Microelectromechanical devices controlled by single-channel signals and their control methods

Abstract

The application provides a single-channel signal control micro-electro-mechanical device and a control method thereof. The device comprises a substrate, a first lower comb tooth and a second lower comb tooth are arranged on the substrate, the first lower comb tooth is electrically connected with a first driving electrode, and the second lower comb tooth is electrically connected with a second driving electrode; a substrate is arranged above the substrate, an upper comb tooth, a rotating mirror, a driving signal input electrode and a driving signal input spring are arranged on the substrate, the driving signal input electrode is electrically connected with the driving signal input spring, a free end of the driving signal input spring is selectively connected to the first driving electrode or the second driving electrode; a first control electrode is further arranged on the substrate, and the first control electrode is connected to a first control comb tooth. The application further provides a control method of the micro-electro-mechanical device. The application can realize the driving of two lower comb teeth through a set of driving circuit, and can reduce the production cost of the micro-electro-mechanical device.

Description

Technical Field

[0001] This invention relates to the field of microelectromechanical device (MEMS) control technology, specifically to a single-channel signal controlled MEMS and a control method for such MEMS. Background Technology

[0002] Microelectromechanical systems (MEMS) are widely used in optical devices. Most commonly used MEMS are electrostatically driven, featuring upper and lower comb teeth and a substrate with a rotating mirror. By changing the voltage applied to the upper or lower comb teeth, the electrostatic force between them is altered, causing the mirror to rotate. This allows for changing the exit angle of the reflected light beam, thus enabling optical path switching. Therefore, MEMS are widely used in optical devices such as optical switches.

[0003] Some existing electrostatically driven microelectromechanical devices (MEMS) have multiple electrodes and corresponding drive circuits for each electrode. This results in a large number of drive circuits required for existing MEMS, leading to a complex overall structure and increased production costs.

[0004] Patent application CN119706734A discloses an electrostatically driven microelectromechanical device (MEMS). This MEMS uses a multiplexer to switch the input voltage. The fixed end of the selector switch in the multiplexer is connected to the drive circuit, and the free end of the selector switch can be selectively connected to one of two electrodes arranged in the same direction. A controller is required to control the operation of the selector switch.

[0005] While this type of microelectromechanical device (MEMS) can reduce the number of drive circuits, it requires a large number of single-pole double-throw (SPD) switches. When applying MEMS in optical switch arrays, the large number of MEMS required necessitates a large number of SPD switches. Since SPD switches are typically located in external drive modules, this increases the production cost and size of the external drive modules. Summary of the Invention

[0006] The first objective of this invention is to provide a microelectromechanical device that can reduce the number of drive circuits, has a small size, and is easy to mass-produce.

[0007] A second objective of this invention is to provide a control method for the microelectromechanical device controlled by the above-mentioned single-channel signal.

[0008] To achieve the first objective of this invention, the single-channel signal controlled microelectromechanical device provided by this invention includes a substrate, on which a first lower comb tooth and a second lower comb tooth are disposed. The first lower comb tooth is electrically connected to a first driving electrode, and the second lower comb tooth is electrically connected to a second driving electrode. A substrate is disposed above the substrate, on which an upper comb tooth and a rotating mirror are disposed. The rotating mirror is supported on the substrate by a pair of cantilever beams. A driving signal input electrode is disposed on the substrate, and the driving signal input electrode is electrically connected to a driving signal input spring. The driving signal input spring is located between the first driving electrode and the second driving electrode, and the free end of the driving signal input spring can be selectively connected to either the first driving electrode or the second driving electrode. A first control electrode is also disposed on the substrate, and the first control electrode is connected to a first control comb tooth. A switching comb tooth is disposed on the driving signal input spring.

[0009] A preferred embodiment is that a second control electrode is also provided on the substrate, the second control electrode is connected to a second control comb tooth, and the switching comb tooth is located between the first control comb tooth and the second control comb tooth.

[0010] As can be seen from the above scheme, two control electrodes are provided on the substrate, and a drive signal input spring is provided. By applying a suitable voltage to the two control electrodes, the free end of the drive signal input spring can be connected to one of the control electrodes. In this way, after the drive signal is applied to the drive signal input electrode, the drive signal can be output to the corresponding drive electrode through the drive signal input spring, and thus output a drive signal to the corresponding lower comb tooth, thereby changing the voltage of one of the first lower comb tooth and the second lower comb tooth, thereby driving the rotation of the rotating mirror.

[0011] Since the two control electrodes, the drive signal input electrode, and the drive signal input spring are all located on the substrate of the microelectromechanical device (MEMS) rather than outside the MEMS, the external drive circuit only needs to provide drive signals and output control signals to the two control electrodes. Therefore, the external drive circuit does not need to set a large number of single-pole double-throw switches, which can reduce the production cost of the drive circuit and also reduce the size of the external drive circuit.

[0012] Furthermore, when microelectromechanical devices (MEMS) are applied to array optical switches, since multiple MEMS have the same structure, each MEMS can be equipped with the same control electrode, drive signal input electrode, and drive signal input spring. Therefore, MEMS can be mass-produced. When the rotating mirrors of multiple MEMS need to move synchronously, only one drive circuit can be set up to simultaneously output drive signals to the drive signal input electrodes of multiple MEMS and output control signals to the control electrodes of multiple MEMS, thereby driving the rotating mirrors of multiple MEMS to rotate.

[0013] A preferred embodiment is that the first control comb tooth includes multiple first control tooth plates, and the second control comb tooth includes multiple second control tooth plates; the switching comb tooth includes multiple first switching tooth plates and multiple second switching tooth plates, the first switching tooth plates are disposed on the side close to the first control comb tooth, and the multiple first switching tooth plates and the multiple first control tooth plates are arranged alternately; the second switching tooth plates are disposed on the side close to the second control comb tooth, and the multiple second switching tooth plates and the multiple second control tooth plates are arranged alternately.

[0014] Therefore, by setting multiple first switching teeth and multiple second switching teeth on the drive signal input spring, after the corresponding control electrode is loaded with a control signal, the voltage of the drive signal input spring changes, thereby causing the free end of the drive signal input spring to deflect, thus changing the connection relationship between the drive signal input spring and the two drive electrodes, and achieving the purpose of applying drive signals to different lower comb teeth.

[0015] A further approach is to set the switching comb teeth at the end of the drive signal input spring near the drive signal input electrode.

[0016] The above settings allow for a larger deflection space at the free end of the drive signal input spring, making the deflection of the drive signal input spring more flexible.

[0017] A further embodiment includes an upper cantilever and a lower cantilever, with an electrically insulating layer formed between them. The upper cantilever is electrically connected to the drive signal input electrode and can be selectively connected to either a first drive electrode or a second drive electrode. Preferably, the switching comb teeth are disposed on the lower cantilever.

[0018] As can be seen, an electrical insulating layer is formed between the upper and lower cantilever, so that the drive signal of the drive signal input electrode is input to the first or second drive electrode through the upper cantilever, while the switching comb teeth set on the lower cantilever are used to drive the deflection of the drive signal input spring, thus avoiding mutual interference between the two different electrical signals.

[0019] A further solution is to fix the fixed end of the drive signal input spring to the collar, and the collar is sleeved on the outer periphery of the drive signal input electrode.

[0020] Therefore, by setting a collar, the drive signal input spring can be reliably fixed on the drive signal input electrode.

[0021] A further option is that the lower end of the first control comb tooth is fixed to the base, and the lower end of the second control comb tooth is fixed to the base.

[0022] It can be seen that the lower ends of the first and second control comb teeth are fixed to the base, which can prevent the first and second control comb teeth from shaking relative to the base and ensure the stability of the control signal loading.

[0023] A further embodiment is that the first control electrode has a first voltage application portion, and the second control electrode has a second voltage application portion; a first through hole and a second through hole are provided on the substrate, the first voltage application portion is located in the first through hole, and the second voltage application portion is located in the second through hole.

[0024] A further embodiment is that the upper end surface of the first voltage application portion is not higher than the upper surface of the substrate; and the upper end surface of the second voltage application portion is not higher than the upper surface of the substrate.

[0025] Therefore, the voltage application portions of the two control electrodes do not protrude from the upper surface of the substrate, which is beneficial for the packaging of microelectromechanical devices.

[0026] A further approach is to make the minimum distance between the first driving electrode and the second driving electrode smaller than the minimum distance between the first lower comb tooth and the second lower comb tooth.

[0027] Therefore, the smaller distance between the first and second driving electrodes allows the free end of the driving signal input spring to deflect within a shorter distance range, thereby reducing the voltage of the applied control signal. Conversely, the larger distance between the first and second lower comb teeth prevents contact between the two lower comb teeth, thus avoiding interference with the rotation of the rotating mirror.

[0028] To achieve the second objective mentioned above, the present invention provides a control method for a single-channel signal-controlled microelectromechanical device (MEMS). The method includes: applying a drive signal to a drive signal input electrode, such that the free end of a drive signal input spring is connected to a first drive electrode; applying a drive signal to the drive signal input electrode, the drive signal being output to a first lower comb tooth via the first drive electrode; or stopping the application of a control signal to a first control electrode, such that the free end of the drive signal input spring is separated from the first drive electrode, and the free end of the drive signal input spring is connected to a second drive electrode; applying a drive signal to the drive signal input electrode, the drive signal being output to a second lower comb tooth via the second drive electrode; and causing a rotating mirror to rotate around a cantilever beam, thereby changing the angle of the rotating mirror relative to the substrate.

[0029] As can be seen from the above scheme, by applying or not applying a control signal to the first control electrode, the electrical connection between the free end of the drive signal input spring and the two drive electrodes can be changed, thereby achieving the switching of the lower comb teeth with the applied drive signal. In this way, only one external drive circuit is needed to meet the drive requirements of the two lower comb teeth.

[0030] Another control method for a single-channel signal-controlled microelectromechanical device provided by the present invention includes: applying a control signal to a target control electrode, wherein the target control electrode is one of a first control electrode and a second control electrode, such that the free end of the drive signal input spring is connected to the first drive electrode or the second drive electrode; applying a drive signal to the drive signal input electrode, wherein the drive signal is output to the first lower comb tooth through the first drive electrode, or output to the second lower comb tooth through the second drive electrode, such that the rotating mirror rotates around the cantilever beam and the angle of the rotating mirror relative to the substrate changes.

[0031] As can be seen from the above scheme, by applying a control signal to the target control electrode, the electrical connection between the free end of the drive signal input spring and the two drive electrodes can be changed, thereby achieving the switching of the lower comb teeth with the applied drive signal. In this way, only one external drive circuit is needed to meet the drive requirements of the two lower comb teeth.

[0032] A preferred approach is to obtain the rotation direction and rotation angle of the rotating mirror before applying a control signal to the target control electrode, and then determine the target control electrode based on the rotation direction and rotation angle. Attached Figure Description

[0033] Figure 1 This is a structural diagram of the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0034] Figure 2 This is an exploded view of the structure of the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0035] Figure 3 This is a structural diagram of the substrate from a first perspective in the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0036] Figure 4 This is a structural diagram of the substrate from a second perspective in the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0037] Figure 5 This is a structural diagram of the base in the first embodiment of the single-channel signal controlled microelectromechanical device of the present invention.

[0038] Figure 6 This is a magnified view of the base structure from a first perspective in the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0039] Figure 7 This is a magnified view of the base structure from a second perspective in the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0040] Figure 8 This is a magnified view of the base structure from a third perspective in the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0041] Figure 9 This is a magnified view of the base structure from a fourth perspective in the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0042] Figure 10 This is a partial structural enlarged view of the base from the fifth perspective in the first embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0043] Figure 11 This is a flowchart of the first embodiment of the control method for a microelectromechanical device controlled by a single signal according to the present invention.

[0044] Figure 12 This is an enlarged view of a portion of the base structure in the second embodiment of the microelectromechanical device controlled by a single signal according to the present invention.

[0045] Figure 13 This is a magnified view of the base structure from another perspective in the second embodiment of the single-channel signal controlled microelectromechanical device of the present invention.

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0047] The single-channel signal controlled microelectromechanical device of the present invention is applied to optical devices such as optical switches. It receives the drive signal output from an external drive circuit and receives a control signal to switch the lower comb teeth to which the drive signal is applied. Only one drive circuit is needed to apply the drive signal to two lower comb teeth of the same microelectromechanical device.

[0048] First embodiment of a microelectromechanical device controlled by a single signal:

[0049] See Figure 1 and Figure 2 The single-signal controlled microelectromechanical device of this embodiment has a substrate 10, on which a substrate 50 is disposed. Both the substrate 10 and the substrate 50 have square cross-sections, and the cross-sectional area of ​​the substrate 10 is equal to that of the substrate 50, so that the substrate 50 can completely cover the substrate 10. In addition, the substrate 50 has a smaller thickness, while the thickness of the substrate 10 is greater than the thickness of the substrate 50.

[0050] See Figure 3 and Figure 4The substrate 50 is provided with upper comb teeth 51. Preferably, the upper comb teeth 51 include first upper comb teeth 61 and second upper comb teeth 62. A generally circular rotating mirror 52 is provided in the middle of the substrate 50. The first upper comb teeth 61 and the second upper comb teeth 62 are respectively located on the left and right sides of the rotating mirror 52. The first upper comb teeth 61 have multiple first upper tooth plates, which are arranged parallel to each other, and there is a gap between adjacent first upper tooth plates. Similarly, the second upper comb teeth 62 have multiple second upper tooth plates, which are arranged parallel to each other, and there is a gap between adjacent second upper tooth plates. Furthermore, the substrate 50, the upper comb teeth 51, and the rotating mirror 52 share a common ground, that is, the grounding of the substrate 50, the upper comb teeth 51, and the rotating mirror 52 are all connected together.

[0051] The rotating mirror 52 is supported on the substrate 50 by a pair of cantilever beams 54. The rotating mirror 52 can rotate around the cantilever beams 54, thereby allowing the rotating mirror 52 to rotate relative to the substrate 50. In addition, a first through hole 55 and a second through hole 56 are provided on the substrate 50. Preferably, the first through hole 55 and the second through hole 56 are both square through holes, and both the first through hole 55 and the second through hole 56 penetrate the upper and lower surfaces of the substrate 50.

[0052] See Figure 5 and Figure 6 The base 10 is provided with a first lower comb tooth 11 and a second lower comb tooth 12. A first pad 13 is provided between the first lower comb tooth 11 and the base 10, and a second pad 14 is provided between the second lower comb tooth 12 and the base 10. A first driving electrode 15 and a second driving electrode 16 are provided on the base 10. The first driving electrode 15 is formed at one end of the first pad 13 and is electrically connected to the first lower comb tooth 11 through the first pad 13. The second driving electrode 16 is formed at one end of the second pad 14 and is electrically connected to the second lower comb tooth 12 through the second pad 14.

[0053] When it is necessary to drive the rotating mirror 52 to rotate, a driving voltage needs to be applied to either the first lower comb tooth 11 or the second lower comb tooth 12. Since only one of the first lower comb tooth 11 and the second lower comb tooth 12 needs to be driven, only one driving circuit can be set up, and the connection relationship between the driving circuit and the first lower comb tooth 11 and the second lower comb tooth 12 can be switched through a switching device 20.

[0054] See Figures 7 to 9The switching device 20 is mounted on the base 10. The switching device 20 includes a drive signal input electrode 46, which in this embodiment is a cylinder. A drive signal input spring 40 is provided on one side of the drive signal input electrode 46. The fixed end 42 of the drive signal input spring 40 is fixed to a collar 45, which is sleeved on the outer periphery of the drive signal input electrode 46 and fixedly connected to it, for example, by interference fit. Furthermore, the drive signal input electrode 46, the collar 45, and the drive signal input spring 40 are all made of conductive material; therefore, the drive signal input electrode 46 and the drive signal input spring 40 can be electrically connected through the collar 45.

[0055] The base 10 is also provided with a first control electrode 21 and a second control electrode 31, which are respectively disposed on both sides of the drive signal input electrode 46. The first control electrode 21 has a first connecting portion 22 and a first voltage applying portion 23. A first control comb tooth 26 is provided at the end of the first connecting portion 22 away from the first voltage applying portion 23. The first control comb tooth 26 has multiple first control teeth 27, which are arranged parallel to each other, and a gap is formed between adjacent first control teeth 27. The second control electrode 31 has a second connecting portion 32 and a second voltage applying portion 33. A second control comb tooth 36 is provided at the end of the second connecting portion 32 away from the second voltage applying portion 33. The second control comb tooth 36 has multiple second control teeth 37, which are arranged parallel to each other, and a gap is formed between adjacent second control teeth 37. In addition, the drive signal input spring 40 is located between the first control electrode 21 and the second control electrode 31. More specifically, the drive signal input spring 40 is located between the first control comb tooth 26 and the second control comb tooth 36.

[0056] A switching comb 43 is provided on the drive signal input spring 40. The switching comb 43 includes multiple first switching teeth 47 and multiple second switching teeth 48. The first switching teeth 47 are located on the side close to the first control comb 26, and the multiple first switching teeth 47 and the multiple first control teeth 27 are arranged alternately. Figure 8 As can be seen, a first switching tooth 47 extends between two adjacent first control tooth 27s, but each first switching tooth 47 does not contact any of the first control tooth 27s. A second switching tooth 48 is disposed on the side near the second control comb tooth 36, and multiple second switching tooth 48s and multiple second control tooth 37s are arranged alternately, meaning that a second switching tooth 48 extends between two adjacent second control tooth 37s, but each second switching tooth 48 does not contact any of the second control tooth 37s.

[0057] from Figure 9 As can be seen, the lower end of the first control comb tooth 26 is fixed on the base 10, and the lower end of the second control comb tooth 36 is also fixed on the base 10. In this way, the first control comb tooth 26 and the second control comb tooth 36 can be firmly fixed on the base 10, which can prevent the first control comb tooth 26 and the second control comb tooth 36 from shifting on the base 10.

[0058] Furthermore, the free end 41 of the drive signal input spring 40 is located between the first drive electrode 15 and the second drive electrode 16. Also, the switching comb 43 is located at the end of the drive signal input spring 40 closest to the drive signal input electrode 46, that is, at the position away from the free end 41 of the drive signal input spring 40. This allows the free end 41 of the drive signal input spring 40 to have a larger deflection space.

[0059] See Figure 10 The drive signal input spring 40 includes an upper cantilever 71 and a lower cantilever 72. An electrical insulation layer 73 is formed between the upper cantilever 71 and the lower cantilever 72, providing electrical insulation between them. The upper cantilever 71 is electrically connected to the drive signal input electrode 46, while the switching comb teeth 43 are disposed on the lower cantilever 72; that is, multiple first switching teeth 47 and multiple second switching teeth 48 are all electrically connected to the lower cantilever 72. In this embodiment, the upper cantilever 71, the lower cantilever 72, and the electrical insulation layer 73 are an integral structure. The upper cantilever 71 and the lower cantilever 72 can be made of conductive materials such as single-crystal silicon, while the electrical insulation layer 73 is made of an oxide insulating material. Furthermore, the lower cantilever 72 is conductive to the base 10, and the lower cantilever 72 and the base 10 share a common ground.

[0060] Furthermore, the first driving electrode 15 extends toward the second driving electrode 16 to form a first overhang 17, and the second driving electrode 16 extends toward the first driving electrode 15 to form a second overhang 18. The upper cantilever 71 can be selectively connected between the first overhang 17 and the second overhang 18, thereby enabling the driving signal input electrode 46 to output a driving signal to the first driving electrode 15 or the second driving electrode 16.

[0061] Because the deflection distance of the free end 41 of the drive signal input spring 40 is limited, the distance between the first drive electrode 15 and the second drive electrode 16 is relatively small. Figure 7It is evident that the minimum distance between the first driving electrode 15 and the second driving electrode 16 is less than the minimum distance between the first lower comb tooth 11 and the second lower comb tooth 12. On one hand, the smaller distance between the first driving electrode 15 and the second driving electrode 16 allows the free end 41 of the driving signal input spring 40 to deflect to a position contacting either the first driving electrode 15 or the second driving electrode 16. On the other hand, the larger distance between the first lower comb tooth 11 and the second lower comb tooth 12 prevents mutual interference between them.

[0062] After the substrate 50 is mounted onto the base 10, the first voltage application portion 23 of the first control electrode 21 will be located within the first through-hole 55, and the second voltage application portion 33 of the second control electrode 31 will be located within the second through-hole 56. Furthermore, the first upper end surface 25 of the first voltage application portion 23 is not higher than the upper surface of the substrate 10, and the second upper end surface 35 of the second voltage application portion 33 is also not higher than the upper surface of the substrate 10. Thus, neither the first voltage application portion 23 nor the second voltage application portion 33 will protrude from the upper surface of the substrate 10, which is beneficial for the packaging of microelectromechanical devices (MEMS).

[0063] First embodiment of the control method for a microelectromechanical device controlled by a single signal:

[0064] The following is combined with Figure 11 The control method for the single-signal controlled microelectromechanical device described above is introduced. In the initial state, neither the first nor the second control electrode is loaded with a control signal. At this time, the drive signal input spring is in its initial position, meaning the free end of the drive signal input spring is neither in contact with the first nor the second drive electrode. The drive signal input electrode is not electrically connected to either the first or second lower comb tooth. Typically, in this state, the rotating mirror remains parallel to the substrate.

[0065] When it is necessary to control the rotation of the rotating mirror, firstly, step S1 is executed to obtain the rotation direction and rotation angle of the rotating mirror. When it is necessary to control the rotation of the rotating mirror, it is necessary to determine which direction the rotating mirror will rotate in and what the rotation angle is. Then, step S2 is executed to determine the target control electrode to which the control signal needs to be applied based on the rotation direction and rotation angle, wherein the target control electrode is one of the first control electrode and the second control electrode.

[0066] Next, step S3 is executed, applying a control signal to the target control electrode, for example, applying a control signal to the first control electrode. The control signal can be a +5V voltage. Since the voltage between the first control electrode and the switching comb tooth changes after the control signal is applied to the first control electrode, the voltage difference between the first control electrode and the switching comb tooth is no longer equal to the voltage difference between the second control electrode and the switching comb tooth. At this time, the free end of the drive signal input spring is deflected under the action of electrostatic attraction, specifically, deflected towards the first drive electrode and comes into contact with it.

[0067] Then, step S4 is executed, applying a driving signal to the driving signal input electrode. At this time, since the upper cantilever of the driving signal input spring is in contact with the first driving electrode, the driving signal will be output to the first lower comb tooth through the first driving electrode, i.e., step S5 is executed. Since the second lower comb tooth is not loaded with a driving signal, the voltage difference between the upper comb tooth and the first lower comb tooth is not equal to the voltage difference between the upper comb tooth and the second lower comb tooth. At this time, the rotating mirror will rotate around the cantilever beam, i.e., step S6 is executed, thereby changing the angle of the rotating mirror relative to the substrate and realizing the optical path transformation of the optical signal.

[0068] Of course, if the target control electrode is the second control electrode, the free end of the upper cantilever of the drive signal input spring will deflect towards the second drive electrode and contact the second drive electrode, so that the drive signal is loaded onto the second drive electrode, which can drive the rotating mirror to rotate in another direction.

[0069] When it is necessary to return the rotating mirror to its initial position, simply stop applying the control signal to the target control electrode. The free end of the drive signal input spring will return to its initial position and will not come into contact with the first or second drive electrode.

[0070] As can be seen, this invention can change the electrical connection between the free end of the drive signal input spring and the two drive electrodes by applying a control signal to the target control electrode, thereby achieving the switching of the lower comb teeth with the applied drive signal. Thus, only one external drive circuit is needed to meet the driving requirements of the two lower comb teeth. When the microelectromechanical device of this invention is applied to an array optical switch, since multiple microelectromechanical devices have the same structure, each microelectromechanical device can be equipped with the same control electrode, drive signal input electrode, and drive signal input spring. Therefore, the microelectromechanical devices can be mass-produced. When the rotating mirrors of multiple microelectromechanical devices need to move synchronously, only one drive circuit needs to be set up to simultaneously output drive signals to the drive signal input electrodes of multiple microelectromechanical devices and output control signals to the control electrodes of multiple microelectromechanical devices, thereby driving the rotating mirrors of multiple microelectromechanical devices to rotate.

[0071] Second embodiment of a microelectromechanical device controlled by a single signal:

[0072] The single-signal controlled microelectromechanical device of this embodiment has a substrate, on which a base plate is disposed. A first upper comb tooth and a second upper comb tooth are disposed on the base plate. A generally circular rotating mirror is disposed in the center of the base plate. The first and second upper comb teeth are respectively disposed on the left and right sides of the rotating mirror. The rotating mirror is supported on the base plate by a pair of cantilever beams and can rotate around the cantilever beams, thereby causing the rotating mirror to rotate relative to the base plate.

[0073] See Figure 12 and Figure 13 The base 10 is provided with a first lower comb tooth 11 and a second lower comb tooth 12, and a first driving electrode 15 and a second driving electrode 16 are provided on the base 10. When it is necessary to drive the rotating mirror to rotate, a driving voltage needs to be applied to the first lower comb tooth 11 or the second lower comb tooth 12. Since only one of the first lower comb tooth 11 and the second lower comb tooth 12 needs to be driven, only one driving circuit can be set up, and a switching device can be used to switch the connection relationship between the driving circuit and the first lower comb tooth 11 and the second lower comb tooth 12.

[0074] The switching device in this embodiment includes a drive signal input electrode 46. A drive signal input spring 40 is provided on one side of the drive signal input electrode 46. The fixed end 42 of the drive signal input spring 40 is fixed on a collar 45. The collar 45 is sleeved on the outer periphery of the drive signal input electrode 46 and is fixedly connected to the drive signal input electrode 46. Furthermore, the drive signal input spring 40 and the collar 45 are also fixedly connected. Therefore, the drive signal input spring 40, the collar 45, and the drive signal input electrode 46 are an integral component.

[0075] Unlike the first embodiment, this embodiment only has one control electrode on the base 10, that is, only a first control electrode 21 is provided, without a second control electrode. The first control electrode 21 has a first connecting portion 22 and a first voltage applying portion 23. A first control comb tooth 26 is provided at the end of the first connecting portion 22 away from the first voltage applying portion 23. The first control comb tooth 26 has multiple first control tooth plates 27, which are arranged parallel to each other, and a gap is formed between adjacent first control tooth plates 27. In addition, the drive signal input spring 40 is located on one side of the first control electrode 21.

[0076] A switching comb tooth 43 is provided on the drive signal input spring 40. The switching comb tooth 43 includes multiple first switching tooth pieces 47, which are disposed on the side close to the first control comb tooth 26, and the multiple first switching tooth pieces 47 and multiple first control tooth pieces 27 are arranged alternately. Furthermore, the lower end of the first control comb tooth 26 is fixed to the base 10 to prevent the first control comb tooth 26 from being displaced on the base 10.

[0077] Furthermore, the free end 41 of the drive signal input spring 40 is disposed on one side of the first drive electrode 15. The drive signal input spring 40 includes an upper cantilever 71 and a lower cantilever 72, and an electrical insulating layer is formed between the upper cantilever 71 and the lower cantilever 72 to achieve electrical insulation between them. The upper cantilever 71 is electrically connected to the drive signal input electrode 46, while the switching comb teeth 43 are disposed on the lower cantilever 72.

[0078] Furthermore, the first driving electrode 15 extends toward the second driving electrode 16 to form a first overhang 17, and the second driving electrode 16 extends toward the first driving electrode 15 to form a second overhang 18. The upper cantilever 71 can be selectively connected between the first overhang 17 and the second overhang 18, thereby enabling the driving signal input electrode 46 to output a driving signal to the first driving electrode 15 or the second driving electrode 16.

[0079] Second embodiment of the control method for a microelectromechanical device controlled by a single signal:

[0080] The control method of the single-channel signal controlled microelectromechanical device according to the second embodiment is described below. In the initial state, no control signal is applied to the first control electrode, and the free end of the drive signal input spring is separated from the first drive electrode. At this time, the free end of the drive signal input spring is connected to the second drive electrode, i.e., it abuts against the second drive electrode. At this time, a drive signal that meets the requirements can be applied to the drive signal input electrode according to the rotation angle requirement of the rotating mirror. The drive signal is output to the second lower comb tooth through the second drive electrode, thereby causing the rotating mirror to rotate around the cantilever beam, and the angle of the rotating mirror relative to the substrate changes.

[0081] When the mirror needs to rotate in another direction, a control signal is applied to the first control electrode. This causes the free end of the drive signal input spring to deflect towards the first drive electrode under the action of electrostatic force, thereby connecting with and abutting against the first drive electrode. At this time, the free end of the drive signal input spring separates from the second drive electrode. Then, a drive signal that meets the required rotation angle can be applied to the drive signal input electrode. The drive signal is output to the first lower comb tooth through the first drive electrode, causing the mirror to rotate around the cantilever beam, thus changing the angle of the mirror relative to the substrate.

[0082] Compared to the first embodiment, the control method of this embodiment is simpler. After determining the rotation direction of the rotating mirror, it is only necessary to control whether to apply a driving signal to the first driving electrode or not, without having to consider the second driving electrode. This reduces the control difficulty, and the structure of the microelectromechanical device controlled by a single signal is simpler and the production cost is lower.

[0083] Finally, it should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A single-path signal control micro-electro-mechanical device, comprising: a substrate, wherein a first lower comb and a second lower comb are arranged on the substrate, the first lower comb is electrically connected with a first driving electrode, and the second lower comb is electrically connected with a second driving electrode; a substrate is arranged above the substrate, wherein an upper comb and a rotating mirror are arranged on the substrate, and the rotating mirror is supported on the substrate by a pair of cantilever beams; characterized in that: a driving signal input electrode is arranged on the substrate, the driving signal input electrode is electrically connected with a driving signal input spring, the driving signal input spring is located between the first driving electrode and the second driving electrode, and a free end of the driving signal input spring is connected to the first driving electrode or the second driving electrode; a first control electrode is further arranged on the substrate, the first control electrode is connected to a first control comb, and a switching comb is arranged on the driving signal input spring; a minimum distance between the first driving electrode and the second driving electrode is smaller than a minimum distance between the first lower comb and the second lower comb. 2.The single-path signal control micro-electro-mechanical device according to claim 1, characterized in that: a second control electrode is further arranged on the substrate, the second control electrode is connected to a second control comb, and the switching comb is located between the first control comb and the second control comb. 3.The single-path signal control micro-electro-mechanical device according to claim 2, characterized in that: the first control comb comprises a plurality of first control teeth, and the second control comb comprises a plurality of second control teeth; the switching comb comprises a plurality of first switching teeth and a plurality of second switching teeth, the first switching teeth are arranged on a side close to the first control comb, and the plurality of first switching teeth and the plurality of first control teeth are arranged in an interlaced manner; and the second switching teeth are arranged on a side close to the second control comb, and the plurality of second switching teeth and the plurality of second control teeth are arranged in an interlaced manner. 4.The single-path signal control micro-electro-mechanical device according to claim 3, characterized in that: the switching comb is arranged on an end of the driving signal input spring close to the driving signal input electrode. 5.The single-path signal control micro-electro-mechanical device according to any one of claims 1 to 4, characterized in that: a fixed end of the driving signal input spring is fixed on a sleeve, and the sleeve is sleeved on an outer periphery of the driving signal input electrode. 6.The single-path signal control micro-electro-mechanical device according to any one of claims 1 to 4, characterized in that: the driving signal input spring comprises an upper cantilever and a lower cantilever, an electrically insulating layer is formed between the upper cantilever and the lower cantilever, the upper cantilever is electrically connected with the driving signal input electrode, and the upper cantilever is connected to the first driving electrode or the second driving electrode. 7.The single-path signal control micro-electro-mechanical device according to claim 6, characterized in that: the switching comb is arranged on the lower cantilever. 8.The single-path signal control micro-electro-mechanical device according to any one of claims 2 to 4, characterized in that: The first control electrode has a first voltage application part, and the second control electrode has a second voltage application part. The substrate is provided with a first through hole and a second through hole, the first voltage application part is located in the first through hole, and the second voltage application part is located in the second through hole.

9. A control method of a single-path signal control micro electro mechanical device, applied to the single-path signal control micro electro mechanical device according to claim 1, characterized in that, The method comprises: The driving signal input electrode is applied with a driving signal, so that the free end of the driving signal input spring piece is connected with the first driving electrode, the driving signal input electrode is applied with a driving signal, and the driving signal is output to the first lower comb tooth through the first driving electrode; Or the first control electrode is applied with a control signal, so that the free end of the driving signal input spring piece is separated from the first driving electrode, and the free end of the driving signal input spring piece is connected with the second driving electrode; the driving signal input electrode is applied with a driving signal, and the driving signal is output to the second lower comb tooth through the second driving electrode; The rotating mirror rotates around the cantilever beam, and the angle of the rotating mirror relative to the substrate changes.

10. A control method of a single-path signal control micro electro mechanical device, applied to the single-path signal control micro electro mechanical device according to any one of claims 2 to 8, characterized in that, The method comprises: The target control electrode is applied with a control signal, the target control electrode being one of the first control electrode and the second control electrode, so that the free end of the driving signal input spring piece is connected to the first driving electrode or the second driving electrode; The driving signal input electrode is applied with a driving signal, the driving signal is output to the first lower comb tooth through the first driving electrode or the second driving electrode, so that the rotating mirror rotates around the cantilever beam, and the angle of the rotating mirror relative to the substrate changes.

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