Optical lens and camera module

Abstract

The present application relates to a parent-child optical lens, which comprises a lens frame, a first carrier and a second carrier and a first lens and a second lens installed in the lens frame, the first carrier is located in the second carrier and can move relative to the second carrier. The first side of the second carrier has a sliding fitting structure and a fitted first track; the second driving device for driving the second carrier comprises a piezoelectric element, a vibration starting part and a driven part, the driven part is linear and serves as the second track; the vibration starting part mechanically vibrates under the driving of the piezoelectric element attached to its surface and moves along the optical axis relative to the second track, and the moving range is at least 6 mm. The vibration starting part is arranged in the interior of the lens frame and is fixed to the lens frame or the second carrier through a mounting part; the moving stroke of the vibration starting part is limited to the middle section area of the lens frame. The present application also provides a corresponding camera module.

Description

Technical Field

[0001] This invention relates to the field of camera module technology, and more specifically, to a mother-daughter optical lens and camera module. Background Technology

[0002] Mobile phone camera modules are a crucial component of smart equipment, and their application scope and volume in the market are constantly growing. With technological advancements, both work and life are increasingly embracing smart technology, and a key prerequisite for achieving this is effective interaction with the external environment. A crucial method for achieving this interaction is visual perception, which primarily relies on camera modules. It can be said that camera modules have transformed from obscurity into a vital and critical component of smart equipment.

[0003] As living standards rise, consumers have increasingly higher demands for the camera functions of mobile phones, tablets, and other terminal devices. They not only require effects such as background blur and night shooting, but also demand telephoto capabilities, needing terminal devices that can clearly capture images at different distances.

[0004] To achieve the aforementioned telephoto function, an optical zoom lens is typically added to the camera module, forming an optical zoom module. An optical zoom module changes the focal length of the lens by altering the distance between the lens elements, thus achieving zoom. It can capture distant objects at different distances with relatively high clarity, and the resulting image quality is also relatively high. Here, zoom refers to changing the focal length to capture scenes at different distances.

[0005] In existing optical zoom drive mechanisms, most drive at least two lenses to move. During autofocus and zoom, multiple lenses can only be driven by their own independent drive devices. However, this method makes it difficult to synchronize the focusing and zooming processes, affecting the sharpness and speed of focusing and zooming. Furthermore, the independent drive methods of multiple lenses can cause positional deviations in the optical axis direction, affecting the image quality and making it impossible to achieve higher precision requirements.

[0006] CN111856695A proposes a master-slave zoom lens. In this zoom lens, the lens group includes a fixed group and two movable groups. The two movable groups are mounted on the same parent carrier, allowing them to move synchronously under the drive of a piezoelectric motor. A slave carrier is mounted within the parent carrier and can move relative to the parent carrier under the action of another driving element. One of the movable groups is mounted on the slave carrier, thus allowing it to move relative to the parent carrier as a sub-group. For ease of understanding, the larger group consisting of these two movable groups is referred to as the parent group, and the movable group mounted on the slave carrier is referred to as the slave group. In this existing solution, the piezoelectric motor drives the parent group for zooming, and another motor separately drives the slave group for high-precision focusing. This avoids positional deviations in the optical axis caused by multiple lenses moving independently, thereby improving the imaging quality of the module. However, nested zoom lenses require multiple carriers, resulting in a large size for the mother carrier. Furthermore, moving the mother group and its associated structures (e.g., the mother carrier housing the daughter carriers and their drive elements) requires significant driving force. These factors contribute to the large volume of the nested zoom lens, making it difficult to miniaturize the camera module. In the solution of CN111856695A, a piezoelectric motor is used to provide a large driving force for the movement of the mother group; however, the surface of the piezoelectric element of this motor is perpendicular to its drive shaft, occupying a large space. It is even difficult to place the piezoelectric element inside the lens frame.

[0007] In conclusion, there is an urgent need for a solution that can reduce the size of the mother-daughter optical lens and camera module. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a solution for a mother-daughter optical lens and camera module that can reduce size.

[0009] To solve the above-mentioned technical problems, the present invention provides a mother-daughter optical lens, comprising: a lens frame having an axis parallel to the optical axis of the optical lens and a first sidewall and a second sidewall located on both sides of the axis; a first carrier; a second carrier located within the lens frame and movably connected to the lens frame; the first carrier located within the second carrier and movably connected to the second carrier, a first gap being formed between a first sidewall and the second carrier, the first gap being provided with a first track parallel to the optical axis, and a second gap being formed between the second sidewall and a second side of the second carrier, the second gap being provided with a second track parallel to the optical axis; a first driving device adapted to drive the first carrier to move relative to the second carrier along the direction of the optical axis; a first lens fixed to the first carrier; a second lens fixed to the second carrier; a third lens fixed to the lens frame, and the first lens, the second lens, and the third lens being coaxially arranged; and a second driving device adapted to drive the second carrier to move relative to the lens frame along the direction of the optical axis. The second carrier has a sliding adapter structure on its first side, which is movably connected to the first track. A second driving device is disposed in the second gap and includes a piezoelectric element, a vibration initiator, and a driven component. The driven component is linear and serves as the second track. The vibration initiator mechanically vibrates under the influence of the piezoelectric element attached to its surface and moves relative to the second track along the optical axis, with a movement range of at least 6 mm. The vibration initiator is disposed inside the lens frame and is fixed to the lens frame or the second carrier by a mounting portion. The lens frame has an image-side end face and an object-side end face. The distance from the image-side end face to the object-side end face is the inner cavity length of the lens frame, which is at least 20 mm. The travel of the vibration starter is limited to the middle section of the lens frame, which is a region that satisfies the following conditions: the position of the mounting part is at least 1 / 4 of the inner cavity length from the object-side end face of the lens frame, and the position of the mounting part is at least 1 / 4 of the inner cavity length from the image-side end face of the lens frame.

[0010] The second driving device is a tuning fork piezoelectric driving device. The oscillation component is a tuning fork resonator, which has two vibrating arms and a connecting portion connecting the two vibrating arms. Each connecting portion has a connecting end and a free end. The connecting portion 75 connects the connecting ends of the two vibrating arms and has a connecting portion through hole. The driven component is a driven rod, which passes through the connecting portion through hole and is held by the two vibrating arms. The axis of the driven rod is parallel to the optical axis. Both the tuning fork resonator and the driven rod are disposed in the gap between the second carrier and the lens frame. Both ends of the driven rod are fixed to the second carrier or the lens frame. When both ends of the driven rod are fixed to the second carrier, the connecting portion is fixed to the lens frame; when both ends of the driven rod are fixed to the lens frame, the connecting portion is fixed to the second carrier. The number of piezoelectric elements is at least two, and the piezoelectric elements are flat. One piezoelectric element is disposed on the outer side of each vibrating arm. The vibrating arm is adapted to resonate under the drive of the piezoelectric elements and form a resultant force pointing in the positive direction of the optical axis at a first vibration frequency and a resultant force pointing in the negative direction of the optical axis at a second vibration frequency.

[0011] The two vibrating arms are configured to be axially symmetrical about the axis of the driven rod. The outer surface of each vibrating arm is a plane parallel to the optical axis. The free end of each vibrating arm has a clamping part, and the shape of the inner surface of the clamping part is adapted to the shape of the outer surface of the driven rod.

[0012] The piezoelectric element is also provided on the inner side of the vibrating arm.

[0013] In this configuration, the piezoelectric element, under the action of a driving signal at a first frequency, drives the vibrating arm to vibrate, causing the tuning fork resonator to resonate at the first frequency. The two vibrating arms cyclically open and close at the first frequency, causing the tuning fork resonator to move relative to the driven rod along the positive direction of the optical axis. Under the action of a driving signal at a second frequency, the piezoelectric element drives the vibrating arm to vibrate, causing the tuning fork resonator to resonate at the second frequency. The two vibrating arms cyclically open and close at the second frequency, causing the tuning fork resonator to move relative to the driven rod along the negative direction of the optical axis.

[0014] The tuning fork resonator also has a mounting portion, which is flat and its thickness direction is parallel to the optical axis.

[0015] One end of the mounting part is connected to the connecting part, and the other end is fixed to the lens frame or the second carrier; wherein when both ends of the driven rod are fixed to the second carrier, the connecting part is fixed to the lens frame through the mounting part, and when both ends of the driven rod are fixed to the lens frame, the connecting part is fixed to the second carrier through the mounting part.

[0016] An auxiliary piezoelectric element is attached to the surface of the mounting portion, and the auxiliary piezoelectric element generates vibration perpendicular to the surface of the mounting portion.

[0017] At least a portion of the piezoelectric elements are piezoelectric elements formed by stacking multiple layers of piezoelectric materials.

[0018] The second carrier includes a lens adapter and a carrier frame. The lens adapter is used to mount the second lens, and the carrier frame forms a carrier receiving cavity. The first carrier and the first driving device are disposed in the carrier receiving cavity. From a top-view angle, the width of the lens adapter is smaller than the width of the carrier frame.

[0019] The lens frame further includes a base plate, a front end and a rear end perpendicular to the optical axis. The front end, the rear end, the first sidewall and the second sidewall surround the second carrier. The base plate is located at the bottom of the second carrier. The third lens is mounted on the front end, and the rear end is adapted to mount a photosensitive component.

[0020] The tuning fork resonator is fixed to the base plate, and the two ends of the driven rod are respectively fixed to the outer side of the lens adapter and the carrier frame.

[0021] The tuning fork resonator is fixed to the outer side of the lens adapter or the carrier frame, and both ends of the driven rod are fixed to the base plate.

[0022] The first track arranged in the first gap is a guide rod, and the two ends of the guide rod are fixed to the lens frame. The sliding adapter structure arranged in the first gap is a through hole adapter structure, and the guide rod passes through the through hole adapter structure and is movably connected to the through hole adapter structure.

[0023] The first track is disposed on the inner side of the first sidewall, the second track is disposed on the inner side of the second sidewall, and the second driving device is a traveling wave piezoelectric driving device or a standing wave piezoelectric driving device.

[0024] This application also provides a camera module, which includes: a mother-daughter optical lens as described in any of the foregoing embodiments; and a photosensitive component fixed to the lens frame, the photosensitive component including a photosensitive chip adapted to receive light passing through the optical lens.

[0025] The camera module is a periscope module, which includes a reflecting prism fixed to the lens frame. The optical axis of the incident end of the reflecting prism is perpendicular to the optical axis of the exit end, and the optical axis of the exit end is parallel to the optical axis of the optical lens.

[0026] Compared with the prior art, this application has at least one of the following technical effects:

[0027] 1. This application can place the piezoelectric element in the gap between the mother carrier and the lens frame, thereby reducing the size of the camera module.

[0028] 2. This application can avoid positional deviation in the optical axis direction caused by the independent movement of multiple lenses, thereby improving the imaging quality of the module.

[0029] 3. In some embodiments of this application, the optical axis direction can be driven by piezoelectric elements and tuning fork structures, and the magnitude and direction of the overall force of the tuning fork structure can be changed by controlling the frequency of driving the piezoelectric element, thereby achieving accurate and reliable control of the movement of the mother group with a small volume cost.

[0030] 4. In some embodiments of this application, the axial movement of the oscillating component can be aligned by configuring the oscillating component and its range of motion in the middle section of the lens frame. This allows a guide rod and a driven rod to achieve high alignment of the parent carrier, thereby reducing the volume of the lens frame and the letter-shaped lens (especially reducing the width dimension).

[0031] 5. The mother-daughter optical lens and camera module of this application are particularly suitable for use in electronic devices such as mobile phones and tablets. Attached Figure Description

[0032] Figure 1 A perspective view of a mother-daughter optical lens according to an embodiment of this application is shown;

[0033] Figure 2 It shows Figure 1 A magnified view of a portion of the area near the second drive unit;

[0034] Figure 3 It shows Figure 1 A top-view diagram of a mother-and-child optical lens;

[0035] Figure 4aA schematic diagram of a tuning fork resonator in one embodiment of this application is shown from a top view.

[0036] Figure 4b A schematic diagram of a tuning fork resonator in one embodiment of this application is shown from an object-side perspective;

[0037] Figure 5 A tuning fork resonator is shown in one modified embodiment of this application;

[0038] Figure 6 A tuning fork resonator is shown in another modified embodiment of this application;

[0039] Figure 7 This illustrates the working principle of the tuning fork resonator in its first state.

[0040] Figure 8 This illustrates the working principle of the tuning fork resonator in the second state;

[0041] Figure 9 A three-dimensional schematic diagram of a mother-daughter optical lens in which a tuning fork resonator is fixed to the second carrier is shown in this application;

[0042] Figure 10 It shows Figure 9 A top-view diagram of a mother-and-child optical lens;

[0043] Figure 11 The diagram shows a mother-daughter optical lens and its axis from a top-down view in one embodiment of this application. Detailed Implementation

[0044] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] It should be noted that in this specification, the terms "first," "second," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first subject discussed below may also be referred to as the second subject.

[0046] In the accompanying drawings, the thickness, size, and shape of the objects have been slightly exaggerated for ease of illustration. The drawings are for illustrative purposes only and are not drawn to scale.

[0047] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed feature, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0048] As used herein, the terms “basically,” “approximately,” and similar terms are used as terms of approximation rather than terms of degree, and are intended to describe inherent biases in measured or calculated values ​​that will be recognized by those skilled in the art.

[0049] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0050] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0051] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0052] Figure 1 A perspective view of a mother-daughter optical lens according to an embodiment of this application is shown. Figure 2 It shows Figure 1 A magnified view of a portion of the area near the second drive unit. Figure 3 It shows Figure 1 A top-view diagram of a mother-and-child optical lens system. (Refer to reference...) Figure 1 , Figure 2 and Figure 3In this embodiment, the mother-daughter optical lens 100 includes a lens frame 10, a first carrier 20, a second carrier 30, a first driving device, a first lens 40, a second lens 50, a third lens 60, and a second driving device 70. The second carrier 30 is located within the lens frame 10 and is movably connected to the lens frame 10; the first carrier 20 is located within the second carrier 30 and is movably connected to the second carrier 30. The first driving device is adapted to drive the first carrier 20 to move relative to the second carrier 30 along the optical axis of the optical lens 100. In this embodiment, the mother-daughter optical lens 100 can be used in a periscope module. For ease of description and understanding, in this document, the optical axis of the mother-daughter optical lens 100 in a periscope module is defined as the principal optical axis, which is perpendicular to the incident optical axis of the incident light ray (i.e., the light ray from the object side). Specifically, the periscope module may include a reflecting prism 200 (or other types of light reflecting elements), the reflecting prism 200 may be fixed to the lens frame 10 (the two may be directly connected or indirectly connected through an intermediary), and the incident optical axis (i.e., the incident optical axis of the incident light) of the reflecting prism 200 is perpendicular to the exit optical axis, wherein the exit optical axis is parallel to the optical axis of the optical lens 100. Further, in this embodiment, the first lens 40 is fixed to the first carrier 20; the second lens 50 is fixed to the second carrier 30; and the third lens 60 is fixed to the lens frame 10, and the first lens 40, the second lens 50, and the third lens 60 are arranged coaxially. The second driving device 70 is adapted to drive the second carrier 30 to move relative to the lens frame 10 in the direction of the optical axis of the optical lens 100. The second driving device 70 includes a tuning fork resonator 71, a driven rod 72, and at least two piezoelectric elements 73. In this embodiment, the tuning fork resonator 71 has two vibrating arms 74 and a connecting portion 75 connecting the two vibrating arms 74. Each connecting portion 75 has a connecting end and a free end. The connecting portion 75 connects the connecting ends of the two vibrating arms 74 and has a connecting portion through hole. The driven rod 72 passes through the connecting portion through hole and is held by the two vibrating arms 74. The axis of the driven rod 72 is parallel to the optical axis. The tuning fork resonator 71 and the driven rod 72 are both disposed in the gap between the second carrier 30 and the lens frame 10. The two ends of the driven rod 72 are fixed to the second carrier 30 or the lens frame 10. When the two ends of the driven rod 72 are fixed to the second carrier 30, the connecting portion 75 is fixed to the lens frame 10. When the two ends of the driven rod 72 are fixed to the lens frame 10, the connecting portion 75 is fixed to the second carrier 30.The piezoelectric element 73 is flat, and one piezoelectric element 73 is attached to the outer side of each vibrating arm 74. The vibrating arm 74 is adapted to resonate under the drive of the piezoelectric element 73, forming a resultant force pointing in the positive direction of the optical axis at a first vibration frequency and a resultant force pointing in the negative direction of the optical axis at a second vibration frequency. In this embodiment, the piezoelectric element 73 and the resonator can be connected by an adhesive with good energy transfer properties, constant thickness, and conductivity, such as an adhesive with added silver epoxy or conductive micro-metal spheres. It should be noted that the way the piezoelectric element 73 is attached to a resonator in this application is not limited to this. For example, in another embodiment, the piezoelectric element 73 can also be directly coated on the outer side of the resonator, or formed on the outer surface of the resonator in a layer-by-layer forming process. In still some embodiments, the piezoelectric element 73 can also be fabricated on the outer side of the resonator by electrolysis technology, and the two can be electrically connected. Furthermore, in this embodiment, the mother-daughter optical lens 100 also includes a guide rod 91 disposed between the second carrier 30 and the lens frame 10. Both ends of the guide rod 91 are fixed to the lens frame 10. One side of the second carrier 30 has a through-hole adapter structure 92, through which the guide rod 91 passes and is movably connected. The guide rod 91 is parallel to the driven rod 72, and both are located on opposite sides of the second carrier 30.

[0053] Furthermore, in conjunction with references Figure 1 and Figure 11In some embodiments of this application, the lens frame 10 has an axis AX parallel to the optical axis of the optical lens 100 and a first sidewall 11 and a second sidewall 12 located on both sides of the axis AX. A second carrier 30 is located within the lens frame 10 and is movably connected to the lens frame 10. A first carrier 20 is located within the second carrier 30 and is movably connected to the second carrier 30. A first gap 13 is formed between the first sidewall 11 and the first side 31 of the second carrier 30, and the first gap 13 is provided with a first track parallel to the optical axis (in this embodiment, the first track is implemented as a guide rod 91). A second gap 14 is formed between the second sidewall 12 and the second side 32 of the second carrier 30, and the second gap 14 is provided with a second track parallel to the optical axis (in this embodiment, the second track is implemented as a driven rod 72). A first driving device is adapted to drive the first carrier 20 to move relative to the second carrier 30 along the direction of the optical axis. A first lens 40 is fixed to the first carrier 20. A second lens 50 is fixed to the second carrier 30. The third lens 60 is fixed to the lens frame 10, and the first lens 40, the second lens 50, and the third lens 60 are arranged coaxially. The second driving device is adapted to drive the second carrier 30 to move relative to the lens frame 10 in the direction of the optical axis. The first side 31 of the second carrier 30 has a sliding adapter structure (in this embodiment, the sliding adapter structure is implemented as a through-hole adapter structure 92), which is movably connected to the first track. The second driving device is disposed in the second gap 14 and includes a piezoelectric element, a vibration initiation component (in this embodiment, the vibration initiation component is implemented as a tuning fork resonator 71), and a driven component. The driven component is linear and serves as the second track (in this embodiment, it is implemented as a driven rod 72). The vibration initiation component mechanically vibrates under the drive of the piezoelectric element attached to its surface and moves along the optical axis relative to the second track, with a movement range of at least 6 mm. The vibration initiation component is disposed inside the lens frame 10 and is fixed to the lens frame 10 by a mounting portion (see reference). Figure 2 The mounting part 76 in the middle) or fixed to the second carrier 30 (see reference) Figure 9The lens frame 10 has an image-side end face 16 and an object-side end face 15. The distance from the image-side end face 16 to the object-side end face 15 is the inner cavity length of the lens frame, which is at least 20 mm. The travel of the oscillation member is limited to the middle section of the lens frame. In this application, the middle section is a region that satisfies the following conditions: the position of the mounting part is at least 1 / 4 of the inner cavity length from the object-side end face of the lens frame, and the position of the mounting part is at least 1 / 4 of the inner cavity length from the image-side end face of the lens frame. That is, the movement of the oscillation member relative to the second track (e.g., the driven rod 72) will not cause the mounting part to enter the front 1 / 4 region of the inner cavity of the lens frame, nor will it cause the mounting part to enter the rear 1 / 4 region of the inner cavity of the lens frame. Here, the front section refers to the section near the object side, and the rear section refers to the section near the image side. These designs allow the mother-daughter lens to be mounted in electronic devices such as mobile phones, enabling optical zoom functionality. The inventors discovered through in-depth research that when a guide rod and a driven rod are respectively positioned on both sides of the second carrier (mother carrier), if the oscillation component and its mounting part are located in the middle section of the lens frame, the movement of the oscillation component relative to the driven rod can achieve high collimation, meeting the optical zoom requirements of the mother-daughter lens (i.e., the movement of the mother carrier will not cause a decrease in the image quality of optical zoom due to insufficient collimation). Therefore, based on the solution of this embodiment, it is not necessary to additionally set a guide rod or other type of track structure at the second gap, thereby reducing the volume of the mother-daughter lens, especially its width dimension (the distance from the first sidewall to the second sidewall is the width of the mother-daughter lens). It should be noted that in this application, the inner cavity length of the lens frame 10 refers to the length of the optical imaging area (i.e., the effective optical area) within the inner cavity. The lengths (in the optical axis direction) of the first gap 13 and the second gap 14 within the inner cavity can be different from (e.g., less than) the length of the optical imaging area. When determining the position of the vibration starter and the mounting part 76, the inner cavity length of the lens frame 10 is based on the length of the optical imaging area of ​​the inner cavity.

[0054] Furthermore, still referencing Figure 1 In some embodiments of this application, in the mother-daughter optical lens 100, the outer surface of the vibrating arm 74 of the tuning fork resonator 71 is a plane, and this plane is parallel to the optical axis (i.e., the principal optical axis mentioned above); the shape of the inner surface of the vibrating arm 74 can be adapted to the outer surface of the driven rod 72. Specifically, the driven rod 72 can be a round rod or a polygonal prism rod, and the inner surface of the vibrating arm 74 of the tuning fork resonator 71 can be a matching arc surface or a polygonal prism inner surface, so that the vibrating arm 74 can better clamp the driven rod 72 and provide axial force to the driven rod 72.

[0055] Furthermore, Figure 4a This illustration shows a top-view schematic diagram of a tuning fork resonator according to one embodiment of this application. Figure 4b This diagram illustrates a tuning fork resonator according to one embodiment of this application from an object-side perspective. The X-axis is the optical axis, i.e., the length direction of the lens; the Y-axis is the width direction of the lens; and the Z-axis is the thickness direction of the lens. Figure 1 The up and down directions within. (Reference) Figure 4a and Figure 4b and in conjunction with references Figures 1-3 In one embodiment of this application, the tuning fork resonator 71 has two vibrating arms 74, which are configured to be axially symmetrical about the axis of the driven rod 72. The outer surface of each vibrating arm 74 is planar and parallel to the optical axis. The free end of each vibrating arm 74 has a clamping portion 78, the shape of which is adapted to the shape of the outer surface of the driven rod 72. The vibrating arm 74 also has an intermediate section 77, which is the section of the vibrating arm 74 located between the clamping portion 78 and the connecting portion 75. The piezoelectric element 73 can be mounted on the intermediate section 77. The tuning fork resonator 71 can have two operating states. In the first state, the piezoelectric element 73 presses the vibrating arm 74 inward (i.e., towards the side facing the driven rod 72), thereby clamping the rear ends of the two clamping parts 78 inward and opening the front ends of the two clamping parts 78. The driven rod 72 moves forward under the action of the static friction of the clamping parts 78, that is, moves in the positive direction of the optical axis (see reference). Figure 7 , Figure 7 The working principle of the tuning fork resonator in the first state is shown. In the second state, the piezoelectric element 73 pulls the vibrating arm 74 outward (i.e., away from the side opposite to the driven rod 72), thereby causing the front ends of the two clamping parts 78 to clamp inward, while the rear ends of the two clamping parts 78 open. The driven rod 72 moves backward under the action of the static friction of the clamping parts 78, that is, moves in the negative direction of the optical axis (see reference). Figure 8 , Figure 8The working principle of the tuning fork resonator in the second state is shown. In actual operation, the piezoelectric element 73 oscillates cyclically under the action of the driving signal. Correspondingly, in the first state, the middle section 77 of the vibrating arm 74 repeatedly performs a squeezing-resetting-squeezing-resetting action, causing the driven rod 72 to continuously move relative to the tuning fork resonator 71 along the positive direction of the optical axis. In the second state, the middle section 77 of the vibrating arm 74 repeatedly performs a pulling-resetting-pulling-resetting action, causing the driven rod 72 to continuously move relative to the tuning fork resonator 71 along the negative direction of the optical axis. In this embodiment, when the vibrating arm 74 and the driven rod 72 move relative to each other, the dynamic friction between them can be reduced or eliminated, thereby reducing wear and improving the reliability of the device. On the one hand, reducing the wear on the contact surface of the vibrating arm 74 and the driven rod 72 can prevent deviations in the movement path and amount of movement of the moving parts, leading to a decrease in image quality. On the other hand, reducing the wear on the contact surface of the vibrating arm 74 and the driven rod 72 also helps to reduce the generation of tiny particles from wear, thereby preventing these tiny particles from entering the imaging optical path and contaminating the captured image.

[0056] Furthermore, in one embodiment of this application, the piezoelectric element 73 attached to the outer surface of the vibrating arm 74, under the action of a driving signal at the first frequency, drives the vibrating arm 74 to vibrate, causing the tuning fork resonator 71 to generate resonance at the first frequency, and causing the tuning fork resonator 71 to move relative to the driven rod 72 along the positive direction of the optical axis. On the other hand, under the action of a driving signal at the second frequency, the piezoelectric element 73 drives the vibrating arm 74 to vibrate, causing the tuning fork resonator 71 to generate resonance at the second frequency, and causing the tuning fork resonator 71 to move relative to the driven rod 72 along the negative direction of the optical axis. Specifically, in this embodiment, the tuning fork structure (i.e., the tuning fork resonator 71) has its inherent multi-mode vibration, and the mode shape corresponding to each mode is fixed. That is to say, the motion of the tuning fork structure depends on the excitation frequency it receives, and the mode shape corresponding to each mode is fixed. Essentially, these characteristics depend on the mass distribution and stiffness distribution of the tuning fork structure, which determine the natural frequency and mode shape. As the excitation frequency increases, the tuning fork structure can transition from the first-order mode to the second-order mode, then to the third-order, fourth-order, and so on. Resonance occurs when the frequency corresponding to each mode is reached. Therefore, inputting voltages of different frequencies to the piezoelectric element 73 can induce vibrations of the piezoelectric element 73 at different frequencies. The piezoelectric element 73 transmits this vibration to the tuning fork resonator 71 for amplification. Macroscopically speaking, the tuning fork resonator 71 is subjected to excitations of different frequencies, generating different mode shapes. In this embodiment, the first-order mode shape of the tuning fork resonator 71 can be configured to cause the driven rod 72 to move towards the front end of the lens (the end of the optical lens 100 closer to the object side), and the second-order mode shape can be configured to cause the driven rod 72 to move towards the rear end (the end of the optical lens 100 closer to the image side). Movement towards the front end corresponds to movement in the positive direction of the optical axis. Movement towards the rear end corresponds to movement in the negative direction of the optical axis. Of course, the definitions of positive and negative directions are not limited to these; for example, those skilled in the art can flexibly define them according to different situations. In this embodiment, the axial movement of the driven rod 72 in the positive and negative directions can be achieved using two different vibration modes of the tuning fork resonator 71. It should be noted that in this application, the vibration modes of the tuning fork resonator 71 are not limited to first-order and second-order modes; for example, the tuning fork resonator 71 can also have third-order and fourth-order modes. The third-order mode shape can be, for example, the mode shape that causes the driven rod 72 to rotate clockwise, and the fourth-order mode shape can be, for example, the mode shape that causes the driven rod 72 to rotate counterclockwise. In this embodiment, the driving signal of the piezoelectric element 73 can be configured to the frequencies corresponding to the first-order and second-order modes (i.e., the first and second frequencies mentioned above).

[0057] Furthermore, still referencing Figure 1In one embodiment of this application, the tuning fork resonator 71 further includes a mounting portion 76, which is flat and its thickness direction is parallel to the optical axis. One end of the mounting portion 76 is connected to the connecting portion 75, and the other end is fixed to the lens frame 10 or the second carrier 30. When both ends of the driven rod 72 are fixed to the second carrier 30, the connecting portion 75 is fixed to the lens frame 10 via the mounting portion 76; when both ends of the driven rod 72 are fixed to the lens frame 10, the connecting portion 75 is fixed to the second carrier 30 via the mounting portion 76.

[0058] In one embodiment of this application, an auxiliary piezoelectric element 73 may be attached to the surface of the mounting portion 76 of the tuning fork resonator 71. This auxiliary piezoelectric element 73 generates vibrations perpendicular to the surface of the mounting portion 76. This vibration can increase the axial motion component of the tuning fork resonator 71. That is, by configuring the drive signal, the axial motion component of the vibrating arm 74 can be superimposed on the vibration of the mounting portion 76, thereby increasing the driving force for the overall axial motion of the tuning fork resonator 71.

[0059] Furthermore, Figure 5 A tuning fork resonator is shown in one modified embodiment of this application. Reference Figure 5 In this embodiment, the piezoelectric element 73 is attached to both the outer and inner surfaces of the vibrating arm 74. This design can enhance the driving force of the tuning fork resonator 71.

[0060] Furthermore, Figure 6 A tuning fork resonator is shown in another modified embodiment of this application. Reference Figure 6 In another embodiment of this application, at least a portion of the piezoelectric element is a piezoelectric element 73a formed by stacking multiple piezoelectric materials. Specifically, the multilayer piezoelectric element 73a may include multiple piezoelectric material layers and electrode layers disposed between adjacent piezoelectric material layers. The electrode layers may include first electrode layers and second electrode layers, which are alternately disposed. Each first electrode layer can be electrically connected through a first conductive layer disposed on one side of the multilayer piezoelectric element 73a, and each second electrode layer can be electrically connected through a second conductive layer disposed on the other side of the multilayer piezoelectric element 73a. This stacked multilayer piezoelectric element 73a can enhance the driving force of the piezoelectric element.

[0061] Furthermore, still referencing Figure 1 In one embodiment of this application, the second carrier 30 includes a lens adapter 38 and a carrier frame 39. The lens adapter 38 is used to mount the second lens 50, and the carrier frame 39 forms a carrier receiving cavity. The first carrier 20 and the first driving device ( Figure 1 (Not shown in the image) is disposed within the carrier receiving cavity, and the width of the lens adapter 38 is smaller than the width of the carrier frame 39 when viewed from above.

[0062] Furthermore, in one embodiment of this application, the lens frame 10 includes a base plate and four side walls surrounding the base plate. The tuning fork resonator 71 is fixed to the base plate, and the two ends of the driven rod 72 are respectively fixed to the outer sides of the lens adapter and the carrier frame.

[0063] Furthermore, in another embodiment of this application, the tuning fork resonator 71 is fixed to the outer side of the second carrier (i.e., the lens adapter or the carrier frame), and both ends of the driven rod 72 are fixed to the base plate. Figure 9 A three-dimensional schematic diagram of a tuning fork resonator fixed to a mother-daughter optical lens of the second carrier is shown in this application. Figure 10 It shows Figure 9 A top-view diagram of a mother-and-child optical lens.

[0064] Furthermore, this application also provides a corresponding camera module. This camera module may include a mother-daughter optical lens 100 and a photosensitive component, as described in any of the preceding embodiments. The photosensitive component can be fixed to the lens frame 10, and the photosensitive component includes a photosensitive chip 80 (see reference 1). Figure 1 , Figure 3 , Figure 9-10 The photosensitive chip 80 is adapted to receive light passing through the optical lens 100.

[0065] Furthermore, in one embodiment of this application, the camera module is a periscope module, the periscope module includes a reflecting prism 200, the reflecting prism 200 is fixed to the lens frame 10, and the optical axis of the incident end of the reflecting prism 200 is perpendicular to the optical axis of the exit end, and the optical axis of the exit end is parallel to the optical axis of the optical lens 100.

[0066] In the above embodiments, the piezoelectric element 73 is a substrate exhibiting the inverse piezoelectric effect and contracting or expanding according to the polarization direction and the electric field direction. Specifically, the piezoelectric element 73 can be polarized along the thickness direction of a piezoelectric material layer such as single-crystal, polycrystalline ceramic, or polymer to achieve the inverse piezoelectric effect. The inverse piezoelectric effect refers to the mechanical deformation of a dielectric when an electric field is applied along its polarization direction, resulting in a potential difference. The piezoelectric element 73 has an electrical connector on a surface parallel to the flat segment for movement in a d31 mode. The d31 mode is the mode in which the elongation or shortening direction of the piezoelectric element 73 is perpendicular to the applied electric field direction. In some embodiments of this application, the flat segment of the vibrating arm 74 is reinforced by the piezoelectric element 73, thus causing significant deformation of the flat segment when the piezoelectric element 73 is excited.

[0067] In the above embodiments, the electrode layer of the piezoelectric element 73 can be made of conductive materials such as silver, nickel, or platinum. In the multilayer piezoelectric element 73, metal electrode layers can be arranged between adjacent piezoelectric material layers. First electrode layers and second electrode layers (e.g., the first electrode layer can be a positive electrode, and the second electrode layer can be a negative electrode) are alternately arranged. Thus, in the multilayer piezoelectric element 73, each piezoelectric material layer can have a different potential; for example, odd-numbered layers can have a first potential, and even-numbered layers can have a second potential. The thickness of a single piezoelectric material layer can be in the range of 10~20 μm, which allows for a lower voltage to be applied to the multilayer piezoelectric element 73 compared to a single-layer piezoelectric element 73 of the same thickness. For example, a 0.25 mm thick single-layer piezoelectric element 73 requires 100 V to achieve a working electric field, while a 20-layer multilayer piezoelectric element 73 with a 12.5 μm thickness can operate at 5 V.

[0068] Furthermore, in some embodiments of this application, the piezoelectric element 73 and the tuning fork resonator 71 can be connected by an adhesive. The adhesive has good energy transfer properties, constant thickness, and conductivity. For example, the adhesive can be an adhesive with added silver epoxy or conductive micro-metal spheres. In other embodiments, the piezoelectric element 73 can also be manufactured by directly coating the piezoelectric material onto the surface (e.g., the outer surface) of the tuning fork resonator 71 and then curing it. When the piezoelectric element 73 is a multilayer piezoelectric element 73, it can be directly molded onto the resonator by layer-by-layer coating. The piezoelectric element 73 can also be electrically connected to the tuning fork resonator 71 (e.g., the vibrating arm 74 of the tuning fork resonator 71) using electrolysis technology.

[0069] In some embodiments of this application, the tuning fork resonator 71 is disposed within the lens frame 10, and its position in the optical axis direction is located at the center of the lens frame 10. That is, the initial position of the tuning fork resonator 71 is located at the center of the driven rod 72. The driven rod 72 passes through the connecting portion 75 of the tuning fork resonator 71, and the axis of the driven rod 72 is parallel to the optical axis. The two vibrating arms 74 of the driven rod 72 are axially symmetrical about the axis of the driven rod 72. The magnitude of the excitation frequency of the piezoelectric element 73 and the vibrating arms 74 depends on the geometry and material of the tuning fork resonator 71 (such as the elastic modulus, lateral shrinkage, and density of the material used to manufacture the tuning fork resonator 71). The tuning fork resonator 71 can be integrally formed from a metallic material (e.g., steel). When the material is steel, the operating frequency of the tuning fork resonator 71 can be, for example, between 300 and 500 kHz (i.e., the first frequency for driving positive movement and the second frequency for driving negative movement can both be selected between 300 and 500 kHz). When the material is aluminum, the operating frequency of the tuning fork resonator 71 can be, for example, between 150 and 300 kHz.

[0070] In some embodiments of this application, the second driving device 70 drives the second carrier 30 to move the first lens 40 and the second lens 50 as a whole. The tuning fork resonator 71 based on the piezoelectric element 73 can provide a large stroke and a large driving force, thereby ensuring the response speed of this overall movement. At the same time, due to the presence of a follower rod 72 parallel to the optical axis, and in conjunction with a guide rod 91 disposed on the opposite side, the collimation of the zoom movement of the first lens 40 and the second lens 50 can be significantly improved. Furthermore, since only one follower rod 72 and one guide rod 91 need to be arranged within the lens frame 10, the second driving device 70 occupies a small volume. In other words, this application can improve the collimation of the zoom movement of the first lens 40 and the second lens 50 at the cost of reduced volume, and accommodate moving parts with heavy weight.

[0071] Furthermore, in this application, the first driving device independently drives the first carrier 20, causing the first lens 40 to move and changing the relative distance between the first lens 40 and the second lens 50, thereby further achieving focusing. The first driving device can be any type of motor, such as a voice coil motor, a piezoelectric motor, etc.

[0072] In the above embodiments, the second driving device is implemented as a tuning fork piezoelectric driving device. However, in other embodiments of this application, the tuning fork piezoelectric driving device can be other types of piezoelectric driving devices. For example, the second driving device can be implemented as a traveling wave piezoelectric driving device or a standing wave piezoelectric driving device. The active component is a metal elastic stator with piezoelectric elements attached, and the driven component is a slide rail (i.e., a sliding track). By applying voltage to the piezoelectric elements, the metal elastic stator undergoes wave-like ultrasonic vibration, thereby driving the active component to move linearly along the slide rail (i.e., the driven component) relative to the slide rail.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A mother-and-child optical lens, characterized in that, include: A lens frame having an axis parallel to the optical axis of the optical lens and a first sidewall and a second sidewall located on both sides of the axis; First carrier; The second carrier is located within the lens frame and is movably connected to the lens frame; the first carrier is located within the second carrier and is movably connected to the second carrier; a first gap is formed between the first sidewall and the first side of the second carrier; a first track parallel to the optical axis is provided in the first gap; a second gap is formed between the second sidewall and the second side of the second carrier; a second track parallel to the optical axis is provided in the second gap. A first driving device is adapted to drive the first carrier to move relative to the second carrier along the direction of the optical axis; The first lens is fixed to the first carrier; The second lens is fixed to the second carrier. The third lens is fixed to the lens frame, and the first lens, the second lens and the third lens are arranged coaxially. as well as A second driving device is adapted to drive the second carrier to move relative to the lens frame along the optical axis. The second carrier has a sliding adapter structure on its first side, which is movably connected to the first track; the second driving device is disposed in the second gap and includes a piezoelectric element, a vibration initiating component, and a driven component, wherein the driven component is linear and serves as the second track; the vibration initiating component is mechanically vibrated under the drive of the piezoelectric element attached to its surface and moves relative to the second track along the optical axis, and its movement range is at least 6 mm; The vibration-inducing component is disposed inside the lens frame, and the vibration-inducing component is fixed to the lens frame or the second carrier by a mounting part; The lens frame has an image-side end face and an object-side end face. The distance from the image-side end face to the object-side end face is the inner cavity length of the lens frame, and the inner cavity length is at least 20 mm. The travel of the vibration starter is limited to the middle section of the lens frame, which is a region that satisfies the following conditions: the position of the mounting part is at least 1 / 4 of the inner cavity length from the object-side end face of the lens frame, and the position of the mounting part is at least 1 / 4 of the inner cavity length from the image-side end face of the lens frame.

2. The optical lens according to claim 1, characterized in that, The second driving device is a tuning fork piezoelectric driving device, wherein the vibration starting component is a tuning fork resonator, which has two vibrating arms and a connecting part connecting the two vibrating arms. Each connecting part has a connecting end and a free end. The connecting part connects the connecting ends of the two vibrating arms, and the connecting part has a connecting part through hole. The driven component is a driven rod, which passes through the through hole of the connecting part and is held by the two vibrating arms; the axis of the driven rod is parallel to the optical axis, and both the tuning fork resonator and the driven rod are disposed in the gap between the second carrier and the lens frame; both ends of the driven rod are fixed to the second carrier or the lens frame; wherein, when both ends of the driven rod are fixed to the second carrier, the connecting part is fixed to the lens frame, and when both ends of the driven rod are fixed to the lens frame, the connecting part is fixed to the second carrier; The number of piezoelectric elements is at least two, and the piezoelectric elements are flat. One piezoelectric element is disposed on the outer side of each vibrating arm. The vibrating arm is adapted to resonate under the drive of the piezoelectric elements and form a resultant force pointing in the positive direction of the optical axis at a first vibration frequency and a resultant force pointing in the negative direction of the optical axis at a second vibration frequency.

3. The optical lens according to claim 2, characterized in that, The two vibrating arms are configured to be axially symmetrical about the axis of the driven rod. The outer surface of each vibrating arm is a plane parallel to the optical axis. The free end of each vibrating arm has a clamping portion, the shape of the inner surface of the clamping portion being adapted to the shape of the outer surface of the driven rod.

4. The optical lens according to claim 2, characterized in that, The piezoelectric element is also provided on the inner side of the vibrating arm.

5. The optical lens according to claim 3, characterized in that, The piezoelectric element drives the vibrating arm to vibrate under the action of a driving signal at the first frequency, so that the tuning fork resonator generates resonance at the first frequency. The two vibrating arms open and close cyclically at the first frequency, and the tuning fork resonator moves relative to the driven rod along the positive direction of the optical axis. The piezoelectric element drives the vibrating arm to vibrate under the action of the driving signal at the second frequency, so that the tuning fork resonator generates resonance at the second frequency. The two vibrating arms open and close cyclically at the second frequency, and the tuning fork resonator moves relative to the driven rod along the negative direction of the optical axis.

6. The optical lens according to claim 5, characterized in that, The tuning fork resonator also has a mounting portion, which is flat and its thickness direction is parallel to the optical axis.

7. The optical lens according to claim 6, characterized in that, One end of the mounting part is connected to the connecting part, and the other end is fixed to the lens frame or the second carrier; wherein when both ends of the driven rod are fixed to the second carrier, the connecting part is fixed to the lens frame through the mounting part, and when both ends of the driven rod are fixed to the lens frame, the connecting part is fixed to the second carrier through the mounting part.

8. The optical lens according to claim 7, characterized in that, An auxiliary piezoelectric element is attached to the surface of the mounting portion, and the auxiliary piezoelectric element generates vibration perpendicular to the surface of the mounting portion.

9. The optical lens according to claim 1, characterized in that, At least a portion of the piezoelectric elements are piezoelectric elements formed by stacking multiple layers of piezoelectric materials.

10. The optical lens according to claim 2, characterized in that, The second carrier includes a lens adapter and a carrier frame. The lens adapter is used to mount the second lens, and the carrier frame forms a carrier receiving cavity. The first carrier and the first driving device are disposed in the carrier receiving cavity. From a top-view angle, the width of the lens adapter is smaller than the width of the carrier frame.

11. The optical lens according to claim 10, characterized in that, The lens frame also includes a base plate and a front end and a rear end perpendicular to the optical axis. The front end, the rear end, the first sidewall and the second sidewall surround the second carrier. The base plate is located at the bottom of the second carrier. The third lens is mounted on the front end, and the rear end is adapted to mount a photosensitive component.

12. The optical lens according to claim 11, characterized in that, The tuning fork resonator is fixed to the base plate, and the two ends of the driven rod are respectively fixed to the outer side of the lens adapter and the carrier frame.

13. The optical lens according to claim 11, characterized in that, The tuning fork resonator is fixed to the outer side of the lens adapter or the carrier frame, and both ends of the driven rod are fixed to the base plate.

14. The optical lens according to claim 2, characterized in that, The first track arranged in the first gap is a guide rod, and the two ends of the guide rod are fixed to the lens frame. The sliding adapter structure arranged in the first gap is a through hole adapter structure, and the guide rod passes through the through hole adapter structure and is movably connected to the through hole adapter structure.

15. The optical lens according to claim 14, characterized in that, The first track is disposed on the inner side of the first sidewall, the second track is disposed on the inner side of the second sidewall, and the second driving device is a traveling wave piezoelectric driving device or a standing wave piezoelectric driving device.

16. A camera module, characterized in that, include: The optical lens according to any one of claims 1-15; as well as A photosensitive component, fixed to the lens frame, the photosensitive component including a photosensitive chip adapted to receive light passing through the optical lens.

17. The camera module according to claim 16, characterized in that, The camera module is a periscope module, which includes a reflecting prism fixed to the lens frame. The optical axis of the incident end of the reflecting prism is perpendicular to the optical axis of the exit end, and the optical axis of the exit end is parallel to the optical axis of the optical lens.

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