Focal length adjusting device of optical assembly and camera module

Abstract

The invention provides a focal length adjusting device of an optical assembly and a camera module. The focal length adjusting device comprises a base, a carrier movably arranged on the base and used for bearing a lens, a driving mechanism arranged on the base and used for driving the carrier to move, and a position detection device. The position detection device comprises a detection magnet arranged on the carrier and a sensor assembly fixed on the base and arranged opposite to the detection magnet; the sensor assembly comprises a magnetoresistive sensor used for detecting the displacement of a carrier and a magnetic field sensor used for detecting the initial position of the carrier. The detection magnet and the sensor assembly are arranged at an interval, and when the detection magnet moves along with the carrier, the magnetic field change can be sensed by the magnetoresistive sensor and the magnetic field sensor. The camera module comprises the focal length adjusting device of the optical assembly.

Description

Technical Field

[0001] This disclosure relates to a focal length adjustment device and a camera module for an optical component. Background Technology

[0002] In the field of optical imaging, devices such as camera modules typically achieve autofocus or optical zoom by moving the lens. This functionality relies on the precise detection and control of the lens mount's position.

[0003] There are some non-contact position detection solutions in the existing technology. However, these solutions still have problems with insufficient detection accuracy and poor reliability in position feedback, which limits the further improvement of the performance of the drive control system. Summary of the Invention

[0004] This disclosure provides a focal length adjustment device for an optical component and a camera module.

[0005] According to one aspect of this disclosure, a focal length adjustment device for an optical component is provided, comprising: a base; a carrier movably disposed on the base for supporting a lens of the optical component; a driving mechanism disposed on the base for driving the carrier to move; and a position detection device, the position detection device comprising: a detection magnet disposed on the carrier; and a sensor assembly fixedly disposed on the base and opposite to the detection magnet, the sensor assembly comprising a magnetoresistive sensor for detecting the displacement of the carrier and a magnetic field sensor for detecting the initial position of the carrier; wherein the detection magnet and the sensor assembly are spaced apart, such that when the detection magnet moves with the carrier, the change in the magnetic field of the detection magnet can be sensed by the magnetoresistive sensor and the magnetic field sensor.

[0006] According to one aspect of the technical solution of this disclosure, the focal length adjustment device of the optical component detects the position of the carrier through magnetic induction between a detection magnet disposed on the carrier and a sensor assembly disposed on the base. When the drive mechanism drives the carrier to move, the detection magnet moves with the carrier, and its magnetic field changes; the magnetoresistive sensor in the sensor assembly is used to detect the displacement and real-time position of the carrier, and the magnetic field sensor is used to detect the initial position of the carrier during movement. By combining the magnetoresistive sensor and the magnetic field sensor, more accurate and reliable position detection of the carrier is achieved, solving the problems of insufficient detection accuracy and poor reliability of existing detection schemes in the background art.

[0007] According to at least one embodiment of the optical component focal length adjustment device of the present disclosure, the magnetoresistive sensor is a tunnel magnetoresistive sensor.

[0008] In the technical solution of this embodiment, the tunnel magnetoresistive sensor has the characteristics of high sensitivity and high precision, which can more accurately detect the displacement of the carrier, thereby improving the accuracy of position detection.

[0009] In a focal length adjustment device of an optical component according to at least one embodiment of the present disclosure, the magnetic field sensor is a Hall sensor.

[0010] In the technical solution of this embodiment, the Hall sensor can reliably detect the presence of a magnetic field, which is used to accurately determine the initial position of the carrier and enhance the stability of the system.

[0011] The focal length adjustment device of the optical component according to at least one embodiment of the present disclosure further includes a flexible circuit board, which is fixed to the base and the sensor component is integrated on the flexible circuit board.

[0012] In this embodiment, the sensor assembly is integrated onto a flexible circuit board, which simplifies the wiring and installation structure of the sensor assembly.

[0013] A focal length adjustment device for an optical component according to at least one embodiment of the present disclosure, wherein a flexible circuit board includes a base plate and a side plate extending from the edge of the base plate, and a sensor assembly is disposed on the side plate.

[0014] In the technical solution of this embodiment, the side plate formed by bending provides an optimized mounting plane for the sensor assembly, enabling it to more accurately align with the detection magnet and ensuring the stability of the sensing distance and direction.

[0015] According to at least one embodiment of the optical component of the present disclosure, the focal length adjustment device detects a magnet fixed to a carrier by a shim.

[0016] In the technical solution of this embodiment, the shim provides a stable mounting reference for the detection magnet, which helps to ensure the accuracy of the relative position between the detection magnet and the sensor assembly and prevents the detection magnet from becoming loose.

[0017] According to at least one embodiment of the present disclosure, the optical component includes a first lens and a second lens, and the carrier includes a first carrier and a second carrier. The first carrier is used to carry the first lens to realize the focusing function of the optical component through its own displacement, and the second carrier is used to carry the second lens to realize the zoom function of the optical component through its own displacement.

[0018] In the technical solution of this embodiment, by setting a first carrier and a second carrier that respectively carry the first lens and the second lens, and driving their displacement respectively, the separation and coordination of focusing and zooming functions are realized, thereby improving the imaging performance of the optical components.

[0019] According to at least one embodiment of the optical component focal length adjustment device of the present disclosure, a first carrier is provided with a first limiting magnet at one end, a second carrier is provided with a second limiting magnet at one end, and a limiting steel plate is provided on the base, the limiting steel plate and the first limiting magnet and the second limiting magnet generate magnetic attraction force.

[0020] In the technical solution of this embodiment, the magnetic attraction force generated between the limiting steel plate and the first limiting magnet and the second limiting magnet can stably attract the first carrier and the second carrier to a specific position in the non-driving state of the driving mechanism, preventing them from undergoing unexpected displacement.

[0021] According to at least one embodiment of the focal length adjustment device of the optical component of the present disclosure, a magnetic shielding sheet is provided on the opposing surfaces of the first limiting magnet and the second limiting magnet.

[0022] In the technical solution of this embodiment, the magnetic shielding sheet can effectively weaken or isolate the mutual magnetic force influence between the first limiting magnet and the second limiting magnet, and avoid unnecessary attraction or repulsion when the two carriers are close to each other.

[0023] According to one aspect of this disclosure, a camera module is provided, comprising: an optical component including a lens; and a focus adjustment device for the optical component of any one of the above.

[0024] According to one aspect of the technical solution of this disclosure, the camera module, through the focal length adjustment device integrating the above-mentioned optical components, can achieve precise and stable driving and control of the lens position, thereby obtaining high-quality focusing and zoom imaging effects. Attached Figure Description

[0025] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0026] Figure 1 This is a schematic diagram of the focal length adjustment device of an optical component according to one embodiment of the present disclosure.

[0027] Figure 2 This is a structural schematic diagram of a position detection device and a flexible circuit board according to one embodiment of the present disclosure.

[0028] Figure 3 This is a schematic diagram of the structure of a reference component according to one embodiment of the present disclosure.

[0029] Figure 4 This is a schematic diagram of the connection between a reference component and a base according to one embodiment of the present disclosure.

[0030] Figure 5This is a schematic diagram of the structure of a base according to one embodiment of the present disclosure.

[0031] Figure 6 This is a schematic diagram of the connection between the clamping mechanism and the driving mechanism according to one embodiment of the present disclosure.

[0032] Figure 7 This is an exploded view of a clamping mechanism according to one embodiment of the present disclosure.

[0033] Figure 8 This is a schematic diagram of the structure connecting the clamping mechanism of an optical component to a carrier according to one embodiment of the present disclosure.

[0034] Explanation of reference numerals in the attached figures: 100 bases 110 Limiting Steel Plate 120 limit stop 121 Positioning slot 200 carriers 210 First Carrier 211 First limiting magnet 220 Second Carrier 221 Second limiting magnet 230 Magnetic shielding sheet 240 Guide V-groove 250 guide groove 300 drive mechanism 310 Piezoelectric Actuator 311 Piezoelectric Drive Shaft 400 Position Detection Device 410 Detecting Magnets 420 Sensor Assembly 421 Tunnel Magnetoresistive Sensor 422 Hall Sensor 430 gasket 500 Flexible Circuit Board 510 base plate 520 side panel 600 Guiding Mechanism 610 First guide rail 620 Second Guide Rail 700 reference component 710 Positioning Department 711 Positioning Card Slot 800 clamping mechanism 810 piezoelectric spring 811 Elastic lever arm 811A First Elastic Lever Arm 811B Second Elastic Lever Arm 811C Third Elastic Lever Arm 811D Fourth Elastic Lever Arm 812 Clamping gap 813 pad 814 Positioning V-groove 815 Hollow Structure 820 Reliability Spring 821 First lever arm 822 Second lever arm 823 Cushion Pad. Detailed Implementation

[0035] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0036] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] Unless otherwise stated, the exemplary implementations / embodiments shown are to be understood as providing exemplary features of various details that provide ways in which the technical concepts of this disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of various implementations / embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of this disclosure.

[0038] To facilitate description and make the technical solutions of this disclosure easier to understand, the terminology of this disclosure will be explained before describing the technical solutions of this disclosure.

[0039] Focal length adjustment device: refers to the mechanism assembly that changes the imaging focal length of the optical system by driving the optical lens to produce physical displacement. Its core function is to realize autofocus and / or optical zoom.

[0040] Position detection device: refers to a component that detects the position of moving parts in real time through non-contact sensing, and its function is to provide accurate position feedback signals.

[0041] In the existing technology, there are some non-contact position detection schemes (such as those based on magnetic detection) for detecting the position of the lens carrier. However, these schemes still face challenges in achieving high-precision and high-stability position feedback. For example, there are problems such as insufficient detection accuracy or poor reliability, which limits the further improvement of the performance of the drive control system.

[0042] Figure 1 This is a schematic diagram of the focal length adjustment device of an optical component according to one embodiment of the present disclosure. Figure 2 This is a structural schematic diagram of a position detection device and a flexible circuit board according to one embodiment of the present disclosure.

[0043] like Figure 1 and Figure 2 As shown, this disclosure provides a focal length adjustment device for an optical component, including a base 100, a carrier 200, a drive mechanism 300, and a position detection device 400.

[0044] The base 100 provides an installation foundation and structural support for the carrier 200, the drive mechanism 300 and the position detection device 400.

[0045] The carrier 200 is movably mounted on the base 100 to support the lens of the optical components and to adjust the focal length by means of its displacement.

[0046] The drive mechanism 300 is located on the base 100 and is used to drive the carrier 200 to move.

[0047] A position detection device 400, used to detect the real-time position of the carrier 200, includes a detection magnet 410 and a sensor assembly 420. The detection magnet 410 is disposed on the carrier 200 and moves synchronously with the carrier 200. The sensor assembly 420 is fixedly disposed on the base 100 and is disposed opposite to the detection magnet 410. The sensor assembly 420 includes a magnetoresistive sensor 421 for detecting the displacement of the carrier 200 and a magnetic field sensor 422 for detecting the initial position of the carrier 200. The detection magnet 410 and the sensor assembly 420 are spaced apart.

[0048] The focal length adjustment device of the optical component in the above technical solution works on the following principle: when the drive mechanism 300 drives the carrier 200 to move, the detection magnet 410 fixed on the carrier 200 moves accordingly, causing a change in the spatial distribution of the magnetic field around it. The sensor component 420 fixed on the base 100 detects the position of the carrier 200 by sensing the change in the magnetic field. Specifically, the magnetic field sensor 422 is used to detect the initial position (zero point) of the carrier 200, while the magnetoresistive sensor 421, with its high sensitivity, detects the displacement and real-time position of the carrier 200 during its movement. The focal length adjustment device of the optical component in the above technical solution combines the magnetic field sensor 422 and the magnetoresistive sensor 421, which can improve the accuracy and reliability of the carrier 200 position detection, effectively solving the problems of insufficient detection accuracy and poor stability of the non-contact position detection scheme mentioned in the background technology, and providing a reliable guarantee for the drive mechanism 300 to achieve precise closed-loop control.

[0049] For example, the magnetoresistive sensor 421 is a tunnel magnetoresistive sensor 421. The tunnel magnetoresistive sensor 421 operates based on the tunnel magnetoresistive effect and has extremely high magnetic field sensitivity. It can detect minute changes in the magnetic field generated by the detection magnet 410 when the carrier 200 moves, thereby achieving high-precision measurement of the displacement of the carrier 200 and providing an extremely accurate position feedback signal for the closed-loop control system.

[0050] As an example, the magnetic field sensor 422 is a Hall sensor 422. The Hall sensor 422 operates based on the Hall effect and can reliably detect the presence and strength of a magnetic field. In this position detection device 400, the Hall sensor 422 is mainly used to detect the initial or zero-point position of the carrier 200. This position information can serve as a reference point for displacement calculation by the tunnel magnetoresistive sensor 421, ensuring the accuracy and repeatability of the system's positioning.

[0051] In some embodiments of this disclosure, a flexible circuit board 500 is also included, which is fixed to the base 100, and the sensor assembly 420 is integrated on the flexible circuit board 500. Integrating the tunnel magnetoresistive sensor 421 and the Hall sensor 422 together on the flexible circuit board 500 simplifies the electrical connections and mechanical mounting structure of the sensor assembly 420. The flexible circuit board 500 is directly fixed to the base 100, providing a stable mounting reference for the sensor assembly 420, while also simplifying wiring and improving assembly efficiency and reliability.

[0052] Furthermore, the flexible circuit board 500 includes a base plate 510 and a side plate 520 extending from the edge of the base plate 510, with the sensor assembly 420 disposed on the side plate 520. By bending a portion of the flexible circuit board 500 to form the side plate 520, the portion carrying the sensor assembly 420 can be adjusted to a suitable spatial orientation, enabling the sensor assembly 420 to maintain an opposing relationship with the detection magnet 410 disposed on the carrier 200, ensuring the stability of the sensing distance and direction, thereby optimizing the detection effect.

[0053] In some embodiments of this disclosure, the detection magnet 410 is fixed to the carrier 200 by a shim 430. The shim 430 serves as an installation accessory, assisting in the positioning and fixation of the detection magnet 410 on the carrier 200. The shim 430 allows for more precise control of the installation height and orientation of the detection magnet 410 relative to the carrier 200, ensuring a preset, consistent sensing distance between it and the sensor assembly 420 on the base 100, while also enhancing the mechanical stability of the detection magnet 410 installation.

[0054] like Figure 1As shown, in some embodiments of this disclosure, the optical component includes a first lens and a second lens (not shown), and the carrier 200 includes a first carrier 210 and a second carrier 220. The first carrier 210 carries the first lens to achieve the focusing function of the optical component through its own displacement, and the second carrier 220 carries the second lens to achieve the zoom function of the optical component through its own displacement. By setting two independent carriers 200 to carry different lenses respectively and controlling their displacement separately, the focusing function and the optical zoom function can be decoupled and work in concert. First, the first carrier 210 is driven to move to complete the focusing, and then the second carrier 220 is driven to move to achieve the zoom, thereby obtaining a higher quality imaging effect.

[0055] For example, one end of the first carrier 210 is provided with a first limiting magnet 211, one end of the second carrier 220 is provided with a second limiting magnet 221, and a limiting steel plate 110 is provided on the base 100. The limiting steel plate 110 generates a magnetic attraction force with the first limiting magnet 211 and the second limiting magnet 221. The first limiting magnet 211, the second limiting magnet 221, and the limiting steel plate 110 on the base 100 together constitute a magnetic attraction limiting mechanism. When the carrier 200 moves to a specific position (such as the focusing and zooming end position of the optical component), the magnetic attraction force can stably attract and hold the carrier 200 in that position, effectively preventing the carrier 200 from undergoing unexpected displacement due to vibration or inertia in a non-driven state, thus improving the anti-interference capability and stability of the device.

[0056] Furthermore, a magnetic shielding sheet 230 is provided on the opposing surfaces of the first limiting magnet 211 and the second limiting magnet 221. The magnetic shielding sheet 230 is made of a magnetic shielding material, and its function is to weaken or block the direct magnetic interaction between the first limiting magnet 211 and the second limiting magnet 221. When the two carriers 200 approach each other, the magnetic shielding sheet 230 can prevent unnecessary attractive or repulsive forces from being generated between their limiting magnets, thereby preventing the movements of the two carriers 200 from interfering with each other and ensuring the independence of their respective movements.

[0057] In the prior art, the guide mechanism 600 and the drive mechanism 300 are installed on the base 100 in a step-by-step and independent manner. Due to the existence of machining tolerances of parts and cumulative errors from multiple assembly, it is difficult to ensure the precise parallelism between the drive direction and the guide direction, which directly affects the motion accuracy and stability of the carrier 200.

[0058] Figure 3 This is a schematic diagram of the structure of a reference component according to one embodiment of the present disclosure.

[0059] like Figure 1 and Figure 3 As shown, the focal length adjustment device of the optical component disclosed herein also includes a guide mechanism 600 and a reference member 700.

[0060] The guide mechanism 600 is disposed on the base 100 and cooperates with the carrier 200 to constrain the movement trajectory of the carrier 200 so that it moves in a predetermined direction.

[0061] The reference component 700 is fixedly mounted on the base 100, and a plurality of positioning parts 710 are provided thereon. These positioning parts 710 form at least two positioning structures that extend or are arranged along two mutually parallel straight lines.

[0062] Among them, a part of the guide mechanism 600 and a part of the drive mechanism 300 are respectively engaged with positioning structures that extend or are arranged along different straight directions.

[0063] The working principle and beneficial effects of the focal length adjustment device of the optical components in the above technical solution are as follows: By installing the components of the guide mechanism 600 and the drive mechanism 300 into a pre-machined parallel positioning structure on the reference component 700, the relative positions of these components can be determined based on the same high-precision reference during assembly. This design replaces the complex process of adjusting and positioning each component separately on the base 100 in the traditional solution, effectively eliminating the cumulative errors caused by multiple adjustments, thereby ensuring that the moving direction of the carrier 200 is strictly parallel to the driving direction of the drive mechanism 300, and solving the parallelism accuracy problem caused by step-by-step independent installation in the background technology.

[0064] In some embodiments of this disclosure, the guiding mechanism 600 includes a first guide rail 610, and a guide V-groove 240 is provided at the bottom of the carrier 200. The first guide rail 610 is disposed within the guide V-groove 240 for guiding the carrier 200 to move in a straight line. The cooperation between the V-groove and the first guide rail 610 has a self-centering characteristic, which can effectively constrain the degree of freedom of the carrier 200 in the horizontal plane, ensure that the carrier 200 moves accurately in a single direction, and prevent deviation during movement.

[0065] Furthermore, the guiding mechanism 600 also includes a second guide rail 620. The bottom of the carrier 200 is provided with a guide groove 250 with a square cross-section. The second guide rail 620 is disposed within the guide groove 250 to support the carrier 200. The cooperation between the square groove and the second guide rail 620 mainly provides a stable support surface to bear the weight of the carrier 200 and the optical lens it supports. The V-groove of the first guide rail 610 is responsible for precise positioning and guidance, while the square groove of the second guide rail 620 is responsible for main support. Together, they ensure the smoothness and accuracy of the carrier 200's movement.

[0066] For example, the positioning part 710 is provided with positioning slots 711, and the two ends of the first guide rail 610 are respectively disposed in the positioning slots 711 of the two positioning parts 710 arranged along the first straight line direction. By embedding the two ends of the first guide rail 610 into the two positioning slots 711 arranged along the same straight line direction, it can be ensured that the first guide rail 610 is accurately positioned on the reference member 700, thereby establishing the reference direction for the movement of the carrier 200.

[0067] In some embodiments of this disclosure, the drive mechanism 300 is a piezoelectric actuator 310, which includes a piezoelectric drive shaft 311. Both ends of the piezoelectric drive shaft 311 are respectively disposed in positioning slots 711 of two positioning portions 710 arranged along a second straight line, which is parallel to the first straight line. The piezoelectric drive shaft 311 is fixed by its two ends being embedded in the positioning slots 711 arranged along the second straight line. Because the second straight line is parallel to the first straight line, the axial direction of the piezoelectric drive shaft 311 automatically aligns with the guiding direction of the first guide rail 610, achieving parallelism between the driving direction and the motion direction, simplifying the assembly process, and improving transmission accuracy.

[0068] Figure 4 This is a schematic diagram of the connection between a reference component and a base according to one embodiment of the present disclosure. Figure 5 This is a schematic diagram of the structure of a base according to one embodiment of the present disclosure.

[0069] As an example, such as Figure 4 and Figure 5 As shown, the reference component 700 is installed and fixed on the base 100 by a mounting structure. The mounting structure includes three mutually perpendicular limiting baffles 120, which form a positioning groove 121 in which the reference component 700 is embedded. The positioning groove 121 formed by the three mutually perpendicular limiting baffles 120 can constrain the reference component 700 from three spatial directions simultaneously. The reference component 700 can achieve quick and accurate positioning and installation by directly embedding it into the groove, without complex adjustments, effectively simplifying the assembly process and ensuring the positional accuracy of the reference component 700 relative to the base 100.

[0070] When the aforementioned focus adjustment device is applied to a camera module, the reference component 700 in the focus adjustment device ensures the parallelism between the guide mechanism 600 and the drive mechanism 300, enabling the camera module to reliably complete autofocus and optical zoom operations, ultimately obtaining high-quality images.

[0071] The working process of the focal length adjustment device of the optical component in the above technical solution is as follows: When the focus needs to be adjusted, the drive mechanism 300 starts to work. If the drive mechanism 300 is a piezoelectric actuator 310, its piezoelectric drive shaft 311 will produce precise micro-amplitude extension and retraction movements under the drive of an electrical signal. Since the two ends of the piezoelectric drive shaft 311 are respectively set in two positioning slots 711 arranged along the second straight line on the reference member 700, its axis of motion has been precisely constrained.

[0072] The driving force of the drive mechanism 300 is transmitted to the carrier 200 through a corresponding transmission structure (such as friction drive), causing the carrier 200 to move. The V-shaped guide groove 240 at the bottom of the carrier 200 cooperates with the first guide rail 610, utilizing the self-centering characteristic of the V-shaped structure to precisely constrain the movement trajectory of the carrier 200 in the horizontal plane and prevent deviation. At the same time, the square guide groove 250 at the bottom of the carrier 200 cooperates with the second guide rail 620 to provide stable rigid support for the entire carrier 200 and bear the main load.

[0073] Throughout the movement, the detection magnet 410 (if present) on the carrier 200 moves synchronously with the carrier 200. Its magnetic field changes can be detected by corresponding sensors (such as tunnel magnetoresistive sensor 421, Hall sensor 422), forming a position closed-loop feedback to achieve precise displacement control.

[0074] After the carrier 200 moves to the target position, the drive stops. At this time, the first limiting magnet 211 on the first carrier 210 and the second limiting magnet 221 on the second carrier 220 will generate a magnetic attraction force with the limiting steel plate 110 on the base 100. This magnetic attraction force can firmly attract and hold the two carriers 200 in this position, preventing them from undergoing unexpected displacement due to external vibration or inertia, and ensuring the stability of the optical system. The magnetic shielding sheet 230 set on the opposite surface of the two limiting magnets effectively avoids unnecessary magnetic interference between their magnets when the two carriers 200 are close together.

[0075] The first guide rail 610 of the guide mechanism 600 is positioned at both ends within two positioning slots 711 arranged along the first straight line on the reference component 700. Since these positioning structures on the reference component 700 are manufactured to ensure that the first straight line and the second straight line (the straight line in which the piezoelectric drive shaft 311 is installed) are strictly parallel, the moving direction of the carrier 200 (guided by the first guide rail 610) and the driving direction of the drive mechanism 300 (axial direction of the piezoelectric drive shaft 311) are automatically aligned from the design source and assembly reference, ensuring extremely high parallelism.

[0076] The reference component 700 itself is embedded in the positioning groove 121 formed by three mutually perpendicular limiting baffles 120 on the base 100, which enables quick and accurate installation and fixation, thus laying a solid structural foundation for the parallelism reference.

[0077] When this focus adjustment device is applied to a camera module, the optical path of the lens it carries (such as the first lens and the second lens) is directed towards the image sensor. By precisely controlling the displacement of the first carrier 210 (focusing) and the second carrier 220 (zooming), a clear, high-quality image with different magnifications is ultimately obtained on the image sensor.

[0078] When the aforementioned optical component's focus adjustment device is applied to a camera module, it enables precise, rapid, and stable driving and control of the lens position. The position detection device 400 in the focus adjustment device ensures closed-loop control of the carrier 200's position, while the drive mechanism 300 provides driving power, enabling the camera module to efficiently and reliably complete autofocus and optical zoom operations, ultimately obtaining clear, high-quality images.

[0079] In existing technologies, clamping mechanisms 800 used for piezoelectric drives often employ a single spring structure. When subjected to external impacts such as drops or collisions, the impact force is directly transmitted to the joint between the spring and the drive shaft, easily causing plastic deformation or damage to the spring. This not only affects transmission accuracy but may also cause the mechanism to malfunction, making it difficult to meet the requirements of high-reliability applications such as mobile devices.

[0080] Figure 6 This is a schematic diagram of the connection between the clamping mechanism and the driving mechanism according to one embodiment of the present disclosure. Figure 7 This is an exploded view of a clamping mechanism according to one embodiment of the present disclosure.

[0081] like Figure 1 , Figure 6 and Figure 7 As shown, the focal length adjustment device of this disclosure also includes a clamping mechanism 800 for the piezoelectric actuator 310. The drive mechanism 300 is the piezoelectric actuator 310, which includes a piezoelectric drive shaft 311. The clamping mechanism 800 includes a piezoelectric spring 810 and a reliability spring 820.

[0082] The piezoelectric spring 810 is the core of the power transmission of the clamping mechanism 800, and includes at least two elastic arms 811. The arms are spaced apart to form a clamping gap 812 for clamping the piezoelectric drive shaft 311. The piezoelectric spring 810 clamps the drive shaft through the elastic arms 811 and transmits the driving force of the piezoelectric drive shaft 311 through friction with the surface of the drive shaft.

[0083] The reliability spring 820 is a reliability-enhancing component of the clamping mechanism 800. One end of it is fixedly connected to the piezoelectric spring 810, and the other end is used to directly or indirectly connect to the carrier 200 that carries the lens assembly. The main function of the reliability spring 820 is to absorb and disperse energy when the clamping mechanism 800 is subjected to external impact.

[0084] Among them, the reliability spring 820 is designed to have a greater elastic coefficient than the piezoelectric spring 810, so that in terms of mechanical response, when the clamping mechanism 800 is subjected to external impact, the reliability spring 820 will act before the piezoelectric spring 810.

[0085] The clamping mechanism 800 for the piezoelectric actuator 310 described above employs a composite structure of a piezoelectric spring 810 and a reliability spring 820. During normal operation, the piezoelectric spring 810 is responsible for power transmission. When subjected to external impact, due to the higher elastic modulus of the reliability spring 820, according to mechanical principles, the impact load preferentially causes the reliability spring 820 to undergo greater elastic deformation. During this process, a large amount of impact energy is consumed and dissipated, effectively preventing the core component, the piezoelectric spring 810, from undergoing permanent plastic deformation or damage due to excessive stress. This not only reduces the risk of functional failure of the clamping mechanism 800, but more importantly, ensures the stability of the clamping force and the accuracy of the relative position between the piezoelectric spring 810 and the drive shaft after the impact, thereby ensuring driving accuracy and the service life of the clamping mechanism 800, and solving the problems of poor impact resistance and insufficient reliability of the single spring structure in existing technologies.

[0086] In some embodiments of this disclosure, the piezoelectric spring 810 includes four elastic arms 811, wherein the extending direction of at least one elastic arm 811 is spatially offset from the extending directions of the other elastic arms 811, so that the four elastic arms 811 together enclose and form a clamping gap 812. This design allows the four arms to surround the piezoelectric drive shaft 311 from different directions, forming a stable multi-point contact, increasing the contact area, and making the clamping force distribution more uniform. At the same time, the arrangement of the arms in different directions enhances the stability of clamping, prevents the drive shaft from shifting or sliding during movement, and improves the accuracy and reliability of power transmission.

[0087] For example, the four elastic arms of the piezoelectric spring 810 can be specifically divided into a first elastic arm 811A, a second elastic arm 811B, a third elastic arm 811C, and a fourth elastic arm 811D. The first elastic arm 811A, the third elastic arm 811C, and the fourth elastic arm 811D are fixed and bent in a forward position, while the second elastic arm 811B is fixed in a different posture in a rearward position, thereby forming a clamping gap 812 from multiple directions (front, back, left, and right) to achieve stable clamping of the piezoelectric drive shaft 311.

[0088] Furthermore, the piezoelectric spring 810 also includes a pad 813, from which four elastic lever arms 811 extend. One end of the reliability spring 820 is soldered to the pad 813. The pad 813 provides a uniform mounting reference for all elastic lever arms 811, ensuring the relative positional accuracy between the lever arms. By directly soldering the reliability spring 820 to the pad 813, a stable connection between the two springs is achieved, and the soldering process is easily automated, ensuring consistency and reliability.

[0089] For example, at least one elastic lever arm 811 has a positioning V-groove 814 formed thereon for positioning and accommodating the piezoelectric drive shaft 311. The positioning V-groove 814 structure forms line contact or surface contact with the cylindrical drive shaft, has self-centering characteristics, and can automatically adjust the position of the drive shaft in the groove to ensure precise positioning. This contact method also increases the contact area and improves the efficiency and stability of friction force transmission.

[0090] As an example, at least one elastic lever arm 811 is provided with a hollow structure 815. The hollow design can reduce the weight of the spring without affecting the clamping function, and at the same time, by adjusting the local stiffness to optimize the stress distribution, it helps to improve the fatigue life and response characteristics of the elastic lever arm 811.

[0091] Figure 8 This is a schematic diagram of the structure connecting the clamping mechanism of an optical component to a carrier according to one embodiment of the present disclosure.

[0092] Combination Figure 8 As shown, in some embodiments of this disclosure, the reliability spring 820 includes a spring body and a buffer pad 823 disposed at the other end of the spring body. The buffer pad 823 is used to connect the carrier 200. The buffer pad 823, as an elastic connection interface, is made of an elastic material with good damping characteristics, and can effectively absorb and attenuate the vibration and impact energy transmitted from the carrier 200, playing multiple roles of buffering, shock absorption, noise reduction, and damping. Together with the spring body of the reliability spring 820, it constitutes a composite structure that simultaneously possesses buffering, noise reduction, and damping functions.

[0093] Furthermore, the main body of the spring includes a first lever arm 821 and a second lever arm 822. One end of the first lever arm 821 is fixedly connected to the piezoelectric spring 810, and the second lever arm 822 extends from the other end of the first lever arm 821 and is located in a different plane from the first lever arm 821. This three-dimensional bending structure of the main body of the spring increases the degree of freedom of deformation of the reliable spring 820 in space, enabling it to more effectively absorb and disperse impact energy from different directions through three-dimensional bending.

[0094] As an example, the first lever arm 821 and the second lever arm 822 are perpendicular to each other. The L-shaped structure arranged at a 90-degree angle enables the reliability spring 820 to convert part of the impact energy into elastic potential energy through vertical deformation when subjected to axial impact, while providing support and cushioning in two mutually perpendicular directions.

[0095] In one specific embodiment, the buffer pad 823 is integrally formed with the main body of the reliability spring 820 (particularly the end of the second lever arm 822) via a glue injection process. During assembly, after assembling the reliability spring 820 with the buffer pad 823 and other metal components such as the carrier 200, the buffer pad 823 can be tightly bonded to the surface of the carrier 200 again via a glue injection process. This process ensures the robustness of the connection of the buffer pad 823 and further optimizes its buffering, damping, and noise reduction effects.

[0096] The working process of the clamping mechanism 800 for the piezoelectric actuator 310 in the above technical solution is as follows: When the piezoelectric drive shaft 311 is displaced, the driving force is transmitted through the friction between the piezoelectric spring 810 and the surface of the drive shaft. The four elastic arms 811 of the piezoelectric spring 810 surround the drive shaft from different directions, with at least one arm's extension direction spatially offset from the others, forming a stable multi-point contact. Specifically, the positioning V-groove 814 structure on the arm forms line or surface contact with the cylindrical drive shaft, utilizing its self-centering characteristic to ensure precise positioning of the drive shaft within the clamping gap 812. The hollow structure 815 provided on some of the elastic arms 811 optimizes the stress distribution and response characteristics of the arms while ensuring clamping force.

[0097] Under normal operating conditions, the four elastic arms 811 formed by the extension of the pad 813 provide a uniform clamping force. The reliability spring 820 is fixedly connected to the pad 813 by welding, and at this time it mainly plays an auxiliary support role.

[0098] When the camera module is subjected to an external impact, the impact force is first transmitted to the carrier 200. The reliability spring 820, which is connected to the carrier 200 via the buffer pad 823, comes into play first. Since the elastic modulus of the reliability spring 820 is greater than that of the piezoelectric spring 810, the impact load will preferentially cause the reliability spring 820 to deform. The main body of the reliability spring 820 adopts a three-dimensional bending design, with the first lever arm 821 and the second lever arm 822 perpendicular to each other to form an L-shaped structure. This multi-plane arrangement allows it to effectively absorb and disperse impact energy from different directions through three-dimensional bending. At the same time, the buffer pad 823, as an elastic connection interface, further absorbs and attenuates vibration energy. This graded impact resistance mechanism ensures that most of the impact energy is absorbed by the reliability spring 820 and the buffer pad 823, effectively protecting the piezoelectric spring 810 and reducing the risk of plastic deformation or damage to the piezoelectric spring 810. After the impact, each component returns to its original shape under elastic action, and the clamping force and relative position between the piezoelectric spring 810 and the drive shaft remain stable, thereby ensuring that the transmission accuracy is not affected.

[0099] When the clamping mechanism 800 is applied to an optical focal length adjustment device or a camera module, the above working process ensures a continuous and stable power transmission, enabling the carrier 200 to accurately drive the lens assembly to achieve focal length adjustment, and maintaining reliable imaging quality even in relatively harsh operating environments.

[0100] When the aforementioned clamping mechanism 800 is applied to an optical focal length adjustment device, the clamping mechanism 800 reliably transmits the displacement of the piezoelectric drive shaft 311 to the carrier 200, thereby achieving precise control of the lens position and ensuring that the device can maintain accuracy and reliability even when subjected to external impacts.

[0101] This disclosure also provides a camera module, including: an optical component (not shown) and the above-mentioned focus adjustment device, wherein the optical component includes a lens assembly, and the lens assembly includes at least one lens.

[0102] Firstly, regarding motion control accuracy and stability, the reference component 700 establishes a unified installation reference for the guide mechanism 600 and the drive shaft, eliminating parallelism errors at the source and ensuring the precise trajectory of the carrier 200's movement. The position detection device 400 provides real-time, closed-loop feedback signals for this motion, enabling the control system to perform extremely precise closed-loop control of the carrier 200's position. The combination of these two components jointly ensures high speed, high precision, and high stability during the focusing and zooming processes.

[0103] Secondly, regarding impact resistance and reliability, the clamping mechanism 800, which works in conjunction with the piezoelectric spring 810 and the reliability spring 820, forms a protective structure. When the module is dropped or impacted, the reliability spring 820, with its larger elastic coefficient, will preferentially undergo elastic deformation, effectively absorbing and dissipating most of the impact energy, protecting the piezoelectric spring 810, which is directly responsible for precision transmission, and the more precise piezoelectric actuator 310 from plastic deformation or damage. The magnetic attraction limiting structure between the carrier 200 and the base 100 further enhances static stability, preventing the carrier 200 from shifting when not in operation.

[0104] In summary, this highly integrated camera module can achieve high image quality, fast response speed, and better durability in an extremely compact space, making it suitable for mobile devices with high requirements for size, image quality, and reliability.

[0105] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0106] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. A focal length adjustment device for an optical component, characterized in that, include: Base; A carrier, which is movably disposed on the base, is used to support the lens of the optical component; A drive mechanism, disposed on the base, is used to drive the carrier to move. Position detection device, the position detection device comprising: A detection magnet, the detection magnet being disposed on the carrier, and A sensor assembly is fixedly mounted on the base and positioned opposite the detection magnet. The sensor assembly includes a magnetoresistive sensor for detecting the displacement of the carrier and a magnetic field sensor for detecting the initial position of the carrier. The detection magnet and the sensor assembly are spaced apart, so that when the detection magnet moves with the carrier, the change in the magnetic field of the detection magnet can be sensed by the magnetoresistive sensor and the magnetic field sensor.

2. The focal length adjustment device for the optical component according to claim 1, characterized in that, The magnetoresistive sensor is a tunnel magnetoresistive sensor.

3. The focal length adjustment device for an optical component according to claim 1, characterized in that, The magnetic field sensor is a Hall sensor.

4. The focal length adjustment device for an optical component according to claim 1, characterized in that, It also includes a flexible circuit board, which is fixed to the base, and the sensor assembly is integrated on the flexible circuit board.

5. The focal length adjustment device for an optical component according to claim 4, characterized in that, The flexible circuit board includes a base plate and a side plate that extends from the edge of the base plate, and the sensor assembly is disposed on the side plate.

6. The focal length adjustment device for an optical component according to claim 1, characterized in that, The detection magnet is fixed to the carrier by a spacer.

7. The focal length adjustment device for an optical component according to claim 1, characterized in that, The optical component includes a first lens and a second lens, and the carrier includes a first carrier and a second carrier. The first carrier is used to support the first lens so that the optical component can achieve focusing by its own displacement, and the second carrier is used to support the second lens so that the optical component can achieve zooming by its own displacement.

8. The focal length adjustment device for an optical component according to claim 7, characterized in that, One end of the first carrier is provided with a first limiting magnet, one end of the second carrier is provided with a second limiting magnet, and a limiting steel plate is provided on the base. The limiting steel plate generates magnetic attraction with the first limiting magnet and the second limiting magnet.

9. The focal length adjustment device for an optical component according to claim 8, characterized in that, A magnetic shielding sheet is provided on the opposite surfaces of the first limiting magnet and the second limiting magnet.

10. A camera module, characterized in that, include: Optical components, including lenses; as well as The focal length adjustment device for the optical component according to any one of claims 1 to 9.

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