Prism motor, rotation angle measurement method for prism motor, and photographing module

Abstract

Embodiments of the present application relate to the technical field of photographing, and disclose a prism motor, a rotation angle measurement method for the prism motor, and a photographing module. The prism motor in the present application comprises: first electrode plates located on the surface of a prism base; second electrode plates located on the surface of a prism carrier, wherein the second electrode plates are arranged opposite to the first electrode plates, each first electrode plate and the corresponding second electrode plate form a capacitor, and when the prism carrier rotates in a single direction about a first rotation axis, the facing area between the first electrode plate and the second electrode plate increases and the distance between the first electrode plate and the second electrode plate decreases, or the facing area between the first electrode plate and the second electrode plate decreases and the distance between the first electrode plate and the second electrode plate increases; and a processing unit used for determining the rotation angle of the prism carrier on the basis of capacitance signals generated by the capacitors formed by the first electrode plates and the second electrode plates. The present application facilitates the miniaturization of motors, and improves the effect of prism carrier offset angle measurement.

Description

A prism motor, a method for detecting the rotation angle of the prism motor, and an imaging module. Cross-references

[0001] This disclosure claims priority to Chinese Patent Application No. 202411572917.9, filed on November 5, 2024, entitled "A Prism Motor, a Method for Detecting the Rotation Angle of a Prism Motor and an Imaging Module", which is incorporated herein by reference in its entirety. Technical Field

[0002] This application relates to the field of camera technology, and in particular to a prism motor, a method for detecting the rotation angle of the prism motor, and a shooting module. Background Technology

[0003] Currently, periscope imaging modules typically use prism motors to refract incident light. By folding the incident light, the focal length of the imaging module is extended, thereby enhancing its zoom capability. When using the imaging module for image acquisition, the propagation angle of the incident light can be changed by rotating the prism carrier in the prism motor, thus altering the imaging effect of the module. The rotation angle of the prism carrier is usually detected by a built-in Hall sensor or a driver chip with Hall detection functionality.

[0004] However, the current rotation angle detection function of periscope imaging modules has at least the following drawbacks: Hall sensors or driver chips with Hall detection functionality need to work in conjunction with corresponding sensing magnets to measure the angle. Placing the Hall sensor and corresponding magnet inside the prism motor occupies a significant amount of internal space, hindering motor miniaturization. Furthermore, with a fixed internal space within the motor, the large space occupied by the Hall sensor and magnet also limits the size of the drive module used to drive the prism motor, thus limiting the improvement of the prism motor's driving capability. Summary of the Invention

[0005] The purpose of this application is to provide a prism motor, a method for detecting the rotation angle of the prism motor, and an imaging module, which saves the internal volume of the prism motor occupied for detecting the rotation angle of the prism motor, which is conducive to the miniaturization of the motor and improves the effect of detecting the offset angle of the prism carrier.

[0006] To address the aforementioned technical problems, embodiments of this application provide a prism motor, comprising: a prism base; a prism carrier, the prism carrier being spaced apart from the prism base and rotatable relative to the prism base; a first electrode plate located on the surface of the prism base; a second electrode plate located on the surface of the prism carrier and disposed opposite to the first electrode plate; the first electrode plate and the second electrode plate forming a capacitor, wherein when the prism carrier rotates unidirectionally around a first rotation axis, the facing area between the first electrode plate and the second electrode plate increases and the distance between the first electrode plate and the second electrode plate decreases, or the facing area between the first electrode plate and the second electrode plate decreases and the distance between the first electrode plate and the second electrode plate increases; and a processing unit configured to determine the rotation angle of the prism carrier based on a capacitance signal generated by the capacitor formed by the first electrode plate and the second electrode plate.

[0007] An embodiment of this application also provides a method for detecting the rotation angle of a prism motor, applied to the aforementioned prism motor. The method includes: determining an initial capacitance signal generated by the capacitance formed by the first and second plates at the initial position of the prism carrier; determining a current capacitance signal when the capacitance signal generated by the capacitance formed by the first and second plates changes; and determining the rotation angle of the prism carrier based on the difference between the current capacitance signal and the initial capacitance signal.

[0008] An embodiment of this application also provides a shooting module, including the aforementioned prism motor, lens, and photosensitive chip; incident light entering the shooting module is reflected by the prism motor and then passes through the lens to reach the photosensitive chip.

[0009] Compared to existing technologies, this application's embodiments involve setting a first electrode plate on the prism base and a second electrode plate on the prism carrier, utilizing the first and second electrode plates to form a capacitor. The rotation angle of the prism carrier is determined by the change in the capacitance signal. Using a smaller electrode plate instead of a Hall sensor in the motor saves internal space in the prism motor required for detecting the rotation angle, thus facilitating motor miniaturization. Furthermore, when the prism carrier rotates in one direction, both the facing area and the spacing between the first and second electrode plates change simultaneously. The change in facing area and spacing has the same effect on the capacitance signal; either the change in facing area or spacing will increase the capacitance signal, or both will decrease it. Therefore, the simultaneous change in facing area and spacing results in a larger amplitude change in capacitance signal under the same rotation angle, leading to more sensitive detection of the prism carrier's rotation angle and improving the effectiveness of prism carrier offset angle detection.

[0010] Furthermore, the number of first electrodes is even, and multiple first electrodes are symmetrically arranged based on the first rotation axis of the prism carrier; the number of second electrodes is also even, and multiple second electrodes are symmetrically arranged based on the first rotation axis of the prism carrier; the first electrodes and second electrodes correspond one-to-one, and each pair of first electrodes and second electrodes forms a capacitor; the processing unit is used to determine the rotation angle of the prism carrier based on the capacitance signals generated by the multiple capacitors formed by the first electrodes and second electrodes. By increasing the number of electrodes, the number of capacitors used to detect the rotation angle is increased, and the accuracy of rotation angle detection can be further improved through comprehensive analysis of the capacitance signals of multiple sets of capacitors.

[0011] Furthermore, the first electrode plate is symmetrically arranged based on the second rotation axis of the prism carrier, and the second electrode plate is also symmetrically arranged based on the second rotation axis of the prism carrier; wherein the first rotation axis and the second rotation axis are perpendicular to each other. When the prism motor can rotate in multiple directions, by arranging the electrode plates in a symmetrical structure, the degree of change in the capacitance signals of the multiple sets of capacitors formed by the multiple electrode plates can be ensured to be approximately the same during rotation. This facilitates subsequent calculations to minimize the influence of rotation angles in other directions on the detection results, improving the accuracy of single-direction rotation angle calculations.

[0012] Furthermore, the length of the first electrode is greater than the length of the second electrode; wherein the direction defining the length is consistent with the direction of the first rotation axis. This reduces the impact of rotation angles in other directions (such as the second rotation axis) on the magnitude of the capacitance signal generated by the first and second electrodes on the first rotation axis.

[0013] In addition, the prism motor further includes: a third electrode plate located on the surface of the prism base; a fourth electrode plate located on the surface of the prism carrier, and the fourth electrode plate being disposed opposite to the third electrode plate; the third and fourth electrode plates forming a capacitor, such that when the prism carrier rotates unidirectionally around the second rotation axis, the facing area between the third and fourth electrode plates increases and the distance between the third and fourth electrode plates decreases, or the facing area between the third and fourth electrode plates decreases and the distance between the third and fourth electrode plates increases; wherein the first rotation axis and the second rotation axis are perpendicular to each other; and a processing unit used to jointly determine the angle of rotation of the prism carrier in space based on the capacitance signal generated by the capacitance formed by the first and second electrode plates, and the signal generated by the capacitance formed by the third and fourth electrode plates. This allows for the design of different electrode plate structures for corresponding detection when the prism carrier can rotate in multiple directions.

[0014] In addition, the number of the third plates is even, and the third plates are symmetrically arranged based on the second rotation axis of the prism carrier; the number of the fourth plates is even, and the fourth plates are symmetrically arranged based on the second rotation axis of the prism carrier; the third plates and the fourth plates correspond one-to-one, and each pair of third plates and fourth plates forms a capacitor.

[0015] In addition, the planes on which the first and second electrode plates are located are parallel to the first rotation axis, and the planes on which the third and fourth electrode plates are located are parallel to the second rotation axis.

[0016] In addition, the orthographic projection of the first electrode plate toward the second electrode plate falls outside the second electrode plate, and the orthographic projection of the second electrode plate toward the first electrode plate falls outside the first electrode plate. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 is a three-dimensional structural diagram of the prism motor according to an embodiment of this solution;

[0019] Figure 2 is a cross-sectional structural diagram of the prism motor according to an embodiment of this solution;

[0020] Figure 3 is a schematic diagram of the structure of the second pole plate of the prism motor rotating around the first rotation axis according to an embodiment of this scheme;

[0021] Figure 4 is a schematic diagram of a first and second electrode plate arrangement of a prism motor according to an embodiment of this solution.

[0022] Figure 5 is a schematic diagram of another arrangement of the first and second pole plates of the prism motor according to an embodiment of this solution;

[0023] Figure 6 is a schematic diagram of the spatial position change of the second pole plate of the prism motor rotating around the first rotation axis according to an embodiment of this scheme.

[0024] Figure 7 is a schematic diagram of the simulation results of the prism motor according to the embodiment of this scheme;

[0025] Figure 8 is a schematic diagram comparing the dimensions of the first and second pole plates of the prism motor according to an embodiment of this scheme.

[0026] Figure 9 is a schematic diagram of the structure of the second pole plate of the prism motor rotating around the second rotation axis according to an embodiment of this scheme;

[0027] Figure 10 is a top view of a structure of a third and fourth pole plate arrangement of a prism motor according to an embodiment of this scheme.

[0028] Figure 11 is a top view of another arrangement of the third and fourth pole plates of the prism motor according to an embodiment of this solution;

[0029] Figure 12 is a top-view view of another arrangement of the third and fourth pole plates of the prism motor according to an embodiment of this scheme;

[0030] Figure 13 is a schematic diagram showing the positional relationship between the first and second pole plates in the prism motor according to an embodiment of this scheme.

[0031] Figure 14 is a schematic diagram of the shape of the first and second pole plates in the prism motor according to an embodiment of the present solution.

[0032] Figure 15 is a schematic diagram of another shape of the first and second pole plate pairs in the prism motor according to an embodiment of the present solution;

[0033] Figure 16 is a schematic diagram of another shape of the first and second pole plate pairs in the prism motor according to an embodiment of this scheme;

[0034] Figure 17 is a flowchart of the rotation angle detection method of the prism motor according to an embodiment of this solution;

[0035] Figure 18 is a schematic diagram of the shooting module according to an embodiment of this solution. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0037] The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0038] The embodiments of this application relate to a prism motor, as shown in Figures 1 and 2. The prism motor includes: a prism base 100; a prism carrier 200, which is spaced apart from the prism base 100 and is rotatable relative to the prism base 100; a first electrode plate 301, which is located on the surface of the prism base 100; and a second electrode plate 302, which is located on the surface of the prism carrier 200 and is opposite to the first electrode plate 301. The first electrode plate 301 and the second electrode plate 302 form a... The capacitor, when the prism carrier 200 rotates in one direction around the first rotation axis, increases the facing area between the first electrode 301 and the second electrode 302 and decreases the distance between the first electrode 301 and the second electrode 302, or decreases the facing area between the first electrode 301 and the second electrode 302 and increases the distance between the first electrode 301 and the second electrode 302; the processing unit is used to determine the rotation angle of the prism carrier 200 based on the capacitance signal generated by the capacitance formed by the first electrode 301 and the second electrode 302.

[0039] Compared to the prior art, this embodiment of the application provides a first electrode plate 301 on the prism base 100 and a second electrode plate 302 on the prism carrier 200. The first electrode plate 301 and the second electrode plate 302 form a capacitor, and the rotation angle of the prism carrier 200 is determined by the change in the capacitance signal, thereby compensating for angle changes caused by jitter. Using a smaller electrode plate instead of a Hall sensor in the motor saves internal space in the prism motor required for the anti-shake technology, which is beneficial for motor miniaturization. Furthermore, when the prism carrier 200 rotates in one direction, it simultaneously changes the facing area and spacing between the first electrode plate 301 and the second electrode plate 302. Moreover, the change in facing area and the change in spacing have the same effect on the capacitance signal. That is, the change in facing area and the change in spacing will both lead to an increase in capacitance signal, or both will lead to a decrease in capacitance signal. Therefore, the simultaneous change in facing area and spacing will make the amplitude of capacitance signal change greater under the same rotation angle, resulting in more sensitive detection of the angular rotation of the prism carrier 200 and improving the effect of prism carrier 200 offset angle detection.

[0040] Additionally, as shown in Figure 2, the prism base 100 includes a base bottom 101 and a base side 102. The first electrode plate 301 can be disposed at the base bottom 101 and / or the base side 102 according to the rotation direction of the prism carrier 200.

[0041] As shown in Figures 1 and 3, the X-axis is the direction in which the incident light enters the prism motor, the Z-axis is the direction in which the incident light enters the lens perpendicularly after reflection, and the Y-axis is perpendicular to the XZ plane. Taking the rotation of the prism carrier 200 around the first rotation axis (Y-axis) as an example, the first electrode plate 301 is fixed on the prism base 100. Before the prism carrier 200 rotates, the position of the second electrode plate 302 is shown by the solid line in Figure 3. When the prism carrier 200 rotates by an angle θ around the first rotation axis (Y-axis), the position of the second electrode plate 302 is shown by the dashed line in Figure 3. After rotation, the area of ​​the first electrode plate 301 and the second electrode plate 302 facing each other decreases, and the average distance between the first electrode plate 301 and the second electrode plate 302 increases. This causes a change in the capacitance signal corresponding to the capacitor formed by the first electrode 301 and the second electrode 302. The rotation angle θ of the second electrode 302 can be determined by the change in the capacitance signal. Since the second electrode 302 is fixed on the prism carrier 200, the rotation angle of the second electrode 302 corresponds to the rotation angle of the prism carrier 200. Therefore, the rotation angle of the prism carrier 200 can be obtained based on the rotation angle of the second electrode 302, thereby compensating for the change in the angle of the prism carrier 200 caused by the shaking.

[0042] In addition, the number of first electrode plates 301 is even, and the multiple first electrode plates 301 are symmetrically arranged based on the first rotation axis of the prism carrier 200; the number of second electrode plates 302 is even, and the multiple second electrode plates 302 are symmetrically arranged based on the first rotation axis of the prism carrier 200; the first electrode plates 301 and the second electrode plates 302 correspond one-to-one, and each pair of first electrode plates 301 and second electrode plates 302 forms a capacitor; the processing unit is used to determine the rotation angle of the prism carrier 200 based on the capacitance signal generated by the multiple capacitors formed by the first electrode plates 301 and the second electrode plates 302.

[0043] Taking an example where there are two first electrode plates 301 and two second electrode plates 302, as shown in Figures 4 and 5, the planes containing the two first electrode plates 301 and the two second electrode plates 302 are parallel to the first rotation axis (Y-axis), and the two first electrode plates 301 are located on opposite sides of the first rotation axis, symmetrically arranged relative to the first rotation axis. The two second electrode plates 302 are located on opposite sides of the first rotation axis, symmetrically arranged relative to the first rotation axis.

[0044] When the first electrode plate 301 is disposed at the bottom 101 of the base, the second electrode plate 302 is disposed at the bottom of the prism carrier 200. In addition, the prism base 100 is a semi-enclosed structure with three sides and one bottom surface. When the first electrode plate 301 is disposed at the rear side of the base, the second electrode plate 302 is disposed at the prism side opposite to the rear side of the base.

[0045] The following section uses the first and second plates of the first rotating axis in Figure 6 as examples to explain in detail how to calculate the capacitance caused by the rotation of the second plate, taking the capacitance calculation of the left plate as an example:

[0046] When the second plate 302 rotates clockwise along the Y-axis, the average gap between the first plate 301 and the second plate 302 on the left side of the figure increases, while the area S of their opposing plates decreases. The increase in the average gap and the decrease in the area S will jointly exacerbate the decrease in capacitance. Therefore, this method can accelerate the change in capacitance, thereby improving the sensitivity of the capacitor.

[0047] The initial plane equation for the second plate 302 on the left side of the diagram is:

[0048] x1 = -Rcosα,

[0049] Where x1 represents the X-axis coordinate value of the initial plane of the second electrode plate 302, T zmin T represents the minimum Z-axis coordinate value of the initial plane of the second pole plate 302 on the left. zmax R represents the maximum Z-axis coordinate value of the initial plane of the second plate 302 on the left; R represents the distance between the center of the initial plane of the second plate and the origin O; α represents the angle between the line connecting the center of the initial plane of the second plate and the origin O and the X-axis; and m represents the width of the second plate.

[0050] The initial plane equation of the second plate 302 on the left is:

[0051] x2 = -Rcosα - gap,

[0052] Where x2 represents the X-axis coordinate value of the initial plane of the first electrode plate 301, R zmin R represents the minimum Z-axis coordinate value of the initial plane of the first left plate 301. zmax represents the maximum Z-axis coordinate value of the initial plane of the first electrode plate 301 on the left; m represents the width of the first electrode plate (taking the first and second electrode plates as having the same width as an example, in actual applications the first and second electrode plates can be set to different widths); shift represents the offset in the width direction between the first and second electrode plates at the initial position.

[0053] When the prism carrier 200 is rotated β degrees clockwise around the Y-axis, the plane equation of the second pole plate 302 on the left side after rotation is:

[0054] z1′=z cosβ-x sinβ=z cosβ+R sinβcosα;

[0055] x1′=z cosβ+x cosβ=z sinβ-R cosαcosβ;

[0056] Where z′1 represents the Z-axis coordinate value of the second pole plate 302 after rotation, x′1 represents the X-axis coordinate value of the second pole plate 302 after rotation, z represents the Z-axis coordinate value of the second pole plate 302 before rotation, x represents the X-axis coordinate value of the second pole plate 302 before rotation, α represents the angle between the line connecting the center of the initial plane of the second pole plate and the origin O and the X-axis, and β represents the rotation angle of the prism carrier 200.

[0057] From the above equations, the average distance Δd between the first electrode plate 301 and the second electrode plate 302 on the left side of the diagram after rotation can be calculated as follows:

[0058] Δd = x′1 - x2;

[0059] After rotation, the coordinate range of the first electrode plate 301 and the second electrode plate 302 overlapping in the Z-axis direction on the left side of the diagram is:

[0060] z max =min(T' zmax ,R zmax );

[0061] z min =max(T' zmin ,R zmin );

[0062] Among them, T' zmax R represents the maximum Z-axis coordinate value of the initial plane of the second pole plate 302 on the left after rotation by angle β. zmax T' represents the maximum Z-axis coordinate value of the initial plane of the first left pole plate 301. zmin R represents the minimum Z-axis coordinate value of the initial plane of the second pole plate 302 on the left after rotation by angle β. zmin The minimum Z-axis coordinate value represents the initial plane of the first pole plate 301 on the left.

[0063] Assuming the length of the plates is L, the capacitance of the two plates after rotating by an angle β is expressed as follows:

[0064]

[0065] Where, ε r It is the dielectric constant of the medium between the first and second plates.

[0066] Regarding the calculation method of the above capacitance expression, the corresponding capacitance signal is determined by rotating around the Y-axis by an angle β for simulation calculation. The initial parameters are shown in the table below:

[0067] Figure 7 shows the simulation results of the capacitance value change corresponding to the rotation angle β under the initial parameters configured above. Under normal operating conditions of the prism motor, the capacitance exhibits good linearity within ±1 degree (60 min) of rotation angle β and good capacitance sensitivity, making it easy to determine the magnitude of the rotation angle change based on the capacitance signal. Furthermore, increasing the length of the plates, i.e., increasing the initial overlap area, makes the capacitance signal change more pronounced, further increasing the capacitance sensitivity.

[0068] Furthermore, the first electrode plate 301 is symmetrically arranged about the left and right sides of the second rotation axis (X-axis) of the prism carrier 200, and the second electrode plate 302 is also symmetrically arranged about the left and right sides of the second rotation axis of the prism carrier 200; wherein, the first rotation axis and the second rotation axis are perpendicular to each other. That is, the first electrode plate and the second electrode plate are symmetrically arranged about the XY plane. In addition, both the first electrode plate 301 and the second electrode plate 302 are symmetrical about the ZX plane. While the prism motor rotates around the first rotation axis, it can also rotate around the second rotation axis. By setting the electrode plates as a centrally symmetrical structure, ensuring symmetry with respect to both the first and second rotation axes, when the prism motor rotates around the axis, the capacitance signal changes of the multiple capacitors formed by the symmetrical electrode plates can be made to be approximately the same. This facilitates the elimination of the influence of rotation angles in other directions on the detection results through subsequent calculations, thereby improving the accuracy of single-direction rotation angle calculations.

[0069] Specifically, the symmetrical arrangement of the first and second electrodes about the ZX plane is as follows: Taking two first electrodes 301 and two electrodes 302 as an example, the two first electrodes 301 are located on opposite sides of the first rotation axis Y-axis, and the Y-axis does not coincide with the central axis of the first electrodes, meaning the two first electrodes are symmetrical about the Y-axis, but a single first electrode is asymmetrical about the Y-axis. The central axes of both first electrodes 301 coincide with the second rotation axis Z-axis, meaning each first electrode is symmetrical about the Z-axis. Similarly, the second electrodes 302 are located on opposite sides of the first rotation axis Y-axis, and the Y-axis does not coincide with the central axis of the second electrodes 302, meaning the two second electrodes 302 are symmetrical about the Y-axis, but a single second electrode 302 is asymmetrical about the Y-axis. The central axes of both second electrodes 302 coincide with the second rotation axis Z-axis, meaning each second electrode 302 is symmetrical about the Z-axis.

[0070] After determining the capacitance signals C1 and C2 generated by the two pairs of first and second plates corresponding to the first rotation axis (Y-axis), the final capacitance signal can be calculated using the formula C1-C2. Since the rotation angle around the first rotation axis causes a negative correlation between the changes in capacitance signals C1 and C2 (i.e., a decrease in C1 corresponds to an increase in C2, or an increase in C1 corresponds to a decrease in C2), calculating the final capacitance signal using formula C1-C2 can superimpose both capacitance signals, thereby improving the capacitance sensitivity. On the other hand, calculating the final capacitance using formula C1-C2 can also, to some extent, eliminate the changes in capacitance signals caused by rotation around the second rotation axis (X-axis). Rotation around the second rotation axis has a positive correlation with the changes in capacitance signals C1 and C2 (i.e., a decrease in C1 corresponds to a decrease in C2, or an increase in C1 corresponds to an increase in C2). Therefore, calculating the final capacitance using formula C1-C2 can, to some extent, eliminate the influence of rotation around the second rotation axis on capacitance signals C1 and C2.

[0071] In addition to using the above formula to superimpose multiple capacitance signals, other formulas can be used for comprehensive analysis, such as using (C1-C2) / (C1+C2) to perform differential processing on the results of multiple capacitance signals. In practical applications, other processing can be performed on the obtained capacitance signals according to the capacitance detection situation, such as correcting or denoising the capacitance signals, to eliminate noise that affects the accuracy of the calculation results caused by environmental factors or human operation factors.

[0072] Furthermore, when the prism carrier 200 rotates only around the second rotation axis, the facing areas of the first electrode 301 and the second electrode 302 are kept as constant as possible. This ensures that the facing areas between the two electrodes remain almost unchanged when the prism carrier 200 rotates around the second rotation axis, with only the average spacing changing. Therefore, the influence of rotation around the second rotation axis on the capacitance signal change between the first electrode 301 and the second electrode 302 can be reduced, and the capacitance signal change between the first electrode 301 and the second electrode 302 will more closely correspond to the angular change of the first rotation axis. As shown in Figure 8, the areas of the opposing surfaces between the first electrode 301 and the second electrode 302 can be set to different sizes, with the area of ​​the first electrode in the opposing surface being larger than the area of ​​the second electrode in the opposing surface, and the width of the first electrode being greater than the width of the second electrode, with the direction of the width consistent with the direction of the first rotation axis. As shown in Figure 9, when the prism carrier is within the rated rotation range ±γ around the second rotation axis (X-axis), the electrode boundary of the second electrode 302 in the width direction does not move beyond the electrode boundary of the first electrode 301 in the width direction, and the facing area of ​​the first electrode and the second electrode remains almost unchanged.

[0073] In addition, the prism motor also includes: a third electrode plate 303, located on the surface of the prism base 100; and a fourth electrode plate 304, located on the surface of the prism carrier 200, with the fourth electrode plate positioned opposite to the third electrode plate. The third and fourth electrode plates form a capacitor. When the prism carrier 200 rotates unidirectionally around the second rotation axis, the facing area between the third and fourth electrode plates increases and the distance between them decreases, or the facing area decreases and the distance between them increases. The first and second rotation axes are perpendicular to each other. A processing unit is used to jointly determine the angle of rotation of the prism carrier 200 in space based on the capacitance signal generated by the capacitor formed by the first electrode plate 301 and the second electrode plate 302, and the signal generated by the capacitor formed by the third electrode plate 303 and the fourth electrode plate 304. This allows for the design of different electrode plate structures for corresponding detection when the prism carrier 200 can rotate in multiple directions.

[0074] As shown in Figures 10 to 12, with the rotation axis being the X-axis, the third electrode plate 303 and the fourth electrode plate 304 can be positioned at different locations on the prism motor. As shown in Figure 10, the third electrode plate 303 can be positioned on the left side of the base side 102 of the prism base 100, and the fourth electrode plate 304 is positioned on the left side of the prism carrier 200. As shown in Figure 11, the third electrode plate 303 can be positioned on the right side of the base side 102 of the prism base 100, and the fourth electrode plate 304 is positioned on the right side of the prism carrier 200. As shown in Figure 12, the third electrode plate 303 can be positioned on the rear side of the base side 102 of the prism base 100, and the fourth electrode plate 304 is positioned on the rear side of the prism carrier 200.

[0075] Furthermore, the arrangement rules for the third electrode 303 and the fourth electrode 304 are the same as those for the first electrode 301 and the second electrode 302. For example, the number of third electrodes is even, and the third electrodes are arranged symmetrically about the rotation axis of the prism carrier 200; the number of fourth electrodes is also even, and the fourth electrodes are arranged symmetrically about the rotation axis of the prism carrier 200; the third and fourth electrodes correspond one-to-one, and each pair of third and fourth electrodes forms a capacitor. The arrangement of the third and fourth electrodes is for detecting the angle of rotation of the prism carrier 200 around the second rotation axis. The calculation method is the same as the simulation results of the capacitance signal generated by the first electrode 301 and the second electrode 302 and the rotation angle, and will not be repeated here.

[0076] Furthermore, as shown in Figure 13, a portion of the orthographic projection of the first electrode 301 onto the second electrode 302 falls outside the second electrode 302, and a portion of the orthographic projection of the second electrode 302 onto the first electrode 301 falls outside the first electrode 301, resulting in a certain offset (shift) between the orthographic projections of the two electrodes. Similarly, a portion of the orthographic projection of the third electrode onto the fourth electrode falls outside the fourth electrode, and a portion of the orthographic projection of the fourth electrode onto the third electrode falls outside the third electrode, also resulting in a certain offset (shift) between the orthographic projections of the two electrodes. To ensure that the prism carrier 200 remains within its rated rotation range, the two capacitors formed by the two first electrodes 301 and the two second electrodes 302 can both maintain a negative correlation between the change in their facing area and the average spacing. This effect can be achieved by limiting the numerical range of shift. The rules for limiting the numerical range of shift are as follows:

[0077] Taking the first electrode 301 and the second electrode 302 as shown in Figure 6 around the first rotation axis (Y-axis) as an example, and using the same initial plane equation calculation method as above, the minimum initial Z coordinate of the second electrode 302 on the left side of Figure 6 is R. zmin The maximum initial Z-coordinate is R. zmax The planar rotation formula is: z′1=z cosβ-x sinβ=z cosβ+R sinβcosα; using the planar rotation formula, the minimum Z coordinate R′ after rotation is obtained. zmin and the maximum Z-coordinate R′ after rotation zmax Using the formula shift>|R′ zmax -R zmax | and shift > |R′ zmin -R zmin | determines the range of values ​​that the shift value can take.

[0078] In addition, considering the compactness of the internal structure of the prism motor, the shapes of the first electrode plate 301 and the second electrode plate 302, as well as the shapes of the third electrode plate 303 and the fourth electrode plate 304, can be other shapes besides rectangles. Depending on the space occupied inside the prism motor, the electrode plates can be set as triangular electrode plates as shown in Figure 14, circular electrode plates as shown in Figure 15, or trapezoidal electrode plates as shown in Figure 16, or polygonal electrode plates or curved electrode plates, and combined in pairs.

[0079] Embodiments of this application also relate to a rotation angle detection method for a prism motor, applied to the aforementioned prism motor, as shown in FIG17. The rotation angle detection method includes:

[0080] Step 1701: Determine the initial capacitance signal generated by the capacitance formed by the first and second plates when the prism carrier is in its initial position.

[0081] Step 1702: When the capacitance signal generated by the capacitor formed by the first and second plates changes, determine the current capacitance signal;

[0082] Step 1703: Determine the rotation angle of the prism carrier based on the difference between the current capacitance signal and the initial capacitance signal.

[0083] Compared to existing technologies, this application's embodiments use smaller electrode plates instead of Hall sensors in the motor. The rotation angle of the motor is calculated by observing changes in the capacitance signal formed between the electrode plates, saving internal space in the prism motor and facilitating its miniaturization. After determining the rotation angle of the prism carrier, the aforementioned angle rotation detection method can be used to achieve image stabilization, controlling the prism carrier to rotate to the target angle. For example, the target angle is the angle required for shake compensation; the prism carrier rotation is controlled based on the difference between the current rotation angle and the target angle. Since shake occurs in real-time during shooting, shake compensation control is also performed in real-time, proceeding to the next round of compensation angle determination and prism carrier rotation control after each compensation cycle.

[0084] The calculation method for the correspondence between the capacitance signal generated by the capacitor formed by the first and second plates and the rotation angle is specifically explained in the previous embodiment. Specifically, the rotation angle corresponding to different capacitance signals is determined based on the simulation curve generated by the simulation of capacitance signal and rotation angle.

[0085] The steps of the various methods described above are only for clarity. In implementation, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this application. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this application.

[0086] Another feasible embodiment of this application relates to a shooting module, as shown in FIG18, including a prism motor, a lens, and a photosensitive chip as described above; incident light entering the shooting module is reflected by the prism motor and passes through the lens 400 to reach the photosensitive chip 500. Specifically, the incident light enters the shooting module through the light-transmitting sheet 201, and the propagation direction of the incident light is changed by the reflecting mirror 202 of the prism motor, so that the incident light can perpendicularly penetrate the lens to reach the photosensitive chip.

[0087] Compared with related technologies, the shooting module provided in this application embodiment is equipped with the prism motor provided in the aforementioned embodiment. Therefore, it also has the technical effects provided in the aforementioned embodiment, which will not be elaborated here.

[0088] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A prism motor, comprising: Prism base; A prism carrier, wherein the prism carrier is spaced apart from the prism base, and the prism carrier is rotatable relative to the prism base; The first electrode plate is located on the surface of the prism base; The second electrode plate is located on the surface of the prism carrier and is disposed opposite to the first electrode plate; the first electrode plate and the second electrode plate form a capacitor. When the prism carrier rotates in one direction about the first rotation axis, the facing area between the first electrode plate and the second electrode plate increases and the distance between the first electrode plate and the second electrode plate decreases, or the facing area between the first electrode plate and the second electrode plate decreases and the distance between the first electrode plate and the second electrode plate increases. The processing unit is used to determine the rotation angle of the prism carrier based on the capacitance signal generated by the capacitance formed by the first electrode plate and the second electrode plate.

2. The prism motor according to claim 1, wherein, The number of the first electrode plates is even, and the plurality of the first electrode plates are symmetrically arranged based on the first rotation axis of the prism carrier; The number of the second electrode plates is even, and the multiple second electrode plates are symmetrically arranged based on the first rotation axis of the prism carrier; The first electrode plate and the second electrode plate are in one-to-one correspondence, and each pair of the first electrode plate and the second electrode plate forms a capacitor; The processing unit is used to determine the rotation angle of the prism carrier based on the capacitance signal generated by the multiple capacitors formed by the first electrode plate and the second electrode plate.

3. The prism motor according to claim 2, wherein, The first electrode plate is symmetrically arranged based on the second rotation axis of the prism carrier, and the second electrode plate is symmetrically arranged based on the second rotation axis of the prism carrier; wherein the first rotation axis and the second rotation axis are perpendicular to each other.

4. The prism motor according to claim 3, wherein, The length of the first electrode plate is greater than the length of the second electrode plate; wherein the direction of the defined length is consistent with the direction of the first rotation axis.

5. The prism motor according to claim 1 or 2, wherein, Also includes: The third electrode plate is located on the surface of the prism base; A fourth electrode plate is located on the surface of the prism carrier and is disposed opposite to the third electrode plate. The third and fourth electrode plates form a capacitor. When the prism carrier rotates in one direction about the second rotation axis, the facing area between the third and fourth electrode plates increases and the distance between the third and fourth electrode plates decreases, or the facing area between the third and fourth electrode plates decreases and the distance between the third and fourth electrode plates increases. The first and second rotation axes are perpendicular to each other. The processing unit is used to jointly determine the angle of rotation of the prism carrier in space based on the capacitance signal generated by the capacitance formed by the first electrode plate and the second electrode plate, and the signal generated by the capacitance formed by the third electrode plate and the fourth electrode plate.

6. The prism motor according to claim 5, wherein, The number of the third electrode plates is even, and the third electrode plates are symmetrically arranged based on the second rotation axis of the prism carrier; The number of the fourth electrode plates is even, and the fourth electrode plates are arranged symmetrically based on the second rotation axis of the prism carrier; The third plate and the fourth plate are in one-to-one correspondence, and each pair of the third plate and the fourth plate forms a capacitor.

7. The prism motor according to claim 1, wherein, The planes containing the first electrode plate and the second electrode plate are both parallel to the first rotation axis.

8. The prism motor according to claim 1, wherein, The orthographic projection of the first electrode plate toward the second electrode plate falls outside the second electrode plate, and the orthographic projection of the second electrode plate toward the first electrode plate falls outside the first electrode plate.

9. A method for detecting the rotation angle of a prism motor, applied to a prism motor as described in any one of claims 1 to 8, comprising: Determine the initial capacitance signal generated by the capacitance formed by the first and second plates at the initial position of the prism carrier. When the capacitance signal generated by the capacitor formed by the first electrode and the second electrode changes, the current capacitance signal is determined; The angle of rotation of the prism carrier is determined based on the difference between the current capacitance signal and the initial capacitance signal.

10. A shooting module, comprising: The prism motor, lens, and photosensitive chip as described in any one of claims 1 to 8; The incident light entering the shooting module is reflected by the prism motor and then passes through the lens to reach the photosensitive chip.

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