Optical position detection device

Abstract

This application discloses an optical position detection device, relating to the field of detection instrument technology. It aims to improve the measurement accuracy of optical position detection devices. The specific solution includes: the optical position detection device comprises a light source, a beam splitter, an optical position sensor, and a light-absorbing component. The beam splitter reflects a portion of the light beam emitted from the light source. The optical position sensor receives the measurement beam and acquires its position coordinates; the measurement beam is a beam reflected by the beam splitter, reflected once by a micromirror, and then transmitted through the beam splitter. The light-absorbing component absorbs the first beam; the first beam is a beam reflected by the beam splitter, reflected twice or more by the micromirror, reflected by the inner surface of a transparent cover, and then transmitted through the beam splitter. This optical position detection device effectively eliminates crosstalk problems caused by back-and-forth reflections between the transparent cover and the micromirror, and between the micromirror and internal optical components. It provides high-precision measurement results for microelectromechanical devices (MEMS).

Description

Technical Field

[0001] This application relates to the field of detection instrument technology, and in particular to an optical position detection device. Background Technology

[0002] Micro-electro-mechanical systems (MEMS) modules have attracted significant attention in fields such as optical imaging, medical detection, micro-displays, and optical communications due to their advantages including large scanning angles, low driving voltages, low manufacturing costs, and ease of control. Particularly in optical communications, MEMS modules are suitable for large-scale optical cross-connect (OXC) devices. Before using MEMS, the relationship between the MEMS's driving voltage and rotation angle needs to be calibrated; the accuracy of this calibration directly affects the MEMS's error.

[0003] Therefore, this application provides an optical position detection device to improve the testing accuracy of the optical position detection device for electrothermal microelectromechanical systems. Summary of the Invention

[0004] This application provides an optical position detection device, which aims to improve the measurement accuracy of the optical position detection device.

[0005] To achieve the above objectives, this application adopts the following technical solution.

[0006] In a first aspect, this application provides an optical position detection device. The optical position detection device is used in a microelectromechanical device (MEMS); the MEMS includes a micromirror and a transparent cover. The micromirror is located inside the transparent cover; the transparent cover includes an inner surface facing the micromirror and an outer surface facing away from the micromirror. The optical position detection device includes a light source, a beam splitter, an optical position sensor, and a light-absorbing component. The beam splitter is used to reflect a portion of the light beam emitted from the light source and to transmit a portion of the light beam emitted from the light source. The optical position sensor is used to receive a measurement beam and obtain the position coordinates of the measurement beam received by the optical position sensor; the measurement beam is a light beam reflected by the beam splitter, reflected once by the micromirror, and then transmitted by the beam splitter. The light-absorbing component is used to absorb a first light beam; the first light beam is a light beam reflected by the beam splitter, reflected twice or more by the micromirror, reflected by the inner surface of the transparent cover, and then transmitted by the beam splitter.

[0007] Therefore, if the first beam is transmitted to the optical position sensor, it will interfere with the measuring beam, leading to inaccurate measurements by the optical position sensor. In this application, the light-absorbing component absorbs the first beam, which can effectively reduce the interference of the first beam on the measuring beam, thus improving the accuracy of the optical position detection device. This, in turn, improves the precision of the microelectromechanical device (MEMS).

[0008] In conjunction with the first aspect, in some feasible embodiments, the light-absorbing assembly includes a first light-absorbing element and a driver, the driver being connected to the first light-absorbing element and used to drive the first light-absorbing element to move along a first direction, the first light-absorbing element being used to absorb the first light beam; the first direction is perpendicular to the optical axis of the first sub-beam. The first sub-beam is: a light beam emitted from the light source and reflected by the beam splitter.

[0009] Thus, during the rotation of the micromirror, the transmission direction of the first light beam changes minimally. The first light-absorbing element moves along the first direction, and even if the transmission direction of the first light beam changes, it can still absorb the beam under the action of the actuator. Therefore, the area of ​​the first light-absorbing element can be smaller, and it can effectively reduce the interference of the first light beam on the measurement results of the optical position sensor.

[0010] In conjunction with the first aspect, in some feasible ways, the photosensitive surface of the optical position sensor is not perpendicular to the optical axis of the second sub-beam; the second sub-beam is a beam emitted from the light source and reflected by the beam splitter.

[0011] In this way, the output beam reflected by the photosensitive surface of the optical position sensor will not be transmitted in the reverse direction along the measurement beam, avoiding the beam returning to the microelectromechanical device and then being reflected back to the photosensitive surface of the optical position sensor, which is beneficial to improving the measurement accuracy of the optical position sensor.

[0012] In conjunction with the first aspect, in some feasible ways, the photosensitive surface of the optical position sensor forms an angle of 65°-82° with the optical axis of the second sub-beam.

[0013] In this way, the measurement beam is almost not transmitted to the microelectromechanical device after being reflected by the photosensitive surface of the optical position sensor, further avoiding the beam returning to the photosensitive surface of the optical position sensor after being transmitted to the microelectromechanical device, thus forming an interfering beam.

[0014] In conjunction with the first aspect, in some feasible embodiments, the optical position detection device further includes a second light-absorbing element. The second light-absorbing element is used to absorb a second light beam. The second light beam is a light beam that is reflected by the beam splitter, then reflected again by the outer surface of the transparent cover, and finally transmitted through the beam splitter.

[0015] Thus, with the combined action of the light-absorbing component and the second light-absorbing element, stray light reflected from the inner and outer surfaces of the transparent cover can be effectively blocked, improving the accuracy of the optical position sensor measurement.

[0016] In conjunction with the first aspect, in some feasible embodiments, the optical position detection device further includes a third light-absorbing element. The third light-absorbing element has a light-transmitting hole extending through it, and the light source is disposed on one side of the third light-absorbing element. The light-transmitting hole allows a light beam emitted from the light source to pass through.

[0017] In this way, the third light-absorbing component hardly intercepts the light beam output by the light source, and the third light-absorbing component can absorb part of the light beam reflected by the beam splitter and originating from the light source, reducing the interference of this part of the light beam on the measurement beam, which is beneficial to making the measurement results of the optical position sensor more accurate.

[0018] In conjunction with the first aspect, in some feasible embodiments, the optical position detection device further includes a fourth light-absorbing element. The fourth light-absorbing element is used to absorb the first sub-beam. The first sub-beam is a light beam transmitted by the beam splitter and originating from the light source.

[0019] Thus, the fourth light-absorbing element can effectively reduce the interference of the second sub-beam on the measurement results of the optical position sensor. For example, the fourth light-absorbing element can absorb at least a portion of the second sub-beam, preventing that portion of the second sub-beam from being transmitted to the photosensitive surface of the optical position sensor.

[0020] In conjunction with the first aspect, in some feasible embodiments, the optical position detection device further includes a reflective element. The reflective element is used to reflect the light beam emitted from the light source back to the beam splitter.

[0021] In this way, the reflective element can change the transmission direction of the light beam from the light source to the beam splitter, causing the light path from the light source to the beam splitter to be folded, reducing the distance from the light source to the beam splitter, which is beneficial to improving the integration of the optical position detection device and reducing the space occupied by the optical position detection device.

[0022] In conjunction with the first aspect, in some feasible embodiments, the optical position detection device further includes a focusing lens. The focusing lens is used to converge the measurement beam and transmit it to the optical position sensor; the focusing lens is also used to converge the first beam and transmit it to the light-absorbing component.

[0023] In this way, the focusing lens can reduce the spot size of the measurement beam, making the coordinates measured by the optical position sensor more accurate.

[0024] In conjunction with the first aspect, in some feasible embodiments, the optical position detection device further includes a housing. The light source, the beam splitter, the optical position sensor, and the light-absorbing component are all located within the housing. The housing includes a light-transmitting opening for a light beam emitted from the light source and reflected by the beam splitter to pass through. The light-transmitting opening also allows the first light beam and the measuring light beam to pass through.

[0025] In this way, the housing can prevent dust or moisture from contaminating the light source, beam splitter, optical position sensor, and light-absorbing components, providing a dry working environment for them. The housing can also reduce interference from other light sources on the measurement results of the optical position sensor.

[0026] Secondly, this application provides an optical position detection device. The optical position detection device is used in a microelectromechanical device (MEMS). The MEMS includes a micromirror and a transparent cover, the transparent cover being used to seal the micromirror; the transparent cover includes an inner surface facing the micromirror and an outer surface facing away from the micromirror. The optical position detection device includes a light source, a beam splitter, an optical position sensor, and a light-absorbing element. The beam splitter is used to reflect a portion of the light beam emitted from the light source and to transmit a portion of the light beam emitted from the light source. The optical position sensor is used to receive a measurement beam and obtain the position coordinates of the measurement beam received by the optical position sensor; the measurement beam is a light beam reflected by the beam splitter, reflected once by the micromirror, and then transmitted by the beam splitter. The light-absorbing element is used to receive the measurement beam and obtain the position coordinates of the measurement beam received by the optical position sensor. The measurement beam is used to absorb interfering beams; the interfering beams are light beams reflected by the beam splitter, reflected by the outer surface of the transparent cover, and then transmitted by the beam splitter.

[0027] Thus, this optical position detection device can effectively reduce the interference of the light beam reflected from the outer surface of the transparent cover on the measurement results of the optical position sensor. When the optical position detection device is used in the context of microelectromechanical devices (MEMS), it provides high-precision measurement results for the MEMS.

[0028] In conjunction with the second aspect, in some feasible ways, the photosensitive surface of the optical position sensor is not perpendicular to the optical axis of the second sub-beam; the second sub-beam is a beam emitted from the light source and reflected by the beam splitter.

[0029] In conjunction with the second aspect, in some feasible ways, the photosensitive surface of the optical position sensor forms an angle of 65°-82° with the optical axis of the second sub-beam.

[0030] In conjunction with the second aspect, in some feasible embodiments, the optical position detection device further includes a reflective element. The reflective element is used to reflect the light beam emitted from the light source back to the beam splitter.

[0031] In conjunction with the second aspect, in some feasible embodiments, the optical position detection device further includes a fourth light-absorbing element. The fourth light-absorbing element is used to absorb the first sub-beam. The first sub-beam is a light beam transmitted by the beam splitter and originating from the light source.

[0032] Regarding the beneficial effects of the second aspect, please refer to the description of any optional implementation method in the first aspect, which will not be repeated here. Based on the implementation methods provided in the above aspects, this application can also be further combined to provide more implementation methods. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the optical transmission component provided in an embodiment of this application.

[0034] Figure 2 This is a schematic diagram of the structure of a microelectromechanical device.

[0035] Figure 3a This is a schematic diagram of the optical path of a microelectromechanical device in one state.

[0036] Figure 3b This is a schematic diagram of the optical path of a microelectromechanical device in another state.

[0037] Figure 4 This is a schematic diagram of the structure of an optical position detection device and a microelectromechanical device provided in the embodiments of this application.

[0038] Figure 5 This is a schematic diagram of the optical path of a beam reflected by a micromirror at different rotation angles.

[0039] Figure 6 This is a schematic diagram of another optical position detection device and microelectromechanical device provided in the embodiments of this application.

[0040] Figure 7 This is a schematic diagram of another optical position detection device and microelectromechanical device provided in the embodiments of this application.

[0041] Figure 8 This is a schematic diagram of another optical position detection device and microelectromechanical device provided in the embodiments of this application.

[0042] Figure 9 This is a schematic diagram of another optical path for the light beam reflected by the micromirror at different rotation angles.

[0043] Figure 10 This is a schematic diagram of the structure of an optical position detection device and a microelectromechanical device provided in the embodiments of this application.

[0044] In the diagram: 20-Optical transmission component; 21-Input port; 22-Output port; 10-Microelectromechanical device; 23-Converging light element; 24-Collimating lens; 13-Inner surface; 14-Outer surface; 15-Substrate; 11-Micromirror; 12-Transparent cover; 16-Power component; 17-Reflector; 100-Optical position detection device; 110-Light source; 120-Optical position sensor; 130-Beam splitter; 140-Light absorption component; 141-First light absorber; 142-Driver; 150-Second light absorber; 160-Focusing lens; 170-Third light absorber; 171-Light passage; 101-Housing shell; 102-Light transmission port; 180-Fourth light absorber; 190-Reflective element; 210-Light absorber. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0046] Hereinafter, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0047] Furthermore, in the embodiments of this application, directional terms such as "up," "down," "left," "right," "horizontal," and "vertical" are defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0048] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, an electrical connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0049] Figure 1 This is a schematic diagram of the structure of the optical transmission component 20 provided in an embodiment of this application. Please refer to... Figure 1 The optical transmission component 20 includes an input port 21, an output port 22, and a microelectromechanical device (MEMS) 10. The MEMS 10 is used to deflect the light beam from the input port 21 to the output port 22.

[0050] For example, input port 21 has multiple ports, and input port 21 may also be referred to as an input port array. Output port 22 has multiple ports, and output port 22 may also be referred to as an output port array.

[0051] In the first state, the microelectromechanical device 10 deflects the light beam from the first port of input port 21 to the first port of output port 22. In the second state, the microelectromechanical device 10 deflects the light beam from the first port of input port 21 to the second port of output port 22. This achieves the switching of the light beam output port.

[0052] For example, input port 21 is used to connect to a fiber array (FA). One port of input port 21 is connected to a corresponding fiber core of the fiber array (FA). Output port 22 is used to connect to the FA. One port of output port 22 is connected to a corresponding fiber core of the fiber array (FA).

[0053] exist Figure 1 In the example, the optical transmission component 20 includes two microelectromechanical devices (MEMS) 10, and may also include a focusing element 23. One MEMS 10 deflects the light beam from the input port 21 to the focusing element 23, which then focuses the light beam and emits it to the other MEMS 10, which deflects the light beam from the focusing element 23 to the output port 22.

[0054] For example, the light-converging element 23 may be a concave mirror.

[0055] In some embodiments of this application, the optical transmission component 20 may further include two collimating lenses 24. One collimating lens 24 is used to collimate the light emitted from the input port 21 before transmitting it to the microelectromechanical device 10. In some embodiments, this collimating lens 24 may also be referred to as an input collimator array, which has the function of collimating and expanding the light beam. The other collimating lens 24 is used to collimate the light beam emitted from the microelectromechanical device 10 before transmitting it to the output port 22. In some embodiments, this collimating lens 24 may also be referred to as an output collimator array, which has the function of collimating and expanding the light beam.

[0056] In some embodiments, the microelectromechanical device 10 can also be referred to as a passive optical pointing element, and the microelectromechanical device 10 has the function of adjusting the deflection direction of the light beam. For example, by changing the driving voltage of the microelectromechanical device 10, the reflecting surface of the microelectromechanical device 10 can achieve angular deflection, thereby switching the light beam projected onto the reflecting surface.

[0057] Thus, by adjusting the driving voltage of the microelectromechanical device 10, the light beam incident at the input port 21 is deflected by the microelectromechanical device 10 and emitted from different ports of the output port 22. In order to make the light beam accurately emitted from one of the output ports 22, the rotation angle of the microelectromechanical device 10 needs to be precisely adjusted.

[0058] Figure 2This is a schematic diagram of the structure of a microelectromechanical device 10. Please refer to [link / reference]. Figure 2 The microelectromechanical device 10 includes a micromirror 11 and a transparent cover 12. The micromirror 11 is located inside the transparent cover 12.

[0059] For example, the microelectromechanical device 10 also includes a substrate 15, a transparent cover 12 and the substrate 15 forming a sealed cavity, and a micromirror 11 located inside the sealed cavity.

[0060] The transparent cover 12 includes an inner surface 13 and an outer surface 14, which are arranged opposite to each other. The inner surface 13 faces the micromirror 11, and the outer surface 14 faces away from the micromirror 11.

[0061] In some embodiments, the microelectromechanical device 10 includes a plurality of micromirrors 11 arranged in an array. A transparent cover 12 seals the micromirrors 11.

[0062] In embodiments of this application, the microelectromechanical device 10 includes a plurality of micromirrors 11 arrayed along the x-direction, and the microelectromechanical device 10 also includes a plurality of micromirrors 11 arrayed along the y-direction. The thickness direction of the substrate 15 is the z-direction, wherein the x-direction, y-direction, and z-direction are mutually perpendicular.

[0063] Figure 2 In the example, along the x-direction, the distance from the inner surface 13 of the transparent cover 12 to the substrate 15 is not exactly equal. Along the y-direction, the distance from the inner surface 13 of the transparent cover 12 to the substrate 15 is equal. In other words, along the x-direction, the transparent cover 12 is not set at equal heights, while along the y-direction, the transparent cover 12 is set at equal heights.

[0064] Figure 3a This is a schematic diagram of the optical path of the microelectromechanical device 10 in one state. Figure 3a The microelectromechanical device 10 in the figure is shown as an exploded structural diagram. Figure 3a The example only shows the optical path diagram of one micromirror 11; the optical path diagrams of the other micromirrors 11 can be obtained in the same way.

[0065] The micromirror 11 includes a power assembly 16 and a reflector 17, which are connected together. The power assembly 16 is configured to receive a driving voltage and drive the reflector 17 to rotate under the action of the driving voltage.

[0066] For example, the power assembly 16 may include materials such as piezoelectric materials, electroactive artificial muscle materials, thermoelectric deformation materials, electrostatic deformation materials, magnetoelectric deformation materials, or stone mastic asphalt (SMA).

[0067] Piezoelectric materials are crystalline materials that exhibit a voltage between their two end faces when subjected to pressure. Furthermore, under the influence of electrical energy, the crystals within the piezoelectric material undergo distortion, converting electrical energy into mechanical energy. Exemplarily, piezoelectric materials can include at least one of piezoelectric single crystals, piezoelectric polycrystalline materials (piezoelectric ceramics), piezoelectric polymers, piezoelectric composite materials, and piezoelectric semiconductors. Piezoelectric single crystals include: piezoelectric quartz crystals, lithium niobate, lithium tantalate, Rochelle salt, ammonium dihydrogen phosphate, potassium dihydrogen phosphate, or dipotassium tartrate, etc. Piezoelectric polycrystalline materials include: barium titanate, lead titanate, potassium sodium niobate, lead metaniobate, lead zirconate titanate, lead barium metaniobate, etc. Piezoelectric polymers include: polyvinylidene fluoride, etc.

[0068] Electroactive artificial muscle materials may include electroelastomers (De). Thermoelectric deformable materials may include shape memory polymers (SMP). Electrostatic deformable materials may include electrostatic actuators. Magnetoelectric deformable materials may include electromagnetic actuators.

[0069] For example, driven by the power assembly 16, the reflector 17 has two degrees of freedom of motion, one of which is rotation about axis m and the other is rotation about axis n.

[0070] Understandably, driven by the power unit 16, the reflector 17 has two directions of rotation about axis m. The reflector 17 also has two directions of rotation about axis n.

[0071] like Figure 3a As shown, the reflector 17 rotates about axis m, and can deflect to the left or to the right. The reflector 17 also rotates about axis n, and can deflect forward or backward.

[0072] Figure 3a In the example of the power component 16 driving the reflector 17 to rotate around the axis m, the voltage received by the power component 16 is the first value, and the rotation angle of the reflector 17 around the axis m is α1. After the light beam a1 is transmitted to the microelectromechanical device 10, it is reflected by the reflector 17 and output as light beam b1.

[0073] This application embodiment does not limit the maximum angle by which the reflector 17 can rotate about the axis of rotation m. For example, the maximum angle by which the reflector 17 can rotate to the left about the axis of rotation m can be 3°-6°. For instance, the maximum angle by which the reflector 17 can rotate to the left about the axis of rotation m can be 3°, 4°, 5°, or 6°. Thus, the angle by which the reflector 17 rotates to the left is between 0° and 6°.

[0074] In the embodiments of this application, when the reflector 17 is rotated at an angle of 0°, the substrate 15 and the reflector 17 are parallel. In other words, when the reflector 17 is rotated at an angle of 0°, the normal of the reflector 17 is perpendicular to the substrate 15.

[0075] Similarly, the angle by which reflector 17 rotates to the right about axis m is also considered. The maximum angle by which reflector 17 rotates to the right about axis m can be 3°-6°.

[0076] Figure 3b This is a schematic diagram of the optical path of the microelectromechanical device 10 in another state. Figure 3b The microelectromechanical device 10 in the figure is shown as an exploded structural diagram. Figure 3b In the process, the power component 16 drives the reflector 17 to rotate around the axis m. The voltage received by the power component 16 is the second value, and the rotation angle of the reflector 17 around the axis m is α2. The first value and the second value are not equal, and the angles α1 and α2 are not equal. After the beam a1 is transmitted to the microelectromechanical device 10, it is reflected by the reflector 17 and output as beam b2. Obviously, the angle between beam b2 and beam a1 is not equal to the angle between beam b1 and beam a1. The angle between beam b1 and beam b2 has a geometrical correspondence with the difference between angles α1 and α2. Thus, by obtaining the angle between beam b1 and beam b2, the difference between angles α1 and α2 can be obtained.

[0077] For example, by receiving light beam b1 through an optical position sensor, the position coordinates of the light spot of light beam b1 on the optical position sensor can be obtained, and this coordinate is named coordinate 1. Similarly, by receiving light beam b2 through an optical position sensor, the position coordinates of the light spot of light beam b2 on the optical position sensor can be obtained, and this coordinate is named coordinate 2. The distance between coordinate 1 and coordinate 2 and the angle between light beam b1 and light beam b2 have a geometrical correspondence. The difference between angle α1 and angle α2 can be calculated based on the angle between light beam b1 and light beam b2. In other words, the distance between light beam b1 and light beam b2 can be calculated from the distance between light beam b1 and light beam b2. Figure 3a status and Figure 3b The angle of rotation of the state reflector 17.

[0078] In other words, by obtaining the distance between the light spots of beam b1 and beam b2 on the optical position sensor, the rotation angle of the reflector 17 can be obtained. The rotation angle of the reflector 17 and the voltage difference received by the power component 16 have a one-to-one correspondence. Thus, the voltage value received by the power component 16 and the position of the light spot obtained by the optical position sensor have a one-to-one correspondence. The voltage-rotation angle curve of the microelectromechanical device 10 can then be obtained. The microelectromechanical device 10 is used for... Figure 2In the scenario of the transmission component 20 shown, by adjusting the voltage-rotation curve described above, the microelectromechanical device 10 can reflect the light beam to the target port in the output port 22 by adjusting the voltage value received by the power component 16.

[0079] The process of the power component 16 driving the reflector 17 to rotate around the n-axis is similar and will not be described in detail here.

[0080] Obviously, the accuracy of the light beam acquired by the optical position sensor directly affects the accuracy of the voltage-angle curve of the microelectromechanical device 10, and thus directly affects the accuracy when using the microelectromechanical device 10. Typically, the calibration accuracy of the angle in the voltage-angle curve is required to be on the order of millidions (mdeg).

[0081] This application provides an optical position detection device for a microelectromechanical device (MEMS) 10. It is used to acquire the position coordinates of a light beam reflected once by a micromirror 11 of the MEMS 10. This optical position detection device has the advantage of precise measurement, providing high-precision measurement results for the MEMS 10.

[0082] Figure 4 This is a schematic diagram illustrating the structure of an optical position detection device 100 and a microelectromechanical device 10 provided in an embodiment of this application. Please refer to... Figure 4 The optical position detection device 100 is used in the microelectromechanical device 10. The optical position detection device 100 includes a light source 110, an optical position sensor 120, a beam splitter 130, and a light-absorbing component 140.

[0083] Light source 110 is used to emit a light beam, and beam splitter 130 is used to reflect a portion of the light beam emitted from light source 110. Beam splitter 130 is also used to transmit a portion of the light beam emitted from light source 110. In the embodiments of this application, the light beam emitted from light source 110 and transmitted by beam splitter 130 is defined as the second sub-beam h2, and the light beam emitted from light source 110 and reflected by beam splitter 130 is defined as the first sub-beam h1.

[0084] During the use of the optical position detection device 100, a portion of the light beam from the light source 110 is reflected by the beam splitter 130 and transmitted to the microelectromechanical device 10 (MEMS 10). The light beam transmitted to the MEMS 10 is reflected by the MEMS 10 and returns to the optical position detection device 100. In other words, the first sub-beam h1 is transmitted to the MEMS 10, the MEMS 10 reflects the first sub-beam h1, and the reflected light beam partially or entirely returns to the optical position detection device 100. The optical position detection device 100 is used to receive the returned light beam.

[0085] The optical position sensor 120 is used to receive the measurement beam g1 and acquire its position coordinates. The measurement beam g1 is a beam reflected by the beam splitter 130, reflected once by the micromirror 11, and then transmitted through the beam splitter 130. In other words, the first sub-beam h1 reflected by the beam splitter 130 is transmitted to the microelectromechanical device 10, reflected once by the micromirror 11, and then transmitted again to the beam splitter 130; the portion transmitted through the beam splitter 130 is the measurement beam g1.

[0086] It is understood that a portion of the beam transmitted back to the beam splitter 130 is transmitted by the beam splitter 130, and this portion is the measurement beam g1 transmitted to the optical position sensor 120. A portion is reflected by the beam splitter 130; this embodiment does not limit the scope of this application.

[0087] The light-absorbing component 140 of the optical position detection device 100 is used to absorb the first light beam f1. The first light beam f1 is a light beam reflected by the beam splitter 130, reflected by the inner surface 13 of the transparent cover 12, reflected twice or more by the micromirror 11, and transmitted by the beam splitter 130.

[0088] In other words, the first sub-beam h1 reflected by the beam splitter 130 is transmitted to the microelectromechanical device 10. The beam transmitted to the microelectromechanical device 10 first passes through the transparent cover 12 and is transmitted to the micromirror 11. After being reflected for the first time by the micromirror 11, it is transmitted to the inner surface 13 of the transparent cover 12. After being reflected again by the inner surface 13 of the transparent cover 12, it is transmitted to the micromirror 11 again. The beam transmitted to the micromirror 11 again is reflected for the second time by the micromirror 11 and then transmitted through the transparent cover 12. The beam transmitted by the transparent cover 12 is transmitted to the beam splitter 130 again, and the portion transmitted by the beam splitter 130 is the first beam f1. Thus, the beam transmitted to the microelectromechanical device 10 is reflected twice by the micromirror 11 and transmitted through the beam splitter 130 to obtain the first beam f1.

[0089] Alternatively, the light beam reflected by the inner surface 13 of the transparent cover 12 is transmitted again to the micromirror 11. This second reflection by the micromirror 11 is followed by a third reflection by the inner surface 13 of the transparent cover 12, and then transmitted to the micromirror 11. This third reflection is then transmitted through the transparent cover 12. The light beam transmitted through the transparent cover 12 is then transmitted to the beam splitter 130, and the portion transmitted through the beam splitter 130 becomes the first beam f1. Thus, the light beam transmitted to the microelectromechanical device 10 is reflected three times by the micromirror 11 and transmitted through the beam splitter 130 to obtain the first beam f1.

[0090] Similarly, the light beam transmitted to the microelectromechanical device 10 can be reflected three, four or more times by the micromirror 11, and the number of times the light beam is reflected by the inner surface 13 of the transparent cover 12 is one less than the number of times the light beam is reflected by the micromirror 11.

[0091] Similarly, a portion of the light beam reflected twice or more by the micromirror 11 and then transmitted to the beam splitter 130 is transmitted by the beam splitter 130, and this portion is the first light beam f1 transmitted to the optical position sensor 120. A portion is reflected by the beam splitter 130; however, this embodiment does not limit the portion reflected by the beam splitter 130.

[0092] Thus, if the first beam f1 is transmitted to the optical position sensor 120, it will interfere with the measurement beam g1, causing inaccurate measurements by the optical position sensor 120. In this application, the light-absorbing component 140 absorbs the first beam f1, which can effectively reduce the interference of the first beam f1 on the measurement beam g1, thereby improving the accuracy of the optical position detection device 100 and thus improving the precision of the microelectromechanical device 10.

[0093] This application does not limit the type of optical position sensor 120. For example, the optical position sensor 120 can be a position sensitive detector (PSD).

[0094] Please return Figure 3b When the reflector 17 rotates to the left or right around the axis m, the transmission direction of the light beam reflected by the reflector 17 changes accordingly.

[0095] It is understandable that the reflector 17 of the micromirror 11 (such as...) Figure 3b As shown, after rotation, the transmission direction of the light beam reflected by the reflector 17 also changes accordingly. Obviously, the transmission direction of the measurement beam g1 obtained after being reflected once by the reflector 17 changes, and the transmission direction of the first beam f1 obtained after being reflected twice or more by the reflector 17 also changes.

[0096] In some embodiments of this application, in order to further reduce the interference of the first beam f1 on the measurement results of the optical position sensor 120, the light-absorbing component 140 can absorb the first beam f1 in multiple transmission directions.

[0097] In some embodiments, the light-absorbing assembly 140 includes a first light-absorbing element 141 and a driver 142, which are connected. The driver 142 drives the first light-absorbing element 141 to move along a first direction. The first light-absorbing element 141 absorbs a first light beam f1; the first direction is perpendicular to the optical axis of the first sub-beam h1. As mentioned above, the first sub-beam h1 is a light beam emitted from the light source 110 and reflected by the beam splitter 130. Exemplarily, the first direction is parallel to the x-direction.

[0098] Typically, the rotation angle of the micromirror 11 is small. During the rotation of the micromirror 11, the angle between the optical axis of the beam reflected once or multiple times by the micromirror 11 and the optical axis of the first sub-beam h1 is small. During the rotation of the micromirror 11, the transmission direction of the first beam f1 changes little. The first light-absorbing element 141 moves along the first direction, so even if the transmission direction of the first beam f1 changes, the first light-absorbing element 141 can still absorb the first beam f1. In this way, the area of ​​the first light-absorbing element 141 can be small, and the first light-absorbing element 141 can also effectively reduce the interference of the first beam f1 on the measurement results of the optical position sensor 120.

[0099] The optical axis of the first sub-beam h1 mentioned above refers to the center line of the first sub-beam h1. It can be understood that the optical axis of the first sub-beam h1 is related to the transmission direction of the light output from the light source 110 and the normal of the reflecting surface of the beam splitter 130.

[0100] For example, the fact that the aforementioned first direction is perpendicular to the optical axis of the first sub-bundle h1 allows for the existence of manufacturing and assembly errors. For instance, the angle between the first direction and the optical axis of the first sub-bundle h1 is 87° to 92°.

[0101] The embodiments of this application do not limit the structure of the first light-absorbing element 141. For example, the first light-absorbing element 141 can be a light-absorbing coating such as a black coating, or the first light-absorbing element 141 can be an aperture structure.

[0102] In some embodiments, the first light-absorbing element 141 absorbs all of the first light beam f1. In some embodiments, the first light-absorbing element 141 absorbs a portion of the first light beam f1, and the remaining portion of the first light beam f1 is scattered or reflected by the first light-absorbing element 141. Since the transmission direction of the first light beam f1 is changed by the first light-absorbing element 141, the portion of the first light beam f1 scattered or reflected by the first light-absorbing element 141 has less interference with the measurement results of the optical position sensor 120.

[0103] The embodiments of this application do not limit the structure of the driver 142. Exemplarily, the driver 142 can be a linear drive structure, such as a linear stepper motor.

[0104] Figure 5 This is a schematic diagram of the optical path of the light beam reflected by the micromirror 11 at different rotation angles. Figure 5 Figure (a) illustrates the micromirror 11 about the m-axis (e.g.) Figure 3b (As shown) A schematic diagram of the optical path rotated 0° to the right, i.e., the micromirror 11 is parallel to the substrate 15. Figure 5 Figure (b) illustrates the micromirror 11 around the m-axis (e.g., Figure 3b (As shown) A schematic diagram of the optical path rotated 2° to the right. Figure 5 Figure (c) illustrates the micromirror 11 around the m-axis (e.g.) Figure 3b(As shown) A schematic diagram of the optical path rotated 4° to the right.

[0105] from Figure 5 As can be seen, the transmission directions of the first beam f1 and the measurement beam g1 differ depending on the angle by which the micromirror 11 rotates to the right around the m-axis. The angle between the transmission directions of the first beam f1 and the measurement beam g1 also changes accordingly.

[0106] In embodiments of this application, driver 142 (e.g. Figure 4 As shown, the first light-absorbing element 141 is driven to move, and the transmission direction of the first beam f1 changes. The driver 142 then drives the first light-absorbing element 141 to move accordingly to the position where the first beam f1 is intercepted. This effectively solves the problem that the first beam f1 interferes with the measurement beam g1 as the micromirror 11 rotates.

[0107] When the micromirror 11 is rotated around the m-axis (e.g.) Figure 3b As shown, during the rightward rotation, the optical path of the beam reflected by the micromirror 11 changes as follows: Figure 5 (a) diagram Figure 5 (b) diagram Figure 5 The relationship in diagram (c) changes sequentially. It can be seen that the distance between the first beam f1 and the measurement beam g1 gradually decreases, and the driver 142 (as shown in diagram (c)...) Figure 4 (As shown) Drive the first light-absorbing element 141 to move, the first light-absorbing element 141 absorbs the first light beam f1, and improves the measurement accuracy of the optical position sensor 120.

[0108] Conversely, when the micromirror 11 is rotated around the m-axis (e.g.) Figure 3b As shown, during the leftward rotation, the optical path of the beam reflected by the micromirror 11 changes as follows: Figure 5 (c) diagram Figure 5 (b) diagram Figure 5 The relationship in Figure (a) changes sequentially. It can be seen that the distance between the first beam f1 and the measuring beam g1 gradually increases. During this process, the driver 142 may not drive the first light-absorbing element 141 to move, but the first light-absorbing element 141 can still absorb the first beam f1, improving the measurement accuracy of the optical position sensor 120. Alternatively, the driver 142 may not drive the first light-absorbing element 141 to move. Even if the first light-absorbing element 141 does not absorb the first beam f1, the first beam f1 will not return to the optical position sensor 120, thus having no impact on the measuring beam g1, and the measurement accuracy of the optical position sensor 120 remains high.

[0109] It is understood that in some embodiments of this application, the light-absorbing component 140 may not have a driver 142. For example, the position of the first light-absorbing element 141 may be fixed relative to the optical position sensor 120. In this way, the first light-absorbing element 141 can absorb the first light beam f1 reflected by the micromirror 11 at a partial angle.

[0110] Please return Figure 4 In some scenarios, the first sub-beam h1 is transmitted to the microelectromechanical device 10, and the outer surface 14 of the transparent cover 12 of the microelectromechanical device 10 may also reflect part of the first sub-beam h1.

[0111] Figure 4 In this optical position detection device 100, a second light-absorbing element 150 may be included, which is used to absorb the second light beam f2. The second light beam f2 is a light beam reflected by the beam splitter 130, then reflected again by the outer surface 14 of the transparent cover 12, and finally transmitted through the beam splitter 130. In other words, the second light beam f2 is a light beam transmitted by the beam splitter 130 after the first sub-beam h1 reflected by the beam splitter 130 is reflected by the outer surface 14 of the transparent cover 12 and then transmitted through the beam splitter 130.

[0112] Thus, the second light-absorbing element 150 can reduce the interference of the light beam reflected by the outer surface 14 of the transparent cover 12 on the measurement results of the optical position sensor 120. This can further improve the measurement accuracy of the optical position detection device 100.

[0113] Similarly, a portion of the light beam reflected by the outer surface 14 of the transparent cover 12 and transmitted to the beam splitter 130 is transmitted by the beam splitter 130, and this portion becomes the second light beam f2 transmitted to the second light absorber 150. A portion is reflected by the beam splitter 130; this embodiment does not limit the scope of this application.

[0114] The embodiments of this application do not limit the structure of the second light-absorbing element 150. Please refer to the description of the first light-absorbing element 141 above, which will not be repeated here.

[0115] During the rotation of the micromirror 11 relative to the substrate 15, there is no relative rotation between the transparent cover 12 and the substrate 15. The transmission direction of the second light-absorbing element 150 does not change with the rotation of the micromirror 11.

[0116] Please refer to it again. Figure 5 ,from Figure 5 As can be seen, the angle between the micromirror 11 and the substrate 15 is different, and the transmission direction of the second beam f2 hardly changes. Thus, during the rotation of the micromirror 11 relative to the substrate 15, the second light-absorbing element 150 and the optical position sensor 120 do not move relative to each other, and can also absorb the second beam f2.

[0117] In some embodiments of this application, in order to reduce the spot size of the first beam f1 and the measurement beam g1, and to make the coordinates measured by the optical position sensor 120 more accurate, the optical position detection device 100 may further include a focusing lens 160. The focusing lens 160 is used to converge the measurement beam and transmit it to the optical position sensor 120.

[0118] In this way, the focusing lens 160 can shape the first beam f1 and the measurement beam g1, further reducing the interference of the first beam f1 on the measurement results of the optical position sensor 120.

[0119] In some embodiments of this application, the focusing lens 160 is also used to converge the first beam f1 and transmit it to the light-absorbing component 140. In this way, the focusing lens 160 can reduce the spot size of the measurement beam g1, thereby enabling the optical position sensor 120 to measure coordinates with greater accuracy.

[0120] It is understood that in some embodiments of this application, the focusing lens 160 may not converge the first beam f1. In other words, the focusing lens 160 may not be located in the optical path of the first beam f1.

[0121] With the combined action of the light-absorbing component 140 and the second light-absorbing component 150, stray light reflected from the inner surface 13 and outer surface 14 of the transparent cover 12 can be effectively blocked, thereby improving the measurement accuracy of the optical position sensor 120.

[0122] In an embodiment where the optical position detection device 100 includes a second light-absorbing element 150, the focusing lens 160 is further used to converge the second light beam f2 and transmit it to the second light-absorbing element 150. Thus, the focusing lens 160 can shape the second light beam f2, further reducing the interference of the second light beam f2 on the measurement results of the optical position sensor 120.

[0123] Alternatively, the focusing lens 160 may not be located in the optical path of the second beam f2.

[0124] As described above, beam splitter 130 transmits a portion of the light beam and also reflects a portion of the light beam. For example, beam splitter 130 transmits a portion of the light beam from light source 110 and reflects a portion of the light beam from light source 110. Beam splitter 130 transmits a portion of the light beam from microelectromechanical device 10 and reflects a portion of the light beam from microelectromechanical device 10.

[0125] In embodiments of this application, to reduce the influence of a portion of the light beam reflected by the beam splitter 130 and originating from the light source 110, the optical position detection device 100 may further include a third light-absorbing element 170 in some embodiments of this application.

[0126] like Figure 4As shown, the third light-absorbing element 170 is provided with a light-transmitting hole 171 extending through the third light-absorbing element 170. The light source 110 is disposed on one side of the third light-absorbing element 170, and the light-transmitting hole 171 is used to allow the light beam emitted from the light source 110 to pass through. In this way, the third light-absorbing element 170 hardly intercepts the light beam output by the light source 110, and the third light-absorbing element 170 can absorb part of the light beam reflected by the beam splitter 130 and originating from the light source 110, reducing the interference of this part of the light beam on the measurement beam g1, which is beneficial to making the measurement results of the optical position sensor 120 more accurate.

[0127] The shape of the third light-absorbing element 170 is not limited in this embodiment. For example, the third light-absorbing element 170 can be a square, circular, or elliptical plate. The shape of the light-transmitting hole 171 can be, for example, a circular hole, a square hole, or an elliptical hole.

[0128] For example, in some embodiments, the third light-absorbing element 170 may be an aperture structure.

[0129] In some embodiments, the third light-absorbing element 170 and the light source 110 are fixedly connected. For example, the third light-absorbing element 170 and the light source 110 are connected by an adhesive layer or a solder layer.

[0130] It is understood that in the embodiments of this application, the third light-absorbing element 170 is not necessary, and the optical position detection device 100 may not be provided with the third light-absorbing element 170.

[0131] like Figure 4 As shown in the embodiments of this application, the optical position detection device 100 further includes a housing 101. The light source 110, beam splitter 130, optical position sensor 120, and light-absorbing assembly 140 are all located within the housing 101. The housing 101 includes a light-transmitting opening 102 for allowing a light beam emitted from the light source 110 and reflected by the beam splitter 130 to pass through. The light-transmitting opening 102 also allows a first light beam f1 and a measurement light beam g1 to pass through. In other words, the light-transmitting opening 102 allows a first sub-beam h1 to pass through. The first sub-beam h1, after being reflected by the microelectromechanical device 10, passes through the light-transmitting opening 102 and returns to the housing 101.

[0132] Thus, the housing 101 can prevent dust or moisture from contaminating the light source 110, beam splitter 130, optical position sensor 120, and light-absorbing assembly 140, providing a dry working environment for them. The housing 101 can also reduce interference from other light sources on the measurement results of the optical position sensor 120.

[0133] In some embodiments of this application, the light source 110, the beam splitter 130, the optical position sensor 120, and the light-absorbing component 140 are all connected to the housing 101, which is used to support the light source 110, the beam splitter 130, the optical position sensor 120, and the light-absorbing component 140.

[0134] In some embodiments, a light-absorbing layer is provided on the inner surface of the housing 101. The light-absorbing layer can absorb the light scattered by the beam splitter 130, optical position sensor 120 and light-absorbing component 140 inside the housing 101, so as to avoid the scattered light from interfering with the measurement results and to prevent the scattered light from causing light pollution.

[0135] The shape of the outer casing 101 is not limited in the embodiments of this application. In some embodiments of this application, the shape of the outer casing 101 can be a square box, a spherical box, or an irregular box-shaped structure.

[0136] In some embodiments of this application, the optical position detection device 100 may also be configured to absorb the light beam scattered within the housing 101.

[0137] Figure 4 In this embodiment, the photosensitive surface of the optical position sensor 120 is not perpendicular to the optical axis of the first sub-beam h1. Therefore, the normal of the photosensitive surface of the optical position sensor 120 is not parallel to the optical axis of the first sub-beam h1.

[0138] After the measurement beam g1 is transmitted to the photosensitive surface of the optical position sensor 120, if the measurement beam g1 is reflected by the photosensitive surface of the optical position sensor 120 to output beam g2, since the normal of the photosensitive surface of the optical position sensor 120 and the optical axis of the first sub-beam h1 are not parallel, the transmission direction of the beam g2 reflected by the photosensitive surface of the optical position sensor 120 is not parallel to the transmission direction of the measurement beam g1. Thus, the output beam g2 reflected by the photosensitive surface of the optical position sensor 120 will not be transmitted in the reverse direction along the measurement beam g1, avoiding beam g2 returning to the microelectromechanical device 10 and being reflected again by the microelectromechanical device 10 before returning to the photosensitive surface of the optical position sensor 120, which helps improve the measurement accuracy of the optical position sensor 120.

[0139] In other words, the photosensitive surface of the optical position sensor 120 is not perpendicular to the optical axis of the first sub-beam h1. Even if the measurement beam g1 is reflected by the photosensitive surface of the optical position sensor 120 to output beam g2, beam g2 cannot be transmitted to the microelectromechanical device 10. This avoids beam g2 returning to the photosensitive surface of the optical position sensor 120 after being transmitted to the microelectromechanical device 10, forming an interference beam, and preventing this interference beam from affecting the measurement results of the optical position sensor 120. This ensures that the measurement results of the optical position sensor 120 can accurately represent the position of the spot of the measurement beam g1 on the photosensitive surface of the optical position sensor 120.

[0140] For example, the photosensitive surface of the optical position sensor 120 refers to the physical plane on which the optical position sensor 120 receives the light spot to be measured. When the light spot to be measured hits the photosensitive surface, the specific position coordinates of the light spot on the photosensitive surface can be obtained according to the output current signal of the optical position sensor 120.

[0141] For example, the photosensitive surface of the optical position sensor 120 forms an angle of 65°-82° with the optical axis of the first sub-beam h1. In this way, the measurement beam g1, after being reflected by the photosensitive surface of the optical position sensor 120, hardly travels to the microelectromechanical device 10, further preventing the beam g2 from traveling to the microelectromechanical device 10 and then returning to the photosensitive surface of the optical position sensor 120 to form an interfering beam.

[0142] In other words, the angle between the direction perpendicular to the optical axis of the first sub-beam h1 and the photosensitive surface of the optical position sensor 120 is 8°-25°. In a scenario where the optical axis of the first sub-beam h1 is vertical, the optical axis of the first sub-beam h1 is parallel to the z-direction. The angle between the photosensitive surface of the optical position sensor 120 and the horizontal plane is 8°-25°.

[0143] For example, the photosensitive surface of the optical position sensor 120 is at an angle of 65°, 67°, 68°, 70°, 71°, 72°, 75°, 78°, 80°, 81° or 82° with respect to the optical axis of the first sub-beam h1.

[0144] In this way, the photosensitive surface of the optical position sensor 120 and the plane of the beam splitter 130 do not coincide, effectively solving the problem of interference caused by the beam g2 returning to the micromirror.

[0145] In some embodiments of this application, the angle between the photosensitive surface of the optical position sensor 120 and the optical axis of the first sub-beam h1 can also be close to 90°. For example, the angle between the photosensitive surface of the optical position sensor 120 and the optical axis of the first sub-beam h1 can be 88° or 89°, etc.

[0146] In some embodiments of this application, the angle between the direction perpendicular to the optical axis of the first sub-beam h1 and the photosensitive surface of the optical position sensor 120 is greater than or equal to twice the rotatable angle of the microelectromechanical device 10. In other words, the angle between the direction perpendicular to the optical axis of the first sub-beam h1 and the photosensitive surface of the optical position sensor 120 is greater than or equal to twice α, where α is the maximum rotatable angle of the micromirror of the microelectromechanical device 10.

[0147] In some embodiments of this application, in order to further improve the measurement results of the optical position sensor 120, the light scattered inside the housing 101 can be reduced.

[0148] Figure 6This is a schematic diagram of another optical position detection device 100 and microelectromechanical device 10 provided in the embodiments of this application. Figure 6 and Figure 4 The differences include:

[0149] The optical position detection device 100 may further include a fourth light-absorbing element 180, which is used to absorb the second sub-beam h2. The second sub-beam h2 is a beam transmitted by the beam splitter 130 and originating from the light source 110.

[0150] Thus, the fourth light-absorbing element 180 can effectively reduce the interference of the second sub-beam h2 on the measurement results of the optical position sensor 120. For example, the fourth light-absorbing element 180 can absorb at least a portion of the second sub-beam h2, preventing that portion of the second sub-beam h2 from being transmitted to the photosensitive surface of the optical position sensor 120.

[0151] In some embodiments, the fourth light-absorbing element 180 is connected to the housing 101. The position of the fourth light-absorbing element 180 is set according to the transmission direction of the second sub-beam h2. The fourth light-absorbing element 180 can be positioned anywhere within the housing 101 without interfering with the transmission direction of the measurement beam g1.

[0152] The structure of the fourth light-absorbing element 180 is described in the aforementioned description of the first light-absorbing element 141, and will not be repeated here.

[0153] In some embodiments, the fourth light-absorbing element 180 is a light-absorbing layer that can absorb the second sub-beam h2.

[0154] The embodiments of this application do not limit the number of the fourth light-absorbing element 180. For example, the number of the fourth light-absorbing element 180 can be one, two, three or more.

[0155] In embodiments of this application, the optical position detection device 100 may further include a fifth light-absorbing element (not shown in the figure), which is used to absorb the light beam reflected by the beam splitter 130 from the microelectromechanical device 10. For example, the fifth light-absorbing element is used to absorb the light beam reflected by the beam splitter 130 and reflected once, twice, or more times by the micromirrors 11 of the microelectromechanical device 10. Alternatively, the fifth light-absorbing element is used to absorb the light beam reflected by the beam splitter 130 and reflected by the outer surface 14 of the transparent cover 12 of the microelectromechanical device 10. In this way, the requirements of the aforementioned light beam on the measurement results of the optical position sensor 120 can be reduced.

[0156] In the embodiments of this application, the fifth light-absorbing element is not necessary, and the optical position detection device 100 may not be equipped with a fifth light-absorbing element.

[0157] In some embodiments of this application, the light transmission path within the optical position detection device 100 can be adjusted according to the volume requirements and space available for the device. For example, the light transmission path within the optical position detection device 100 can be adjusted using a reflective element.

[0158] Figure 7 This is a schematic diagram of the structure of another optical position detection device 100 and microelectromechanical device 10 provided in the embodiments of this application. Figure 7 and Figure 6 The differences include:

[0159] The optical position detection device 100 may further include a reflective element 190, which reflects the light beam emitted from the light source 110 to the beam splitter 130. In this way, the reflective element 190 can change the transmission direction of the light beam from the light source 110 to the beam splitter 130, causing the optical path from the light source 110 to the beam splitter 130 to be folded, reducing the distance between the light source 110 and the beam splitter 130. This is beneficial for improving the integration of the optical position detection device 100 and reducing the space occupied by the optical position detection device 100.

[0160] In some embodiments of this application, the reflective element 190 may be a reflective mirror. In some embodiments, the reflective element 190 may be a reflective film.

[0161] As mentioned above, the photosensitive surface of the optical position sensor 120 is not perpendicular to the optical axis of the first sub-beam h1. In other words, the direction perpendicular to the optical axis of the first sub-beam h1 is not parallel to the photosensitive surface of the optical position sensor 120. That is, the x-direction is not parallel to the photosensitive surface of the optical position sensor 120.

[0162] Figure 7 In the example, the photosensitive surface of the optical position sensor 120 is tilted in the same direction as the transparent cover 12. In other words, the photosensitive surface of the optical position sensor 120 and the outer surface 14 of the transparent cover 12 are nearly parallel.

[0163] In some embodiments of this application, the tilt direction of the photosensitive surface of the optical position sensor 120 and the tilt direction of the transparent cover 12 may be different.

[0164] Figure 8 This is a schematic diagram of the structure of another optical position detection device 100 and microelectromechanical device 10 provided in the embodiments of this application. Figure 8 and Figure 7 The differences include: the tilt direction of the photosensitive surface of the optical position sensor 120 is different from the tilt direction of the transparent cover 12.

[0165] and Figure 7Similarly, the photosensitive surface of the optical position sensor 120 is not perpendicular to the optical axis of the first sub-beam h1. In other words, the direction perpendicular to the optical axis of the first sub-beam h1 is not parallel to the photosensitive surface of the optical position sensor 120.

[0166] Figure 8 In the example, the tilt direction of the photosensitive surface of the optical position sensor 120 is different from the tilt direction of the transparent cover 12; the tilt direction of the photosensitive surface of the optical position sensor 120 is opposite to the tilt direction of the transparent cover 12. Similarly, the measurement beam g1, after being reflected by the photosensitive surface of the optical position sensor 120, hardly travels to the microelectromechanical device 10, further preventing the beam g2 from traveling to the microelectromechanical device 10 and then returning to the photosensitive surface of the optical position sensor 120 to form an interfering beam.

[0167] In some embodiments of this application, the photosensitive surface of the optical position sensor 120 may not be tilted. In other words, the photosensitive surface of the optical position sensor 120 may be parallel to the first direction.

[0168] Figure 9 This is another schematic diagram of the optical path of the light beam reflected by the micromirror 11 at different rotation angles. Figure 9 Figure (a) and Figure 9 In Figure (b), the photosensitive surface of the optical position sensor 120 is parallel to the first direction. The photosensitive surface of the optical position sensor 120 is not tilted; in other words, the first sub-beam h1 (as shown in Figure (b)) is parallel to the first direction. Figure 8 The optical axis (as shown) is perpendicular to the optical position sensor 120.

[0169] Figure 9 Figure (a) illustrates the micromirror 11 about the m-axis (e.g.) Figure 3b (As shown) A schematic diagram of the optical path rotated 0° to the right, i.e., the micromirror 11 and the substrate 15 (as shown) Figure 3b (As shown) parallel. Figure 9 Figure (b) illustrates the micromirror 11 around the m-axis (e.g., Figure 3b (As shown) A schematic diagram of the optical path rotated 2° to the right.

[0170] from Figure 9 Figure (a) and Figure 9 In diagram (b), since the first light-absorbing element 141 can absorb the first light beam f1, then... Figure 9 Figure (a) and Figure 9 The optical position sensor 120 in Figure (b) has high measurement accuracy.

[0171] In some embodiments of this application, the optical position detection device 100 may not include a light-absorbing component for absorbing the first light beam. For example, including a light-absorbing component for absorbing the second light beam f2 can also improve the accuracy of the optical position detection device 100.

[0172] Figure 10 This is a schematic diagram of the structure of an optical position detection device 100 and a microelectromechanical device provided in the embodiments of this application. Figure 10 and Figure 4 The differences include: the optical position detection device 100 does not include... Figure 4 The light-absorbing component 140 shown.

[0173] Figure 10 In the example, the optical position detection device 100 includes a light source 110, an optical position sensor 120, a beam splitter 130, and a light absorber 210. The beam splitter 130 reflects and transmits a portion of the light beam emitted from the light source 110. The optical position sensor 120 receives the measurement beam and acquires its position coordinates; the measurement beam is a beam reflected by the beam splitter 130, reflected once by the micromirror 11, and then transmitted through the beam splitter 130.

[0174] The structure of the light source 110, the optical position sensor 120, and the beam splitter 130, and their relationship in the optical path, are described in the foregoing. Figure 4 The description in the text will not be repeated here.

[0175] The light-absorbing element 210 is used to absorb interfering light beams. The interfering light beam is a light beam that is reflected by the beam splitter 130, then reflected by the outer surface of the transparent cover 12, and then transmitted through the beam splitter 130.

[0176] Figure 10 Please refer to the foregoing for the structure of the light-absorbing element 210 and its relationship in the optical path. Figure 4 Description of the second light-absorbing element 150. For interference beams, please refer to the preceding section. Figure 4 The description of the second beam is omitted here.

[0177] in this way, Figure 10 The optical position detection device 100 shown can effectively reduce the interference of the light beam reflected from the outer surface of the transparent cover 12 on the measurement results of the optical position sensor 120. When the optical position detection device 100 is used in the scenario of microelectromechanical device 10, it provides high-precision measurement results for the microelectromechanical device 10.

[0178] The optical position detection device 100 provided in this application embodiment also has the advantage of high-precision measurement for microelectromechanical devices 10 with large rotation angles. It can also solve the problem of low testing efficiency of the optical position detection device 100. The optical position detection device 100 provided in this application embodiment overcomes the problem of the transparent cover 12 affecting measurement accuracy. Measurement can be performed even when the transparent cover 12 is fastened to the micromirror 11, avoiding the scenario where the transparent cover 12 is not fastened before measurement and is fastened after measurement. This eliminates the problem of large errors before and after fastening.

[0179] In addition, the optical position detection device 100 effectively eliminates crosstalk problems caused by back-and-forth reflections between the transparent cover 12 and the micromirror 11, and between the micromirror 11 and the internal optical components of the optical position detection device 100.

[0180] This application does not limit the method by which the optical position detection device 100 measures the microelectromechanical device 10.

[0181] Exemplarily, in an embodiment of this application, the method of the optical position detection device 100 measuring the microelectromechanical device 10 includes:

[0182] Step 1: The power component 16 receives voltage, drives the reflector 17 to rotate to the right around the axis m, the light source 110 outputs a light beam, and the optical position sensor 120 outputs position coordinates. Based on the position coordinates output by the optical position sensor 120, the rotation angle of the light beam received by the optical position sensor 120 is calculated, resulting in the voltage-rotation angle curve for the scenario where the reflector 17 rotates to the right around the axis m.

[0183] During the process of the power component 16 driving the reflector 17 to rotate to the right around the axis m, the first beam f1 (as shown) Figure 5 (as shown) and measurement beam g1 (as shown) Figure 5 As the angle between the reflector 17 and the optical position sensor 120 gradually increases, the angle at which the reflector 17 rotates to the right around the axis m increases, and the interference of the first light beam f1 on the measurement beam g1 decreases. During this process, the driver 142 may not drive the first light-absorbing element 141 to move along the first direction. In other words, during the process of driving the reflector 17 to rotate to the right around the axis m, the first light-absorbing element 141 may not move relative to the optical position sensor 120, and the first light beam f1 will not return to the optical position sensor 120. Therefore, it will not affect the measurement beam g1, improving the measurement accuracy of the optical position sensor 120.

[0184] Step 2: The power component 16 receives voltage, drives the reflector 17 to rotate to the left around the axis m, the light source 110 outputs a light beam, and the optical position sensor 120 outputs position coordinates. Based on the position coordinates output by the optical position sensor 120, the rotation angle of the light beam received by the optical position sensor 120 is calculated, resulting in the voltage-rotation angle curve for the scenario where the reflector 17 rotates to the left around the axis m.

[0185] During the process of the power component 16 driving the reflector 17 to rotate to the left around the axis m, the first beam f1 (as shown in the image) Figure 5 (as shown) and measurement beam g1 (as shown) Figure 5 As the angle between the reflector 17 and the optical position sensor 120 gradually decreases, the greater the angle at which the reflector 17 rotates to the left around the axis m, the greater the interference of the first light beam f1 on the measurement beam g1. In this step, the driver 142 can drive the first light-absorbing element 141 to move along the first direction. In other words, during the process of driving the reflector 17 to rotate to the left around the axis m, the first light-absorbing element 141 moves relative to the optical position sensor 120 to absorb the first light beam f1, thereby improving the measurement accuracy of the optical position sensor 120.

[0186] For example, the driver 142 controls the first light-absorbing element 141 to move to a position that can block or absorb the first light beam f1 based on the position of the light spot of the measurement beam obtained by the optical position sensor 120 on the optical position sensor 120, so that the first light beam f1 is absorbed and thus will not affect the measurement beam g1, thereby improving the measurement accuracy of the optical position sensor 120.

[0187] Step 3: The power component 16 receives voltage, drives the reflector 17 to rotate forward around the axis n, the light source 110 outputs a light beam, and the optical position sensor 120 outputs position coordinates. Based on the position coordinates output by the optical position sensor 120, the rotation angle of the light beam received by the optical position sensor 120 is calculated, and the voltage-rotation angle curve for the scenario where the reflector 17 rotates forward around the axis n is obtained.

[0188] During the process of the power assembly 16 driving the reflector 17 to rotate forward around the axis n, the first light beam f1 moves along the y-direction, and the measuring light beam g1 also moves along the y-direction. During this process, the driver 142 may not drive the first light-absorbing element 141 to move along the first direction. The first light-absorbing element 141 may not move relative to the optical position sensor 120, or it may absorb the first light beam f1, improving the measurement accuracy of the optical position sensor 120. For example, if the first light-absorbing element 141 has a large dimension along the y-direction, when the power assembly 16 drives the reflector 17 to rotate forward around the axis n at its maximum angle, the first light-absorbing element 141 may also absorb the first light beam f1, improving the measurement accuracy of the optical position sensor 120.

[0189] Step 4: The power component 16 receives voltage, drives the reflector 17 to rotate backward around the axis n, the light source 110 outputs a light beam, and the optical position sensor 120 outputs position coordinates. Based on the position coordinates output by the optical position sensor 120, the rotation angle of the light beam received by the optical position sensor 120 is calculated, and the voltage-rotation angle curve for the scenario where the reflector 17 rotates backward around the axis n is obtained.

[0190] Similar to step three above, during the process of the power assembly 16 driving the reflector 17 to rotate backward around the axis n, the first light beam f1 moves along the y-direction, and the measuring light beam g1 also moves along the y-direction. During this process, the driver 142 may not drive the first light-absorbing element 141 to move along the first direction. The first light-absorbing element 141 may not move relative to the optical position sensor 120, or it may absorb the first light beam f1, improving the measurement accuracy of the optical position sensor 120. For example, if the first light-absorbing element 141 has a large dimension along the y-direction, when the power assembly 16 drives the reflector 17 to rotate backward around the axis n to its maximum angle, the first light-absorbing element 141 may also absorb the first light beam f1, improving the measurement accuracy of the optical position sensor 120.

[0191] Thus, during the process of the power assembly 16 driving the reflector 17 to rotate to the left around the rotation axis m, the driver 142 drives the first light-absorbing element 141 to chase the first light beam f1 in order to absorb the first light beam f1. During the process of the power assembly 16 driving the reflector 17 to rotate to the right around the rotation axis m, to rotate forward around the rotation axis n, and to rotate backward around the rotation axis n, the driver 142 may not drive the first light-absorbing element 141 to move.

[0192] It is understood that the embodiments of this application do not limit the order of the steps of the above method, and the aforementioned steps one, two, three and four can be arbitrarily ordered.

[0193] Thus, the optical position sensor 120 achieves high measurement accuracy, and the optical position detection device 100 also achieves correspondingly high testing efficiency. This reduces the impact of noise on the measurement results and improves the linearity of the voltage-angle curve of the microelectromechanical device 10 and the stability of the measurement results.

[0194] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0195] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optical position detection device, characterized in that, The optical position detection device is used in a microelectromechanical device (MEMS); the MEMS includes a micromirror and a transparent cover, the micromirror being located inside the transparent cover; the transparent cover includes an inner surface facing the micromirror and an outer surface facing away from the micromirror; The optical position detection device includes: light source; A beam splitter is used to reflect a portion of the light beam emitted from the light source and to transmit a portion of the light beam emitted from the light source. An optical position sensor is used to receive a measurement beam and obtain the position coordinates of the optical position sensor for receiving the measurement beam; the measurement beam is a beam reflected by the beam splitter, reflected once by the micromirror, and then transmitted by the beam splitter. A light-absorbing component is used to absorb a first light beam; the first light beam is a light beam reflected by the beam splitter, reflected twice or more by the micromirror, and then transmitted by the beam splitter after being reflected by the inner surface of the transparent cover.

2. The optical position detection device according to claim 1, characterized in that, The light-absorbing component includes a first light-absorbing element and a driver. The driver is connected to the first light-absorbing element and is used to drive the first light-absorbing element to move along a first direction. The first light-absorbing element is used to absorb the first light beam. The first direction is perpendicular to the optical axis of the first sub-beam; The first sub-beam is: the beam emitted from the light source and reflected by the beam splitter.

3. The optical position detection device according to claim 1 or 2, characterized in that, The photosensitive surface of the optical position sensor is not perpendicular to the optical axis of the second sub-beam; The second sub-beam is the beam emitted from the light source and reflected by the beam splitter.

4. The optical position detection device according to claim 3, characterized in that, The photosensitive surface of the optical position sensor forms an angle of 65°-82° with the optical axis of the second sub-beam.

5. The optical position detection device according to any one of claims 1-4, characterized in that, The optical position detection device further includes: The second light-absorbing element is used to absorb the second light beam. The second beam is a beam that is reflected by the beam splitter, then reflected by the outer surface of the transparent cover, and then transmitted through the beam splitter.

6. The optical position detection device according to any one of claims 1-5, characterized in that, The optical position detection device further includes: The third light-absorbing element has a light-transmitting hole that passes through it. The light source is located on one side of the third light-absorbing element, and the light-transmitting hole is used to allow the light beam emitted from the light source to pass through.

7. The optical position detection device according to any one of claims 1-6, characterized in that, The optical position detection device further includes: The fourth light-absorbing element is used to absorb the first sub-beam; The first sub-beam is a beam of light transmitted through the beam splitter and originating from the light source.

8. The optical position detection device according to any one of claims 1-7, characterized in that, The optical position detection device further includes a reflective element, which is used to reflect the light beam emitted from the light source to the beam splitter.

9. The optical position detection device according to any one of claims 1-8, characterized in that, The optical position detection device further includes: a focusing lens; The focusing lens is used to converge the measurement beam and transmit it to the optical position sensor.

10. The optical position detection device according to claim 9, characterized in that, The focusing lens is also used to converge the first beam and transmit it to the light-absorbing component.

11. The optical position detection device according to any one of claims 1-10, characterized in that, The optical position detection device further includes: a housing, wherein the light source, the beam splitter, the optical position sensor and the light-absorbing component are all located inside the housing; The housing includes a light-transmitting opening for a light beam emitted from the light source and reflected by the beam splitter to pass through. The light-transmitting opening is also used to allow the first light beam and the measuring light beam to pass through.

12. An optical position detection device, characterized in that, The optical position detection device is used in a microelectromechanical device (MEMS); the MEMS includes a micromirror and a transparent cover, the transparent cover being used to seal the micromirror; the transparent cover includes an inner surface facing the micromirror and an outer surface facing away from the micromirror; The optical position detection device includes: light source; A beam splitter is used to reflect a portion of the light beam emitted from the light source and to transmit a portion of the light beam emitted from the light source. An optical position sensor is used to receive a measurement beam and acquire the position coordinates of the optical position sensor receiving the measurement beam; the measurement beam is a beam reflected by the beam splitter, reflected once by the micromirror, and then transmitted by the beam splitter; the optical position sensor is used to receive the measurement beam and acquire the position coordinates of the optical position sensor receiving the measurement beam; the measurement beam is: A light-absorbing component is used to absorb interfering light beams; the interfering light beam is a light beam that is reflected by the beam splitter, then reflected by the outer surface of the transparent cover, and then transmitted through the beam splitter.

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