Prism motor, rotational angle detection method for prism motor, and imaging device

Abstract

A prism motor, a rotational angle detection method for the prism motor, and an imaging device, relating to the technical field of electronic products. The prism motor comprises: a base (100), the base (100) comprising a base plate (101); a prism carrier (200), the prism carrier (200) being arranged above the base plate (101), the prism carrier (200) being configured to carry a prism (201), and the prism carrier (200) being rotatable relative to the base (100) about a first rotational axis (X) and a second rotational axis (Y), the intersection point of the first rotational axis (X) and the second rotational axis (Y) being the center of rotation (O); a first electrode plate (301), the first electrode plate (301) being located on the surface of the base (100), the orthographic projection of the geometric center of the first electrode plate (301) on the base plate (101) coinciding with that of the center of rotation (O) on the base plate (101); a plurality of second electrode plates (302) arranged at intervals, at least two second electrode plates (302) being symmetrically arranged with respect to the plane where the geometric center of the first electrode plate (301) and the first rotational axis (X) are located; and a floating electrode plate (303), the floating electrode plate (303) being located on the bottom surface of the prism carrier (200), and the floating electrode plate (303) being arranged directly opposite the first electrode plate (301) and directly opposite the second electrode plates (302); this at least facilitates improvement to the image stabilization accuracy of the prism motor.

Description

Prism motor, prism motor rotation angle detection method, and camera device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present disclosure claims priority to Chinese Patent Application No. 2024111035309, filed on August 12, 2024, entitled “Prism motor, prism motor rotation angle detection method, and camera device,” which is incorporated by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the technical field of electronic products, and in particular to a prism motor, a prism motor rotation angle detection method, and a camera device. BACKGROUND

[0003] With the development of technology, many electronic devices (such as tablet computers or smart phones) today are equipped with lens modules and have camera or video functions. Lenses can be roughly divided into wide-angle lenses with short focal lengths and telephoto lenses with long focal lengths; however, placing a long focal length lens in an optical module increases the thickness of the electronic device, making it difficult to meet the demand for thin and light mobile terminal devices. In the prior art, a periscope type design is usually used, that is, the optical path is arranged horizontally and a turning prism is added to turn the optical path by 90 degrees, so that the entire optical system is laid flat to reduce the overall height.

[0004] The periscope lens driving device includes a reflection module (prism motor) and a lens module (periscope motor), the reflection module reflects the imaging light by 90° and then enters the lens module, and the lens module performs focusing and imaging. The anti-shake scheme of the periscope module is responsible for anti-shake in two directions by the reflection module and the lens module respectively or jointly.

[0005] However, the anti-shake of the prism motor has the problem of poor precision. SUMMARY

[0006] Embodiments of the present application provide a prism motor, a prism motor rotation angle detection method, and a camera device, which at least help to improve the anti-shake precision of the prism motor.

[0007] According to some embodiments of the present application, the prism motor comprises a base, the base comprising a base plate; a prism carrier, the prism carrier being disposed above the base plate, the prism carrier being configured to carry a prism, the prism carrier being rotatable relative to the base about a first rotation axis and a second rotation axis, the first rotation axis and the second rotation axis being parallel to a surface of the base plate, an intersection of the first rotation axis and the second rotation axis being a rotation center; a first electrode plate, the first electrode plate being disposed on the surface of the base, a geometric center of the first electrode plate having a projection on the base plate that coincides with a projection of the rotation center on the base plate; a plurality of second electrode plates, the second electrode plates being disposed on the surface of the base and spaced apart from the first electrode plate, at least two of the second electrode plates being symmetrically disposed with respect to a plane that passes through the geometric center of the first electrode plate and the first rotation axis; and a floating electrode plate, the floating electrode plate being disposed on a bottom surface of the prism carrier, the floating electrode plate being disposed opposite the first electrode plate and opposite the second electrode plates.

[0008] In some embodiments, at least two of the second electrode plates are symmetrically disposed with respect to a plane that passes through the geometric center of the first electrode plate and the second rotation axis.

[0009] In some embodiments, the first electrode plate comprises a central electrode plate and a plurality of extension electrode plates, the geometric center of the central electrode plate having a projection on the base plate that coincides with a projection of the rotation center on the base plate, the plurality of extension electrode plates being disposed around the central electrode plate and symmetrically with respect to the geometric center of the central electrode plate, each of the extension electrode plates being electrically connected to the central electrode plate; and along a circumferential direction of the central electrode plate, the second electrode plates are disposed between adjacent extension electrode plates.

[0010] In some embodiments, the first electrode plate comprises a hollow portion that extends through the first electrode plate in a thickness direction of the first electrode plate, a geometric center of the hollow portion having a projection on the surface of the base that coincides with a projection of the rotation center on the base, and the second electrode plates are disposed within the hollow portion.

[0011] In some embodiments, the second electrode plates are disposed around the first electrode plate.

[0012] In some embodiments, a projection of the first electrode plate on the surface of the base is within a projection of the floating electrode plate on the surface of the base, and a projection of the second electrode plates on the surface of the base is within a projection of the floating electrode plate on the surface of the base.

[0013] In some embodiments, the floating electrode plate comprises a plurality of conductive plates, the plurality of conductive plates being electrically connected to each other, and a projection of each of the conductive plates on the surface of the base covers a first electrode plate or a second electrode plate.

[0014] In some embodiments, the prism carrier is initially disposed in a position in which the bottom surface of the prism carrier is parallel to the base plate, and relative to the initial position, the prism carrier is rotatable relative to the base about the first rotation axis by an angle of less than or equal to 5°, and the prism carrier is rotatable relative to the base about the second rotation axis by an angle of less than or equal to 5°.

[0015] According to some embodiments of the present application, another aspect of the embodiments of the present application further provides a method for detecting the rotation angle of a prism motor, applied to the prism motor in the above embodiments, comprising: rotating the bottom surface of the prism carrier to an initial position parallel to the bottom plate; rotating the prism carrier clockwise with the first rotation axis to a first target angle, and in the process of rotation, acquiring a plurality of first capacitance values between each second pole plate and the first pole plate at a plurality of rotation angles, fitting a first curve diagram with the rotation angle and the corresponding plurality of first capacitance values; rotating the prism carrier to the initial position; rotating the prism carrier counterclockwise with the first rotation axis to a second target angle, and in the process of rotation, acquiring a plurality of second capacitance values between each second pole plate and the first pole plate at a plurality of rotation angles, fitting a second curve diagram with the rotation angle and the corresponding plurality of second capacitance values; combining the first curve diagram and the second curve diagram to obtain a first capacitance angle curve diagram, the first capacitance angle curve diagram representing the relationship between the capacitance value between each second pole plate and the first pole plate when the prism carrier is rotated to different angles with the first rotation axis relative to the base; acquiring a plurality of first real-time capacitances between the first pole plate and each second pole plate; and bringing the plurality of first real-time capacitances into the first capacitance angle curve diagram to obtain the rotation angle of the prism carrier with the first rotation axis relative to the base.

[0016] According to some embodiments of the present application, still another aspect of the embodiments of the present application further provides a camera device, comprising: the prism motor in the above embodiments; a prism, the prism being arranged on the prism carrier, the incident light direction of the prism being perpendicular to the surface of the bottom plate, and the reflected light direction of the prism being parallel to the first rotation axis; a lens, the focusing direction of the lens being reverse coincident with the reflected light of the prism; and a photosensitive chip, the photosensitive chip being located on the side of the lens away from the prism, and the photosensitive chip being used for receiving the reflected light passing through the lens.

[0017] The technical solutions provided by the embodiments of the present application have at least the following advantages:

[0018] In the prism motor provided by the embodiment of the present application, the prism carrier can rotate relative to the base around the first rotation axis or the second rotation axis, thereby driving the prism carried on the prism carrier to rotate around the first rotation axis or the second rotation axis. When the prism carrier is shaken due to the shaking of the electronic device loaded with the prism motor during the use of the prism motor, the driving assembly in the prism motor can drive the prism carrier to rotate in the opposite direction to offset the displacement caused by the shaking. The bottom plate of the prism motor is provided with a first polar plate and a plurality of second polar plates arranged at intervals, and the bottom surface of the prism carrier is provided with a floating polar plate. The first polar plate and the second polar plates are used to be connected with a detection circuit. A group of capacitors (first capacitors) can be formed between the first polar plate and the floating polar plate. A group of capacitors (second capacitors) can be formed between any second polar plate and the floating polar plate. The capacitance value between any second polar plate and the first polar plate is the series capacitance value of the first capacitors and the second capacitors. The geometric center of the first polar plate is projected on the bottom plate to coincide with the projection of the rotation center on the bottom plate. At least two second polar plates are arranged symmetrically with the geometric center of the first polar plate and the plane where the first rotation axis is located. No matter whether the prism carrier rotates clockwise or counterclockwise relative to the base around the first rotation axis, at least two groups of capacitance values are corresponded to each rotation angle. According to the plurality of groups of capacitance values corresponded to different angles, the change relationship between the rotation angle of the prism carrier around the first rotation axis and the plurality of capacitors can be obtained. Then, during the use of the prism motor, the rotation angle of the prism carrier can be deduced according to the plurality of corresponding capacitance values. In this way, the position state of the prism carrier can be accurately obtained, and the driving assembly can accurately drive the rotation of the prism carrier to offset the displacement caused by the shaking, thereby improving the anti-shaking precision. In addition, the floating polar plate does not need to be connected with the detection circuit, so that the instability of the detection circuit caused by the shaking of the prism carrier can be avoided, which is beneficial to improving the precision of the capacitance value between the first polar plate and the second polar plate, and then improving the accurate calculation of the rotation angle of the prism carrier, so as to improve the anti-shaking precision. BRIEF DESCRIPTION OF DRAWINGS

[0019] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which are illustrative of various embodiments of devices, systems, and methods. In the drawings, like references indicate similar elements in the various figures. Unless otherwise noted, the drawings provided herein are not to scale and are shown as simple schematic illustrations of embodiments of the present disclosure. Unless specifically stated otherwise, the drawings are not to be construed as portraying the proportions of a structure or component. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. It is to be understood that the terminology, such as terms used with semiconductor circuit design and fabrication, can be used interchangeably with comparable terminology in the art. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises" and / or "comprising," or "includes" and / or "including" when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0020] FIG. 1 is a schematic diagram of the overall structure of a prism motor according to an embodiment of the present application;

[0021] Fig. 2 is a schematic view of a cross-section of a prism motor along a first rotation axis according to an embodiment of the present application;

[0022] Fig. 3 is a top view of a first electrode plate and a second electrode plate according to an embodiment of the present application;

[0023] Fig. 4 is a top view of another first electrode plate and another second electrode plate according to an embodiment of the present application;

[0024] Fig. 5 is a top view of still another first electrode plate and still another second electrode plate according to an embodiment of the present application;

[0025] Fig. 6 is a top view of a first electrode plate, a second electrode plate and a floating electrode plate according to an embodiment of the present application;

[0026] Fig. 7 is a top view of another first electrode plate, another second electrode plate and another floating electrode plate according to an embodiment of the present application;

[0027] Fig. 8 is a schematic view of a position of point R in a rectangular coordinate system according to an embodiment of the present application;

[0028] Fig. 9 is a simulation curve when the prism carrier rotates around the first rotation axis according to an embodiment of the present application;

[0029] Fig. 10 is a simulation curve when the prism carrier rotates around the first rotation axis with the second rotation axis rotating ±1° relative to the base according to an embodiment of the present application;

[0030] Fig. 11 is a simulation curve when the prism carrier rotates around the first rotation axis with the second rotation axis rotating every 0.5° according to an embodiment of the present application;

[0031] Fig. 12 is a schematic view of a structure of a camera device according to an embodiment of the present application. DETAILED DESCRIPTION

[0032] As can be seen from the background, the prism motor has the problem of low anti-shake precision.

[0033] The prism motor generally comprises a prism carrier for carrying a prism and a base connected with the prism carrier by elastic sheets to suspend the prism carrier above the base. The prism motor further comprises a first driving assembly and a second driving assembly. The first driving assembly can drive the prism carrier to rotate relative to the base around a first horizontal direction, and the second driving assembly can drive the prism carrier to rotate relative to the base around a second horizontal direction. The intersection of the first horizontal direction and the second horizontal direction is the rotation center of the prism motor. In the use of the prism motor, it is inevitable that the prism carrier cannot be aligned with a lens due to shaking caused by operation problems. The first driving assembly and the second driving assembly can offset the shaking displacement of the prism carrier relative to the base, thereby achieving anti-shake. In the related art, the emitter plate is arranged on the base and the receiver plate is arranged on the prism carrier. When the prism carrier rotates relative to the base, the capacitance between the emitter plate and the receiver plate changes, and the position of the prism carrier is detected according to the change of the capacitance. However, the rotation of the prism carrier relative to the base is not simply the change of the area or distance of the plate, and therefore the capacitance change between the emitter plate and the receiver plate is not a simple linear relationship, which leads to the fact that the relationship between a single capacitance change and the position of the prism carrier cannot be accurately obtained, and further leads to the reduction of the anti-shake precision of the prism motor.

[0034] The prism motor, the method for detecting the rotation angle of the prism motor and the camera device provided in the embodiments of the present application are at least beneficial to improving the anti-shake precision of the prism motor.

[0035] In the description of the embodiments of the present application, the technical terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0036] In this document, the term "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments of the present application, the technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0038] In the description of the embodiments of the present application, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components can also be further included.

[0039] The terms used in the description of various described embodiments herein are only used to describe specific embodiments, and are not intended to be limiting. As used in the description of various described embodiments and the appended claims, "component" is also intended to include the plural form, unless the context clearly indicates otherwise.

[0040] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present application, many technical details are presented in order to enable the reader to better understand the present application. However, the technical solutions claimed by the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0041] FIG. 1 is a schematic diagram of the overall structure of a prism motor according to an embodiment of the present application; FIG. 2 is a schematic diagram of a cross-sectional structure of a prism motor along a first rotation axis according to an embodiment of the present application; FIG. 3 is a top view of a first pole plate and a second pole plate according to an embodiment of the present application; FIG. 4 is a top view of another first pole plate and a second pole plate according to an embodiment of the present application; and FIG. 5 is a top view of still another first pole plate and a second pole plate according to an embodiment of the present application.

[0042] Referring to FIG. 1 to FIG. 5, according to some embodiments of the present application, the prism motor comprises: a base 100 and a prism carrier 200, the base 100 comprises a bottom plate 101, the prism carrier 200 is arranged above the bottom plate 101, the prism carrier 200 is used to carry a prism 201, the prism carrier 200 can rotate around a first rotation axis X relative to the base 100, and the prism carrier 200 can rotate around a second rotation axis Y relative to the base 100, the first rotation axis X and the second rotation axis Y are both parallel to the surface of the bottom plate 101, and the intersection of the first rotation axis X and the second rotation axis Y is a rotation center O. The prism motor further comprises: a first pole plate 301, a plurality of second pole plates 302 arranged at intervals, and a floating pole plate 303, the first pole plate 301 and the second pole plate 302 are both located on the surface of the base 100, the geometric center of the first pole plate 301 coincides with the projection of the rotation center O on the bottom plate 101, the second pole plate 302 is arranged at intervals with the first pole plate 301, and referring to FIG. 3 to FIG. 5, at least two second pole plates 302 are arranged symmetrically with the geometric center of the first pole plate 301 and the plane where the first rotation axis X is located; the floating pole plate 303 is located on the bottom surface of the prism carrier 200, the floating pole plate 303 is arranged opposite to the first pole plate 301 and arranged opposite to the second pole plate 302.

[0043] In the prism motor provided by the embodiments of the present application, the prism carrier 200 can rotate relative to the base 100 about the first rotation axis X or the second rotation axis Y, thereby driving the prism 201 carried on the prism carrier 200 to rotate about the first rotation axis X or the second rotation axis Y. When the prism carrier 200 is shaken due to shaking of the electronic device loaded with the prism motor during use of the prism motor, the driving assembly in the prism motor can drive the prism carrier 200 to rotate in the opposite direction to offset the displacement caused by the shaking. The bottom plate 101 of the prism motor is provided with the first electrode plate 301 and a plurality of second electrode plates 302 arranged at intervals, and the bottom surface of the prism carrier 200 is provided with the floating electrode plate 303. The first electrode plate 301 is used to be connected with the detection circuit, and the first electrode plate 301 and the floating electrode plate 303 can form a group of capacitors (first capacitors). Any second electrode plate 302 and the floating electrode plate 303 can form a group of capacitors (second capacitors). The capacitance value between any second electrode plate and the first electrode plate is the series capacitance value of the first capacitors and the second capacitors. The geometric center of the first electrode plate 301 is projected on the bottom plate 101 to coincide with the projection of the rotation center O on the bottom plate 101, and at least two second electrode plates 302 are arranged symmetrically with the geometric center of the first electrode plate 301 and the plane in which the first rotation axis X is located. No matter whether the prism carrier 200 rotates clockwise or counterclockwise relative to the base 100 about the first rotation axis X, at least two groups of capacitance values are corresponded to each rotation angle. According to the plurality of groups of capacitance values corresponded to different angles, the change relationship between the rotation angle of the prism carrier 200 about the first rotation axis X and the plurality of capacitors can be obtained. Then, during use of the prism motor, the rotation angle of the prism carrier 200 can be deduced according to the plurality of corresponding capacitance values. In this way, the position state of the prism carrier 200 can be accurately obtained, and the driving assembly can accurately drive the rotation of the prism carrier 200 according to the corresponding position state to offset the displacement caused by shaking, thereby improving the anti-shaking precision. In addition, the floating electrode plate 303 does not need to be connected with the detection circuit, and thus the instability of the detection circuit caused by shaking of the prism carrier 200 can be avoided, which is beneficial to improving the precision of the capacitance value obtained between the first electrode plate 301 and the second electrode plate 302, and further improving the accurate calculation of the rotation angle of the prism carrier 200, so as to improve the anti-shaking precision.

[0044] In the embodiments, the first rotation axis X and the second rotation axis Y are perpendicular, i.e., the included angle between the first rotation axis X and the second rotation axis Y is 90°. In some embodiments, the included angle between the first rotation axis and the second rotation axis can be 30°, 45° or 60°.

[0045] In some embodiments, referring to FIG. 2, the base 100 further comprises a side plate 102, which is arranged perpendicularly to the bottom plate 101, and the first rotation axis X is perpendicular to the surface of the side plate 102. Referring to FIGS. 1 and 2, the light path direction L of the prism 201 is parallel to the Z-axis direction, and after being reflected by the prism 201, the light path direction L is refracted to be parallel to the first rotation axis X.

[0046] In some embodiments, a coil assembly can be arranged on the side plate, and a magnet assembly can be arranged on the surface of the prism carrier facing the side plate. The magnet assembly and the coil assembly constitute a driving assembly. When the coil assembly is energized, a magnetic field is generated, and an interaction force is generated between the magnetic field and the magnetic field of the magnet assembly to make the prism carrier rotate.

[0047] With reference to FIGS. 1 to 5, in some embodiments, at least two second plates 302 are arranged symmetrically with respect to the geometric center of the first plate 301 and the plane in which the second rotation axis Y is located. Thus, one second plate 302 and the first plate 301 constitute a group of capacitors (third capacitors), and another second plate 302 and the first plate 301 constitute a group of capacitors (fourth capacitors). Regardless of whether the prism carrier 200 rotates clockwise or counterclockwise about the second rotation axis Y relative to the base 100, at least two groups of capacitance values correspond to each rotation angle. According to the plurality of capacitance values corresponding to different angles, the change relationship between the rotation angle of the prism carrier 200 about the second rotation axis Y and the plurality of capacitances can be obtained. Then, during the use of the prism motor, the rotation angle of the prism carrier 200 can be inferred according to the plurality of corresponding capacitance values. Thus, the position state of the prism carrier 200 can be accurately obtained, and the driving assembly can accurately drive the rotation of the prism carrier 200 according to the corresponding position state to offset the displacement of the shake, thereby improving the anti-shake precision. In combination with the plurality of capacitance change curves corresponding to different angles of the prism carrier 200 rotating about the first rotation axis X and the plurality of capacitance change curves corresponding to different angles of the prism carrier 200 rotating about the second rotation axis Y, the real-time position state of the prism carrier 200 in space rotation can be obtained, thereby realizing double-axis high-precision anti-shake of the prism motor.

[0048] With reference to FIGS. 1 to 3, in some embodiments, the first plate 301 comprises a center plate 311 and a plurality of extension plates 321. The geometric center of the center plate 311 coincides with the orthographic projection of the rotation center O on the bottom plate 101, and the plurality of extension plates 321 are arranged perpendicularly to the center plate 311 and are symmetrically arranged with respect to the geometric center of the center plate 311. Each extension plate 321 is electrically connected to the center plate 311. Along the circumferential direction of the center plate 311, the second plate 302 is located between adjacent extension plates 321.

[0049] In some embodiments, the center plate 311 and the extension plate 321 can be an integral structure; or, in some embodiments, the center plate 311 and the extension plate 321 can be independent of each other and connected by an electrical connection line.

[0050] With reference to FIGS. 1-2 and 4, in some embodiments, the first plate 301 includes a hollow portion 331 extending through the first plate 301 from the thickness direction of the first plate 301, and a geometric center of the hollow portion 331 coincides with a projection of the rotation center O on the surface of the base 100.

[0051] With reference to FIGS. 1-2 and 5(a) or 5(b), in some embodiments, the second plate 302 is located around the first plate 301.

[0052] In some embodiments, with reference to FIGS. 1-5, the second plate 302 is arranged in a central symmetry with respect to the geometric center of the first plate 301. In this way, the change trend of the capacitance value of the corresponding first capacitor when the prism carrier 200 rotates clockwise around the first rotation axis X relative to the base 100 is the same as the change trend of the capacitance value of the second capacitor when the prism carrier 200 rotates counterclockwise around the first rotation axis X relative to the base 100; the change trend of the capacitance value of the corresponding second capacitor when the prism carrier 200 rotates clockwise around the first rotation axis X relative to the base 100 is the same as the change trend of the capacitance value of the first capacitor when the prism carrier 200 rotates counterclockwise around the first rotation axis X relative to the base 100. Similarly, the change trend of the capacitance value of the corresponding third capacitor when the prism carrier 200 rotates clockwise around the second rotation axis Y relative to the base 100 is the same as the change trend of the capacitance value of the fourth capacitor when the prism carrier 200 rotates counterclockwise around the second rotation axis Y relative to the base 100; the change trend of the capacitance value of the corresponding fourth capacitor when the prism carrier 200 rotates clockwise around the second rotation axis Y relative to the base 100 is the same as the change trend of the capacitance value of the third capacitor when the prism carrier 200 rotates counterclockwise around the second rotation axis Y relative to the base 100. In this way, the correspondence between the position state of the prism carrier 200 and the plurality of sets of capacitance values can be facilitated.

[0053] FIG. 6 is a top view of a first plate, a second plate, and a floating plate according to an embodiment of the present application; and FIG. 7 is a top view of another first plate, a second plate, and a floating plate according to an embodiment of the present application. For ease of illustration, the floating plate 303 is transparent in FIGS. 6 and 7.

[0054] With reference to FIGS. 1, 2, 6 and 7, in some embodiments, during the rotation of the prism carrier 200 relative to the base 100 about the first rotation axis X or the second rotation axis Y, the orthographic projection of the first electrode plate 301 on the surface of the base plate 101 is always within the orthographic projection of the floating electrode plate 303 on the surface of the base plate 101, and the orthographic projection of the second electrode plate 302 on the surface of the base plate 101 is always within the orthographic projection of the floating electrode plate 303 on the surface of the base plate 101. In this way, during the rotation of the floating electrode plate 303 driven by the rotation of the prism carrier 200, the effective area of the capacitor formed between the first electrode plate 301 and the floating electrode plate 303 is always the area of the first electrode plate 301, and the effective area of the capacitor formed between the second electrode plate 302 and the floating electrode plate 303 is always the area of the second electrode plate 302, so as to avoid the situation that the change of the capacitor caused by the sudden change of the effective area between the floating electrode plate 303 and the first electrode plate 301 or the second electrode plate 302 fluctuates. The effective area refers to the actual area between the two electrode plates that can store electric charges.

[0055] With reference to FIG. 6, in some embodiments, the floating electrode plate 303 can be a full-surface structure.

[0056] With reference to FIGS. 2 and 7, in some embodiments, the floating electrode plate 303 can include a plurality of conductive plates 313, the plurality of conductive plates 313 are electrically connected to each other, and each conductive plate 313 covers a first electrode plate 301 or a second electrode plate 302 in the orthographic projection on the surface of the base plate 101. In this way, the shape of the floating electrode plate 303 can be designed according to the position and shape of each first electrode plate 301 and second electrode plate 302.

[0057] In some embodiments, the plurality of conductive plates 313 can be in electrical contact with each other, that is, the plurality of conductive plates 313 are integrally formed; or in some embodiments, the plurality of conductive plates 313 can be independent of each other and connected by an electrical connection line.

[0058] In some embodiments, taking the bottom surface of the prism carrier 200 being parallel to the base plate 101 as the initial position, relative to the initial position, the angle of the rotation of the prism carrier 200 relative to the base 100 about the first rotation axis X is less than or equal to 5°, for example, 1°, 1.4°, 2°, 2.5°, 3°, 3.3°, 4°, 4.8° or 5°; and the angle of the rotation of the prism carrier 200 relative to the base 100 about the second rotation axis Y is less than or equal to 5°, for example, 1°, 1.4°, 2°, 2.5°, 3°, 3.3°, 4°, 4.8° or 5°. It should be noted that the rotation of the prism carrier 200 relative to the base 100 about the first rotation axis X can be in the clockwise direction or the counterclockwise direction; and the rotation of the prism carrier 200 relative to the base 100 about the second rotation axis Y can be in the clockwise direction or the counterclockwise direction.

[0059] In the prism motor provided by the embodiments of the present application, the prism carrier 200 can rotate relative to the base 100 about the first rotation axis X or the second rotation axis Y, thereby driving the prism 201 carried on the prism carrier 200 to rotate about the first rotation axis X or the second rotation axis Y. When the prism carrier 200 is shaken due to shaking of the electronic device loaded with the prism motor during use of the prism motor, the driving assembly in the prism motor can be used to drive the prism carrier 200 to rotate in the opposite direction, so as to offset the displacement caused by shaking. The bottom plate 101 of the prism motor is provided with the first electrode plate 301 and a plurality of second electrode plates 302 arranged at intervals, and the bottom surface of the prism carrier 200 is provided with the floating electrode plate 303. The first electrode plate 301 is used to be connected with the detection circuit, and the first electrode plate 301 and the floating electrode plate 303 can form a group of capacitors (first capacitors). Any second electrode plate 302 and the floating electrode plate 303 can form a group of capacitors (second capacitors). The capacitance value between any second electrode plate and the first electrode plate is the series capacitance value of the first capacitors and the second capacitors. The geometric center of the first electrode plate 301 is projected on the bottom plate 101 to coincide with the projection of the rotation center O on the bottom plate 101, and at least two second electrode plates 302 are arranged symmetrically with the geometric center of the first electrode plate 301 and the plane in which the first rotation axis X is located. No matter whether the prism carrier 200 rotates clockwise or counterclockwise relative to the base 100 about the first rotation axis X, at least two groups of capacitance values are corresponded to each rotation angle. According to the plurality of groups of capacitance values corresponded to different angles, the change relationship between the rotation angle of the prism carrier 200 about the first rotation axis X and the plurality of capacitors can be obtained. Then, during use of the prism motor, the rotation angle of the prism carrier 200 can be inversely deduced according to the plurality of corresponding capacitance values. In this way, the position state of the prism carrier 200 can be accurately obtained, and the driving assembly can accurately drive the rotation of the prism carrier 200 according to the corresponding position state to offset the displacement caused by shaking, thereby improving the anti-shake precision. In addition, the floating electrode plate 303 does not need to be connected with the detection circuit, so that the instability of the detection circuit caused by shaking of the prism carrier 200 can be avoided, which is beneficial to improving the precision of the capacitance value between the first electrode plate 301 and the second electrode plate 302, and further improving the accurate calculation of the rotation angle of the prism carrier 200, so as to improve the anti-shake precision.

[0060] Correspondingly, another embodiment of the present application also provides a rotation angle detection method of a prism motor, which is applied to the prism motor in the above embodiments to improve the anti-shake precision of the prism motor. The same or corresponding parts as the previous embodiment can refer to the corresponding description of the previous embodiments, which will not be described in detail below.

[0061] The rotation angle detection method of the prism motor comprises the following steps: rotating the bottom surface of the prism carrier to an initial position parallel to the bottom plate; rotating the prism carrier clockwise around the first rotation axis to a first target angle, and in the process of rotation, obtaining a plurality of first capacitance values between each second electrode plate and the first electrode plate at a plurality of rotation angles, fitting a first curve diagram of the rotation angle and the corresponding plurality of first capacitance values; rotating the prism carrier to the initial position; rotating the prism carrier counterclockwise around the first rotation axis to a second target angle, and in the process of rotation, obtaining a plurality of second capacitance values between each second electrode plate and the first electrode plate at a plurality of rotation angles, fitting a second curve diagram of the rotation angle and the corresponding plurality of second capacitance values; combining the first curve diagram and the second curve diagram to obtain a first capacitance angle curve diagram, which represents the relationship between the capacitance value between each second electrode plate and the first electrode plate when the prism carrier is rotated to different angles around the first rotation axis relative to the base; obtaining a plurality of first real-time capacitances between the first electrode plate and each second electrode plate; and obtaining the rotation angle of the prism carrier around the first rotation axis relative to the base by inputting the plurality of first real-time capacitances into the first capacitance angle curve diagram.

[0062] In some embodiments, when at least two second electrode plates in the prism motor are symmetrically arranged with the geometric center of the first electrode plate and the plane where the second rotation axis is located, the rotation angle detection method of the prism motor further comprises: before rotating the prism carrier clockwise around the first rotation axis to the first target angle, first rotating the prism carrier around the second rotation axis to a preset angle, rotating the prism carrier clockwise around the first rotation axis to the first target angle without changing the preset angle, and in the process of rotation, obtaining a plurality of third capacitance values between each second electrode plate and the first electrode plate at a plurality of rotation angles, fitting a third curve diagram of the rotation angle and the corresponding plurality of third capacitance values; after rotating the prism carrier to the initial position, before rotating the prism carrier counterclockwise around the first rotation axis to the second target angle, first rotating the prism carrier around the second rotation axis to the preset angle, rotating the prism carrier counterclockwise around the first rotation axis to the second target angle without changing the preset angle, and in the process of rotation, obtaining a plurality of fourth capacitance values between each second electrode plate and the first electrode plate at a plurality of rotation angles, fitting a fourth curve diagram of the rotation angle and the corresponding plurality of fourth capacitance values; combining the third curve diagram and the fourth curve diagram to obtain a second capacitance angle curve diagram, which represents the relationship between the capacitance value between each second electrode plate and the first electrode plate when the prism carrier is rotated to different angles around the first rotation axis relative to the base under the condition that the prism carrier is rotated around the second rotation axis relative to the base to the preset angle; obtaining a plurality of second real-time capacitances between the first electrode plate and each second electrode plate; and obtaining the rotation angle of the prism carrier around the first rotation axis and the second rotation axis relative to the base by inputting the plurality of second real-time capacitances into the first capacitance angle curve and the second capacitance angle curve diagram.

[0063] FIG. 8 is a schematic diagram of the position of point R in a rectangular coordinate system according to an embodiment of the present application.

[0064] The first rotation axis X, the second rotation axis Y and the Z axis are taken as a rectangular coordinate system. In the initial position, the intersection of the floating electrode plate and the Z axis is marked as point R. Assuming that the coordinates of any point on the floating electrode plate are (a, b, c), after the floating electrode plate is driven to any angle by the rotation of the prism carrier, the radius d of the point on the floating electrode plate and the center O is unchanged. Since the coordinates of point R in space can be calculated by the following formulas: (1) a2+ b2+ c2= d2; (2) a / c = tan θ; b / c = tan φ', the coordinates of point R (a', b', c') are taken into the above formulas to calculate the surface space equation of the floating electrode plate in the rectangular coordinate system: a a' + b b' + c c' = a2+ b2+ c2. Thus, the distance of any point on the first electrode plate and the second electrode plate to the normal projection point of the floating electrode plate along the Z axis direction can be obtained. Given the shape and corresponding coordinates of the first electrode plate and the second electrode plate, the capacitance calculation formula can be obtained as: C = A * ∫∫1 / [f(a, b) + gap] df(a, b). Wherein, A represents a constant, f(a, b) represents the shape equation of the second electrode plate, and gap represents the distance between the floating electrode plate and the second electrode plate in the initial state.

[0065] Simulation calculation is performed on the first electrode plate and the second electrode plate shown in FIG. 3. FIG. 9 is a simulation curve when the prism carrier rotates around the first rotation axis; FIG. 10 is a simulation curve when the prism carrier rotates around the first rotation axis with the second rotation axis rotating ±1° relative to the base; and FIG. 11 is a simulation curve when the prism carrier rotates around the first rotation axis with the second rotation axis rotating every 0.5°. In FIGS. 9 to 11, the horizontal coordinate represents different angles of the prism carrier rotating around the first rotation axis, and the vertical coordinate represents the capacitance value between a certain second electrode plate and the first electrode plate at the corresponding rotation angle.

[0066] According to FIG. 9, it can be seen that the capacitance values between the first electrode plate and the two second electrode plates which are symmetrical around the first rotation axis and the geometric center of the first electrode plate change obviously, and the capacitance change values between the first electrode plate and the two second electrode plates which are arranged on the two sides of the first rotation axis are very small. Processing the two groups of signals respectively can obtain the corresponding relationship between the angle of the prism carrier rotating around the first rotation axis relative to the base and the capacitance values between different second electrode plates and the first electrode plate.

[0067] According to FIG. 10, it can be seen that the change of the capacitance value between the second electrode plate and the first electrode plate has a good linear relationship with the rotation angle, and since the first electrode plate and the second electrode plate are both arranged in a central symmetric distribution with the geometric center of the first electrode plate as the center, the simulation curve when the prism carrier is rotated around the first rotation axis with the second rotation axis rotating ±1° relative to the base is the same as the simulation curve when the prism carrier is rotated around the second rotation axis with the first rotation axis rotating ±1° relative to the base.

[0068] According to FIG. 11, it can be seen that when the prism carrier is rotated to different angles with the second rotation axis, the corresponding relationship between the rotation angle of the prism carrier when rotated with the first rotation axis and the capacitance value between different second electrode plates and the first electrode plate has a high coincidence degree, and through decoupling processing, the angle of the prism carrier relative to the base around the first rotation axis and the angle of the prism carrier relative to the base around the second rotation axis can be accurately obtained, thereby facilitating the formation of a closed-loop control system, accurately controlling the spatial position of the prism, and improving the anti-shake performance of the prism motor.

[0069] Correspondingly, another embodiment of the present application also provides a camera device, which comprises the prism motor in the above embodiments, and can accurately obtain the position state of the prism carrier, so that the driving assembly can accurately drive the rotation of the prism carrier according to the corresponding position state to offset the displacement of the shake, thereby improving the anti-shake precision. The same or corresponding parts as the previous embodiment can refer to the corresponding description of the previous embodiment, and will not be described in detail hereinafter.

[0070] FIG. 12 is a structural schematic diagram of a camera device according to an embodiment of the present application. For the convenience of description, only the reflecting surface 211 of the prism 201 is shown in FIG. 12.

[0071] With reference to FIGS. 1, 2 and 12, the camera device comprises the prism motor in the above embodiments, the prism 201 arranged on the prism carrier 200, the incident light direction of the prism 201 being perpendicular to the surface of the base plate 101, and the reflected light direction of the prism 201 being parallel to the first rotation axis X; the lens 401, the focusing direction of which is reversely coincident with the reflected light of the prism 201; and the photosensitive chip 402, which is located on the side of the lens 401 away from the prism 201 and is used to receive the reflected light passing through the lens 401.

[0072] In some embodiments, the camera assembly can further comprise the light-transmitting sheet 403, through which the incident light is irradiated on the prism 201.

[0073] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for realizing the present application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the present application. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A prism motor, comprising: a base, the base comprising a base plate; a prism carrier, the prism carrier being disposed above the base plate, the prism carrier being configured to carry a prism, the prism carrier being rotatable relative to the base about a first rotation axis and a second rotation axis, the first rotation axis and the second rotation axis both being parallel to a surface of the base plate, an intersection of the first rotation axis and the second rotation axis being a rotation center; a first electrode plate, the first electrode plate being located on the surface of the base, a geometric center of the first electrode plate having a projection on the base plate that coincides with a projection of the rotation center on the base plate; a plurality of second electrode plates, the second electrode plates being located on the surface of the base and being spaced apart from the first electrode plate, at least two of the second electrode plates being symmetrically disposed with respect to a plane that includes the geometric center of the first electrode plate and the first rotation axis; a floating electrode plate, the floating electrode plate being located on a bottom surface of the prism carrier, the floating electrode plate being disposed opposite the first electrode plate and opposite the second electrode plates.

2. The prism motor of claim 1, wherein, at least two of the second electrode plates are symmetrically disposed with respect to a plane that includes the geometric center of the first electrode plate and the second rotation axis.

3. The prism motor of claim 1, wherein, the first electrode plate comprises a central electrode plate and a plurality of extension electrode plates, the central electrode plate having a geometric center that coincides with a projection of the rotation center on the base plate, the plurality of extension electrode plates being located around the central electrode plate and being symmetrically disposed with respect to the geometric center of the central electrode plate, each of the extension electrode plates being electrically connected to the central electrode plate, the second electrode plates being located between adjacent extension electrode plates along a circumferential direction of the central electrode plate.

4. The prism motor of claim 1, wherein, the first electrode plate comprises a hollow portion that extends through the first electrode plate in a thickness direction of the first electrode plate, the hollow portion having a geometric center that coincides with a projection of the rotation center on the base plate, the second electrode plates being located within the hollow portion.

5. The prism motor of claim 1, wherein, the second electrode plates are located around the first electrode plate.

6. The prism motor of claim 1, wherein, a projection of the first electrode plate on the surface of the base plate is located within a projection of the floating electrode plate on the surface of the base plate, and a projection of the second electrode plates on the surface of the base plate is located within the projection of the floating electrode plate on the surface of the base plate.

7. The prism motor of claim 1, wherein, the floating electrode plate comprises a plurality of conductive plates, the conductive plates being electrically connected to each other, each of the conductive plates having a projection on the surface of the base plate that covers a first electrode plate or a second electrode plate.

8. The prism motor of claim 1, wherein, with a bottom surface of the prism carrier being parallel to the base plate as an initial position, the prism carrier being rotatable relative to the base about the first rotation axis by an angle that is less than or equal to 5° with respect to the initial position, and the prism carrier being rotatable relative to the base about the second rotation axis by an angle that is less than or equal to 5° with respect to the initial position. 9.A method for detecting a rotation angle of a prism motor, applied to the prism motor according to any one of claims 1 to 8, comprising: rotating a bottom surface of the prism carrier to an initial position in which the bottom surface is parallel to the base plate; rotating the prism carrier clockwise to a first target angle along the first rotation axis, and acquiring a plurality of first capacitance values between each of the second plates and the first plate at a plurality of rotation angles during the rotation, and fitting a first curve graph of rotation angle and corresponding plurality of first capacitance values; rotating the prism carrier to the initial position; rotating the prism carrier counterclockwise to a second target angle along the first rotation axis, and acquiring a plurality of second capacitance values between each of the second plates and the first plate at a plurality of rotation angles during the rotation, and fitting a second curve graph of rotation angle and corresponding plurality of second capacitance values; acquiring a first capacitance angle curve graph by combining the first curve graph and the second curve graph, the first capacitance angle curve graph representing a relationship between a capacitance value between each of the second plates and the first plate when the prism carrier is rotated to different angles relative to the base along the first rotation axis; acquiring a plurality of first real-time capacitances between the first plate and each of the second plates; acquiring a rotation angle of the prism carrier relative to the base along the first rotation axis by inputting the plurality of first real-time capacitances into the first capacitance angle curve graph.

10. A camera device, comprising: the prism motor according to any one of claims 1-8; a prism disposed on the prism carrier, an incident light direction of the prism being perpendicular to the bottom surface, and a reflected light direction of the prism being parallel to the first rotation axis; a lens, a focusing direction of the lens being reverse coincident with the reflected light of the prism; a photosensitive chip located on a side of the lens away from the prism, the photosensitive chip being configured to receive the reflected light through the lens.

Images