Zoom lenses, camera modules and mobile terminals

Abstract

A zoom lens (4), a camera module (40), and a mobile terminal (100) are disclosed. The zoom lens (4) includes a first lens group (G1), a second lens group (G2), and a third lens group (G3) arranged from the object side to the image side. The first lens group (G1) is a fixed lens group with positive optical power; the second lens group (G2) is a zoom lens group with negative optical power; and the third lens group (G3) is a compensating lens group with positive optical power. During the zoom process from the short focal length end to the long focal length end of the zoom lens (4), the second lens group (G2) moves along the optical axis to the image side, and the third lens group (G3) moves along the optical axis to the object side. The zoom lens (4) has better imaging quality.

Description

[0001] This application is a divisional application. The original application has the application number 202180002224.4 and the original application date is March 15, 2021. The entire contents of the original application are incorporated herein by reference.

[0002] This application claims priority to Chinese Patent Application No. 202010183912.2, filed on March 16, 2020, entitled "Zoom Lens, Camera Module and Mobile Terminal", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of terminal technology, and in particular to a zoom lens, a camera module, and a mobile terminal. Background Technology

[0004] In recent years, with the development of technology, consumers have increasingly higher demands for mobile phone photography performance, such as wider zoom range, higher resolution, and higher image quality. These demands place higher requirements on mobile phone lenses, and single-focal-length lenses and digital zoom methods can no longer meet consumers' needs.

[0005] Currently, most high-magnification optical zoom lenses released on the market are "jump zoom," which means they use two or three lenses with different focal lengths, combined with algorithm-based digital zoom, to achieve hybrid optical zoom. However, jump digital zoom is based on multiple cameras with different focal lengths and relies on algorithm processing to achieve continuous zoom, which is not actual continuous zoom. Its disadvantage is that during the zoom process, the image clarity of the disconnected parts outside the focal length range of the multiple cameras is reduced compared to continuous optical zoom, affecting the image quality. Summary of the Invention

[0006] This application provides a zoom lens, a camera module, and a mobile terminal. The zoom lens can achieve continuous zoom to improve image quality.

[0007] In a first aspect, this application provides a zoom lens. The zoom lens includes: a first lens group, a second lens group, and a third lens group arranged along the object side to the image side.

[0008] The first lens group is a fixed lens group with positive optical power. It converges light to compress the beam aperture of the second and third lens groups. The position of the first lens group within the zoom lens is fixed. The second lens group is a zoom lens group with negative optical power. The third lens group is a compensating lens group with positive optical power. The second and third lens groups act as focusing lenses for each other. Both the second and third lens groups are movable along the optical axis of the zoom lens (hereinafter referred to as the optical axis). The second lens group, as the zoom lens group, is used to change the focal length of the optical system. The third lens group, as the compensating lens group, is used to compensate for the image plane position, ensuring that the focal point of the zoom lens falls on the imaging plane of the image sensor. In other words, the third lens group can compensate for the focusing range of the second lens group. The third lens group can also be used to compress the beam angle during zooming to match the principal ray angle of the zoom lens with that of the image sensor. The third lens group can also be used for field curvature correction to correct aberrations.

[0009] During the zoom process from the short focal length end to the long focal length end of the zoom lens, the second lens group moves along the optical axis to the image side, and the third lens group moves along the optical axis to the object side.

[0010] In this application, the zoom lens is equipped with movable second and third lens groups. The zoom lens can continuously zoom by moving the second and third lens groups, thereby obtaining better image quality. Since the second and third lens groups move in opposite directions during the zoom process, the stroke of the motors driving the second and third lens groups can be shortened, thereby reducing the design complexity of the motors, improving the control precision of the motors, and further improving the image quality of the zoom lens.

[0011] Because zoom lenses achieve continuous zoom through only three lens groups, they are easier to assemble due to the smaller number of lens groups. Furthermore, the final lens group in a zoom lens is the third lens group, which can be actively aligned and assembled directly. As the core lens group, the assembly precision of this core lens group is effectively guaranteed, resulting in higher overall assembly accuracy and a higher product yield.

[0012] In one possible implementation, the zoom lens further includes a lens mount, a first lens barrel, a first motor, and a second motor fixed inside the lens mount. A first lens group is fixed inside the first lens barrel. A second lens group is mounted on the first motor, which drives the second lens group to move along the optical axis. A third lens group is mounted on the second motor, which drives the third lens group to move along the optical axis.

[0013] In one possible implementation, the total number N of lenses in the first lens group, the second lens group, and the third lens group satisfies: 6≤N≤11.

[0014] In this implementation, the total number of lenses in the zoom lens is greater than or equal to 6, thus meeting the basic optical requirements of three lens groups and ensuring the imaging quality of the zoom lens. At the same time, the total number of lenses in the zoom lens is less than or equal to 11, which limits the total length (TTL) of the zoom lens, thereby facilitating its miniaturization.

[0015] In one possible implementation, the first lens group includes at least one lens with positive optical power and at least one lens with negative optical power, wherein the lens closest to the object side of the first lens group has positive optical power. The second lens group includes at least one lens, wherein the lens closest to the object side of the second lens group has negative optical power. The third lens group includes at least three lenses, wherein the lens closest to the object side of the third lens group has positive optical power.

[0016] In one possible implementation, the third lens group includes at least one lens with negative optical power. In this case, the lens with negative optical power can diffuse light, thereby enabling the zoom lens to meet the image height requirements and also helping to meet the small aperture size requirements of the third lens group.

[0017] In one possible implementation, the zoom lens includes at least one lens made of glass. That is, the first lens group, the second lens group, and the third lens group all include at least one lens made of glass.

[0018] In this implementation, since the first lens group, the second lens group, and the third lens group are each equipped with at least one lens made of glass, the temperature drift of the zoom lens from -25° to 60° can be controlled within 30μm, thereby improving the focusing experience.

[0019] In one possible implementation, the ratio of the total length TTL of the zoom lens from the surface closest to the object to the imaging plane to the focal length f1 of the first lens group satisfies: 0.7 ≤ TTL / f1 ≤ 3.2. The ratio of the total length TTL of the zoom lens from the surface closest to the object to the imaging plane to the focal length f2 of the second lens group satisfies: -7 ≤ TTL / f2 ≤ -3. The ratio of the total length TTL of the zoom lens from the surface closest to the object to the imaging plane to the focal length f3 of the third lens group satisfies: 1.7 ≤ TTL / f3 ≤ 4.5.

[0020] In this implementation, the zoom lens controls the ratio of the total length TTL to the focal length of the three lens groups within a certain range, thereby achieving better image quality during continuous zooming.

[0021] In one possible implementation, the ratio of the travel distance L1 of the second lens group along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane satisfies: |L1 / TTL|≤0.3.

[0022] In this implementation, since the ratio between the movement stroke L1 of the second lens group and the total length TTL of the zoom lens is less than or equal to 0.3, the movement stroke L1 of the second lens group can be controlled within a small range. The stroke requirement of the motor (i.e., the first motor) that drives the second lens group is low, thereby reducing the design difficulty of the motor, improving the control accuracy of the motor, and further improving the imaging quality of the zoom lens.

[0023] In one possible implementation, the ratio of the travel distance L2 of the third lens group along the optical axis to the total length TTL of the zoom lens from the surface closest to the object to the imaging plane satisfies: |L2 / TTL|≤0.3.

[0024] In this implementation, since the ratio between the motion stroke L2 of the third lens group and the total length TTL of the zoom lens is less than or equal to 0.3, the motion stroke L2 of the third lens group can be controlled within a small range. The stroke requirement of the motor (i.e., the second motor) that drives the third lens group is low, thereby reducing the design difficulty of the motor, improving the control accuracy of the motor, and further improving the imaging quality of the zoom lens.

[0025] In one possible implementation, the ratio of the total length TTL of the zoom lens from the surface closest to the object to the imaging plane to the focal length Fmax at the telephoto end satisfies: |TTL / Fmax|≤2.0.

[0026] In this implementation, the zoom lens can achieve a longer focal length with a shorter total TTL length, thereby effectively reducing the size of the zoom lens while ensuring telephoto shooting, making the zoom lens easier to install and more widely applicable.

[0027] In one possible implementation, the ratio of the focal length Fmax at the telephoto end of the zoom lens to the focal length Fmin at the short focal end satisfies: Fmax / Fmin≤5.0.

[0028] In this implementation, by controlling the ratio of the focal length Fmax at the telephoto end to the focal length Fmin at the short focal length end, the design difficulty and zoom performance requirements of the zoom lens are well balanced, so that the zoom lens can take into account both performance and cost and has better product competitiveness.

[0029] In one possible implementation, each lens of the zoom lens has a notch for reducing the height of the lens.

[0030] Because zoom lenses have notches to reduce their height, the dimensions of the optical system in the height direction can be effectively reduced. This results in zoom lenses with smaller overall dimensions, making them more suitable for miniaturized mobile devices and increasing their applicability. Furthermore, since the lens's height is reduced through the notch, a larger aperture can be incorporated, increasing the amount of light transmitted through the optical system and leading to better image quality.

[0031] In one possible implementation, the ratio of the effective height h of each lens of the zoom lens to the maximum aperture d satisfies: h / d≥0.45.

[0032] In this implementation, the zoom lens controls the ratio of the effective height h of the lens to the maximum light-transmitting aperture d to be greater than or equal to 0.45, so that the zoom lens can reduce the lens height to achieve miniaturization while its light image has better surface shape and resolution.

[0033] In one possible implementation, the effective height h of each lens in the zoom lens satisfies: h ≤ 6.5 mm. In this implementation, by limiting the effective height h of all lenses, the zoom lens restricts the height H of all lenses, allowing the size of the zoom lens to better match the miniaturized mobile terminal.

[0034] In one possible implementation, the maximum aperture d of each lens in the zoom lens satisfies: d ≤ 10mm. In this implementation, by limiting the maximum aperture d of all lenses, the maximum diameter D of all lenses in the zoom lens is restricted, allowing the size of the zoom lens to be better matched to the miniaturized mobile terminal.

[0035] In one possible implementation, the maximum aperture diameter d of each lens in the zoom lens satisfies: d ≤ 6.5 mm. In this case, the zoom lens module size is relatively small, making it well-suited for miniaturized mobile terminals.

[0036] In one possible implementation, the third lens group includes an aperture stop, and the third lens group includes a first lens and a second lens arranged from the object side to the image side. The aperture stop is located on the object side of the first lens of the third lens group, or between the first lens and the second lens of the third lens group.

[0037] In this implementation, by placing the aperture stop in the third lens group, the aperture stop can better confine the light within the optical system, thereby improving the image quality of the zoom lens. In some other implementations, the aperture stop can also be located between the first and second lenses of the third lens group.

[0038] In one possible implementation, the working F-number of the zoom lens satisfies: 2.0 ≤ working F-number ≤ 6.5.

[0039] In this implementation, the working F-number refers to the equivalent aperture F-number of the zoom lens after the lens has been chamfered. When the working F-number meets the above requirements, the zoom lens can achieve better resolution and image quality.

[0040] Secondly, this application also provides a camera module, including an image sensor and a zoom lens as described in any of the preceding claims, wherein light can pass through the zoom lens and illuminate the image sensor. The camera module employing the aforementioned zoom lens can achieve better image quality.

[0041] In one possible implementation, the camera module also includes a prism or reflector located on the object side of the zoom lens to deflect light toward the zoom lens.

[0042] In this implementation, the camera module uses a prism or mirror to change the direction of light propagation, allowing the optical axis of the zoom lens to differ from the direction of external light entering the mobile terminal. This makes the placement, angle, and spatial arrangement of the camera module more flexible, enabling the zoom lens to be used in periscope camera modules. For example, the optical axis of the zoom lens can be parallel to the display screen.

[0043] Thirdly, this application also provides a mobile terminal, including an image processor and a camera module as described in any of the foregoing claims. The image processor is communicatively connected to the camera module and is used to acquire and process image data from the camera module. The camera module of the mobile terminal has better image quality, resulting in a better shooting experience for the user. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure of the mobile terminal provided in some embodiments of this application;

[0045] Figure 2 yes Figure 1 The diagram shows a partial structural view of the mobile terminal cut along line AA.

[0046] Figure 3 yes Figure 2 A schematic diagram of the zoom lens of the camera module shown.

[0047] Figure 4 yes Figure 3 The diagram shows a partial structural schematic of the zoom lens in some embodiments.

[0048] Figure 5 yes Figure 4A schematic diagram of the zoom process of the zoom lens shown.

[0049] Figure 6 yes Figure 4 A schematic diagram of the structure of a lens in the first lens group of the zoom lens shown.

[0050] Figure 7 yes Figure 6 A schematic diagram of the lens structure at another angle is shown;

[0051] Figure 8 yes Figure 4 A schematic diagram of the structure of a lens in the second lens group of the zoom lens shown.

[0052] Figure 9 yes Figure 4 The zoom lens shown has an axial spherical aberration curve at the first magnification.

[0053] Figure 10 yes Figure 4 The distortion curve of the zoom lens shown is at the first magnification.

[0054] Figure 11 yes Figure 4 The zoom lens shown has an axial spherical aberration curve at the second magnification.

[0055] Figure 12 yes Figure 4 The distortion curve of the zoom lens shown is at the second magnification.

[0056] Figure 13 yes Figure 4 The zoom lens shown has an axial spherical aberration curve at the third magnification.

[0057] Figure 14 yes Figure 4 The distortion curve of the zoom lens shown is at the third magnification.

[0058] Figure 15 yes Figure 4 The zoom lens shown has an axial spherical aberration curve at the fourth magnification.

[0059] Figure 16 yes Figure 4 The distortion curve of the zoom lens shown is at the fourth magnification.

[0060] Figure 17 yes Figure 3 The diagram shows a partial structural schematic of the zoom lens in some other embodiments;

[0061] Figure 18 yes Figure 17 A schematic diagram of the zoom process of the zoom lens shown.

[0062] Figure 19yes Figure 17 The zoom lens shown has an axial spherical aberration curve at the first magnification.

[0063] Figure 20 yes Figure 17 The distortion curve of the zoom lens shown is at the first magnification.

[0064] Figure 21 yes Figure 17 The zoom lens shown has an axial spherical aberration curve at the second magnification.

[0065] Figure 22 yes Figure 17 The distortion curve of the zoom lens shown is at the second magnification.

[0066] Figure 23 yes Figure 17 The zoom lens shown has an axial spherical aberration curve at the third magnification.

[0067] Figure 24 yes Figure 17 The distortion curve of the zoom lens shown is at the third magnification.

[0068] Figure 25 This is a schematic diagram of the structure of the mobile terminal provided in this application embodiment in other embodiments;

[0069] Figure 26 yes Figure 25 A schematic diagram of the portion of the mobile terminal cut along line BB.

[0070] Figure 27 yes Figure 26 The diagram shows a partial structural schematic of the camera module in some embodiments.

[0071] Figure 28 yes Figure 26 The diagram shows a partial structural schematic of the camera module in some other embodiments. Detailed Implementation

[0072] The embodiments of this application are described below with reference to the accompanying drawings.

[0073] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0074] Optical power is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam; it characterizes the ability of an optical system to deflect light rays.

[0075] A lens or lens group with positive optical power, having a positive focal length, and having the effect of converging light rays;

[0076] A lens or lens group with negative optical power has a negative focal length and has the effect of diverging light.

[0077] Focal length, also known as focal length, is a measure of the convergence or divergence of light in an optical system. It refers to the perpendicular distance from the optical center of a lens or lens group to the focal plane when a distant object is focused into a sharp image. From a practical perspective, it can be understood as the distance from the center of the lens to the focal plane. For prime lenses, the position of their optical center remains constant; for zoom lenses, changes in the optical center result in changes in the focal length.

[0078] Using a lens or lens group as a boundary, the side where the subject is located is called the object side, and the side where the image of the subject is located is called the image side; the surface of the lens closer to the object side can be called the object side surface, and the surface of the lens closer to the image side can be called the image side surface.

[0079] The aperture, also known as the diaphragm, is a device used to control the amount of light passing through the lens and entering the sensor inside the camera body. It is usually located inside the lens.

[0080] The aperture F-number (also known as the F-value) is a relative value derived from the lens's focal length and the diameter of the light passing through it (the reciprocal of the relative aperture). A smaller F-number allows more light to enter the lens in the same unit of time. A larger F-number results in a shallower depth of field, blurring the background and creating an effect similar to a telephoto lens.

[0081] The working F-number (also known as the working F-value) is a relative value derived from the lens's focal length divided by its light-gathering diameter (the reciprocal of the relative aperture). It is often used in optical systems where light is blocked. A smaller working F-number allows more light to enter the lens per unit of time. A larger working F-number results in a shallower depth of field, blurring the background and creating an effect similar to a telephoto lens.

[0082] Total track length (TTL) refers to the total length from the surface of the lens closest to the object to the image plane. TTL is a major factor in determining camera height.

[0083] The imaging plane is located on the image side of all lenses in a zoom lens, and is the surface on which the image is formed after light passes through each lens in the zoom lens in sequence.

[0084] The optical axis is a line that passes perpendicularly through the center of a lens. The optical axis of a lens is a line that passes through the center of the lens. When light rays parallel to the optical axis enter a convex lens, an ideal convex lens should converge all the light rays to a single point behind the lens; this point where all the light rays converge is called the focal point.

[0085] The Abbe coefficient, also known as the dispersion coefficient, is the ratio of the difference in refractive index of an optical material at different wavelengths, representing the degree of dispersion of the material.

[0086] Spherical aberration, also known as spherical image aberration, is the difference between the position of the actual image point and the ideal image point.

[0087] On-axis spherical aberration is the difference between the position of the actual image point and the ideal image point in the direction parallel to the optical axis.

[0088] Distortion, also known as image distortion, refers to the degree of distortion in the image formed by an optical system relative to the object itself. Distortion occurs due to the spherical aberration of the aperture. The height of the intersection point between the principal ray from different fields of view and the Gaussian image plane is not equal to the ideal image height; this difference is the distortion. Therefore, distortion only changes the imaging position of an off-axis object point on the ideal plane, causing a distortion in the image shape, but it does not affect the image's sharpness.

[0089] This application provides a zoom lens, a camera module using the zoom lens, and a mobile terminal including the camera module. The zoom lens includes three lens groups arranged sequentially from the object side to the image side. The second and third lens groups are movable along the optical axis, enabling continuous zooming to achieve better image quality. Furthermore, during zooming from the short focal length to the long focal length, the two middle lens groups move closer to each other to achieve zoom. Because the two lens groups move in opposite directions, the motor stroke can be shortened, thereby reducing the design complexity of the motor, improving the control precision of the motor, and further improving the image quality of the zoom lens. The mobile terminal can be a mobile phone, tablet computer, laptop, or other device with photo or video recording capabilities.

[0090] Please refer to the following: Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the mobile terminal 100 provided in some embodiments of this application. Figure 2 yes Figure 1 The diagram shows a partial structural view of the mobile terminal 100 cut along line AA. In this embodiment, the mobile terminal 100 is described as a mobile phone.

[0091] The mobile terminal 100 includes a housing 10, a display screen 20, an image processor 30, and a camera module 40. In some embodiments, the housing 10 includes a frame 101 and a back cover 102. The frame 101 and the back cover 102 can be integrally formed or assembled into an integral structure. The display screen 20 and the back cover 102 are respectively mounted on both sides of the frame 101, together enclosing the internal cavity 50 of the entire device.

[0092] The image processor 30 and the camera module 40 are housed within the internal cavity 50 of the entire device. The image processor 30 is communicatively connected to the camera module 40, and is used to acquire and process image data from the camera module 40. The communication connection between the camera module 40 and the image processor 30 can include data transmission via electrical connections such as wiring, or data transmission via coupling. It is understood that the camera module 40 and the image processor 30 can also be connected via other methods capable of data transmission.

[0093] The function of the image processor 30 is to optimize the digital image signal through a series of complex mathematical algorithms, and finally transmit the processed signal to the display. The image processor 30 can be an image processing chip or a digital signal processing chip. Its role is to transmit the data obtained by the photosensitive chip to the central processing unit in a timely and fast manner and refresh the photosensitive chip. Therefore, the quality of the image processor 30 chip directly affects the image quality (such as color saturation, sharpness, etc.).

[0094] In this embodiment, the back cover 102 is provided with a camera hole 103, through which the camera module 40 collects light, serving as the rear camera of the mobile terminal 100. Exemplarily, the back cover 102 includes a light-transmitting lens 104, which is mounted on the camera hole 103 to allow light to pass through and to provide dust and water resistance. In other embodiments, the camera module 40 may also serve as the front camera of the mobile terminal 100.

[0095] Understandable Figure 1 The installation position of the camera module 40 in the illustrated embodiment of the mobile terminal 100 is merely illustrative, and this application does not strictly limit the installation position of the camera module 40. In some other embodiments, the camera module 40 may also be installed in other locations on the mobile terminal 100, such as the upper middle or upper right corner of the back of the mobile terminal 100. In some other embodiments, the mobile terminal 100 may include a terminal body and an auxiliary component that can rotate, move, or be detached relative to the terminal body, and the camera module 40 may also be disposed on the auxiliary component.

[0096] In some embodiments, the mobile terminal 100 may further include an analog-to-digital converter (also known as an A / D converter, not shown in the figure). The analog-to-digital converter is connected between the camera module 40 and the image processor 30. The analog-to-digital converter is used to convert the signal generated by the camera module 40 into a digital image signal and transmit it to the image processor 30. The image processor 30 then processes the digital image signal and finally displays the image or video on the display screen 20.

[0097] In some embodiments, the mobile terminal 100 may further include a memory (not shown in the figure), which is communicatively connected to the image processor 30. The image processor 30 processes the digital image signal and then transmits the image to the memory, so that the image can be retrieved from the memory and displayed on the display screen 20 at any time when it is needed to view the image later. In some embodiments, the image processor 30 may also compress the processed digital image signal before storing it in the memory to save memory space.

[0098] like Figure 2 As shown, in some embodiments, the camera module 40 includes a circuit board 1, an image sensor 2, a holder 3, a zoom lens 4, and a filter 5. The holder 3 is fixed to the circuit board 1, and the image sensor 2 is fixed to the circuit board 1 and located inside the holder 3. The zoom lens 4 is mounted on the holder 3 and located on the side of the image sensor 2 facing away from the circuit board 1. The image sensor 2 is located on the image side of the zoom lens 4. The filter 5 is mounted on the holder 3 and located between the zoom lens 4 and the image sensor 2. Light can pass through the zoom lens 4 and illuminate the imaging surface 21 of the image sensor 2. Exemplarily, the working principle of the camera module 40 is as follows: the light reflected from the subject passes through the zoom lens 4 to generate an optical image, which is projected onto the imaging surface 21 of the image sensor 2. The image sensor 2 converts the optical image into an electrical signal, i.e., an analog image signal, and transmits it to an analog-to-digital converter (ADC) to convert it into a digital image signal for the image processor 30.

[0099] Image sensor 2 (also known as a photosensitive element) is a semiconductor chip containing hundreds of thousands to millions of photodiodes on its surface. When illuminated, these photodiodes generate electrical charges. Image sensor 2 can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device. CCDs are made using a highly sensitive semiconductor material that converts light into electrical charges. They consist of many photosensitive units, typically measured in megapixels. When light illuminates the surface of a CCD, each photosensitive unit reflects a charge onto the component. The signals generated by all the photosensitive units are combined to form a complete image. CMOS devices primarily utilize semiconductors made of silicon and germanium, allowing N-type (negative) and P-type (positive) semiconductors to coexist. The current generated by these complementary effects can be recorded and interpreted by the processing chip as an image.

[0100] The zoom lens 4 affects the image quality and imaging effect. It mainly uses the refraction principle of the lens to form an image, that is, the light of the scene passes through the zoom lens 4 and forms a clear image on the focal plane, and the image of the scene is recorded by the image sensor 2 located on the focal plane.

[0101] The filter 5 is used to eliminate unwanted light projected onto the image sensor 2, preventing the image sensor 2 from producing false colors or ripples, thereby improving its effective resolution and color reproduction. For example, the filter 5 can be an infrared filter 5.

[0102] Please see Figure 3 , Figure 3 yes Figure 2 The diagram shows the structure of the zoom lens 4 in the camera module 40. Figure 3 The diagram simplifies the structure of all the lenses in the lens group of zoom lens 4 into a single lens. Figure 3 The structure does not impose limitations on the number and shape of lenses in the lens group.

[0103] In some embodiments, the zoom lens 4 includes a first lens group G1, a second lens group G2, and a third lens group G3 arranged from the object side to the image side. The first lens group G1 is a fixed lens group with positive optical power. The first lens group G1 can converge light to compress the beam aperture of the second lens group G2 and the third lens group G3. The position of the first lens group G1 in the zoom lens 4 is fixed. The second lens group G2 is a zoom lens group with negative optical power, and the third lens group G3 is a compensating lens group with positive optical power. The second lens group G2 and the third lens group G3 are focusing lens groups for each other. Both the second lens group G2 and the third lens group G3 can be moved along the optical axis 401 (hereinafter referred to as the optical axis 401) of the zoom lens 4. The second lens group G2 is a zoom lens group used to change the focal length of the optical system. The third lens group G3 is a compensating lens group used to compensate for the image plane position so that the focal point of the zoom lens 4 falls on the imaging plane 21 of the image sensor 2. In other words, the third lens group G3 can compensate for the focusing range of the second lens group G2. The third lens group G3 can also be used to compress the beam angle during zooming so that the chief ray angle (CRA) of the zoom lens 4 matches the chief ray angle of the image sensor 2. The third lens group G3 can also be used for field curvature correction to correct aberrations.

[0104] In this embodiment, the zoom lens 4 is provided with a movable second lens group G2 and a third lens group G3. The zoom lens 4 can perform continuous zoom by moving the second lens group G2 and the third lens group G3, thereby obtaining better image quality. Since the zoom lens 4 can achieve continuous zoom through three lens groups, the zoom lens 4 has fewer lens groups, making it easier to assemble. In addition, the last lens group of the zoom lens 4 is the third lens group G3. The zoom lens 4 can directly perform active alignment (AA) assembly on the third lens group G3. The third lens group G3 is the core lens group of the zoom lens 4, so the assembly accuracy of the core lens group of the zoom lens 4 can be effectively guaranteed, resulting in higher overall assembly accuracy and higher product yield of the zoom lens 4.

[0105] In some embodiments, the zoom lens 4 further includes a lens mount 402, a first lens barrel 403 fixed inside the lens mount 402, a first motor 404, and a second motor 405. A first lens group G1 is fixed inside the first lens barrel 403. A second lens group G2 is mounted on the first motor 404, which drives the second lens group G2 to move along the optical axis 401. A third lens group G3 is mounted on the second motor 405, which drives the third lens group G3 to move along the optical axis 401. It is understood that the first motor 404 and the second motor 405 can be of the same or different types. Other designs are also possible for the structure in the zoom lens 4 for mounting multiple lens groups, and this application does not impose strict limitations on these designs.

[0106] Please see Figure 4 , Figure 4 yes Figure 3 The diagram shows a partial structural schematic of the zoom lens 4 in some embodiments. Figure 4 The diagram mainly illustrates the structure of multiple lens groups of the zoom lens 4. For ease of explanation, the filter 5 and imaging surface 21 of the camera module 40 are also shown.

[0107] In some embodiments, the total number N of lenses in the first lens group G1, the second lens group G2, and the third lens group G3 satisfies: 6 ≤ N ≤ 11. For example, ... Figure 4 As shown, the zoom lens 4 has a total of 8 lenses in its three lens groups. In some other embodiments, the total number N of lenses N in the three lens groups of the zoom lens 4 can also be 6, 7, 9, 10, or 11. It is understood that in the embodiments of this application, the lenses in the zoom lens 4 are all lenses with positive or negative optical power. When a plane mirror is inserted between multiple lenses, the plane mirror is not considered as a lens of the zoom lens 4.

[0108] In this embodiment, the total number of lenses in the zoom lens 4 is greater than or equal to 6, thereby meeting the basic optical requirements of the three lens groups and ensuring the imaging quality of the zoom lens 4. At the same time, the total number of lenses in the zoom lens 4 is less than or equal to 11, which limits the total length (TTL) of the zoom lens 4, thus facilitating its miniaturization.

[0109] In some embodiments, the first lens group G1 includes at least one lens with positive optical power and at least one lens with negative optical power, wherein the lens closest to the object side of the first lens group G1 has positive optical power. For example, Figure 4 As shown, the first lens group G1 may include two lenses, and the optical powers of the two lenses may be one positive and one negative. The lens 41, which is closer to the object side, has a positive optical power, and the lens 42, which is closer to the image side, has a negative optical power. In some other embodiments, the first lens group G1 may include three lenses, and the optical powers of the three lenses may be two positive and one negative, or one positive and two negative. The lens closest to the object side among the three lenses has a positive optical power. The optical surfaces of the lenses in the first lens group G1 may be spherical or aspherical. Each lens includes two optical surfaces, one facing the object side (object-side surface) and the other facing the image side (image-side surface).

[0110] In some embodiments, the second lens group G2 includes at least one lens, and the lens closest to the object side of the second lens group G2 has negative optical power. For example, Figure 4 As shown, the second lens group G2 may include two lenses: lens 43, which is closer to the object side, has negative optical power, and lens 44, which is closer to the image side, may have positive or negative optical power. The optical surfaces of the lenses in the second lens group G2 may be spherical or aspherical. In some other embodiments, the second lens group G2 may also include one, three, or four lenses.

[0111] In some embodiments, the third lens group G3 includes at least three lenses, with the lens closest to the object side having positive optical power. Alternatively, the third lens group G3 may include at least one lens with negative optical power. In this case, the lens with negative optical power can diffuse light, thereby enabling the zoom lens 4 to meet the image height requirements and also facilitating the small aperture size requirement of the third lens group G3.

[0112] For example, such as Figure 4 As shown, the third lens group G3 may include four lenses. The lens 45, which is closest to the object side, has positive optical power; the lens 48, which is closest to the image side, has negative optical power; the lens 46, which is in the middle, has positive optical power; and the lens 47 has negative optical power. In some other embodiments, the third lens group G3 may also include three or five lenses.

[0113] In some embodiments, the ratio of the total length TTL of the zoom lens 4 from the surface closest to the object side to the imaging plane 21 to the focal length f1 of the first lens group G1 satisfies: 0.7 ≤ TTL / f1 ≤ 3.2. For example, the value of TTL / f1 can be 0.7, 0.9, 1.5, 1.69, 2.26, 2.8, 3.0, 3.2, etc.

[0114] The ratio of the total length TTL of the zoom lens 4 from the surface closest to the object to the imaging plane 21 to the focal length f2 of the second lens group G2 satisfies: -7≤TTL / f2≤-3. For example, the value of TTL / f2 can be -7, -5, -4.6, -4.2, -3.5, -3, etc.

[0115] The ratio of the total length TTL of the zoom lens 4 from the surface closest to the object to the imaging plane 21 to the focal length f3 of the third lens group G3 satisfies: 1.7 ≤ TTL / f3 ≤ 4.5. For example, the value of TTL / f3 can be 1.7, 2.3, 3.2, 3.6, 3.89, 4.23, 4.5, etc.

[0116] In this embodiment, the zoom lens 4 controls the ratio of the total length TTL to the focal length of the three lens groups within a certain range, thereby achieving better image quality during continuous zooming.

[0117] In some embodiments, the zoom lens 4 includes at least one lens made of glass. That is, the first lens group G1, the second lens group G2, and the third lens group G3 each include at least one lens made of glass. In this embodiment, because the first lens group G1, the second lens group G2, and the third lens group G3 are each provided with at least one lens made of glass, the temperature drift of the zoom lens 4 in the range of -25°C to 60°C can be controlled within 30μm, thereby improving the focusing experience.

[0118] In this embodiment, the optical surface of the lens made of glass can be spherical or aspherical. In some embodiments, the first and second lenses of the first lens group G1, arranged from the object side to the image side, can be made of glass. In other embodiments, the lens of the third lens group G3 closest to the object side can be made of glass.

[0119] In this zoom lens 4, the remaining lenses can be made of plastic, and their optical surfaces can all be aspherical. The aspherical design can improve the image quality of the zoom lens 4. In some other embodiments, the optical surfaces of the plastic lenses of the zoom lens 4 can also be partially spherical, partially aspherical, or entirely spherical.

[0120] In some embodiments, such as Figure 4As shown, the third lens group G3 includes an aperture stop 49. The third lens group G3 includes a first lens 45 and a second lens 46 arranged from the object side to the image side. The aperture stop 49 is located on the object side of the first lens 45 of the third lens group G3. In this embodiment, by placing the aperture stop 49 in the third lens group G3, the aperture stop 49 can better confine the light within the optical system, improving the image quality of the zoom lens 4. In some other embodiments, the aperture stop 49 may also be located between the first lens 45 and the second lens 46 of the third lens group G3.

[0121] In some embodiments, the total length TTL of the zoom lens 4 satisfies: TTL≤45mm, which is beneficial to the miniaturization of the zoom lens 4 and enables the zoom lens 4 to be better applied to the miniaturized mobile terminal 100.

[0122] Please see Figure 5 , Figure 5 yes Figure 4 The diagram shows the structure of the zoom process of the zoom lens 4. Wherein, Figure 5 The diagram mainly illustrates the structure of the lens group of the zoom lens 4. For ease of explanation, the filter 5 and the imaging surface 21 of the camera module 40 are also shown.

[0123] Figure 5 The diagram illustrates the four focal length states of the zoom lens 4, including the first magnification (i.e., the short focal length end), the second magnification (i.e., the first intermediate magnification), the third magnification (i.e., the second intermediate magnification), and the fourth magnification (i.e., the long focal length end). As the zoom lens 4 is adjusted from the first magnification to the fourth magnification, the focal length increases.

[0124] like Figure 5 As shown, in some embodiments, during the zoom process of the zoom lens 4 from the short focal length end to the long focal length end, the second lens group G2 moves towards the image side along the optical axis 401, and the third lens group G3 moves towards the object side along the optical axis 401. That is, during the zoom process of the zoom lens 4 from the short focal length end to the long focal length end, the second lens group G2 and the third lens group G3 move towards each other, and their directions of movement are opposite.

[0125] During the zoom process of zoom lens 4 from the telephoto end to the short focal length end, the second lens group G2 moves towards the object side along the optical axis 401, and the third lens group G3 moves towards the image side along the optical axis 401. That is, during the zoom process of zoom lens 4 from the short focal length end to the telephoto end, the second lens group G2 and the third lens group G3 move away from each other, and their directions of movement are opposite.

[0126] In this embodiment, since the second lens group G2 and the third lens group G3 move in opposite directions during the zoom process, the stroke of the motor (i.e., the first motor 404) used to drive the second lens group G2 and the stroke of the motor (i.e., the second motor 405) used to drive the third lens group G3 can be shortened, thereby reducing the design difficulty of the motor, improving the control precision of the motor, and further improving the imaging quality of the zoom lens 4.

[0127] In some embodiments, the ratio of the movement distance L1 of the second lens group G2 along the optical axis 401 to the total length TTL of the zoom lens 4 from the surface closest to the object side to the imaging plane 21 satisfies: |L1 / TTL|≤0.3. For example, the ratio of the movement distance L1 of the second lens group G2 along the optical axis 401 to the total length TTL of the zoom lens 4 can satisfy: 0.05≤|L1 / TTL|≤0.15. For instance, the value of |L1 / TTL| can be 0.075, 0.08, 0.095, 0.12, 0.16, 0.25, 0.3, etc.

[0128] In this embodiment, since the ratio between the movement stroke L1 of the second lens group G2 and the total length TTL of the zoom lens 4 is less than or equal to 0.3, the movement stroke L1 of the second lens group G2 can be controlled within a small range. The stroke requirement of the motor (i.e., the first motor 404) that drives the second lens group G2 is low, thereby reducing the design difficulty of the motor, improving the control accuracy of the motor, and further improving the imaging quality of the zoom lens 4.

[0129] In some embodiments, the ratio of the travel distance L2 of the third lens group G3 along the optical axis 401 to the total length TTL of the zoom lens 4 from the surface closest to the object side to the imaging plane 21 satisfies: |L2 / TTL|≤0.3. For example, the ratio of the travel distance L2 of the third lens group G3 along the optical axis 401 to the total length TTL of the zoom lens 4 can satisfy: 0.07≤|L2 / TTL|≤0.15. For instance, the value of |L2 / TTL| can be 0.084, 0.09, 0.13, 0.156, 0.23, 0.26, 0.3, etc.

[0130] In this embodiment, since the ratio between the movement stroke L2 of the third lens group G3 and the total length TTL of the zoom lens 4 is less than or equal to 0.3, the movement stroke L2 of the third lens group G3 can be controlled within a small range. The stroke requirement of the motor (i.e., the second motor 405) that drives the third lens group G3 to move is low, thereby reducing the design difficulty of the motor, improving the control accuracy of the motor, and further improving the imaging quality of the zoom lens 4.

[0131] In some embodiments, the ratio of the total length TTL of the zoom lens 4 from the surface closest to the object to the imaging plane 21 to the focal length Fmax at the telephoto end satisfies: |TTL / Fmax|≤2.0. For example, the value of |TTL / Fmax| can be 0.82, 0.934, 0.96, 1.21, 1.3, 1.42, 1.5, 1.7, 2.0, etc.

[0132] In this embodiment, the zoom lens 4 can achieve a longer focal length with a shorter total TTL length, thereby effectively reducing the size of the zoom lens 4 while ensuring telephoto shooting, making the zoom lens 4 easier to install and more widely applicable.

[0133] In some embodiments, the ratio of the focal length Fmax at the telephoto end to the focal length Fmin at the short focal end of the zoom lens 4 satisfies the condition: Fmax / Fmin ≤ 5.0. For example, the value of Fmax / Fmin can be 2.5, 3.3, 3.7, 4.2, 5, etc.

[0134] In this embodiment, by controlling the ratio of the focal length Fmax at the telephoto end to the focal length Fmin at the short focal length end, the design difficulty and zoom performance requirements of the zoom lens 4 are well balanced, so that the zoom lens 4 takes into account both performance and cost, and has better product competitiveness.

[0135] Please refer to the following: Figure 6 and Figure 7 , Figure 6 yes Figure 4 The diagram shows the structure of a lens 41 in the first lens group G1 of the zoom lens 4. Figure 7 yes Figure 6 The diagram shows the structure of the lens at another angle.

[0136] In some embodiments, lens 41 includes an effective optical region 41a and a non-effective optical region 41b surrounding the effective optical region 41a. The effective optical region 41a is the area used to deflect light rays. The effective optical region 41a is also the region containing the effective optical path. The non-effective optical region 41b is the area not used to deflect light rays but can be used for lens support or mounting. The non-effective optical region 41b is also the region containing the non-effective optical path. The effective and non-effective optical regions of other lenses in zoom lens 4 are defined in the same way.

[0137] In some embodiments, each lens of the first lens group G1 has a notch for reducing the lens height. The notch portion of each lens in the first lens group G1 is located in the effective optical region and the portion is located in the ineffective optical region. For example... Figure 7As shown, the lens 41 of the first lens group G1 has a notch 411. There are two notches 411, located on opposite sides of the lens 41, with the notch planes parallel to each other. The height H of the lens 41 is the dimension of the entire lens 41 in the vertical direction of the notch plane. The effective height h of the lens 41 is the dimension of the effective optical area 41a of the lens 41 in the vertical direction of the notch plane. Figure 7 The effective height h of the lens 41 shown is the same as its height H. The maximum aperture d of the lens 41 is the maximum diameter of the effective optical area 41a of the lens 41. The maximum diameter D of the lens 41 is the overall diameter of the lens. The effective height h, height H, maximum aperture d, and maximum diameter D of the other lenses in the zoom lens 4 are defined in the same way. In some other embodiments, the number of notches 411 may also be one.

[0138] In this embodiment, since the lens of the first lens group G1 is relatively large, the cut-out part is located in the effective optical area and part is located in the non-effective optical area. Although it will reduce the image resolution and illumination of the zoom lens 4 to a certain extent, it can significantly reduce the height of the lens of the first lens group G1, thereby significantly reducing the height of the zoom lens 4, which is beneficial to the miniaturization of the zoom lens 4.

[0139] Please see Figure 8 , Figure 8 yes Figure 4 A schematic diagram of the structure of a lens 43 in the second lens group G2 of the zoom lens 4 shown.

[0140] In some embodiments, each lens of the second lens group G2 has a notch for reducing the lens height. The notches of each lens in the second lens group G2 are located in a non-effective optical area. For example... Figure 8 As shown, the lens 43 of the second lens group G2 has a notch 431. There are two notches 431, located on opposite sides of the lens 43, with their planes parallel to each other. The notches 431 are located in the non-effective optical region 43b of the lens 43. In some other embodiments, there may be only one notch 431.

[0141] In this embodiment, since the lens of the second lens group G2 is smaller in size and the cut of the second lens group G2 is not in the effective optical area, the cut on the lens can reduce the height of the lens of the second lens group G2 without affecting the imaging quality of the zoom lens 4.

[0142] like Figure 8As shown, in this embodiment, the effective height h of lens 43 in the second lens group G2 is equal to the maximum aperture d. The direction of the effective height h of lens 43 in the second lens group G2 is the same as the direction of the effective height h of lens 41 in the first lens group G1. The effective height h of lens 43 is less than the height H of lens 43.

[0143] In some embodiments, each lens of the third lens group G3 has a notch for reducing the lens height. The notches of each lens in the third lens group G3 are located in a non-effective optical area. In this embodiment, because the lenses of the third lens group G3 are small in size, and the notches of the third lens group G3 are located in a non-effective optical area, the lens notches can reduce the height of the lenses in the second lens group G2 without affecting the image quality of the zoom lens 4.

[0144] In some embodiments, as described above, each lens of the zoom lens 4 has a notch for reducing the lens height. The notch can be implemented using an I-CUT process. Because the lenses in the zoom lens 4 have notches for reducing their height, the dimensions of the optical system in the height direction can be effectively reduced, resulting in a smaller height dimension for the zoom lens 4, making it more suitable for miniaturized mobile terminals 100 and increasing its applicability. Furthermore, because the lens height is reduced through the notch, the lens can have a larger aperture, thereby increasing the light transmission of the optical system and resulting in better image quality from the zoom lens 4.

[0145] In some embodiments, the ratio of the effective height h of each lens of the zoom lens 4 to the maximum aperture d satisfies: h / d ≥ 0.45. For example, the value of h / d can be 0.45, 0.5, 0.52, 0.6, 0.68, 0.8, etc. Figure 7 and Figure 8 As shown, the effective height h and maximum aperture d of lenses 41 and 43 meet the above requirements. Similarly, the effective height h and maximum aperture d of the other lenses in the zoom lens 4 also meet the above requirements.

[0146] In this embodiment, the zoom lens 4 controls the ratio of the effective height h of the lens to the maximum light-transmitting aperture d to be greater than or equal to 0.45, so that the zoom lens 4 can reduce the lens height to achieve miniaturization while its light image has better surface shape and better resolution.

[0147] In some embodiments, the effective height h of each lens of the zoom lens 4 satisfies the condition: h ≤ 6.5 mm. For example, the effective height h of the lens can be 3.8 mm, 4 mm, 4.4 mm, 4.8 mm, 5.5 mm, 6.2 mm, 6.5 mm, etc. In this embodiment, by limiting the effective height h of all lenses, the zoom lens 4 restricts the height H of all lenses, allowing the size of the zoom lens 4 to better match the miniaturized mobile terminal 100.

[0148] In some embodiments, the maximum aperture d of each lens in the zoom lens 4 satisfies the condition: d ≤ 10 mm. For example, the maximum aperture d of the lens can be 7 mm, 7.2 mm, 8 mm, 8.5 mm, 9.2 mm, 10 mm, etc. In this embodiment, by limiting the maximum aperture d of all lenses, the zoom lens 4 restricts the maximum diameter D of all lenses, allowing the size of the zoom lens 4 to better match the miniaturized mobile terminal 100.

[0149] In some embodiments, the working F-number of the zoom lens 4 satisfies the following condition: 2.0 ≤ working F-number ≤ 6.5. In this embodiment, the working F-number refers to the equivalent aperture F-number of the lens of the zoom lens 4 after the lens has been chamfered. When the working F-number meets the above requirement, the zoom lens 4 can achieve better resolution and image quality. For example, the working F-number of the zoom lens 4 can be 2.0 at the short focal length end and 6.5 at the long focal length end. When the zoom lens 4 is in other magnification states, the working F-number can be 2.8, 2.9, 3.1, 3.5, 3.6, 3.75, 3.8, 3.9, 4.2, 4.45, 4.8, 5.6, etc.

[0150] In some other embodiments, the lenses of the zoom lens 4 may not have a notch, and the lenses may be circular. The maximum aperture diameter d of each lens in the zoom lens 4 satisfies the condition: d ≤ 6.5 mm. For example, the maximum aperture diameter d of the lens can be 3.8 mm, 4 mm, 4.4 mm, 4.8 mm, 5.5 mm, 6.2 mm, 6.5 mm, etc. In this case, the module size of the zoom lens 4 is relatively small, making it well-suited for miniaturized mobile terminals 100.

[0151] To facilitate understanding of the effect of the zoom lens 4 provided in the embodiments of this application, the imaging effect of the zoom lens 4 will be described in detail below with reference to specific embodiments.

[0152] In some embodiments, please refer again Figure 4The zoom lens 4 comprises multiple lens groups from the object side to the image side as follows: a first lens group G1 with positive optical power, the ratio of the total length TTL of the zoom lens 4 to the focal length f1 of the first lens group G1 is TTL / f1 = 2.14; a second lens group G2 with negative optical power, the ratio of the total length TTL of the zoom lens 4 to the focal length f2 of the second lens group G2 is TTL / f2 = -6.22; and a third lens group G3 with positive optical power, the ratio of the total length TTL of the zoom lens 4 to the focal length f3 of the third lens group G3 is TTL / f3 = 3.83.

[0153] The zoom lens 4 comprises eight lenses with optical power, all of which are aspherical. The first lens group G1 contains two lenses (41 and 42), with positive and negative optical powers respectively along the object-to-image direction. The second lens group G2 contains two lenses (43 and 44), with negative and positive optical powers respectively along the object-to-image direction. The third lens group G3 contains four lenses (45, 46, 47, and 48), with positive, positive, negative, and negative optical powers respectively along the object-to-image direction. The third lens group G3 includes an aperture stop 49, located on the object side of the lens 45 closest to the object side of the third lens group G3. Both lenses in the first lens group G1 are made of glass, while the other lenses in the zoom lens 4 are made of plastic. The maximum effective height h of all lenses in zoom lens 4 is 4.6 mm. The maximum aperture d of all lenses in zoom lens 4 is 7 mm.

[0154] Please refer to Tables 1a and 1b. Table 1a shows the radius of curvature, spacing, refractive index (Nd), and Abbe coefficient (Vd) of each lens and filter 5 of the zoom lens 4 in the first magnification (short focal length) state. The spacing includes the thickness (corresponding to d1 to d9) and the distance between the lenses (corresponding to a1 to a9). Table 1b shows the aspherical coefficients of each lens.

[0155] Table 1a

[0156]

[0157]

[0158] Table 1b

[0159] <![CDATA[A2]]> <![CDATA[A3]]> <![CDATA[A4]]> <![CDATA[A5]]> <![CDATA[A6]]> S1 2.4431E-04 -1.3605E-05 3.2713E-06 -5.1859E-07 3.6765E-08 S2 8.5930E-04 3.5253E-06 -1.0917E-06 7.7315E-08 -3.8615E-09 S3 -2.2279E-05 3.1213E-05 1.4546E-06 -1.2206E-07 8.3020E-09 S4 5.7610E-05 4.6182E-07 7.8737E-06 -9.2620E-07 6.7697E-08 S5 1.1109E-03 1.7967E-04 -3.0778E-05 2.1576E-06 -1.0112E-07 S6 -1.8258E-03 -1.4022E-04 -5.0866E-05 4.6710E-06 -1.8971E-06 S7 -3.5014E-03 -4.5011E-04 -1.3291E-05 7.0722E-07 -2.8105E-07 S8 -4.0815E-03 -1.0674E-04 -9.2967E-06 4.2232E-06 4.3140E-08 S9 -9.1747E-05 2.0427E-05 8.9724E-06 -6.3055E-07 3.7225E-08 S10 2.6558E-03 -1.0465E-05 3.9708E-06 -5.3621E-07 3.1918E-07 S11 2.5452E-04 1.3098E-04 2.8114E-05 -3.1038E-06 -1.2903E-06 S12 -6.3607E-04 -8.6718E-05 4.9199E-06 1.7262E-05 2.6828E-06 S13 2.1100E-03 -7.3888E-04 1.2962E-04 -1.8314E-05 9.5404E-06 S14 7.2169E-03 -1.9541E-03 1.7804E-04 -4.9392E-06 -2.5584E-08 S15 9.1060E-03 -2.9168E-03 3.9342E-04 -2.3855E-05 5.3626E-07 S16 3.4667E-03 -9.2570E-04 1.9490E-04 -1.6261E-05 9.7289E-07

[0160] From Table 1a, we can see that the total length TTL of the zoom lens 4 from the surface closest to the object to the imaging plane 21 is 28.3741 mm.

[0161] Of the 16 aspherical surfaces of the zoom lens 4 shown in Table 1b, all even-order aspherical surface shapes z can be defined using, but are not limited to, the following aspherical formulas:

[0162]

[0163] Where z is the sag of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the curvature of the vertex sphere of the aspherical surface, K is the quadratic surface constant, and in this embodiment, K is 0. A2, A3, A4, A5, and A6 are aspherical coefficients.

[0164] Depend on Figure 5 It can be seen that during the zoom process from the short focal length end to the long focal length end, the second lens group G2 moves towards the image side and the third lens group G3 moves towards the object side.

[0165] The ratio of the travel distance L1 of the second lens group G2 along the optical axis 401 to the total length TTL of the zoom lens 4 from the surface closest to the object side to the imaging surface 21 is: |L1 / TTL| = 0.059. The ratio of the travel distance L2 of the third lens group G3 along the optical axis 401 to the total length TTL of the zoom lens 4 from the surface closest to the object side to the imaging surface 21 is: |L2 / TTL| = 0.077.

[0166] The ratio of the total length TTL of the zoom lens 4 from the surface closest to the object to the imaging plane 21 to the focal length Fmax at the telephoto end is: |TTL / Fmax|=0.978.

[0167] Please refer to Tables 1c and 1d together. Table 1c shows the basic parameters of zoom lens 4, and Table 1d shows the spacing between lens groups of zoom lens 4 at multiple magnifications.

[0168] Table 1c

[0169] magnification one two three Four Focal length / mm 15 18.5 23.5 29 Working F number 3.5 3.5 3.7 3.9 Like high IMH 2.5mm 2.5mm 2.5mm 2.5mm

[0170] Table 1d

[0171]

[0172] right Figure 4 The zoom lens 4 shown is simulated, and the simulation effect is explained in detail below with reference to the attached diagram.

[0173] Please see Figure 9 , Figure 9 yes Figure 4 The zoom lens 4 shown is depicted with axial spherical aberration curves at the first magnification. The five curves represent wavelengths of 650nm, 610nm, 555nm, 510nm, and 470nm, with a center wavelength of 555nm. Figure 9As can be seen, under normalized aperture coordinates, the defocusing amount of the center wavelength is less than 10 μm, and the difference between the defocusing amount of any wavelength and the center wavelength is controlled within a small range.

[0174] Please see Figure 10 , Figure 10 yes Figure 4 The distortion curve of zoom lens 4 shown is at the first magnification. Figure 10 As can be seen from the distortion curve, the distortion at the maximum image height is controlled within 2%, which meets the imaging requirements.

[0175] Please see Figure 11 , Figure 11 yes Figure 4 The zoom lens 4 shown is depicted with axial spherical aberration curves at the second magnification. The five curves represent wavelengths of 650nm, 610nm, 555nm, 510nm, and 470nm, with a center wavelength of 555nm. Figure 11 As can be seen, under normalized aperture coordinates, the defocusing amount of the center wavelength is less than 10 μm, and the difference between the defocusing amount of any wavelength and the center wavelength is controlled within a small range.

[0176] Please see Figure 12 , Figure 12 yes Figure 4 The distortion curve of zoom lens 4 shown is at the second magnification. Figure 12 As can be seen from the distortion curve, the distortion at the maximum image height is controlled within 2%, which meets the imaging requirements.

[0177] Please see Figure 13 , Figure 13 yes Figure 4 The diagram shows the axial spherical aberration curves of zoom lens 4 at the third magnification. The five curves represent wavelengths of 650nm, 610nm, 555nm, 510nm, and 470nm, with a center wavelength of 555nm. Figure 13 As can be seen, under normalized aperture coordinates, the defocusing amount of the center wavelength is less than 10 μm, and the difference between the defocusing amount of any wavelength and the center wavelength is controlled within a small range.

[0178] Please see Figure 14 , Figure 14 yes Figure 4 The distortion curve of zoom lens 4 at the third magnification is shown. Figure 14 As can be seen from the distortion curve, the distortion at the maximum image height is controlled within 2%, which meets the imaging requirements.

[0179] Please see Figure 15 , Figure 15 yes Figure 4The diagram shows the axial spherical aberration curves of zoom lens 4 at the fourth magnification. The five curves represent wavelengths of 650nm, 610nm, 555nm, 510nm, and 470nm, with a center wavelength of 555nm. Figure 15 As can be seen, under normalized aperture coordinates, the defocusing amount of the center wavelength is less than 10 μm, and the difference between the defocusing amount of any wavelength and the center wavelength is controlled within a small range.

[0180] Please see Figure 16 , Figure 16 yes Figure 4 The distortion curve of zoom lens 4 shown is at the fourth magnification. Figure 16 As can be seen from the distortion curve, the distortion at the maximum image height is controlled within 2%, which meets the imaging requirements.

[0181] Please refer to the following: Figure 17 and Figure 18 , Figure 17 yes Figure 3 The diagram shows a partial structural representation of the zoom lens 4 in some other embodiments. Figure 18 yes Figure 17 The diagram shows the structure of the zoom process of the zoom lens 4. Wherein, Figure 17 and Figure 18 The diagram mainly illustrates the structure of multiple lens groups of the zoom lens 4. For ease of explanation, the filter 5 and imaging surface 21 of the camera module 40 are also shown.

[0182] In some embodiments, the zoom lens 4 includes multiple lens groups, which, from the object side to the image side, are as follows: a first lens group G1 with positive optical power, where the ratio of the total length TTL of the zoom lens 4 to the focal length f1 of the first lens group G1 is TTL / f1 = 1.96; a second lens group G2 with negative optical power, where the ratio of the total length TTL of the zoom lens 4 to the focal length f2 of the second lens group G2 is TTL / f2 = -5.57; and a third lens group G3 with positive optical power, where the ratio of the total length TTL of the zoom lens 4 to the focal length f3 of the third lens group G3 is TTL / f3 = 3.93. The second lens group G2 and the third lens group G3 are movable along the optical axis 401, enabling the zoom lens 4 to achieve continuous zoom.

[0183] The zoom lens 4 comprises seven lenses with optical power, all of which are aspherical. The first lens group G1 contains two lenses (41 and 42), with positive and negative optical powers respectively along the object-to-image direction. The second lens group G2 contains two lenses (43 and 44), with negative and positive optical powers respectively along the object-to-image direction. The third lens group G3 contains three lenses (45, 46, and 47), with positive, positive, and negative optical powers respectively along the object-to-image direction. The third lens group G3 includes an aperture stop 49, located on the object side of the lens 45 closest to the object side of the third lens group G3. Both lenses in the first lens group G1 are made of glass, while the other lenses in the zoom lens 4 are made of plastic. The maximum effective height h of all lenses in the zoom lens 4 is 4.6 mm. The maximum aperture d of all lenses in zoom lens 4 is 7mm.

[0184] Please refer to Tables 2a and 2b. Table 2a shows the radius of curvature, spacing, refractive index (Nd), and Abbe coefficient (Vd) of each lens and filter 5 of the zoom lens 4 in the first magnification (short focal length) state. The spacing includes the thickness (corresponding to d1 to d8) and the distance between the lenses (corresponding to a1 to a8). Table 2b shows the aspherical coefficients of each lens.

[0185] Table 2a

[0186]

[0187]

[0188] Table 2b

[0189] <![CDATA[A2]]> <![CDATA[A3]]> <![CDATA[A4]]> <![CDATA[A5]]> <![CDATA[A6]]> S1 7.7258E-04 9.4033E-06 5.6372E-07 8.2522E-08 4.3584E-09 S2 3.2303E-03 -4.4331E-06 -3.1125E-06 3.5531E-07 -1.2414E-08 S3 -1.2917E-03 1.2299E-04 1.0540E-06 -7.9510E-07 2.5310E-08 S4 -2.5147E-03 1.4982E-04 1.0347E-05 -2.0346E-06 9.4795E-08 S5 -3.3338E-05 2.8261E-04 -2.0895E-05 -1.1744E-06 1.8988E-07 S6 -8.6280E-03 -1.8896E-04 -4.3557E-05 -1.1069E-05 1.9091E-06 S7 -8.4006E-03 -5.0089E-04 -6.0653E-05 -2.0726E-06 5.0352E-07 S8 -4.0294E-03 1.5644E-05 -6.1672E-05 8.1074E-06 -5.5763E-07 S9 3.8711E-04 -2.9561E-05 5.0459E-05 -1.9233E-06 3.7251E-07 S10 2.2702E-03 1.2971E-03 -1.3428E-04 1.8174E-05 -1.2587E-06 S11 -2.6706E-03 1.5754E-03 -3.4675E-04 2.9474E-05 -3.4213E-06 S12 -2.3288E-03 2.1220E-03 -5.9465E-04 4.8581E-05 -2.3181E-06 S13 5.9017E-03 1.4073E-03 -3.5923E-04 4.0329E-05 -2.3486E-06 S14 5.5519E-03 1.3915E-04 1.0388E-05 6.4525E-06 -5.5151E-07

[0190] From Table 2a, we can see that the total length TTL of the zoom lens 4 from the surface closest to the object to the imaging plane 21 is 26.3195 mm.

[0191] Of the 14 aspherical surfaces of the zoom lens 4 shown in Table 2b, all even-order aspherical surface shapes z can be defined using, but are not limited to, the following aspherical formulas:

[0192]

[0193] Where z is the sag of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the curvature of the vertex sphere of the aspherical surface, K is the quadratic surface constant, and in this embodiment, K is 0. A2, A3, A4, A5, and A6 are aspherical coefficients.

[0194] like Figure 18 As shown, Figure 18The diagram illustrates the three focal length states of the zoom lens 4, including the first magnification (i.e., the short focal length end), the second magnification (i.e., the intermediate magnification), and the third magnification (i.e., the long focal length end). As the zoom lens 4 is adjusted from the first magnification to the third magnification, the focal length increases.

[0195] Depend on Figure 18 It can be seen that during the zoom process from the short focal length end to the long focal length end, the second lens group G2 moves towards the image side, and the third lens group G3 moves towards the object side. The ratio of the movement distance L1 of the second lens group G2 along the optical axis 401 to the total length TTL of the zoom lens 4 from the surface closest to the object side to the imaging plane 21 is: |L1 / TTL| = 0.072. The ratio of the movement distance L2 of the third lens group G3 along the optical axis 401 to the total length TTL of the zoom lens 4 from the surface closest to the object side to the imaging plane 21 is: |L2 / TTL| = 0.084. The ratio of the total length TTL of the zoom lens 4 from the surface closest to the object side to the imaging plane 21 to the focal length Fmax at the long focal length end is:

[0196] |TTL / Fmax|=1.1.

[0197] Please refer to Tables 2c and 2d together. Table 2c shows the basic parameters of zoom lens 4, and Table 2d shows the spacing between lens groups of zoom lens 4 at multiple magnifications.

[0198] Table 2c

[0199] magnification one two three Focal length / mm 15 17 23.5 Working F number 3.5 3.5 3.8 Like high IMH 3.28mm 3.28mm 3.28mm

[0200] Table 2d

[0201]

[0202] right Figure 17 The zoom lens 4 shown is simulated, and the simulation effect is explained in detail below with reference to the attached diagram.

[0203] Please see Figure 19 , Figure 19 yes Figure 17 The zoom lens 4 shown is depicted with axial spherical aberration curves at the first magnification. The five curves represent wavelengths of 650nm, 610nm, 555nm, 510nm, and 470nm, with a center wavelength of 555nm. Figure 19 As can be seen, under normalized aperture coordinates, the defocusing amount of the center wavelength is less than 10 μm, and the difference between the defocusing amount of any wavelength and the center wavelength is controlled within a small range.

[0204] Please see Figure 20 , Figure 20 yes Figure 17 The distortion curve of zoom lens 4 shown is at the first magnification. Figure 20 As can be seen from the distortion curve, the distortion at the maximum image height is controlled within 2%, which meets the imaging requirements.

[0205] Please see Figure 21 , Figure 21 yes Figure 17 The zoom lens 4 shown is depicted with axial spherical aberration curves at the second magnification. The five curves represent wavelengths of 650nm, 610nm, 555nm, 510nm, and 470nm, with a center wavelength of 555nm. Figure 21 As can be seen, under normalized aperture coordinates, the defocusing amount of the center wavelength is less than 10 μm, and the difference between the defocusing amount of any wavelength and the center wavelength is controlled within a small range.

[0206] Please see Figure 22 , Figure 22 yes Figure 17 The distortion curve of zoom lens 4 shown is at the second magnification. Figure 22 As can be seen from the distortion curve, the distortion at the maximum image height is controlled within 2%, which meets the imaging requirements.

[0207] Please see Figure 23 , Figure 23 yes Figure 17 The diagram shows the axial spherical aberration curves of zoom lens 4 at the third magnification. The five curves represent wavelengths of 650nm, 610nm, 555nm, 510nm, and 470nm, with a center wavelength of 555nm. Figure 23 As can be seen, under normalized aperture coordinates, the defocusing amount of the center wavelength is less than 10 μm, and the difference between the defocusing amount of any wavelength and the center wavelength is controlled within a small range.

[0208] Please see Figure 24 , Figure 24 yes Figure 17 The distortion curve of zoom lens 4 at the third magnification is shown. Figure 24 As can be seen from the distortion curve, the distortion at the maximum image height is controlled within 2%, which meets the imaging requirements.

[0209] Please refer to the following: Figure 25 and Figure 26 , Figure 25 This is a schematic diagram of the structure of the mobile terminal 100 provided in this application embodiment in other embodiments. Figure 26 yes Figure 25 The diagram shows a partial structural view of the mobile terminal 100 cut along line BB. The mobile terminal 100 of this embodiment includes most of the features of the mobile terminal 100 of the aforementioned embodiments. The following mainly describes the main differences between the two, while the majority of the content that is the same will not be repeated.

[0210] Mobile terminal 100 includes a periscope camera module 40. The periscope camera module 40 may include most of the features of the camera module 40 described in the previous embodiments, the main difference being that the periscope camera module 40 also includes a reflector 6. The reflector 6 is located on the object side of the zoom lens 4 and is used to deflect light onto the zoom lens 4. Figure 26 As shown, light from outside the mobile terminal 100 passes through the light-transmitting lens 104 of the mobile terminal 100 and then shines on the reflector 6. The reflector 6 deflects the light to the zoom lens 4. After passing through the zoom lens 4, the light is imaged on the image sensor 2, and the camera module 40 realizes light acquisition.

[0211] In this embodiment, the camera module 40 changes the direction of light propagation by setting a reflector 6, so that the optical axis 401 of the zoom lens 4 can be different from the direction of external light entering the mobile terminal 100. This makes the placement, angle, and space of the camera module 40 more flexible, and the zoom lens 4 can be applied to the periscope camera module 40. For example, the optical axis of the zoom lens 4 can be parallel to the display screen 20.

[0212] Please see Figure 27 , Figure 27 yes Figure 26 The diagram shows a partial structural schematic of the camera module 40 in some embodiments.

[0213] In some embodiments, the reflector 6 is a prism. The prism deflects the light to the first lens group G1 of the zoom lens 4. The light then passes through the first lens group G1, the second lens group G2, the third lens group G3, and the filter 5 in sequence, and finally forms an image on the imaging surface 21 of the image sensor.

[0214] For example, the prism includes two straight edges and one bevel. Light enters the prism through one straight edge, is reflected by the bevel, and exits the prism through the other straight edge. The bevel can form a 45° angle with the optical axis of the zoom lens 4, and this angle can be adjusted as needed, for example, to form an angle of 30° or 60°, thereby enabling the camera module 40 to achieve periscope-style shooting. This application does not strictly limit the structure, bevel position, or angle of the prism.

[0215] Please see Figure 28 , Figure 28 yes Figure 26 The diagram shows a partial structural representation of the camera module 40 in some other embodiments.

[0216] In some embodiments, the reflector 6 is a mirror. The mirror deflects the light to the first lens group G1 of the zoom lens 4. The light passes sequentially through the first lens group G1, the second lens group G2, the third lens group G3, and the filter 5 before forming an image on the imaging surface 21 of the image sensor.

[0217] For example, the mirror surface of the reflector can form a 45° angle with the optical axis of the zoom lens 4. This angle can also be adjusted as needed, such as forming a 30° or 60° angle, thereby enabling the camera module 40 to achieve periscope shooting. This application does not strictly limit the position, angle, etc. of the mirror surface.

[0218] Understandable Figure 27 and Figure 28 In the illustrated embodiment, the reflector 6 is described using one prism or mirror as an example. In other embodiments, the reflector 6 may also include multiple prisms or mirrors to change the direction of light propagation multiple times, making the placement and angle of the zoom lens 4 more flexible, and enabling the camera module 40 to achieve periscope shooting with less assembly difficulty.

[0219] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Where there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A zoom lens, characterized in that, It consists of a first lens group, a second lens group, and a third lens group arranged along the object side to the image side; wherein... The first lens group is a fixed lens group with positive optical power; The second lens group is a zoom lens group with negative optical power; The third lens group is a compensating lens group with positive optical power; During the zoom process from the short focal length end to the long focal length end of the zoom lens, the second lens group moves along the optical axis to the image side, and the third lens group moves along the optical axis to the object side. The total length TTL of the zoom lens satisfies: TTL≤45mm; The ratio of the total length TTL of the zoom lens from the surface closest to the object to the imaging plane to the focal length f3 of the third lens group satisfies: 1.7≤TTL / f3≤4.5; The ratio of the travel distance L2 of the third lens group along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane satisfies: 0.07≤|L2 / TTL|≤0.09; The total number of lenses in the first lens group, the second lens group, and the third lens group is 7 or 8.

2. The zoom lens according to claim 1, characterized in that, The first lens group consists of a lens with positive optical power and a lens with negative optical power arranged sequentially from the object side to the image side; the second lens group consists of a lens with negative optical power and a lens with positive optical power arranged sequentially from the object side to the image side; and the third lens group consists of a lens with positive optical power, a lens with positive optical power and a lens with negative optical power arranged sequentially from the object side to the image side, or a lens with positive optical power, a lens with positive optical power, a lens with negative optical power and a lens with negative optical power arranged sequentially from the object side to the image side.

3. The zoom lens according to claim 1 or 2, characterized in that, The zoom lens includes at least one lens made of glass.

4. The zoom lens according to claim 1 or 2, characterized in that, The ratio of the total length TTL of the zoom lens from the surface closest to the object to the imaging plane to the focal length f1 of the first lens group satisfies: 0.7≤TTL / f1≤3.2; The ratio of the total length TTL of the zoom lens from the surface closest to the object to the imaging plane to the focal length f2 of the second lens group satisfies: -7≤TTL / f2≤-3.

5. The zoom lens according to claim 1 or 2, characterized in that, The ratio of the travel distance L1 of the second lens group along the optical axis to the total length TTL of the zoom lens from the surface closest to the object to the imaging plane satisfies: |L1 / TTL|≤0.

3.

6. The zoom lens according to claim 1 or 2, characterized in that, The ratio of the total length TTL of the zoom lens from the surface closest to the object to the imaging plane to the focal length Fmax at the telephoto end satisfies: |TTL / Fmax|≤2.

0.

7. The zoom lens according to claim 1 or 2, characterized in that, The ratio of the focal length Fmax at the telephoto end to the focal length Fmin at the short focal end of the zoom lens satisfies: Fmax / Fmin≤5.

0.

8. The zoom lens according to claim 1, characterized in that, Each lens of the zoom lens has a notch for reducing the height of the lens.

9. The zoom lens according to claim 8, characterized in that, The ratio of the effective height h of each lens of the zoom lens to the maximum aperture d satisfies: h / d≥0.

45.

10. The zoom lens according to claim 8 or 9, characterized in that, The effective height h of each lens in the zoom lens satisfies the following: h≤6.5mm.

11. The zoom lens according to claim 8 or 9, characterized in that, The maximum aperture d of each lens in the zoom lens satisfies the following: d≤10mm.

12. The zoom lens according to claim 1 or 2, characterized in that, The maximum aperture d of each lens in the zoom lens satisfies the following condition: d≤6.5mm.

13. The zoom lens according to claim 1 or 2, characterized in that, The third lens group includes an aperture stop, and the third lens group includes a first lens and a second lens arranged from the object side to the image side; The aperture stop is located on the object side of the first lens of the third lens group, or between the first and second lenses of the third lens group.

14. The zoom lens according to claim 1 or 2, characterized in that, The operating F-number of the zoom lens satisfies: 2.0 ≤ working F number ≤ 6.

5.

15. A camera module, characterized in that, It includes an image sensor and a zoom lens according to any one of claims 1 to 14, wherein light can pass through the zoom lens and illuminate the image sensor.

16. The camera module according to claim 15, characterized in that, The camera module also includes a prism or a reflector, which is located on the object side of the zoom lens and is used to deflect light onto the zoom lens.

17. A mobile terminal, characterized in that, The device includes an image processor and a camera module as described in claim 15 or 16, wherein the image processor is communicatively connected to the camera module and is used to acquire image data from the camera module and process the image data.

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