and the eighth lens are adhesively connected and arranged.
4. The zoom projection optical system as described in claim 2, characterized in that, The focal length of the first lens is f1, -60 < f1 < -10; the focal length of the second lens is f2, -150 < f2 < -100; the focal length of the third lens is f3, -60 < f3 < -10; the focal length of the fourth lens is f4, 10 < f4 < 60; the focal length of the fifth lens is f5, 10 < f5 < 60; the focal length of the sixth lens is f6, -60 < f6 < -10; the focal length of the seventh lens is f7, 10 < f7 < 60; the focal length of the eighth lens is f8, -60 < f8 < -10; the focal length of the ninth lens is f9, 10 < f9 < 60; the focal length of the tenth lens is f10, 10 < f10 < 60.
5. The zoom projection optical system as described in claim 2, characterized in that, The first lens has a refractive index of n1 and a dispersion coefficient of v1, where 1.40 ≤ n1 ≤ 1.60; 50.0 ≤ v1 ≤ 60.0; the second lens has a refractive index of n2 and a dispersion coefficient of v2, where 1.40 ≤ n2 ≤ 1.60; 50.0 ≤ v2 ≤ 60.0; the third lens has a refractive index of n3 and a dispersion coefficient of v3, where 1.40 ≤ n3 ≤ 1.60; 50.0 ≤ v3 ≤ 90.0; the fourth lens has a refractive index of n4 and a dispersion coefficient of v4, where 1.60 ≤ n4 ≤ 1.80; 20.0 ≤ v4 ≤ 40.0; the fifth lens has a refractive index of n5 and a dispersion coefficient of v5, where 1.60 ≤ n5 ≤ 1.80; 20.0 ≤ v5 ≤ 40.0; The sixth lens has a refractive index of n6 and a dispersion coefficient of v6, with 1.70≤n6≤1.90 and 20.0≤v6≤40.0; the seventh lens has a refractive index of n7 and a dispersion coefficient of v7, with 1.40≤n7≤1.60 and 60.0≤v7≤90.0; the eighth lens has a refractive index of n8 and a dispersion coefficient of v8, with 1.70≤n8≤1.90 and 20.0≤v8≤50.0; the ninth lens has a refractive index of n9 and a dispersion coefficient of v9, with 1.40≤n9≤1.60 and 60.0≤v9≤90.0; the tenth lens has a refractive index of n10 and a dispersion coefficient of v10, with 1.80≤n10≤2.00 and 10.0≤v10≤40.
0.
6. The zoom projection optical system as described in claim 2, characterized in that, The diameter of the first lens is D1, where D1 < 30.6 mm.
7. The zoom projection optical system as described in claim 1, characterized in that, The zoom projection optical system also includes an aperture stop, which is located between the third lens group and the fourth lens group. The aperture stop is used to adjust the aperture value F of the zoom projection optical system, where 1.7 ≤ F ≤ 2.
6.
8. The zoom projection optical system as described in claim 1, characterized in that, The total length of the zoom projection optical system is L = 50mm. <L<70mm。 9. The zoom projection optical system as described in claim 8, characterized in that, The fifth lens group includes a tenth lens; the zoom projection optical system also includes an aperture stop, which is located between the third and fourth lens groups, and the distance between the aperture stop and the tenth lens is set to the back working distance BFL, 0.
05. <BFL / L<1。 10. The zoom projection optical system as described in claim 1, characterized in that, The end face of the light-emitting chip facing the fifth mirror group is the light-emitting surface, and the diameter of the light-emitting surface is IC, where IC ≤ 11.4 mm.