Lens module and zooming method and device

Abstract

The invention discloses a lens module, and belongs to the technical field of image processing. The lens module sequentially comprises a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group and a sixth lens group from an object side to an image side along an optical axis, the second lens group can move along the optical axis; the third lens group can move along the optical axis; the position of the fourth lens group is fixed in the zooming process; wherein the second lens group and the third lens group are configured to be capable of moving along an optical axis, so that the lens module is switched between a first state and a second state; the focal length of the lens module in the first state is smaller than the focal length of the lens module in the second state.

Description

Technical Field

[0001] This application belongs to the field of image processing technology, specifically relating to a lens module, zoom method and device. Background Technology

[0002] With the rapid popularization of smartphone photography functions and the continuous improvement of user demands, photography performance has become one of the important indicators for measuring the mobile phone experience. Among them, telephoto shooting capabilities are often limited by the internal space of the mobile phone and the size of the lens module, resulting in insufficient clarity and degraded image quality in high-magnification telephoto scenarios. To address this, products that enhance telephoto performance by using external physical telephoto lenses have gradually emerged in the market, making them stand out in scenarios such as concerts, sporting events, and nature observation, and have been widely welcomed by consumers.

[0003] Currently, most external telephoto lenses for mobile phones on the market are fixed-focus designs. Although they can further magnify the image through digital zoom, they cannot extend the optical focal length downwards. When users need to shoot a wider field of view, they must remove the external lens and switch to the phone's native lens, which is cumbersome and affects the continuity of shooting.

[0004] Therefore, the current market urgently needs a lens module that combines portability with flexible zoom capabilities. Summary of the Invention

[0005] The purpose of this application is to provide a lens module, zoom method, and device that can solve the problem of the urgent need for a lens module that balances portability and flexible zoom capabilities.

[0006] In a first aspect, embodiments of this application provide a lens module, which includes, along the optical axis from the object side to the image side, the following components in sequence: The first lens group, the position of the first lens group is fixed during zooming; The second lens group can move along the optical axis; The third lens group can move along the optical axis; The fourth lens group's position remains fixed during zooming; The second and third lens groups are configured to move along the optical axis, allowing the lens module to switch between the first and second states. The focal length of the lens module in the first state is less than the focal length of the lens module in the second state.

[0007] Secondly, embodiments of this application provide a zoom method, wherein an electronic device is connected to a lens module, and the lens module comprises, in sequence along the optical axis from the object side to the image side, a first lens group, a second lens group, a third lens group, and a fourth lens group; the method includes: Receive zoom commands; When the zoom command instructs the lens module to switch to the first state, the second and third lens groups within the lens module are driven to move along the optical axis to the object side. When the zoom command instructs the lens module to switch to the second state, the second and third lens groups within the lens module are driven to move along the optical axis to the image side.

[0008] Thirdly, embodiments of this application provide a zoom device executed by an electronic device connected to a lens module. The lens module comprises, along the optical axis from the object side to the image side, a first lens group, a second lens group, a third lens group, and a fourth lens group. The device includes: The receiving module is used to receive zoom commands; The first drive module is used to drive the second lens group and the third lens group in the lens module to move along the optical axis to the object side when the zoom command indicates that the lens module is switched to the first state. The second drive module is used to drive the second lens group and the third lens group within the lens module to move along the optical axis to the image side when the zoom command indicates that the lens module is switched to the second state.

[0009] Fourthly, embodiments of this application provide an electronic device including a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions, when executed by the processor, implementing the steps of the method described in the first aspect.

[0010] Fifthly, embodiments of this application provide a readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect.

[0011] In a sixth aspect, embodiments of this application provide a chip, the chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the method as described in the first aspect.

[0012] In a seventh aspect, embodiments of this application provide a computer program product stored in a storage medium, which is executed by at least one processor to implement the method described in the first aspect.

[0013] In the embodiments of this application, the lens module comprises, sequentially from the object side to the image side along the optical axis: a first lens group, the position of which is fixed during zooming; a second lens group, which is movable along the optical axis; a third lens group, which is movable along the optical axis; and a fourth lens group, the position of which is fixed during zooming. The second and third lens groups are configured to be movable along the optical axis, allowing the lens module to switch between a first state and a second state. By coordinating the axial displacement of the second and third lens groups, the effective length of the optical path and the equivalent optical power of the lens combination can be changed. The focal length of the lens module in the first state is smaller than the focal length of the lens module in the second state. The dual movable lens groups provide more degrees of freedom for adjusting optical parameters, thereby allowing effective optical zoom from a wider field of view to a longer focal length within a relatively compact mechanical travel. Thus, a balance can be achieved between zoom capability, image quality, and portability in the lens module. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a lens module provided in an embodiment of this application; Figure 2 This is a flowchart of a zoom method provided in an embodiment of this application; Figure 3 This is a schematic diagram of a modulation transfer function (MTF) curve in a wide-angle state provided in an embodiment of this application; Figure 4 This is a schematic diagram of an MTF curve under telescopic conditions provided in an embodiment of this application; Figure 5 This is a structural diagram of a zoom device provided in an embodiment of this application; Figure 6 This is one of the hardware structure diagrams of the electronic device according to an embodiment of this application; Figure 7 This is the second schematic diagram of the hardware structure of the electronic device according to an embodiment of this application. Detailed Implementation

[0015] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0016] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0017] The technical terms used in the embodiments of this application are explained below: A lens module refers to a detachable, independent optical component mounted in front of the native camera module of an electronic device. As a front-facing optical relay system, it significantly extends the system's equivalent focal length by altering the optical path characteristics entering the device's native camera, with a particular focus on enhancing telephoto shooting capabilities.

[0018] The lens module and the electronic device form a master-slave collaborative optical system: the lens module is responsible for the main optical zoom and telephoto functions, while the built-in camera of the electronic device acts as a fixed image receiver, utilizing its own autofocus, image sensor, and processing system to complete the final image. The lens module and the electronic device are physically connected and aligned along their optical axes through a precise mechanical interface, ensuring that light can pass through the lens module and the electronic device's lens sequentially and unobstructed, coaxially.

[0019] In this optical system, the optical axis refers to a straight line passing through the center of all optical elements. It represents the main reference axis of the imaging optical path and serves as a reference for defining the spatial position of all optical elements and the direction of light propagation. Along this optical axis, with the direction of light propagation as a reference, the object side refers to the side facing the subject, i.e., the end where the light enters the system; the image side refers to the side where the image is finally formed, i.e., the end where the light converges after passing through the system and reaches the image sensor.

[0020] A lens assembly refers to a collection of lenses that have specific optical functions, consisting of at least one optical lens arranged in a specific order and spacing.

[0021] The zoom method provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0022] Figure 1 This is a schematic diagram of the structure of a lens module provided in an embodiment of this application.

[0023] The lens module, along the optical axis from the object side to the image side, includes the following components in sequence: The first lens group 110, the position of the first lens group is fixed during zooming; The second lens group 120 is movable along the optical axis; The third lens group 130 can move along the optical axis; The fourth lens group is 140mm, and its position remains fixed during zooming. Among them, the lens module switches between the first state and the second state by moving the second lens group and the third lens group along the optical axis; The focal length of the lens module in the first state is less than the focal length of the lens module in the second state.

[0024] This embodiment provides a lens module for an electronic device. This lens module, as a standalone optical module, can be installed in front of the device's native camera. Its optical architecture is arranged along a virtual reference line, the optical axis, which represents the centerline of the ideal imaging optical path. Along this optical axis, the end where light enters is defined as the object side, and the end where light ultimately exits and points towards the image sensor built into the electronic device is defined as the image side. From the object side to the image side, the lens module consists of four optically relatively independent lens groups arranged sequentially. Each lens group contains at least one lens and functions as a single unit, performing a specific optical function.

[0025] In this system, the first and fourth lens groups maintain a fixed spatial position along the optical axis during zoom operations. The second and third lens groups are designed to move precisely along the optical axis. By controlling the relative movement of the second and third lens groups along the optical axis according to a specific pattern, the optical focal length of the entire lens module can be switched between two discrete states: a first state and a second state. In the first state, the focal length of the entire lens module system is less than its focal length in the second state.

[0026] In the first configuration, both the second and third lens groups are positioned close to the object-side of the first lens group. For example, the second lens group can be positioned adjacent to the image-side of the first lens group, and the third lens group can be positioned adjacent to the image-side of the second lens group. In this configuration, light entering from the object side is refracted sequentially through the first, second, and third lens groups before entering the fourth lens group. With this spatial arrangement, the light experiences a relatively short optical path in the second and third lens groups, thus shortening the effective focal length of the entire system and corresponding to a wider field of view.

[0027] In the second state, both the second and third lens groups start from their positions in the first state and move along the optical axis towards the image side, but the amount of displacement differs. For example, the second lens group moves a smaller distance towards the image side, while the third lens group moves a larger distance, bringing it closer to the fourth lens group. At this point, the third lens group is physically close to the fourth lens group and optically works in conjunction with it, forming a composite eyepiece system. After passing through the first and second lens groups, light enters this eyepiece system composed of the third and fourth lens groups. Due to the significant rearward shift of the third lens group, the light path within the second and third lens groups is effectively lengthened, thus extending the effective focal length of the entire system and corresponding to a narrower telephoto field of view.

[0028] There are several ways to achieve fixed positions. One method is to rigidly connect or integrate the first and fourth lens groups with the lens module's barrel housing, ensuring their physical positions relative to the lens barrel remain unchanged. Another method is to design specific fixing brackets or retaining rings to lock the two lens groups in predetermined positions within the lens barrel, preventing axial movement during zooming. Specific implementations allowing movement along the optical axis also include various approaches. For example, precision linear guides or guide rods can be installed within the lens barrel, with the second and third lens groups mounted on these guides via corresponding sliders, driven by a miniature stepper motor or voice coil motor for linear motion. Another implementation can employ a manual mechanical structure, such as rotating the zoom ring on the lens barrel to drive an internal precision cam mechanism or threaded mechanism, thereby converting rotational motion into independent linear movement of the second and third lens groups.

[0029] By distributing zoom functionality to two movable lens groups and integrating one of the movable lens groups into the fixed eyepiece group in telephoto mode, an optical design achieves two discrete high-quality focal lengths within a limited volume. Compared to traditional external fixed-focus lenses, it provides optical switching capabilities from a wider field of view to a longer telephoto field of view, allowing users to obtain different framing ranges without disassembling the lens, significantly improving operational convenience. Compared to birdwatching scope adapters using traditional continuous zoom structures, this two-section structure effectively controls the overall system length and the total number of lenses by optimizing the displacement trajectory and optical power distribution of the movable group, thus achieving a more compact and lightweight overall structure while ensuring excellent aberration correction and image sharpness at both fixed focal lengths.

[0030] like Figure 1The structural diagram shown also includes a built-in camera 150 of the electronic device and an intermediate image 160 formed by the optical system. Specifically, in the first state, light first passes through a fixed first lens group 110, and then sequentially through a second lens group 120 and a third lens group 130 located in a forward position. These three lens groups work together as the objective lens of the system to converge the light from the subject, forming an intermediate real image 160 in the optical path. This intermediate real image is then received by a fixed fourth lens group 140, which in this state independently acts as an eyepiece, magnifying the intermediate image and projecting it onto the sensor of the camera 150 of the electronic device to complete the final imaging.

[0031] In the second state, the lens module undergoes dynamic optical reconstruction. The second lens group 120 and the third lens group 130 move to the right image side along the optical axis. At this time, the light rays converge after passing through the first lens group 110 and the moved second lens group 120 to form an intermediate real image 160. The third lens group 130 has now moved to a position very close to the fourth lens group 140. Therefore, the intermediate real image 160 is located between the second and third lens groups. The third lens group 130 and the fourth lens group 140 are optically tightly integrated to form a composite eyepiece system. This composite eyepiece further magnifies the intermediate image and projects it onto the electronic device camera 150.

[0032] In one possible embodiment, the first lens group includes at least five lenses, wherein the first lens and the third lens in the first lens group, along the optical axis from the object side to the image side, are made of a low-dispersion material.

[0033] Along the optical axis from the object side to the image side, the first lens group contains no fewer than five lenses. As the first component to act on light, the first lens group needs to effectively correct axial chromatic aberration and magnification chromatic aberration. For this reason, the first lens and the third lens of the first lens group, counting from the object side, are made of low-dispersion optical materials.

[0034] Low dispersion materials are special optical materials with high Abbe numbers and small differences in refractive index for different wavelengths of light. Using such materials can significantly reduce chromatic aberration caused by the different focal points of different colors of light, thereby improving image sharpness and color fidelity.

[0035] In one possible embodiment, the second lens group includes at least three lenses, wherein the last two lenses of the middle group of the second lens group are cemented together along the optical axis from the object side to the image side to form a first cemented lens.

[0036] The second lens group comprises at least three lenses. As a whole, the second lens group moves during zooming, and the stability of its optical performance is crucial. For this reason, the last two lenses in this group, arranged along the optical axis, are designed to be cemented together to form the first cemented lens.

[0037] Cemented lenses are composite lenses made by bonding two lenses with different curvatures and materials together using optical adhesives. For example, UV-curing adhesives or epoxy resins can be used for bonding. This structure can effectively utilize the bonded surface to correct monochromatic aberrations. At the same time, because the two lenses are mechanically integrated, they can maintain extremely high coaxiality and spacing stability during movement, avoiding assembly sensitivity and performance fluctuations that may be caused by air gaps.

[0038] In one possible embodiment, the third lens group includes at least three lenses, wherein the first two lenses in the third lens group are cemented together along the optical axis from the object side to the image side to form a second cemented lens.

[0039] The third lens assembly comprises at least three lenses, which are also movable components and work in conjunction with the subsequent fixed assembly in telescopic mode. The first two lenses in this assembly, arranged along the optical axis, are cemented together to form a second cemented lens.

[0040] For example, by bonding a positive lens and a negative lens together through a precision centering process, not only can aberrations be corrected within the group, but also, considering that the group will function as an eyepiece in the second state, the bonding design at the front can better control the angle and aberration state of light emitted towards the image side, laying the foundation for the cooperation between the third and fourth lens groups.

[0041] In one possible embodiment, the fourth lens group includes at least two lenses, wherein the first lens in the fourth lens group along the optical axis from the object side to the image side is an aspherical lens and has positive optical power.

[0042] The fourth lens group comprises at least two lenses in fixed positions. The first lens in this group, measured from the object side, is an aspherical lens with positive optical power. An aspherical lens is a lens whose surface radius of curvature changes continuously from the center to the edge, unlike a standard sphere. This lens's positive optical power allows it to effectively converge light rays, while its aspherical characteristics are specifically used to correct residual field curvature and distortion in the system. Field curvature causes the image plane to bend; the aspherical lens adjusts the optical path of peripheral rays, ensuring they are simultaneously and clearly focused on a flat image plane along with the central rays. Simultaneously, the aspherical lens significantly corrects distortion caused by increased field of view, ensuring accurate image geometry.

[0043] Therefore, the first lens group employs low-dispersion lenses at specific locations to strongly suppress chromatic aberration from the light entry point, laying the foundation for high contrast and color purity. Cemented lenses are used in key positions in the second and third moving lens groups, which not only enhances the aberration correction capabilities within each unit but also ensures high consistency and stability of optical performance during repeated movements. This is the core guarantee for reliable and repeatable zoom operation. The positive-power aspherical lens used at the fourth lens group's entry point precisely handles the last segment of the light path before reaching the image, ensuring a flat and geometrically faithful image plane projected onto the phone's sensor. Within a compact physical space, high-resolution, low-chromatic-aberration, and low-distortion optical performance is achieved in both discrete focal length states. This allows the lens module to provide flexible zoom capabilities without sacrificing portability and final image quality.

[0044] In one possible embodiment, the lens module is connected to an electronic device, and the ratio of the focal length of the lens module in the second state to the focal length of the lens module in the first state is between 1.5 and 2.3; the ratio of the focal length of the lens module in the first state to the focal length of the electronic device is between 1 and 1.7.

[0045] The focal length of a lens module refers to its equivalent focal length as an independent optical system; the focal length of an electronic device specifically refers to the equivalent focal length of its original telephoto camera. The ratio of the focal length of the lens module in its second state to its focal length in its first state is controlled within the range of 1.5 to 2.3, defining the optical zoom capability of the lens module itself.

[0046] For example, the lens module itself can switch between equivalent focal lengths from 100mm to 200mm, with a ratio of exactly 2.0. Choosing a lower limit of 1.5 ensures that the field of view is significantly narrowed when switching from the first state to the second state; setting an upper limit of 2.3 effectively constrains the optical complexity and lens movement required to achieve zoom, which is a key design trade-off that ensures the compact structure and portability of the entire lens module.

[0047] Specifically, the focal length fw of the lens module in the first state, the focal length ft of the lens module in the second state, and the focal length fs of the electronic device satisfy the following conditions: 1.5≤ft / fw≤2.3; 1≤fw / fs≤1.7.

[0048] For example, ft / fw=2.24; fw / fs=1.58.

[0049] The ratio of the focal length of the lens module in its first state to the focal length of the original telephoto camera of the electronic device is controlled between 1 and 1.7. For example, if the original telephoto lens has a focal length of 80mm, the wide-angle focal length of the lens module can be designed to be 120mm, with a ratio of 1.5. A ratio of 1 means that the wide-angle field of view of the lens module is exactly the same as that of the original telephoto lens of the phone; setting the upper limit to 1.7 ensures that even if the user installs this lens module, in scenarios requiring a slightly wider field of view, the angle of view provided by the wide-angle end of the lens module will not be much narrower than that of the original lens. Thus, in most daily telephoto needs, users do not need to frequently remove the lens; they can obtain a continuous shooting experience coverage from "slightly wider" to "further" simply by switching the working state of the lens module, greatly improving operational convenience.

[0050] The synergistic design of the two focal length ratio ranges mentioned above achieves a balance between optical performance, structural size, and user experience. Limiting the zoom ratio of the lens module itself to 1.5 to 2.3 allows for the use of two sets of movable structures. With relatively simple mechanical movement and a limited total optical length, this achieves two distinct focal lengths with clear, high-quality images, avoiding system bulk and image quality degradation caused by pursuing higher magnification. Furthermore, limiting the ratio of the wide-angle focal length of the lens module to the focal length of the phone lens to 1 to 1.7 expands the lens module into a practical tool providing both everyday telephoto enhancement and dedicated telephoto modes. This significantly reduces the frequency of lens removal for users, resulting in a substantial improvement in the lens module's usability.

[0051] In one possible embodiment, the ratio of the focal length of the first lens group to the focal length of the fourth lens group is greater than or equal to 25; the ratio of the focal length of the second lens group to the focal length of the third lens group is between 1.5 and 2.0.

[0052] The ratio of the focal length of the first lens group to the focal length of the fourth lens group is set to be greater than or equal to 25. This means that the first lens group has a considerably long positive focal length, while the fourth lens group has a very short positive focal length. For example, the focal length of the first lens group could be 200 mm, and the focal length of the fourth lens group could be 8 mm, resulting in a ratio of 25. Alternatively, the focal length of the first lens group could be 250 mm, and the focal length of the fourth lens group could be 9 mm, resulting in a ratio of approximately 27.8. This ratio constitutes a classic telescope system architecture in optics: the long focal length objective lens, i.e., the first lens group, is responsible for collecting light and forming the primary intermediate image, while the short focal length eyepiece, i.e., the fourth lens group, magnifies this intermediate image.

[0053] Specifically, the focal lengths f1 of the first lens group, f2 of the second lens group, f3 of the third lens group, and f4 of the fourth lens group satisfy the following conditions: 25≤f1 / f4; 1.5≤f2 / f3≤2.0.

[0054] For example, f1 / f4 = 33.8; f2 / f3 = 1.86.

[0055] The ratio of the focal length of the second lens group to that of the third lens group is limited to between 1.5 and 2.0. This defines the relative optical power relationship between the two moving groups. For example, the second lens group could have a focal length of 60mm and the third lens group a focal length of 40mm, resulting in a ratio of 1.5. Alternatively, the second lens group could have a focal length of 80mm and the third lens group a focal length of 40mm, resulting in a ratio of 2.0. This range ensures smooth zooming and stable image quality.

[0056] As one of the moving components, the second lens group needs to have sufficient optical power to effectively participate in changing the system's focal length, but it cannot be too strong, lest it place an excessive burden on aberration correction. The optical power of the third lens group needs to be in a specific ratio to achieve this, so that when the two move together, they can not only realize the focal length jump between the first and second states, but also effectively compensate for image plane shift and aberration changes caused by zooming, especially ensuring that clear and corrected images can be obtained at both discrete state points.

[0057] The extremely high focal length ratio of 25 or greater between the first and fourth lens groups powerfully compresses the optical path at the system level, ensuring that the physical entity maintains the compact size required for portability while providing telephoto capabilities. The focal length ratio of 1.5 to 2.0 between the second and third lens groups allows the entire lens module to reliably switch between two aberration-corrected, high-quality focal lengths within a very compact lens barrel through the limited travel of the two moving groups, achieving a balance between miniaturization and high performance.

[0058] Specifically, the lens module involved in this application embodiment achieves focusing by utilizing the focusing group within the lens of the electronic device when shooting objects at different distances, and the basic specifications achieved are shown in Table 1: Table 1

[0059] Where efl is the system focal length, Fno is the system aperture, fs is the focal length of the lens of the paired electronic device, f1 is the focal length of the first lens group, f2 is the focal length of the second lens group, f3 is the focal length of the third lens group, and f4 is the focal length of the fourth lens group.

[0060] The surface type, radius of curvature, thickness, refractive index, and Abbe number of each lens in the optical imaging system are shown in Table 2. Table 2

[0061] The aspherical coefficients of aspherical lenses are shown in Table 3, where s1 represents the first aspherical surface and s2 represents the second aspherical surface.

[0062] Table 3

[0063] In one possible embodiment, when the lens module is in the first state, the objective lens system of the lens module includes: a first lens group, a second lens group, and a third lens group; the eyepiece system of the lens module includes a fourth lens group. When the lens module is in the second state, the objective lens system of the lens module includes: a first lens group and a second lens group; the eyepiece system of the lens module includes: a third lens group and a fourth lens group.

[0064] A telescopic optical system can be clearly divided into two parts: the objective lens and the eyepiece. The objective lens is responsible for receiving light from the subject and forming an intermediate real image. The eyepiece then uses this intermediate image as the object, re-images it, and projects it onto the final image plane.

[0065] When the lens module is in its first state, its optical functions are divided as follows: the objective lens system includes a first lens group, a second lens group, and a third lens group; the eyepiece system only includes a fourth lens group. This means that light entering from the object side needs to pass through the combined action of the first, second, and third lens groups in sequence to form an intermediate real image located within the system. This intermediate image is then transmitted to the fixed fourth lens group, which independently assumes the function of the eyepiece, ultimately imaging it onto the sensor of the electronic device. At this time, the third lens group functionally belongs to the front-end objective lens section.

[0066] When the lens module switches to the second state, the functional division of the system is restructured as the second and third lens groups move axially: the objective lens system includes only the first and second lens groups; the eyepiece system includes the third and fourth lens groups. In this state, light passes through the first and second lens groups and completes the initial imaging, forming an intermediate real image. At this time, the third lens group, which has moved to the image side, is physically adjacent to the fourth lens group and optically deeply integrated with it, together forming a composite eyepiece system. This composite eyepiece system takes the aforementioned intermediate image as its target, magnifies it again, and projects it onto the sensor. Thus, the functional role of the third lens group dynamically changes from the rear half of the objective lens system in the first state to the front half of the eyepiece system in the second state.

[0067] By altering the boundary between the objective and eyepiece in the optical system—specifically, by moving the third lens group from the objective to the eyepiece—it is equivalent to significantly shortening the objective's focal length while simultaneously changing the combined focal length of the eyepiece. The total equivalent focal length is directly proportional to the objective's focal length and inversely proportional to the eyepiece's focal length. This shift in functional roles, achieved through the limited movement of two lens groups, enables a significant leap from the first focal length to the second. This not only makes the zoom mechanism simpler and more reliable.

[0068] In the embodiments of this application, the lens module comprises, sequentially from the object side to the image side along the optical axis: a first lens group, the position of which is fixed during zooming; a second lens group, which is movable along the optical axis; a third lens group, which is movable along the optical axis; and a fourth lens group, the position of which is fixed during zooming. The second and third lens groups are configured to be movable along the optical axis, allowing the lens module to switch between a first state and a second state. By coordinating the axial displacement of the second and third lens groups, the effective length of the optical path and the equivalent optical power of the lens combination can be changed. The focal length of the lens module in the first state is smaller than the focal length of the lens module in the second state. The dual movable lens groups provide more degrees of freedom for adjusting optical parameters, thereby allowing effective optical zoom from a wider field of view to a longer focal length within a relatively compact mechanical travel. Thus, a balance can be achieved between zoom capability, image quality, and portability in the lens module.

[0069] like Figure 2 The figure shows the characteristic curve of the modulation transfer function (MTF) of the lens module as a function of defocusing amount in wide-angle operation. The horizontal axis represents the offset position of the image plane along the optical axis relative to the theoretical optimal focus, i.e., the defocusing amount, in millimeters. Zero represents the ideal focusing plane in optical design; negative values ​​indicate that the image plane is offset towards the lens, while positive values ​​indicate that it is offset towards the sensor. The vertical axis represents the modulation depth, i.e., the MTF value, which quantifies the lens's ability to reproduce the contrast of the scene; the range of the vertical axis shown in the figure is a very small fluctuation range around a certain high reference value.

[0070] Each point on the curve corresponds to the simulated or measured MTF value of the optical system at a specific spatial frequency at a particular defocus position. The peak appears at approximately +0.01 mm of defocus, indicating that in wide-angle mode, the system's optimal imaging plane may be intentionally fine-tuned to balance the effects of different fields of view or aberrations. A significant decrease in depth of modulation occurs when the defocus shifts from the optimal position to only approximately ±0.02 mm.

[0071] like Figure 3The diagram illustrates the modulation transfer function (MTF) of the lens module as a function of defocus in telephoto operation. The horizontal axis represents the defocus position, i.e., the offset of the imaging sensor plane from the optimal theoretical focal point of the lens optical system, measured in millimeters. The zero point corresponds to the focal plane; negative values ​​indicate the sensor is too close to the lens, while positive values ​​indicate the sensor is too far away. The vertical axis represents the modulation depth, i.e., the MTF value, which reflects the system's ability to reproduce target contrast. Each data point on the curve corresponds to the theoretically calculated or measured MTF value of the optical system at a specific spatial frequency under a certain precise defocus amount. The curve's shape shows a very sharp and narrow peak, indicating that the MTF value is extremely sensitive to changes in defocus amount when viewed from a telephoto perspective. Even a tiny shift in the sensor plane from its optimal position can cause a rapid decrease in image contrast, i.e., the MTF value.

[0072] In response to the problems in related technologies, this application provides a lens module, zoom method, and apparatus that can solve the problem of low image quality in fused images generated based on images acquired from multiple imaging devices in related technologies.

[0073] The zoom method provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0074] Figure 4 This is a flowchart of a zoom method provided in an embodiment of this application.

[0075] like Figure 4 As shown, the zoom method may include steps 410-430. This method is applied to a zoom device and executed by an electronic device. The electronic device is connected to a lens module. The lens module includes, along the optical axis from the object side to the image side, a first lens group, a second lens group, a third lens group, and a fourth lens group, as detailed below: Step 410: Receive zoom command; Receive zoom commands. These commands can originate from direct user input, such as triggering a specific button on the lens module or in an application on a connected electronic device; or they can originate from control signals automatically issued by the electronic device based on the scene. Zoom commands are used to explicitly request that the optical operating state of the lens module be switched from its current state to another target state, i.e., from wide-angle to telephoto, or vice versa.

[0076] Step 420: When the zoom command indicates that the lens module is switched to the first state, the second lens group and the third lens group in the lens module are driven to move along the optical axis to the object side. In response to a zoom command indicating a switch from wide-angle to telephoto mode, the drive mechanism within the lens module is controlled to move the second and third lens groups along the optical axis towards the image side. During this process, the two moving lens groups extend towards the fixed fourth lens group on the image side. For example, the controller drives two motors to push the second and third lens groups towards the image side with different displacements, with the third lens group moving further. The second lens group remains in the middle position, while the third lens group moves to a position adjacent to the fourth lens group, and the entire optical system switches to the longer focal length telephoto mode.

[0077] Step 430: When the zoom command indicates that the lens module is switched to the second state, the second lens group and the third lens group in the lens module are driven to move along the optical axis to the image side.

[0078] In response to a zoom command indicating a switch from telephoto to wide-angle mode, the drive mechanism within the lens module is controlled to move the second and third lens groups along the optical axis towards the object side. During this process, the two moving lens groups approach the fixed first lens group on the object side. For example, according to a preset program, the controller simultaneously sends commands to the micromotors driving the second and third lens groups, causing them to retract towards the object side at a predetermined speed and trajectory until they reach the mechanical positioning point set for the wide-angle mode. At this point, both the second and third lens groups are positioned close to the first lens group, and the entire optical system switches to a wide-angle mode with a shorter focal length.

[0079] When the instruction requires a wider field of view, step 520 retracts the moving lens group to the objective lens end, shortening the effective optical path of the system and thus reducing the equivalent focal length. When the instruction requires a longer telephoto capability, step 530 pushes the moving lens group, especially the third lens group, to the eyepiece end. This not only lengthens the optical path but, more importantly, changes the optical role of the third lens group, making it work with the fourth lens group to form a new eyepiece system, thereby significantly improving the overall equivalent focal length of the system.

[0080] By controlling the coordinated but asynchronous simple linear movements of two groups, reliable switching between two high-performance, aberration-corrected discrete focal length states can be achieved. This is accomplished autonomously by the lens module, providing a stable, fast, and image-quality-assured zoom experience, resolving the conflict between zoom and portability in the lens module, and realizing dynamic reconstruction of the optical architecture.

[0081] In the embodiments of this application, the lens module comprises, sequentially from the object side to the image side along the optical axis: a first lens group, the position of which is fixed during zooming; a second lens group, which is movable along the optical axis; a third lens group, which is movable along the optical axis; and a fourth lens group, the position of which is fixed during zooming. The second and third lens groups are configured to be movable along the optical axis, allowing the lens module to switch between a first state and a second state. By coordinating the axial displacement of the second and third lens groups, the effective length of the optical path and the equivalent optical power of the lens combination can be changed. The focal length of the lens module in the first state is smaller than the focal length of the lens module in the second state. The dual movable lens groups provide more degrees of freedom for adjusting optical parameters, thereby allowing effective optical zoom from a wider field of view to a longer focal length within a relatively compact mechanical travel. Thus, a balance can be achieved between zoom capability, image quality, and portability in the lens module.

[0082] The zoom method provided in this application can be executed by a zoom device. This application uses a zoom device executing the zoom method as an example to illustrate the zoom device provided in this application.

[0083] Figure 5 This is a block diagram of a zoom device provided in an embodiment of this application. The device 500 includes: Receiver module 510 is used to receive zoom commands; The first drive module 520 is used to drive the second lens group and the third lens group in the lens module to move along the optical axis to the object side when the zoom command indicates that the lens module is switched to the first state. The second drive module 530 is used to drive the second lens group and the third lens group in the lens module to move along the optical axis to the image side when the zoom command indicates that the lens module is switched to the second state. In the embodiments of this application, the lens module comprises, sequentially from the object side to the image side along the optical axis: a first lens group, the position of which is fixed during zooming; a second lens group, which is movable along the optical axis; a third lens group, which is movable along the optical axis; and a fourth lens group, the position of which is fixed during zooming. The second and third lens groups are configured to be movable along the optical axis, allowing the lens module to switch between a first state and a second state. By coordinating the axial displacement of the second and third lens groups, the effective length of the optical path and the equivalent optical power of the lens combination can be changed. The focal length of the lens module in the first state is smaller than the focal length of the lens module in the second state. The dual movable lens groups provide more degrees of freedom for adjusting optical parameters, thereby allowing effective optical zoom from a wider field of view to a longer focal length within a relatively compact mechanical travel. Thus, a balance can be achieved between zoom capability, image quality, and portability in the lens module.

[0084] The zoom device in this application embodiment can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices besides a terminal. For example, the electronic device can be a mobile phone, tablet computer, laptop computer, PDA, in-vehicle electronic device, mobile internet device (MID), augmented reality (AR) / virtual reality (VR) device, robot, wearable device, ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA), etc. It can also be a server, network attached storage (NAS), personal computer (PC), television (TV), ATM, or self-service machine, etc. This application embodiment does not specifically limit the scope of the device.

[0085] The zoom device in this application embodiment can be a device with a motion system. The motion system can be an Android motion system, an iOS motion system, or other possible motion systems; this application embodiment does not specifically limit it.

[0086] The zoom device provided in this application embodiment can realize all the processes implemented in the above method embodiments, and will not be described again here to avoid repetition.

[0087] Optionally, such as Figure 6As shown, this application embodiment also provides an electronic device 610, including a processor 611, a memory 612, and a program or instructions stored in the memory 612 and executable on the processor 611. When the program or instructions are executed by the processor 611, they implement the various steps of any of the above zoom method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0088] It should be noted that the electronic devices in the embodiments of this application include the mobile electronic devices and non-mobile electronic devices described above.

[0089] Figure 7 A schematic diagram of the hardware structure of an electronic device to implement an embodiment of this application. The electronic device 700 includes, but is not limited to, components such as: radio frequency unit 701, network module 702, audio output unit 703, input unit 704, sensor 705, display unit 706, user input unit 707, interface unit 708, memory 709, and processor 710.

[0090] Those skilled in the art will understand that the electronic device 700 may also include a power supply (such as a battery) for supplying power to various components. The power supply may be logically connected to the processor 710 through a power management system, thereby enabling functions such as managing charging, discharging, and power consumption through the power management system. Figure 7 The electronic device structure shown does not constitute a limitation on the electronic device. The electronic device may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0091] The processor 710 is used to receive zoom commands; The processor 710 is further configured to drive the second lens group and the third lens group within the lens module to move along the optical axis to the object side when the zoom command instructs the lens module to switch to the first state; The processor 710 is further configured to drive the second lens group and the third lens group within the lens module to move along the optical axis to the image side when the zoom command instructs the lens module to switch to the second state. In the embodiments of this application, the lens module comprises, sequentially from the object side to the image side along the optical axis: a first lens group, the position of which is fixed during zooming; a second lens group, which is movable along the optical axis; a third lens group, which is movable along the optical axis; and a fourth lens group, the position of which is fixed during zooming. The second and third lens groups are configured to be movable along the optical axis, allowing the lens module to switch between a first state and a second state. By coordinating the axial displacement of the second and third lens groups, the effective length of the optical path and the equivalent optical power of the lens combination can be changed. The focal length of the lens module in the first state is smaller than the focal length of the lens module in the second state. The dual movable lens groups provide more degrees of freedom for adjusting optical parameters, thereby allowing effective optical zoom from a wider field of view to a longer focal length within a relatively compact mechanical travel. Thus, a balance can be achieved between zoom capability, image quality, and portability in the lens module.

[0092] It should be understood that, in this embodiment, the input unit 704 may include a graphics processing unit (GPU) 7041 and a microphone 7042. The GPU 7041 processes image data of still images or video images obtained by an image capture device (such as a camera) in video image capture mode or image capture mode. The display unit 706 may include a display panel 7061, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, etc. The user input unit 707 includes at least one of a touch panel 7071 and other input devices 7072. The touch panel 7071 is also called a touch screen. The touch panel 7071 may include a touch detection device and a touch controller. Other input devices 7072 may include, but are not limited to, physical keyboards, function keys (such as volume control buttons, power buttons, etc.), trackballs, mice, and joysticks, which will not be described in detail here. The memory 709 can be used to store software programs and various data, including but not limited to applications and motion systems. Processor 710 can integrate an application processor and a modem processor. The application processor mainly handles the action system, user page, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may also not be integrated into processor 710.

[0093] The memory 709 can be used to store software programs and various data. The memory 709 may primarily include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area may store the operating system, application programs or instructions required for at least one function (such as sound playback, image playback, etc.). Furthermore, the memory 709 may include volatile memory or non-volatile memory, or it may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DRRAM). The memory 709 in the embodiments of this application includes, but is not limited to, these and any other suitable types of memory.

[0094] Processor 710 may include one or more processing units; optionally, processor 710 integrates an application processor and a modem processor, wherein the application processor mainly handles operations involving the operating system, user interface, and applications, and the modem processor mainly handles wireless communication signals, such as a baseband processor. It is understood that the aforementioned modem processor may also not be integrated into processor 710.

[0095] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described zoom method embodiments and achieve the same technical effects. To avoid repetition, they will not be described again here.

[0096] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0097] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above zoom method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0098] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0099] This application provides a computer program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the zoom method embodiment described above, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0100] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0101] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0102] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A lens module, characterized in that, The lens module comprises, along the optical axis from the object side to the image side, the following components in sequence: The first lens group, the position of the first lens group is fixed during zooming; A second lens assembly, which is movable along the optical axis; A third lens group, which is movable along the optical axis; The fourth lens group, the position of which is fixed during zooming; The lens module switches between a first state and a second state by moving the second lens group and the third lens group along the optical axis. The focal length of the lens module in the first state is less than the focal length of the lens module in the second state.

2. The lens module according to claim 1, characterized in that, The first lens group includes at least five lenses, wherein the first lens and the third lens in the first lens group, along the optical axis from the object side to the image side, are made of a low-dispersion material.

3. The lens module according to claim 1, characterized in that, The second lens group includes at least three lenses, wherein the last two lenses of the middle group of the second lens group are cemented together along the optical axis from the object side to the image side to form a first cemented lens.

4. The lens module according to claim 1, characterized in that, The third lens group includes at least three lenses, wherein the first two lenses in the third lens group, along the optical axis from the object side to the image side, are cemented together to form a second cemented lens.

5. The lens module according to claim 1, characterized in that, The fourth lens group includes at least two lenses. The first lens in the fourth lens group, along the optical axis from the object side to the image side, is an aspherical lens with positive optical power.

6. The lens module according to claim 1, characterized in that, The lens module is connected to an electronic device, and the ratio of the focal length of the lens module in the second state to the focal length of the lens module in the first state is between 1.5 and 2.

3. The ratio of the focal length of the lens module in the first state to the focal length of the electronic device is between 1 and 1.

7.

7. The lens module according to claim 1, characterized in that, The ratio of the focal length of the first lens group to the focal length of the fourth lens group is greater than or equal to 25; the ratio of the focal length of the second lens group to the focal length of the third lens group is between 1.5 and 2.

0.

8. The lens module according to claim 1, characterized in that, When the lens module is in the first state, the objective lens system of the lens module includes: the first lens group, the second lens group, and the third lens group; the eyepiece system of the lens module includes the fourth lens group. When the lens module is in the second state, the objective lens system of the lens module includes: the first lens group and the second lens group; the eyepiece system of the lens module includes: the third lens group and the fourth lens group.

9. A zoom method, characterized in that, Performed by an electronic device connected to a lens module, the lens module comprising, sequentially from the object side to the image side along the optical axis: a first lens group, a second lens group, a third lens group, and a fourth lens group; the method includes: Receive zoom commands; When the zoom command instructs the lens module to switch to the first state, the second lens group and the third lens group within the lens module are driven to move along the optical axis to the object side. When the zoom command instructs the lens module to switch to the second state, the second lens group and the third lens group within the lens module are driven to move along the optical axis to the image side.

10. A zoom device, characterized in that, Performed by an electronic device connected to a lens module, the lens module comprising, sequentially from the object side to the image side along the optical axis: a first lens group, a second lens group, a third lens group, and a fourth lens group; the device includes: The receiving module is used to receive zoom commands; The first drive module is used to drive the second lens group and the third lens group in the lens module to move along the optical axis to the object side when the zoom command indicates that the lens module is switched to the first state; The second drive module is used to drive the second lens group and the third lens group within the lens module to move along the optical axis to the image side when the zoom command indicates that the lens module is switched to the second state.

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